path: root/epan/dissectors/packet-epl.c

/* packet-epl.c
 * Routines for "Ethernet POWERLINK 2.0" dissection
 * (Ethernet POWERLINK V2.0 Communication Profile Specification Draft Standard Version 1.0.0)
 *
 * Copyright (c) 2006: Zurich University of Applied Sciences Winterthur (ZHW)
 *                     Institute of Embedded Systems (InES)
 *                     http://ines.zhwin.ch
 *
 *                     - Dominic Bechaz <bdo[AT]zhwin.ch>
 *                     - Damir Bursic <bum[AT]zhwin.ch>
 *                     - David Buechi <bhd[AT]zhwin.ch>
 *
 * Copyright (c) 2007: SYS TEC electronic GmbH
 *                     http://www.systec-electronic.com
 *                     - Daniel Krueger <daniel.krueger[AT]systec-electronic.com>
 *
 * $Id$
 *
 * A plugin for:
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * Copyright 1999 Gerald Combs
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */


#ifdef HAVE_CONFIG_H
    #include "config.h"
#endif

#include <glib.h>

#include <epan/packet.h>
#include <epan/etypes.h>
#include <epan/prefs.h>

#ifndef UDP_PORT_EPL
#define UDP_PORT_EPL            3819
#endif

/* Allow heuristic dissection */
static heur_dissector_list_t heur_epl_subdissector_list;

/* Container for tapping relevant data */
typedef struct _epl_info_t {
    unsigned char epl_mtyp;
} epl_info_t;


/*EPL Addressing*/
#define EPL_INVALID_NODEID                        0
#define EPL_MN_NODEID                           240
#define EPL_DIAGNOSTIC_DEVICE_NODEID            253
#define EPL_TO_LEGACY_ETHERNET_ROUTER_NODEID    254
#define EPL_BROADCAST_NODEID                    255

static const value_string addr_str_vals[] = {
    {EPL_INVALID_NODEID,                    " (invalid)"                        },
    {EPL_MN_NODEID,                         " (Managing Node)"                  },
    {EPL_DIAGNOSTIC_DEVICE_NODEID,          " (Diagnostic Device)"              },
    {EPL_TO_LEGACY_ETHERNET_ROUTER_NODEID,  " (EPL to legacy Ethernet Router)"  },
    {EPL_BROADCAST_NODEID,                  " (broadcast)"                      },
    {0,NULL}
};

static const value_string addr_str_abbr_vals[] _U_ = {
    {EPL_INVALID_NODEID,                    " (inv.)"   },
    {EPL_MN_NODEID,                         " (MN)"     },
    {EPL_DIAGNOSTIC_DEVICE_NODEID,          " (diag.)"  },
    {EPL_TO_LEGACY_ETHERNET_ROUTER_NODEID,  " (router)" },
    {EPL_BROADCAST_NODEID,                  " (bc)"     },
    {0,NULL}
};
/*
static const gchar* addr_str_abbr_cn  = " (CN)";
static const gchar* addr_str_abbr_res = " (res.)";
*/



/* Offsets of fields within an EPL packet. */
#define EPL_MTYP_OFFSET             0   /* same offset for all message types*/
#define EPL_DEST_OFFSET             1   /* same offset for all message types*/
#define EPL_SRC_OFFSET              2   /* same offset for all message types*/

#define EPL_SOA_SVID_OFFSET         6
#define EPL_SOA_SVTG_OFFSET         7
#define EPL_SOA_EPLV_OFFSET         8

#define EPL_ASND_SVID_OFFSET        3
#define EPL_ASND_DATA_OFFSET        4


/* EPL message types */
#define EPL_SOC     0x01
#define EPL_PREQ    0x03
#define EPL_PRES    0x04
#define EPL_SOA     0x05
#define EPL_ASND    0x06

static const value_string mtyp_vals[] = {
    {EPL_SOC,  "Start of Cycle (SoC)"       },
    {EPL_PREQ, "PollRequest (PReq)"         },
    {EPL_PRES, "PollResponse (PRes)"        },
    {EPL_SOA,  "Start of Asynchronous (SoA)"},
    {EPL_ASND, "Asynchronous Send (ASnd)"   },
    {0,NULL}
};

#define EPL_SOC_MC_MASK              0x80
#define EPL_SOC_PS_MASK              0x40
#define EPL_PDO_RD_MASK              0x01

/* RequestedServiceID s for EPL message type "SoA" */
#define EPL_SOA_NOSERVICE               0
#define EPL_SOA_IDENTREQUEST            1
#define EPL_SOA_STATUSREQUEST           2
#define EPL_SOA_NMTREQUESTINVITE        3
#define EPL_SOA_UNSPECIFIEDINVITE     255

static const value_string soa_svid_vals[] = {
    {EPL_SOA_NOSERVICE,           "NoService"        },
    {EPL_SOA_IDENTREQUEST,        "IdentRequest"     },
    {EPL_SOA_STATUSREQUEST,       "StatusRequest"    },
    {EPL_SOA_NMTREQUESTINVITE,    "NMTRequestInvite" },
    {EPL_SOA_UNSPECIFIEDINVITE,   "UnspecifiedInvite"},
    {0,NULL}
};

/* ServiceID values for EPL message type "ASnd" */
#define EPL_ASND_IDENTRESPONSE          1
#define EPL_ASND_STATUSRESPONSE         2
#define EPL_ASND_NMTREQUEST             3
#define EPL_ASND_NMTCOMMAND             4
#define EPL_ASND_SDO                    5

static const value_string asnd_svid_vals[] = {
    {EPL_ASND_IDENTRESPONSE,  "IdentResponse" },
    {EPL_ASND_STATUSRESPONSE, "StatusResponse"},
    {EPL_ASND_NMTREQUEST,     "NMTRequest"    },
    {EPL_ASND_NMTCOMMAND,     "NMTCommand"    },
    {EPL_ASND_SDO,            "SDO"           },
    {0,NULL}
};

/* NMTCommand values for EPL message type "ASnd" */
#define EPL_ASND_NMTCOMMAND_NMTSTARTNODE                0x21
#define EPL_ASND_NMTCOMMAND_NMTSTOPNODE                 0x22
#define EPL_ASND_NMTCOMMAND_NMTENTERPREOPERATIONAL2     0x23
#define EPL_ASND_NMTCOMMAND_NMTENABLEREADYTOOPERATE     0x24
#define EPL_ASND_NMTCOMMAND_NMTRESETNODE                0x28
#define EPL_ASND_NMTCOMMAND_NMTRESETCOMMUNICATION       0x29
#define EPL_ASND_NMTCOMMAND_NMTRESETCONFIGURATION       0x2A
#define EPL_ASND_NMTCOMMAND_NMTSWRESET                  0x2B

#define EPL_ASND_NMTCOMMAND_NMTSTARTNODEEX              0x41
#define EPL_ASND_NMTCOMMAND_NMTSTOPNODEEX               0x42
#define EPL_ASND_NMTCOMMAND_NMTENTERPREOPERATIONAL2EX   0x43
#define EPL_ASND_NMTCOMMAND_NMTENABLEREADYTOOPERATEEX   0x44
#define EPL_ASND_NMTCOMMAND_NMTRESETNODEEX              0x48
#define EPL_ASND_NMTCOMMAND_NMTRESETCOMMUNICATIONEX     0x49
#define EPL_ASND_NMTCOMMAND_NMTRESETCONFIGURATIONEX     0x4A
#define EPL_ASND_NMTCOMMAND_NMTSWRESETEX                0x4B

#define EPL_ASND_NMTCOMMAND_NMTNETHOSTNAMESET           0x62
#define EPL_ASND_NMTCOMMAND_NMTFLUSHARPENTRY            0x63
#define EPL_ASND_NMTCOMMAND_NMTPUBLISHCONFIGUREDNODES   0x80
#define EPL_ASND_NMTCOMMAND_NMTPUBLISHACTIVENODES       0x90
#define EPL_ASND_NMTCOMMAND_NMTPUBLISHPREOPERATIONAL1   0x91
#define EPL_ASND_NMTCOMMAND_NMTPUBLISHPREOPERATIONAL2   0x92
#define EPL_ASND_NMTCOMMAND_NMTPUBLISHREADYTOOPERATE    0x93
#define EPL_ASND_NMTCOMMAND_NMTPUBLISHOPERATIONAL       0x94
#define EPL_ASND_NMTCOMMAND_NMTPUBLISHSTOPPED           0x95
#define EPL_ASND_NMTCOMMAND_NMTPUBLISHEMERGENCYNEW      0xA0
#define EPL_ASND_NMTCOMMAND_NMTPUBLISHTIME              0XB0
#define EPL_ASND_NMTCOMMAND_NMTINVALIDSERVICE           0xFF

static const value_string asnd_cid_vals[] = {
    {EPL_ASND_NMTCOMMAND_NMTSTARTNODE,                "NMTStartNode"              },
    {EPL_ASND_NMTCOMMAND_NMTSTOPNODE,                 "NMTStopNode"               },
    {EPL_ASND_NMTCOMMAND_NMTENTERPREOPERATIONAL2,     "NMTEnterPreOperational2"   },
    {EPL_ASND_NMTCOMMAND_NMTENABLEREADYTOOPERATE,     "NMTEnableReadyToOperate"   },
    {EPL_ASND_NMTCOMMAND_NMTRESETNODE,                "NMTResetNode"              },
    {EPL_ASND_NMTCOMMAND_NMTRESETCOMMUNICATION,       "NMTResetCommunication"     },
    {EPL_ASND_NMTCOMMAND_NMTRESETCONFIGURATION,       "NMTResetConfiguration"     },
    {EPL_ASND_NMTCOMMAND_NMTSWRESET,                  "NMTSwReset"                },
    {EPL_ASND_NMTCOMMAND_NMTSTARTNODEEX,              "NMTStartNodeEx"            },
    {EPL_ASND_NMTCOMMAND_NMTSTOPNODEEX,               "NMTStopNodeEx"             },
    {EPL_ASND_NMTCOMMAND_NMTENTERPREOPERATIONAL2EX,   "NMTEnterPreOperational2Ex" },
    {EPL_ASND_NMTCOMMAND_NMTENABLEREADYTOOPERATEEX,   "NMTEnableReadyToOperateEx" },
    {EPL_ASND_NMTCOMMAND_NMTRESETNODEEX,              "NMTResetNodeEx"            },
    {EPL_ASND_NMTCOMMAND_NMTRESETCOMMUNICATIONEX,     "NMTCommunicationEx"        },
    {EPL_ASND_NMTCOMMAND_NMTRESETCONFIGURATIONEX,     "NMTResetConfigurationEx"   },
    {EPL_ASND_NMTCOMMAND_NMTSWRESETEX,                "NMTSwResetEx"              },
    {EPL_ASND_NMTCOMMAND_NMTNETHOSTNAMESET,           "NMTNetHostNameSet"         },
    {EPL_ASND_NMTCOMMAND_NMTFLUSHARPENTRY,            "NMTFlushArpEntry"          },
    {EPL_ASND_NMTCOMMAND_NMTPUBLISHCONFIGUREDNODES,   "NMTPublishConfiguredNodes" },
    {EPL_ASND_NMTCOMMAND_NMTPUBLISHACTIVENODES,       "NMTPublishActiveNodes"     },
    {EPL_ASND_NMTCOMMAND_NMTPUBLISHPREOPERATIONAL1,   "NMTPublishPreOperational1" },
    {EPL_ASND_NMTCOMMAND_NMTPUBLISHPREOPERATIONAL2,   "NMTPublishPreOperational2" },
    {EPL_ASND_NMTCOMMAND_NMTPUBLISHREADYTOOPERATE,    "NMTPublishReadyToOperate"  },
    {EPL_ASND_NMTCOMMAND_NMTPUBLISHOPERATIONAL,       "NMTPublishOperational"     },
    {EPL_ASND_NMTCOMMAND_NMTPUBLISHSTOPPED,           "NMTPublishStopped"         },
    {EPL_ASND_NMTCOMMAND_NMTPUBLISHEMERGENCYNEW,      "NMTPublishEmergencyNew"    },
    {EPL_ASND_NMTCOMMAND_NMTPUBLISHTIME,              "NMTPublishTime"            },
    {EPL_ASND_NMTCOMMAND_NMTINVALIDSERVICE,           "NMTInvalidService"         },
    /* "special" values to cover all possibilities of CommandID in NMTRequests */
    {EPL_ASND_IDENTRESPONSE,                          "IdentResponse"             },
    {EPL_ASND_STATUSRESPONSE,                         "StatusResponse"            },
    {0,NULL}
};

/* Priority values for EPL message type "ASnd", "", "", field PR */
#define EPL_PR_GENERICREQUEST   0x03
#define EPL_PR_NMTREQUEST       0x07

static const value_string epl_pr_vals[] = {
    {0,                       "lowest"},
    {1,                       "lower"},
    {2,                       "below generic"},
    {EPL_PR_GENERICREQUEST,   "GenericRequest"},
    {4,                       "above generic"},
    {5,                       "higher"},
    {6,                       "below NMTRequest"},
    {EPL_PR_NMTREQUEST,       "NMTRequest"},
    {0,NULL}
};

/* NMT State values (for CN)*/
#define EPL_NMT_GS_OFF                  0x00
#define EPL_NMT_GS_INITIALIZING         0x19
#define EPL_NMT_GS_RESET_APPLICATION    0x29
#define EPL_NMT_GS_RESET_COMMUNICATION  0x39
#define EPL_NMT_CS_NOT_ACTIVE           0x1C
#define EPL_NMT_CS_PRE_OPERATIONAL_1    0x1D
#define EPL_NMT_CS_PRE_OPERATIONAL_2    0x5D
#define EPL_NMT_CS_READY_TO_OPERATE     0x6D
#define EPL_NMT_CS_OPERATIONAL          0xFD
#define EPL_NMT_CS_STOPPED              0x4D
#define EPL_NMT_CS_BASIC_ETHERNET       0x1E

static const value_string epl_nmt_cs_vals[] = {
    {EPL_NMT_GS_OFF,                  "NMT_GS_OFF"                },
    {EPL_NMT_GS_INITIALIZING,         "NMT_GS_INITIALIZING"       },
    {EPL_NMT_GS_RESET_APPLICATION,    "NMT_GS_RESET_APPLICATION"  },
    {EPL_NMT_GS_RESET_COMMUNICATION,  "NMT_GS_RESET_COMMUNICATION"},
    {EPL_NMT_CS_NOT_ACTIVE,           "NMT_CS_NOT_ACTIVE"         },
    {EPL_NMT_CS_PRE_OPERATIONAL_1,    "NMT_CS_PRE_OPERATIONAL_1"  },
    {EPL_NMT_CS_PRE_OPERATIONAL_2,    "NMT_CS_PRE_OPERATIONAL_2"  },
    {EPL_NMT_CS_READY_TO_OPERATE,     "NMT_CS_READY_TO_OPERATE"   },
    {EPL_NMT_CS_OPERATIONAL,          "NMT_CS_OPERATIONAL"        },
    {EPL_NMT_CS_STOPPED,              "NMT_CS_STOPPED"            },
    {EPL_NMT_CS_BASIC_ETHERNET,       "NMT_CS_BASIC_ETHERNET"     },
    {0,NULL}
};

/* NMT State values (for MN)*/
#define EPL_NMT_GS_OFF                  0x00
#define EPL_NMT_GS_INITIALIZING         0x19
#define EPL_NMT_GS_RESET_APPLICATION    0x29
#define EPL_NMT_GS_RESET_COMMUNICATION  0x39
#define EPL_NMT_MS_NOT_ACTIVE           0x1C
#define EPL_NMT_MS_PRE_OPERATIONAL_1    0x1D
#define EPL_NMT_MS_PRE_OPERATIONAL_2    0x5D
#define EPL_NMT_MS_READY_TO_OPERATE     0x6D
#define EPL_NMT_MS_OPERATIONAL          0xFD
#define EPL_NMT_MS_BASIC_ETHERNET       0x1E

static const value_string epl_nmt_ms_vals[] = {
    {EPL_NMT_GS_OFF,                  "NMT_GS_OFF"                },
    {EPL_NMT_GS_INITIALIZING,         "NMT_GS_INITIALIZING"       },
    {EPL_NMT_GS_RESET_APPLICATION,    "NMT_GS_RESET_APPLICATION"  },
    {EPL_NMT_GS_RESET_COMMUNICATION,  "NMT_GS_RESET_COMMUNICATION"},
    {EPL_NMT_MS_NOT_ACTIVE,           "NMT_MS_NOT_ACTIVE"         },
    {EPL_NMT_MS_PRE_OPERATIONAL_1,    "NMT_MS_PRE_OPERATIONAL_1"  },
    {EPL_NMT_MS_PRE_OPERATIONAL_2,    "NMT_MS_PRE_OPERATIONAL_2"  },
    {EPL_NMT_MS_READY_TO_OPERATE,     "NMT_MS_READY_TO_OPERATE"   },
    {EPL_NMT_MS_OPERATIONAL,          "NMT_MS_OPERATIONAL"        },
    {EPL_NMT_MS_BASIC_ETHERNET,       "NMT_MS_BASIC_ETHERNET"     },
    {0,NULL}
};



/* EPL Device Profiles according to CANopen */
#define EPL_PROFILE_NO              0
#define EPL_PROFILE_GENERIC_IO      401
#define EPL_PROFILE_DRIVE           402
#define EPL_PROFILE_HMI             403
#define EPL_PROFILE_MEASURING       404
#define EPL_PROFILE_PLC             405
#define EPL_PROFILE_ENCODER         406


static const value_string epl_device_profiles[] = {
    {EPL_PROFILE_NO,         "No Standard Device"},
    {EPL_PROFILE_GENERIC_IO, "Generic I/O module"},
    {EPL_PROFILE_DRIVE,      "Drive and motion control"},
    {EPL_PROFILE_HMI,        "Human Machine Interface"},
    {EPL_PROFILE_MEASURING,  "Measuring device"},
    {EPL_PROFILE_PLC,        "IEC 61131-3 PLC"},
    {EPL_PROFILE_ENCODER,    "Encoder"},
    {0,NULL}
};


/* SDO SequenceLayer */
#define EPL_ASND_SDO_SEQ_RECEIVE_SEQUENCE_NUMBER_OFFSET        4
#define EPL_ASND_SDO_SEQ_RECEIVE_CON_OFFSET                    4

#define EPL_ASND_SDO_SEQ_SEND_SEQUENCE_NUMBER_OFFSET           5
#define EPL_ASND_SDO_SEQ_SEND_CON_OFFSET                       5

#define EPL_ASND_SDO_SEQ_RECEIVE_CON_NO_CONNECTION          0x00
#define EPL_ASND_SDO_SEQ_RECEIVE_CON_INITIALIZATION         0x01
#define EPL_ASND_SDO_SEQ_RECEIVE_CON_CONNECTION_VALID       0x02
#define EPL_ASND_SDO_SEQ_RECEIVE_CON_ERROR_RESPONSE         0x03
#define EPL_ASND_SDO_SEQ_CON_MASK                           0x03

static const value_string epl_sdo_receive_con_vals[] = {
    {EPL_ASND_SDO_SEQ_RECEIVE_CON_NO_CONNECTION,      "No connection"                          },
    {EPL_ASND_SDO_SEQ_RECEIVE_CON_INITIALIZATION,     "Initialization"                         },
    {EPL_ASND_SDO_SEQ_RECEIVE_CON_CONNECTION_VALID,   "Connection valid"                       },
    {EPL_ASND_SDO_SEQ_RECEIVE_CON_ERROR_RESPONSE,     "Error Response (retransmission request)"},
    {0,NULL}
};

#define EPL_ASND_SDO_SEQ_SEND_CON_NO_CONNECTION             0x00
#define EPL_ASND_SDO_SEQ_SEND_CON_INITIALIZATION            0x01
#define EPL_ASND_SDO_SEQ_SEND_CON_CONNECTION_VALID          0x02
#define EPL_ASND_SDO_SEQ_SEND_CON_ERROR_VALID_ACK_REQ       0x03

static const value_string epl_sdo_send_con_vals[] = {
    {EPL_ASND_SDO_SEQ_SEND_CON_NO_CONNECTION,         "No connection"                             },
    {EPL_ASND_SDO_SEQ_SEND_CON_INITIALIZATION,        "Initialization"                            },
    {EPL_ASND_SDO_SEQ_SEND_CON_CONNECTION_VALID,      "Connection valid"                          },
    {EPL_ASND_SDO_SEQ_SEND_CON_ERROR_VALID_ACK_REQ,   "Connection valid with acknowledge request" },
    {0,NULL}
};

/* SDO EPL Command Layer Protocol */
#define EPL_ASND_SDO_CMD_ABORT_FILTER                    0x40
#define EPL_ASND_SDO_CMD_SEGMENTATION_FILTER             0x30
#define EPL_ASND_SDO_CMD_RESPONSE_FILTER                 0x80


/* SDO - Abort Transfer */
static const value_string sdo_cmd_abort_code[] = {
    {0x05030000, "reserved" },
    {0x05040000, "SDO protocol timed out." },
    {0x05040001, "Client/server Command ID not valid or unknown." },
    {0x05040002, "Invalid block size." },
    {0x05040003, "Invalid sequence number." },
    {0x05040004, "reserved" },
    {0x05040005, "Out of memory." },
    {0x06010000, "Unsupported access to an object." },
    {0x06010001, "Attempt to read a write-only object." },
    {0x06010002, "Attempt to write a read-only object." },
    {0x06020000, "Object does not exist in the object dictionary." },
    {0x06040041, "Object cannot be mapped to the PDO." },
    {0x06040042, "The number and length of the objects to be mapped would exceed PDO length." },
    {0x06040043, "General parameter incompatibility." },
    {0x06040047, "General internal incompatibility in the device." },
    {0x06060000, "Access failed due to a hardware error." },
    {0x06070010, "Data type does not match, length of service parameter does not match." },
    {0x06070012, "Data type does not match, length of service parameter too high." },
    {0x06070013, "Data type does not match, length of service parameter too low." },
    {0x06090011, "Sub-index does not exist." },
    {0x06090030, "Value range of parameter exceeded (only for write access)." },
    {0x06090031, "Value of parameter written too high." },
    {0x06090032, "Value of parameter written too low." },
    {0x06090036, "Maximum value is less then minimum value." },
    {0x08000000, "General error" },
    {0x08000020, "Data cannot be transferred or stored to the application." },
    {0x08000021, "Data cannot be transferred or stored to the application because of local control." },
    {0x08000022, "Data cannot be transferred or stored to the application because of the present device state." },
    {0x08000023, "Object dictionary dynamic generation fails or no object dictionary is present." },
    {0x08000024, "EDS, DCF or Concise DCF Data set empty." },
    {0,NULL}
};


#define EPL_ASND_SDO_CMD_RESPONSE_RESPONSE      0
#define EPL_ASND_SDO_CMD_RESPONSE_REQUEST       1

static const value_string epl_sdo_asnd_cmd_response[] = {
    {EPL_ASND_SDO_CMD_RESPONSE_RESPONSE,  "Request"   },
    {EPL_ASND_SDO_CMD_RESPONSE_REQUEST,   "Response"  },
    {0,NULL}
};

#define EPL_ASND_SDO_CMD_ABORT_TRANSFER_OK      0
#define EPL_ASND_SDO_CMD_ABORT_ABORT_TRANSFER   1

static const value_string epl_sdo_asnd_cmd_abort[] = {
    {EPL_ASND_SDO_CMD_ABORT_TRANSFER_OK,      "Transfer OK"    },
    {EPL_ASND_SDO_CMD_ABORT_ABORT_TRANSFER,   "Abort Transfer" },
    {0,NULL}
};

#define EPL_ASND_SDO_CMD_SEGMENTATION_EPEDITED_TRANSFER 0
#define EPL_ASND_SDO_CMD_SEGMENTATION_INITIATE_TRANSFER 1
#define EPL_ASND_SDO_CMD_SEGMENTATION_SEGMENT           2
#define EPL_ASND_SDO_CMD_SEGMENTATION_TRANSFER_COMPLETE 3

static const value_string epl_sdo_asnd_cmd_segmentation[] = {
    {EPL_ASND_SDO_CMD_SEGMENTATION_EPEDITED_TRANSFER, "Expedited Transfer" },
    {EPL_ASND_SDO_CMD_SEGMENTATION_INITIATE_TRANSFER, "Initiate Transfer"  },
    {EPL_ASND_SDO_CMD_SEGMENTATION_SEGMENT,           "Segment"            },
    {EPL_ASND_SDO_CMD_SEGMENTATION_TRANSFER_COMPLETE, "Transfer Complete"  },
    {0,NULL}
};

#define EPL_ASND_SDO_COMMAND_NOT_IN_LIST                        0x00
#define EPL_ASND_SDO_COMMAND_WRITE_BY_INDEX                     0x01
#define EPL_ASND_SDO_COMMAND_READ_BY_INDEX                      0x02
#define EPL_ASND_SDO_COMMAND_WRITE_ALL_BY_INDEX                 0x03
#define EPL_ASND_SDO_COMMAND_READ_ALL_BY_INDEX                  0x04
#define EPL_ASND_SDO_COMMAND_WRITE_BY_NAME                      0x05
#define EPL_ASND_SDO_COMMAND_READ_BY_NAME                       0x06
#define EPL_ASND_SDO_COMMAND_FILE_WRITE                         0x20
#define EPL_ASND_SDO_COMMAND_FILE_READ                          0x21
#define EPL_ASND_SDO_COMMAND_WRITE_MULTIPLE_PARAMETER_BY_INDEX  0x31
#define EPL_ASND_SDO_COMMAND_READ_MULTIPLE_PARAMETER_BY_INDEX   0x32
#define EPL_ASND_SDO_COMMAND_MAXIMUM_SEGMENT_SIZE               0x70
#define EPL_ASND_SDO_COMMAND_LINK_NAME_TO_INDEX                 0x71

static const value_string epl_sdo_asnd_commands[] = {
    {EPL_ASND_SDO_COMMAND_NOT_IN_LIST                      , "Not in List"                       },
    {EPL_ASND_SDO_COMMAND_WRITE_BY_INDEX                   , "Write by Index"                    },
    {EPL_ASND_SDO_COMMAND_READ_BY_INDEX                    , "Read by Index"                     },
    {EPL_ASND_SDO_COMMAND_WRITE_ALL_BY_INDEX               , "Write All by Index"                },
    {EPL_ASND_SDO_COMMAND_READ_ALL_BY_INDEX                , "Read All by Index"                 },
    {EPL_ASND_SDO_COMMAND_WRITE_BY_NAME                    , "Write by Name"                     },
    {EPL_ASND_SDO_COMMAND_READ_BY_NAME                     , "Read by Name"                      },
    {EPL_ASND_SDO_COMMAND_FILE_WRITE                       , "File Write"                        },
    {EPL_ASND_SDO_COMMAND_FILE_READ                        , "File Read"                         },
    {EPL_ASND_SDO_COMMAND_WRITE_MULTIPLE_PARAMETER_BY_INDEX, "Write Multiple Parameter by Index" },
    {EPL_ASND_SDO_COMMAND_READ_MULTIPLE_PARAMETER_BY_INDEX , "Read Multiple Parameter by Index"  },
    {EPL_ASND_SDO_COMMAND_MAXIMUM_SEGMENT_SIZE             , "Maximum Segment Size"              },
    {EPL_ASND_SDO_COMMAND_LINK_NAME_TO_INDEX               , "Link objects only accessible via name to an index/sub-index"},
    {0,NULL}
};
static const gchar* addr_str_cn  = " (Controlled Node)";
static const gchar* addr_str_res = " (reserved)";

static gint dissect_epl_soc(proto_tree *epl_tree, tvbuff_t *tvb, packet_info *pinfo, gint offset);
static gint dissect_epl_preq(proto_tree *epl_tree, tvbuff_t *tvb, packet_info *pinfo, gint offset);
static gint dissect_epl_pres(proto_tree *epl_tree, tvbuff_t *tvb, packet_info *pinfo, guint8 epl_src, gint offset);
static gint dissect_epl_soa(proto_tree *epl_tree, tvbuff_t *tvb, packet_info *pinfo, guint8 epl_src, gint offset);

static gint dissect_epl_asnd_ires(proto_tree *epl_tree, tvbuff_t *tvb, packet_info *pinfo, guint8 epl_src, gint offset);
static gint dissect_epl_asnd_sres(proto_tree *epl_tree, tvbuff_t *tvb, packet_info *pinfo, guint8 epl_src, gint offset);
static gint dissect_epl_asnd_nmtcmd(proto_tree *epl_tree, tvbuff_t *tvb, packet_info *pinfo, gint offset);
static gint dissect_epl_asnd_nmtreq(proto_tree *epl_tree, tvbuff_t *tvb, packet_info *pinfo, gint offset);
static gint dissect_epl_asnd(proto_tree *epl_tree, tvbuff_t *tvb, packet_info *pinfo, guint8 epl_src, gint offset);

static gint dissect_epl_asnd_sdo(proto_tree *epl_tree, tvbuff_t *tvb, packet_info *pinfo, gint offset);
static gint dissect_epl_sdo_sequence(proto_tree *epl_tree, tvbuff_t *tvb, packet_info *pinfo, gint offset);
static gint dissect_epl_sdo_command(proto_tree *epl_tree, tvbuff_t *tvb, packet_info *pinfo, gint offset);
static gint dissect_epl_sdo_command_write_by_index(proto_tree *epl_tree, tvbuff_t *tvb, packet_info *pinfo, gint offset, guint8 segmented, gboolean response);
static gint dissect_epl_sdo_command_read_by_index(proto_tree *epl_tree, tvbuff_t *tvb, packet_info *pinfo, gint offset, guint8 segmented, gboolean response);

static const gchar* decode_epl_address(guchar adr);

static gint dissect_epl(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree);


/* Initialize the protocol and registered fields */
static gint proto_epl            = -1;
static gint hf_epl_mtyp          = -1;
static gint hf_epl_dest          = -1;
static gint hf_epl_src           = -1;

static gint hf_epl_soc_mc        = -1;
static gint hf_epl_soc_ps        = -1;
static gint hf_epl_soc_nettime   = -1;
static gint hf_epl_soc_relativetime = -1;

static gint hf_epl_preq_ms       = -1;
static gint hf_epl_preq_ea       = -1;
static gint hf_epl_preq_rd       = -1;
static gint hf_epl_preq_pdov     = -1;
static gint hf_epl_preq_size     = -1;
static gint hf_epl_preq_pl       = -1;

static gint hf_epl_pres_stat_ms  = -1;
static gint hf_epl_pres_stat_cs  = -1;
static gint hf_epl_pres_ms       = -1;
static gint hf_epl_pres_en       = -1;
static gint hf_epl_pres_rd       = -1;
static gint hf_epl_pres_pr       = -1;
static gint hf_epl_pres_rs       = -1;
static gint hf_epl_pres_pdov     = -1;
static gint hf_epl_pres_size     = -1;
static gint hf_epl_pres_pl       = -1;

static gint hf_epl_soa_stat_ms   = -1;
static gint hf_epl_soa_stat_cs   = -1;
static gint hf_epl_soa_ea        = -1;
static gint hf_epl_soa_er        = -1;
static gint hf_epl_soa_svid      = -1;
static gint hf_epl_soa_svtg      = -1;
static gint hf_epl_soa_eplv      = -1;

static gint hf_epl_asnd_svid     = -1;
static gint hf_epl_asnd_data     = -1;

/*IdentResponse*/
static gint hf_epl_asnd_identresponse_en             = -1;
static gint hf_epl_asnd_identresponse_ec             = -1;
static gint hf_epl_asnd_identresponse_pr             = -1;
static gint hf_epl_asnd_identresponse_rs             = -1;
static gint hf_epl_asnd_identresponse_stat_ms        = -1;
static gint hf_epl_asnd_identresponse_stat_cs        = -1;
static gint hf_epl_asnd_identresponse_ever           = -1;
static gint hf_epl_asnd_identresponse_feat           = -1;
static gint hf_epl_asnd_identresponse_feat_bit0      = -1;
static gint hf_epl_asnd_identresponse_feat_bit1      = -1;
static gint hf_epl_asnd_identresponse_feat_bit2      = -1;
static gint hf_epl_asnd_identresponse_feat_bit3      = -1;
static gint hf_epl_asnd_identresponse_feat_bit4      = -1;
static gint hf_epl_asnd_identresponse_feat_bit5      = -1;
static gint hf_epl_asnd_identresponse_feat_bit6      = -1;
static gint hf_epl_asnd_identresponse_feat_bit7      = -1;
static gint hf_epl_asnd_identresponse_feat_bit8      = -1;
static gint hf_epl_asnd_identresponse_feat_bit9      = -1;
static gint hf_epl_asnd_identresponse_feat_bitA      = -1;
static gint hf_epl_asnd_identresponse_feat_bitB      = -1;
static gint hf_epl_asnd_identresponse_feat_bitC      = -1;
static gint hf_epl_asnd_identresponse_feat_bitD      = -1;
static gint hf_epl_asnd_identresponse_mtu            = -1;
static gint hf_epl_asnd_identresponse_pis            = -1;
static gint hf_epl_asnd_identresponse_pos            = -1;
static gint hf_epl_asnd_identresponse_rst            = -1;
static gint hf_epl_asnd_identresponse_dt             = -1;
static gint hf_epl_asnd_identresponse_profile        = -1;
static gint hf_epl_asnd_identresponse_vid            = -1;
static gint hf_epl_asnd_identresponse_productcode    = -1;
static gint hf_epl_asnd_identresponse_rno            = -1;
static gint hf_epl_asnd_identresponse_sno            = -1;
static gint hf_epl_asnd_identresponse_vex1           = -1;
static gint hf_epl_asnd_identresponse_vcd            = -1;
static gint hf_epl_asnd_identresponse_vct            = -1;
static gint hf_epl_asnd_identresponse_ad             = -1;
static gint hf_epl_asnd_identresponse_at             = -1;
static gint hf_epl_asnd_identresponse_ipa            = -1;
static gint hf_epl_asnd_identresponse_snm            = -1;
static gint hf_epl_asnd_identresponse_gtw            = -1;
static gint hf_epl_asnd_identresponse_hn             = -1;
static gint hf_epl_asnd_identresponse_vex2           = -1;

/*StatusResponse*/
static gint hf_epl_asnd_statusresponse_en            = -1;
static gint hf_epl_asnd_statusresponse_ec            = -1;
static gint hf_epl_asnd_statusresponse_pr            = -1;
static gint hf_epl_asnd_statusresponse_rs            = -1;
static gint hf_epl_asnd_statusresponse_stat_ms       = -1;
static gint hf_epl_asnd_statusresponse_stat_cs       = -1;
static gint hf_epl_asnd_statusresponse_seb           = -1;

/*StaticErrorBitField */
static gint hf_epl_asnd_statusresponse_seb_err_errorregister_u8_bit0 = -1;
static gint hf_epl_asnd_statusresponse_seb_err_errorregister_u8_bit1 = -1;
static gint hf_epl_asnd_statusresponse_seb_err_errorregister_u8_bit2 = -1;
static gint hf_epl_asnd_statusresponse_seb_err_errorregister_u8_bit3 = -1;
static gint hf_epl_asnd_statusresponse_seb_err_errorregister_u8_bit4 = -1;
static gint hf_epl_asnd_statusresponse_seb_err_errorregister_u8_bit5 = -1;
static gint hf_epl_asnd_statusresponse_seb_err_errorregister_u8_bit7 = -1;
static gint hf_epl_asnd_statusresponse_seb_devicespecific_err        = -1;

/*List of Errors/Events*/
static gint hf_epl_asnd_statusresponse_el                    = -1;
static gint hf_epl_asnd_statusresponse_el_entry              = -1;
static gint hf_epl_asnd_statusresponse_el_entry_type         = -1;
static gint hf_epl_asnd_statusresponse_el_entry_type_profile = -1;
static gint hf_epl_asnd_statusresponse_el_entry_type_mode    = -1;
static gint hf_epl_asnd_statusresponse_el_entry_type_bit14   = -1;
static gint hf_epl_asnd_statusresponse_el_entry_type_bit15   = -1;
static gint hf_epl_asnd_statusresponse_el_entry_code         = -1;
static gint hf_epl_asnd_statusresponse_el_entry_time         = -1;
static gint hf_epl_asnd_statusresponse_el_entry_add          = -1;

/*NMTRequest*/
static gint hf_epl_asnd_nmtrequest_rcid                      = -1;
static gint hf_epl_asnd_nmtrequest_rct                       = -1;
static gint hf_epl_asnd_nmtrequest_rcd                       = -1;

/*NMTCommand*/
static gint hf_epl_asnd_nmtcommand_cid                       = -1;
static gint hf_epl_asnd_nmtcommand_cdat                      = -1;
/*static gint hf_epl_asnd_nmtcommand_nmtnetparameterset_mtu    = -1;*/
static gint hf_epl_asnd_nmtcommand_nmtnethostnameset_hn      = -1;
static gint hf_epl_asnd_nmtcommand_nmtflusharpentry_nid      = -1;
static gint hf_epl_asnd_nmtcommand_nmtpublishtime_dt         = -1;

/*Asynchronuous SDO Sequence Layer*/
static gint hf_epl_asnd_sdo_seq_receive_sequence_number      = -1;
static gint hf_epl_asnd_sdo_seq_receive_con                  = -1;
static gint hf_epl_asnd_sdo_seq_send_sequence_number         = -1;
static gint hf_epl_asnd_sdo_seq_send_con                     = -1;

/*Asynchronuous SDO Command Layer*/
static gint hf_epl_asnd_sdo_cmd_transaction_id               = -1;
static gint hf_epl_asnd_sdo_cmd_response                     = -1;
static gint hf_epl_asnd_sdo_cmd_abort                        = -1;

static gint hf_epl_asnd_sdo_cmd_segmentation                 = -1;
static gint hf_epl_asnd_sdo_cmd_command_id                   = -1;
static gint hf_epl_asnd_sdo_cmd_segment_size                 = -1;
static gint hf_epl_asnd_sdo_cmd_data_size                    = -1;

static gint hf_epl_asnd_sdo_cmd_abort_code                   = -1;
/*static gint hf_epl_asnd_sdo_cmd_abort_flag                   = -1;*/
/*static gint hf_epl_asnd_sdo_cmd_segmentation_flag            = -1;*/
/*static gint hf_epl_asnd_sdo_cmd_cmd_valid_test               = -1;*/

/*static gint hf_epl_asnd_sdo_actual_command_id                = -1;*/

static gint hf_epl_asnd_sdo_cmd_write_by_index_index         = -1;
static gint hf_epl_asnd_sdo_cmd_write_by_index_subindex      = -1;
static gint hf_epl_asnd_sdo_cmd_write_by_index_data          = -1;
/*static gint hf_epl_asnd_sdo_cmd_write_by_index_response      = -1;*/

static gint hf_epl_asnd_sdo_cmd_read_by_index_index          = -1;
static gint hf_epl_asnd_sdo_cmd_read_by_index_subindex       = -1;
static gint hf_epl_asnd_sdo_cmd_read_by_index_data           = -1;
/*static gint hf_epl_asnd_sdo_cmd_read_by_index_response       = -1;*/

/*static gint hf_epl_asnd_sdo_actual_segment_size              = -1;*/
/*static gint hf_epl_asnd_sdo_actual_payload_size_read         = -1;*/

/* Initialize the subtree pointers */
static gint ett_epl                 = -1;
static gint ett_epl_feat            = -1;
static gint ett_epl_seb             = -1;
static gint ett_epl_el              = -1;
static gint ett_epl_el_entry        = -1;
static gint ett_epl_el_entry_type   = -1;
static gint ett_epl_sdo_entry_type  = -1;

/* preference whether or not display the SoC flags in info column */
gboolean show_soc_flags = FALSE;


/* Define the tap for epl */
/*static gint epl_tap = -1;*/


/* Code to actually dissect the packets */
static int
dissect_epl(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
    guint8 epl_mtyp, epl_src, epl_dest;
    const  gchar *src_str, *dest_str;
    gboolean udpencap = FALSE;
    /* static epl_info_t mi; */
    /* Set up structures needed to add the protocol subtree and manage it */
    proto_item *ti;
    proto_tree *epl_tree = NULL, *epl_src_item, *epl_dest_item;
    gint offset = 0;

    if (tvb_length(tvb) < 3)
    {
        /* Not enough data for an EPL header; don't try to interpret it */
        return FALSE;
    }

    /* Make entries in Protocol column and Info column on summary display */
    if (pinfo->ethertype == ETHERTYPE_EPL_V2)
    {
        col_set_str(pinfo->cinfo, COL_PROTOCOL, "EPL");
        udpencap = FALSE;
    }
    else
    {   /* guess that this is an EPL frame encapsulated into an UDP datagram */
        col_set_str(pinfo->cinfo, COL_PROTOCOL, "EPL/UDP");
        udpencap = TRUE;
    }

    /*
     * In case the packet is a protocol encoded in the basic EPL transport stream,
     * give that protocol a chance to make a heuristic dissection, before we continue
     * to dissect it as a normal EPL packet.
     */
    if (dissector_try_heuristic(heur_epl_subdissector_list, tvb, pinfo, tree))
      return TRUE;

    /* Get message type */
    epl_mtyp = tvb_get_guint8(tvb, EPL_MTYP_OFFSET) & 0x7F;

    /* tap */
    /*  mi.epl_mtyp = epl_mtyp;
    tap_queue_packet(epl_tap, pinfo, &mi);
    */

    /* Get Destination */
    epl_dest = tvb_get_guint8(tvb, EPL_DEST_OFFSET);
    dest_str = decode_epl_address(epl_dest);

    /* Get Source */
    epl_src = tvb_get_guint8(tvb, EPL_SRC_OFFSET);
    src_str = decode_epl_address(epl_src);

    if (check_col(pinfo->cinfo, COL_INFO))
    {
        col_clear(pinfo->cinfo, COL_INFO);

        /* Choose the right string for "Info" column (message type) */
        switch (epl_mtyp)
        {
            case EPL_SOC:
                /* source and destination NodeID are fixed according to the spec */
                col_set_str(pinfo->cinfo, COL_INFO, "SoC    ");
                break;

            case EPL_PREQ:
                /* show only destination NodeID, because source is always 240 (MN) */
                col_add_fstr(pinfo->cinfo, COL_INFO, "PReq   dst = %3d   ", epl_dest);
                break;

            case EPL_PRES:
                /* show only source NodeID, because destination is always 255 (broadcast) */
                col_add_fstr(pinfo->cinfo, COL_INFO, "PRes   src = %3d   ", epl_src);
                break;

            case EPL_SOA:
                /* source and destination NodeID are fixed according to the spec */
                col_set_str(pinfo->cinfo, COL_INFO, "SoA    ");
                break;

            case EPL_ASND:
                if (udpencap)
                {
                    col_set_str(pinfo->cinfo, COL_INFO, "ASnd   ");
                }
                else
                {
                    col_add_fstr(pinfo->cinfo, COL_INFO, "ASnd   src = %3d   dst = %3d   ", epl_src, epl_dest);
                }
                break;

            default:    /* no valid EPL packet */
                return FALSE;

        }

    }

    if (tree)
    {
        /* create display subtree for the protocol */
        ti = proto_tree_add_item(tree, proto_epl, tvb, 0, -1, ENC_NA);
        epl_tree = proto_item_add_subtree(ti, ett_epl);

        proto_tree_add_item(epl_tree,
            hf_epl_mtyp, tvb, offset, 1, ENC_LITTLE_ENDIAN);
    }
    offset += 1;

    if (tree && !udpencap)
    {
        epl_dest_item = proto_tree_add_item(epl_tree, hf_epl_dest, tvb, offset, 1, ENC_LITTLE_ENDIAN);
        proto_item_append_text (epl_dest_item, "%s", dest_str);
        offset += 1;

        epl_src_item = proto_tree_add_item(epl_tree, hf_epl_src, tvb, offset, 1, ENC_LITTLE_ENDIAN);
        proto_item_append_text (epl_src_item, "%s", src_str);
        offset += 1;
    }
    else
    {
        offset += 2;
    }

    /* The rest of the EPL dissector depends on the message type  */
    switch (epl_mtyp)
    {
        case EPL_SOC:
            offset = dissect_epl_soc(epl_tree, tvb, pinfo, offset);
            break;

        case EPL_PREQ:
            offset = dissect_epl_preq(epl_tree, tvb, pinfo, offset);
            break;

        case EPL_PRES:
            offset = dissect_epl_pres(epl_tree, tvb, pinfo, epl_src, offset);
            break;

        case EPL_SOA:
            offset = dissect_epl_soa(epl_tree, tvb, pinfo, epl_src, offset);
            break;

        case EPL_ASND:
            offset = dissect_epl_asnd(epl_tree, tvb, pinfo, epl_src, offset);
            break;

        default:    /* no valid EPL packet */
            return FALSE;
    }

    return offset;
}



const gchar*
decode_epl_address (guchar adr)
{
    const gchar *addr_str;

    addr_str = match_strval(adr, addr_str_vals);

    if (addr_str != NULL)
    {
        return addr_str;
    }
    else
    {
        if (( adr < EPL_MN_NODEID) && (adr > EPL_INVALID_NODEID))
        {
            return addr_str_cn;
        }
        else
        {
            return addr_str_res;
        }
    }
}

gint
dissect_epl_soc(proto_tree *epl_tree, tvbuff_t *tvb, packet_info *pinfo, gint offset)
{
    nstime_t nettime;
    guint8  flags;

    offset += 1;

    flags = tvb_get_guint8(tvb, offset);
    if (epl_tree)
    {
        proto_tree_add_boolean(epl_tree, hf_epl_soc_mc, tvb, offset, 1, flags);
        proto_tree_add_boolean(epl_tree, hf_epl_soc_ps, tvb, offset, 1, flags);
    }
    offset += 2;

    if (show_soc_flags && check_col(pinfo->cinfo, COL_INFO))
    {
        col_append_fstr(pinfo->cinfo, COL_INFO, "MC = %d   PS = %d",
                        ((EPL_SOC_MC_MASK & flags) >> 7), ((EPL_SOC_PS_MASK & flags) >> 6));
    }

    if (epl_tree)
    {
        nettime.secs  = tvb_get_letohl(tvb, offset);
        nettime.nsecs = tvb_get_letohl(tvb, offset+4);
        proto_tree_add_time(epl_tree, hf_epl_soc_nettime, tvb, offset, 8, &nettime);

        proto_tree_add_item(epl_tree, hf_epl_soc_relativetime, tvb, offset+8, 8, ENC_LITTLE_ENDIAN);
    }
    offset += 16;

    return offset;
}



gint
dissect_epl_preq(proto_tree *epl_tree, tvbuff_t *tvb, packet_info *pinfo, gint offset)
{
    guint16 len;
    guint8  pdoversion;
    guint8  flags;

    offset += 1;

    flags = tvb_get_guint8(tvb, offset);
    if (epl_tree)
    {
        proto_tree_add_boolean(epl_tree, hf_epl_preq_ms, tvb, offset, 1, flags);
        proto_tree_add_boolean(epl_tree, hf_epl_preq_ea, tvb, offset, 1, flags);
        proto_tree_add_boolean(epl_tree, hf_epl_preq_rd, tvb, offset, 1, flags);
    }
    offset += 2;

    pdoversion = tvb_get_guint8(tvb, offset);
    if (epl_tree)
    {
        proto_tree_add_string_format(epl_tree, hf_epl_preq_pdov, tvb, offset,
        1, "", "PDOVersion %d.%d",  hi_nibble(pdoversion), lo_nibble(pdoversion));
    }
    offset += 2;

    /* get size of payload */
    len = tvb_get_letohs(tvb, offset);
    if (epl_tree)
    {
        proto_tree_add_uint(epl_tree, hf_epl_preq_size, tvb, offset, 2, len);
    }

    offset += 2;

    if (epl_tree && (len > 0))
    {
        proto_tree_add_item(epl_tree, hf_epl_preq_pl, tvb, offset, len, ENC_NA);
    }
    offset += len;

    if (check_col(pinfo->cinfo, COL_INFO))
    {
        col_append_fstr(pinfo->cinfo, COL_INFO, "RD = %d   size = %d   ver = %d.%d",
                        (EPL_PDO_RD_MASK & flags), len, hi_nibble(pdoversion), lo_nibble(pdoversion));
    }

    return offset;
}



gint
dissect_epl_pres(proto_tree *epl_tree, tvbuff_t *tvb, packet_info *pinfo, guint8 epl_src, gint offset)
{
    guint16  len;
    guint8  pdoversion;
    guint8  flags;

    if (epl_tree)
    {
        if (epl_src != EPL_MN_NODEID)   /* check if the sender is CN or MN */
        {
            proto_tree_add_item(epl_tree, hf_epl_pres_stat_cs, tvb, offset, 1, ENC_LITTLE_ENDIAN);
        }
        else /* MN */
        {
            proto_tree_add_item(epl_tree, hf_epl_pres_stat_ms, tvb, offset, 1, ENC_LITTLE_ENDIAN);
        }
    }
    offset += 1;

    flags = tvb_get_guint8(tvb, offset);
    if (epl_tree)
    {
        proto_tree_add_boolean(epl_tree, hf_epl_pres_ms, tvb, offset, 1, flags);
        proto_tree_add_boolean(epl_tree, hf_epl_pres_en, tvb, offset, 1, flags);
        proto_tree_add_boolean(epl_tree, hf_epl_pres_rd, tvb, offset, 1, flags);
    }
    offset += 1;

    if (epl_tree)
    {
        proto_tree_add_item(epl_tree, hf_epl_pres_pr, tvb, offset, 1, ENC_LITTLE_ENDIAN);
        proto_tree_add_item(epl_tree, hf_epl_pres_rs, tvb, offset, 1, ENC_LITTLE_ENDIAN);
    }
    offset += 1;

    pdoversion = tvb_get_guint8(tvb, offset);
    if (epl_tree)
    {
        proto_tree_add_string_format(epl_tree, hf_epl_pres_pdov, tvb, offset,
        1, "", "PDOVersion %d.%d",  hi_nibble(pdoversion), lo_nibble(pdoversion));
    }
    offset += 2;

    /* get size of payload */
    len = tvb_get_letohs(tvb, offset);
    if (epl_tree)
    {
        proto_tree_add_uint(epl_tree, hf_epl_pres_size, tvb, offset, 2, len);
    }

    offset += 2;
    if (epl_tree && (len > 0))
    {
        proto_tree_add_item(epl_tree, hf_epl_pres_pl, tvb, offset, len, ENC_NA);
    }
    offset += len;

    if (check_col(pinfo->cinfo, COL_INFO))
    {
        col_append_fstr(pinfo->cinfo, COL_INFO, "RD = %d   size = %d   ver = %d.%d",
                        (EPL_PDO_RD_MASK & flags), len, hi_nibble(pdoversion), lo_nibble(pdoversion));
    }

    return offset;
}



gint
dissect_epl_soa(proto_tree *epl_tree, tvbuff_t *tvb, packet_info *pinfo, guint8 epl_src, gint offset)
{
    guint8 eplversion;
    guint8 svid, target;

    if (epl_tree)
    {
        if (epl_src != EPL_MN_NODEID)   /* check if CN or MN */
        {
            proto_tree_add_item(epl_tree, hf_epl_soa_stat_cs, tvb, offset, 1, ENC_LITTLE_ENDIAN);
        }
        else /* MN */
        {
            proto_tree_add_item(epl_tree, hf_epl_soa_stat_ms, tvb, offset, 1, ENC_LITTLE_ENDIAN);
        }
    }
    offset += 1;

    if (epl_tree)
    {
        proto_tree_add_item(epl_tree, hf_epl_soa_ea, tvb, offset, 1, ENC_LITTLE_ENDIAN);
        proto_tree_add_item(epl_tree, hf_epl_soa_er, tvb, offset, 1, ENC_LITTLE_ENDIAN);
    }
    offset += 2;

    svid = tvb_get_guint8(tvb, offset);
    if (epl_tree)
    {
        proto_tree_add_uint(epl_tree, hf_epl_soa_svid, tvb, offset, 1, svid);
    }
    offset += 1;

    target = tvb_get_guint8(tvb, offset);
    if (epl_tree)
    {
        proto_tree_add_uint(epl_tree, hf_epl_soa_svtg, tvb, offset, 1, target);
    }
    offset += 1;

    if (svid != EPL_SOA_NOSERVICE && check_col(pinfo->cinfo, COL_INFO))
    {
        col_append_fstr(pinfo->cinfo, COL_INFO, "tgt = %3d   %s",
                        target, val_to_str(svid, soa_svid_vals, "Unknown (%d)"));
    }

    if (epl_tree)
    {
        eplversion = tvb_get_guint8(tvb, offset);
        proto_tree_add_string_format(epl_tree, hf_epl_soa_eplv, tvb, offset,
            1, "", "EPLVersion %d.%d",  hi_nibble(eplversion), lo_nibble(eplversion));
    }
    offset += 1;

    return offset;
}



gint
dissect_epl_asnd(proto_tree *epl_tree, tvbuff_t *tvb, packet_info *pinfo, guint8 epl_src, gint offset)
{
    guint8  svid;

    /* get ServiceID of payload */
    svid = tvb_get_guint8(tvb, offset);
    if (epl_tree)
    {
        proto_tree_add_uint(epl_tree, hf_epl_asnd_svid, tvb, offset, 1, svid);
    }

    offset += 1;

    if (check_col(pinfo->cinfo, COL_INFO))
    {
        col_append_fstr(pinfo->cinfo, COL_INFO, "%s   ",
                        val_to_str(svid, asnd_svid_vals, "Unknown (%d)"));
    }

    switch (svid)
    {
        case EPL_ASND_IDENTRESPONSE:
            offset = dissect_epl_asnd_ires(epl_tree, tvb, pinfo, epl_src, offset);
            break;

        case EPL_ASND_STATUSRESPONSE:
            offset = dissect_epl_asnd_sres(epl_tree, tvb, pinfo, epl_src, offset);
            break;

        case EPL_ASND_NMTREQUEST:
            offset = dissect_epl_asnd_nmtreq(epl_tree, tvb, pinfo, offset);
            break;

        case EPL_ASND_NMTCOMMAND:
            offset = dissect_epl_asnd_nmtcmd(epl_tree, tvb, pinfo, offset);
            break;

        case EPL_ASND_SDO:
            offset = dissect_epl_asnd_sdo(epl_tree, tvb, pinfo, offset);
            break;
    }

    return offset;
}



gint
dissect_epl_asnd_nmtreq(proto_tree *epl_tree, tvbuff_t *tvb, packet_info *pinfo, gint offset)
{
    guint8 rcid;

    rcid = tvb_get_guint8(tvb, offset);

    if (epl_tree)
    {
        proto_tree_add_uint(epl_tree, hf_epl_asnd_nmtrequest_rcid, tvb, offset, 1, rcid);

        proto_tree_add_item(epl_tree, hf_epl_asnd_nmtrequest_rct, tvb, offset+1, 1, ENC_LITTLE_ENDIAN);

        proto_tree_add_item(epl_tree, hf_epl_asnd_nmtrequest_rcd, tvb, offset+2, -1, ENC_NA);
    }

    offset += 2;

    if (check_col(pinfo->cinfo, COL_INFO))
    {
        col_append_str(pinfo->cinfo, COL_INFO,
                        val_to_str(rcid, asnd_cid_vals, "Unknown (%d)"));
    }

    return offset;
}



gint
dissect_epl_asnd_nmtcmd(proto_tree *epl_tree, tvbuff_t *tvb, packet_info *pinfo, gint offset)
{
    guint8 epl_asnd_nmtcommand_cid;

    epl_asnd_nmtcommand_cid = tvb_get_guint8(tvb, offset);
    proto_tree_add_uint(epl_tree, hf_epl_asnd_nmtcommand_cid, tvb, offset, 1, epl_asnd_nmtcommand_cid);
    offset += 2;

    switch (epl_asnd_nmtcommand_cid)
    {
        case EPL_ASND_NMTCOMMAND_NMTNETHOSTNAMESET:
            proto_tree_add_item(epl_tree, hf_epl_asnd_nmtcommand_nmtnethostnameset_hn, tvb, offset, 32, ENC_NA);
            offset += 32;
            break;

        case EPL_ASND_NMTCOMMAND_NMTFLUSHARPENTRY:
            proto_tree_add_item(epl_tree, hf_epl_asnd_nmtcommand_nmtflusharpentry_nid, tvb, offset, 1, ENC_LITTLE_ENDIAN);
            offset += 1;
            break;

        case EPL_ASND_NMTCOMMAND_NMTPUBLISHTIME:
            proto_tree_add_item(epl_tree, hf_epl_asnd_nmtcommand_nmtpublishtime_dt, tvb, offset, 6, ENC_NA);
            offset += 6;
            break;

        default:
            proto_tree_add_item(epl_tree, hf_epl_asnd_nmtcommand_cdat, tvb, offset, -1, ENC_NA);
    }

    if (check_col(pinfo->cinfo, COL_INFO))
    {
        col_append_str(pinfo->cinfo, COL_INFO,
                        val_to_str(epl_asnd_nmtcommand_cid, asnd_cid_vals, "Unknown (%d)"));
    }

    return offset;
}



gint
dissect_epl_asnd_ires(proto_tree *epl_tree, tvbuff_t *tvb, packet_info *pinfo, guint8 epl_src, gint offset)
{
    guint8  eplversion;
    guint16 profile,additional;
    guint32 epl_asnd_identresponse_ipa, epl_asnd_identresponse_snm, epl_asnd_identresponse_gtw;
    guint32 epl_asnd_ires_feat;
    proto_item  *ti_feat;
    proto_tree  *epl_feat_tree;

    proto_tree_add_item(epl_tree, hf_epl_asnd_identresponse_en, tvb, offset, 1, ENC_LITTLE_ENDIAN);
    proto_tree_add_item(epl_tree, hf_epl_asnd_identresponse_ec, tvb, offset, 1, ENC_LITTLE_ENDIAN);
    offset += 1;

    proto_tree_add_item(epl_tree, hf_epl_asnd_identresponse_pr, tvb, offset, 1, ENC_LITTLE_ENDIAN);
    proto_tree_add_item(epl_tree, hf_epl_asnd_identresponse_rs, tvb, offset, 1, ENC_LITTLE_ENDIAN);
    offset += 1;

    if (epl_src != EPL_MN_NODEID)   /* check if CN or MN */
    {
        proto_tree_add_item(epl_tree, hf_epl_asnd_identresponse_stat_cs, tvb, offset, 1, ENC_LITTLE_ENDIAN);
    }
    else /* MN */
    {
        proto_tree_add_item(epl_tree, hf_epl_asnd_identresponse_stat_ms, tvb, offset, 1, ENC_LITTLE_ENDIAN);
    }
    offset += 2;

    eplversion = tvb_get_guint8(tvb, offset);
    proto_tree_add_string_format(epl_tree, hf_epl_asnd_identresponse_ever, tvb, offset,
                                 1, "", "EPLVersion %d.%d",  hi_nibble(eplversion), lo_nibble(eplversion));
    offset += 2;

    /* decode FeatureFlags */
    epl_asnd_ires_feat = tvb_get_letohl(tvb, offset);
    ti_feat = proto_tree_add_uint(epl_tree, hf_epl_asnd_identresponse_feat, tvb, offset, 4, epl_asnd_ires_feat);
    epl_feat_tree = proto_item_add_subtree(ti_feat, ett_epl_feat);
    proto_tree_add_boolean(epl_feat_tree, hf_epl_asnd_identresponse_feat_bit0, tvb, offset, 4, epl_asnd_ires_feat);
    proto_tree_add_boolean(epl_feat_tree, hf_epl_asnd_identresponse_feat_bit1, tvb, offset, 4, epl_asnd_ires_feat);
    proto_tree_add_boolean(epl_feat_tree, hf_epl_asnd_identresponse_feat_bit2, tvb, offset, 4, epl_asnd_ires_feat);
    proto_tree_add_boolean(epl_feat_tree, hf_epl_asnd_identresponse_feat_bit3, tvb, offset, 4, epl_asnd_ires_feat);
    proto_tree_add_boolean(epl_feat_tree, hf_epl_asnd_identresponse_feat_bit4, tvb, offset, 4, epl_asnd_ires_feat);
    proto_tree_add_boolean(epl_feat_tree, hf_epl_asnd_identresponse_feat_bit5, tvb, offset, 4, epl_asnd_ires_feat);
    proto_tree_add_boolean(epl_feat_tree, hf_epl_asnd_identresponse_feat_bit6, tvb, offset, 4, epl_asnd_ires_feat);
    proto_tree_add_boolean(epl_feat_tree, hf_epl_asnd_identresponse_feat_bit7, tvb, offset, 4, epl_asnd_ires_feat);
    proto_tree_add_boolean(epl_feat_tree, hf_epl_asnd_identresponse_feat_bit8, tvb, offset, 4, epl_asnd_ires_feat);
    proto_tree_add_boolean(epl_feat_tree, hf_epl_asnd_identresponse_feat_bit9, tvb, offset, 4, epl_asnd_ires_feat);
    proto_tree_add_boolean(epl_feat_tree, hf_epl_asnd_identresponse_feat_bitA, tvb, offset, 4, epl_asnd_ires_feat);
    proto_tree_add_boolean(epl_feat_tree, hf_epl_asnd_identresponse_feat_bitB, tvb, offset, 4, epl_asnd_ires_feat);
    proto_tree_add_boolean(epl_feat_tree, hf_epl_asnd_identresponse_feat_bitC, tvb, offset, 4, epl_asnd_ires_feat);
    proto_tree_add_boolean(epl_feat_tree, hf_epl_asnd_identresponse_feat_bitD, tvb, offset, 4, epl_asnd_ires_feat);
    offset += 4;

    proto_tree_add_item(epl_tree, hf_epl_asnd_identresponse_mtu, tvb, offset, 2, ENC_LITTLE_ENDIAN);
    offset += 2;

    proto_tree_add_item(epl_tree, hf_epl_asnd_identresponse_pis, tvb, offset, 2, ENC_LITTLE_ENDIAN);
    offset += 2;

    proto_tree_add_item(epl_tree, hf_epl_asnd_identresponse_pos, tvb, offset, 2, ENC_LITTLE_ENDIAN);
    offset += 2;

    proto_tree_add_item(epl_tree, hf_epl_asnd_identresponse_rst, tvb, offset, 4, ENC_LITTLE_ENDIAN);
    offset += 6;

    profile    = tvb_get_letohs(tvb, offset);
    additional = tvb_get_letohs(tvb, offset+2);
    proto_tree_add_string_format(epl_tree, hf_epl_asnd_identresponse_dt, tvb, offset,
                                 4, "", "Device Type: Profile %d (%s), Additional Information: 0x%4.4X",
                                 profile, val_to_str(profile, epl_device_profiles, "Unknown Profile"), additional);

    proto_tree_add_item(epl_tree, hf_epl_asnd_identresponse_profile, tvb, offset, 2, ENC_LITTLE_ENDIAN);
    offset += 4;

    proto_tree_add_item(epl_tree, hf_epl_asnd_identresponse_vid, tvb, offset, 4, ENC_LITTLE_ENDIAN);
    offset += 4;

    proto_tree_add_item(epl_tree, hf_epl_asnd_identresponse_productcode, tvb, offset, 4, ENC_LITTLE_ENDIAN);
    offset += 4;

    proto_tree_add_item(epl_tree, hf_epl_asnd_identresponse_rno, tvb, offset, 4, ENC_LITTLE_ENDIAN);
    offset += 4;

    proto_tree_add_item(epl_tree, hf_epl_asnd_identresponse_sno, tvb, offset, 4, ENC_LITTLE_ENDIAN);
    offset += 4;

    proto_tree_add_item(epl_tree, hf_epl_asnd_identresponse_vex1, tvb, offset, 8, ENC_LITTLE_ENDIAN);
    offset += 8;

    proto_tree_add_item(epl_tree, hf_epl_asnd_identresponse_vcd, tvb, offset, 4, ENC_LITTLE_ENDIAN);
    offset += 4;

    proto_tree_add_item(epl_tree, hf_epl_asnd_identresponse_vct, tvb, offset, 4, ENC_LITTLE_ENDIAN);
    offset += 4;

    proto_tree_add_item(epl_tree, hf_epl_asnd_identresponse_ad, tvb, offset, 4, ENC_LITTLE_ENDIAN);
    offset += 4;

    proto_tree_add_item(epl_tree, hf_epl_asnd_identresponse_at, tvb, offset, 4, ENC_LITTLE_ENDIAN);
    offset += 4;

    epl_asnd_identresponse_ipa = tvb_get_ntohl(tvb, offset);
    proto_tree_add_ipv4(epl_tree , hf_epl_asnd_identresponse_ipa, tvb, offset, 4, epl_asnd_identresponse_ipa);
    offset += 4;

    epl_asnd_identresponse_snm = tvb_get_ntohl(tvb, offset);
    proto_tree_add_ipv4(epl_tree , hf_epl_asnd_identresponse_snm, tvb, offset, 4, epl_asnd_identresponse_snm);
    offset += 4;

    epl_asnd_identresponse_gtw = tvb_get_ntohl(tvb, offset);
    proto_tree_add_ipv4(epl_tree , hf_epl_asnd_identresponse_gtw, tvb, offset, 4, epl_asnd_identresponse_gtw);
    offset += 4;

    proto_tree_add_item(epl_tree, hf_epl_asnd_identresponse_hn, tvb, offset, 32, ENC_ASCII|ENC_NA);
    offset += 32;

    proto_tree_add_item(epl_tree, hf_epl_asnd_identresponse_vex2, tvb, offset, 48, ENC_NA);
    offset += 48;

    if (check_col(pinfo->cinfo, COL_INFO))
    {
        col_append_str(pinfo->cinfo, COL_INFO, val_to_str(profile, epl_device_profiles, "Device Profile %d"));
    }

    return offset;
}



gint
dissect_epl_asnd_sres(proto_tree *epl_tree, tvbuff_t *tvb, packet_info *pinfo, guint8 epl_src, gint offset)
{
    proto_item  *ti_seb, *ti_el, *ti_el_entry, *ti_el_entry_type;
    proto_tree  *epl_seb_tree, *epl_el_tree, *epl_el_entry_tree, *epl_el_entry_type_tree;
    guint       number_of_entries, cnt;    /* used for dissection of ErrorCodeList */
    guint8      nmt_state;

    if (epl_tree)
    {
        proto_tree_add_item(epl_tree, hf_epl_asnd_statusresponse_en, tvb, offset, 1, ENC_LITTLE_ENDIAN);
        proto_tree_add_item(epl_tree, hf_epl_asnd_statusresponse_ec, tvb, offset, 1, ENC_LITTLE_ENDIAN);
        offset += 1;

        proto_tree_add_item(epl_tree, hf_epl_asnd_statusresponse_pr, tvb, offset, 1, ENC_LITTLE_ENDIAN);
        proto_tree_add_item(epl_tree, hf_epl_asnd_statusresponse_rs, tvb, offset, 1, ENC_LITTLE_ENDIAN);
        offset += 1;
    }
    else
    {
        offset += 2;
    }

    nmt_state = tvb_get_guint8(tvb, offset);
    if (check_col(pinfo->cinfo, COL_INFO))
    {
        col_append_fstr(pinfo->cinfo, COL_INFO, "%s   ", val_to_str(nmt_state, epl_nmt_cs_vals, "Unknown (%d)"));
    }

    if (epl_src != EPL_MN_NODEID)   /* check if CN or MN */
    {
        proto_tree_add_uint(epl_tree, hf_epl_asnd_statusresponse_stat_cs, tvb, offset, 1, nmt_state);
    }
    else /* MN */
    {
        proto_tree_add_uint(epl_tree, hf_epl_asnd_statusresponse_stat_ms, tvb, offset, 1, nmt_state);
    }
    offset += 4;

    /* Subtree for the static error bitfield */
    ti_seb = proto_tree_add_text(epl_tree, tvb, offset, 8, "StaticErrorBitfield");

    epl_seb_tree = proto_item_add_subtree(ti_seb, ett_epl_seb);

    proto_tree_add_item(epl_seb_tree, hf_epl_asnd_statusresponse_seb_err_errorregister_u8_bit0, tvb, offset, 1, ENC_LITTLE_ENDIAN);
    proto_tree_add_item(epl_seb_tree, hf_epl_asnd_statusresponse_seb_err_errorregister_u8_bit1, tvb, offset, 1, ENC_LITTLE_ENDIAN);
    proto_tree_add_item(epl_seb_tree, hf_epl_asnd_statusresponse_seb_err_errorregister_u8_bit2, tvb, offset, 1, ENC_LITTLE_ENDIAN);
    proto_tree_add_item(epl_seb_tree, hf_epl_asnd_statusresponse_seb_err_errorregister_u8_bit3, tvb, offset, 1, ENC_LITTLE_ENDIAN);
    proto_tree_add_item(epl_seb_tree, hf_epl_asnd_statusresponse_seb_err_errorregister_u8_bit4, tvb, offset, 1, ENC_LITTLE_ENDIAN);
    proto_tree_add_item(epl_seb_tree, hf_epl_asnd_statusresponse_seb_err_errorregister_u8_bit5, tvb, offset, 1, ENC_LITTLE_ENDIAN);
    proto_tree_add_item(epl_seb_tree, hf_epl_asnd_statusresponse_seb_err_errorregister_u8_bit7, tvb, offset, 1, ENC_LITTLE_ENDIAN);
    offset += 2;

    proto_tree_add_item(epl_seb_tree, hf_epl_asnd_statusresponse_seb_devicespecific_err, tvb,offset, 6, ENC_NA);
    offset += 6;

    /* List of errors / events */
    /* get the number of entries in the error code list*/
    number_of_entries = (tvb_length(tvb)-offset)/20;

    ti_el = proto_tree_add_text(epl_tree, tvb, offset, -1, "ErrorCodeList: %d entries", number_of_entries);

    epl_el_tree = proto_item_add_subtree(ti_el, ett_epl_el);

    /*Dissect the whole Error List (display each entry)*/
    for (cnt = 0; cnt<number_of_entries; cnt++)
    {
        ti_el_entry = proto_tree_add_text(epl_el_tree, tvb, offset, 20, "Entry %d", cnt+1);

        epl_el_entry_tree = proto_item_add_subtree(ti_el_entry, ett_epl_el_entry);

        /*Entry Type*/
        ti_el_entry_type = proto_tree_add_item(ti_el_entry,
                                               hf_epl_asnd_statusresponse_el_entry_type, tvb, offset, 2, ENC_LITTLE_ENDIAN);

        epl_el_entry_type_tree = proto_item_add_subtree(ti_el_entry_type,
                                                        ett_epl_el_entry_type);

        proto_tree_add_item(epl_el_entry_type_tree,
                            hf_epl_asnd_statusresponse_el_entry_type_profile, tvb, offset, 2, ENC_LITTLE_ENDIAN);

        proto_tree_add_item(epl_el_entry_type_tree,
                            hf_epl_asnd_statusresponse_el_entry_type_mode, tvb, offset, 2, ENC_LITTLE_ENDIAN);

        proto_tree_add_item(epl_el_entry_type_tree,
                            hf_epl_asnd_statusresponse_el_entry_type_bit14, tvb, offset, 2, ENC_LITTLE_ENDIAN);

        proto_tree_add_item(epl_el_entry_type_tree,
                            hf_epl_asnd_statusresponse_el_entry_type_bit15, tvb, offset, 2, ENC_LITTLE_ENDIAN);
        offset += 2;

        proto_tree_add_item(epl_el_entry_tree, hf_epl_asnd_statusresponse_el_entry_code, tvb, offset, 2, ENC_LITTLE_ENDIAN);
        offset += 2;

        proto_tree_add_item(epl_el_entry_tree, hf_epl_asnd_statusresponse_el_entry_time, tvb, offset, 8, ENC_LITTLE_ENDIAN);
        offset += 8;

        proto_tree_add_item(epl_el_entry_tree, hf_epl_asnd_statusresponse_el_entry_add, tvb, offset, 8, ENC_LITTLE_ENDIAN);
        offset += 8;
    }

    return offset;
}



gint
dissect_epl_asnd_sdo(proto_tree *epl_tree, tvbuff_t *tvb, packet_info *pinfo, gint offset)
{
    offset = dissect_epl_sdo_sequence(epl_tree, tvb, pinfo, offset);

    if (tvb_reported_length_remaining(tvb, offset) > 0)
    {
        offset = dissect_epl_sdo_command(epl_tree, tvb, pinfo, offset);
    }
    else col_append_str(pinfo->cinfo, COL_INFO, "Empty CommandLayer");

    return offset;
}


gint
dissect_epl_sdo_sequence(proto_tree *epl_tree, tvbuff_t *tvb, packet_info *pinfo, gint offset)
{
    guint8 seq_recv, seq_send;

    /* Asynchronuous SDO Sequence Layer */
    seq_recv = tvb_get_guint8(tvb, offset);

    if (epl_tree)
    {
        proto_tree_add_uint(epl_tree, hf_epl_asnd_sdo_seq_receive_sequence_number, tvb, offset, 1, seq_recv);
        proto_tree_add_uint(epl_tree, hf_epl_asnd_sdo_seq_receive_con,             tvb, offset, 1, seq_recv);
    }
    offset += 1;

    seq_send = tvb_get_guint8(tvb, offset);

    if (epl_tree)
    {
        proto_tree_add_uint(epl_tree, hf_epl_asnd_sdo_seq_send_sequence_number, tvb, offset, 1, seq_send);
        proto_tree_add_uint(epl_tree, hf_epl_asnd_sdo_seq_send_con, tvb, offset, 1, seq_send);
    }
    offset += 3;

    if (check_col(pinfo->cinfo, COL_INFO))
    {
        seq_recv &= EPL_ASND_SDO_SEQ_CON_MASK;
        seq_send &= EPL_ASND_SDO_SEQ_CON_MASK;
        if ((seq_recv == 0x00) && (seq_send == 0x00))
        {   /* Sequence layer will be closed */
            col_append_str(pinfo->cinfo, COL_INFO, "Close  ");
        }
        else if ((seq_recv < 0x02) || (seq_send < 0x02))
        {
            col_append_fstr(pinfo->cinfo, COL_INFO, "Init=%d%d  ",
                            seq_recv, seq_send);
        }
    }

    return offset;
}



gint
dissect_epl_sdo_command(proto_tree *epl_tree, tvbuff_t *tvb, packet_info *pinfo, gint offset)
{
    guint8  segmented, command_id;
    gboolean response, abort_flag;
    guint32 abort_code;
    guint16 segment_size;

    offset += 1;

    command_id = tvb_get_guint8(tvb, offset + 2);

    abort_flag      = tvb_get_guint8(tvb, offset + 1) & EPL_ASND_SDO_CMD_ABORT_FILTER;

    /* test if CommandField == empty */
    if (command_id != 0 || abort_flag)
    {
        segmented  = (tvb_get_guint8(tvb, offset + 1) & EPL_ASND_SDO_CMD_SEGMENTATION_FILTER) >> 4;
        response   = tvb_get_guint8(tvb, offset + 1) & EPL_ASND_SDO_CMD_RESPONSE_FILTER;
        segment_size = tvb_get_letohs(tvb, offset + 3);

        if (epl_tree)
        {
            proto_tree_add_item(epl_tree, hf_epl_asnd_sdo_cmd_transaction_id, tvb, offset, 1, ENC_LITTLE_ENDIAN);
            offset += 1;

            proto_tree_add_item(epl_tree, hf_epl_asnd_sdo_cmd_response, tvb, offset, 1, ENC_LITTLE_ENDIAN);
            proto_tree_add_item(epl_tree, hf_epl_asnd_sdo_cmd_abort,    tvb, offset, 1, ENC_LITTLE_ENDIAN);

            proto_tree_add_item(epl_tree, hf_epl_asnd_sdo_cmd_segmentation, tvb, offset, 1, ENC_LITTLE_ENDIAN);
            offset += 1;

            proto_tree_add_item(epl_tree, hf_epl_asnd_sdo_cmd_command_id, tvb, offset, 1, ENC_LITTLE_ENDIAN);
            offset += 1;

            proto_tree_add_item(epl_tree, hf_epl_asnd_sdo_cmd_segment_size, tvb, offset, 2, ENC_LITTLE_ENDIAN);
            offset += 4;
        }
        else
        {
            offset += 7;
        }

        /* adjust size of packet */
        tvb_set_reported_length(tvb, offset + segment_size);

        if (segmented == EPL_ASND_SDO_CMD_SEGMENTATION_INITIATE_TRANSFER)
        {
            /* if Segmentation = Initiate then print DataSize */
            if (epl_tree)
            {
                proto_tree_add_item(epl_tree, hf_epl_asnd_sdo_cmd_data_size, tvb, offset, 4, ENC_LITTLE_ENDIAN);
            }
            segmented = TRUE;
            offset += 4;
        }

        if (abort_flag)
        {
            abort_code = tvb_get_letohl(tvb, offset);
            /* if AbortBit is set then print AbortMessage */
            if (epl_tree)
            {
                proto_tree_add_uint(epl_tree, hf_epl_asnd_sdo_cmd_abort_code, tvb, offset, 4, abort_code);
            }
            if (check_col(pinfo->cinfo, COL_INFO))
            {
                col_append_fstr(pinfo->cinfo, COL_INFO, "Abort = 0x%08X", abort_code);
            }
        }
        else
        {
            switch (command_id)
            {
                case EPL_ASND_SDO_COMMAND_WRITE_BY_INDEX:
                    offset = dissect_epl_sdo_command_write_by_index(epl_tree, tvb, pinfo, offset, segmented, response);
                    break;

                case EPL_ASND_SDO_COMMAND_READ_BY_INDEX:
                    offset = dissect_epl_sdo_command_read_by_index(epl_tree, tvb, pinfo, offset, segmented, response);
                    break;

                default:
                    return FALSE;
            }
        }
    }
    return offset;
}



gint
dissect_epl_sdo_command_write_by_index(proto_tree *epl_tree, tvbuff_t *tvb, packet_info *pinfo, gint offset, guint8 segmented, gboolean response)
{
    gint size;
    guint16 index;
    guint8 subindex;
    guint32 val;
    proto_item* item;

    if (!response)
    {   /* request */
        if (segmented <= EPL_ASND_SDO_CMD_SEGMENTATION_INITIATE_TRANSFER)
        {
            index = tvb_get_letohs(tvb, offset);
            if (epl_tree)
            {
                proto_tree_add_uint(epl_tree, hf_epl_asnd_sdo_cmd_write_by_index_index, tvb, offset, 2, index);
            }
            offset += 2;

            subindex = tvb_get_guint8(tvb, offset);
            if (epl_tree)
            {
                proto_tree_add_uint(epl_tree, hf_epl_asnd_sdo_cmd_write_by_index_subindex, tvb, offset, 1, subindex);
            }
            offset += 2;

            if (check_col(pinfo->cinfo, COL_INFO))
            {
                col_append_fstr(pinfo->cinfo, COL_INFO, "Write 0x%04X/%d", index, subindex);
            }
        }
        else if (check_col(pinfo->cinfo, COL_INFO))
        {
            col_append_fstr(pinfo->cinfo, COL_INFO, "Requ. %s",
                            val_to_str(segmented, epl_sdo_asnd_cmd_segmentation, "Unknown (%d)"));
        }

        size = tvb_reported_length_remaining(tvb, offset);
        item = proto_tree_add_item(epl_tree, hf_epl_asnd_sdo_cmd_write_by_index_data, tvb, offset, size, ENC_NA);

        if (size == 4)
        {
            val = tvb_get_letohl(tvb, offset);
            proto_item_append_text(item, " (%d)", val);
        }
        else if (size == 2)
        {
            val = tvb_get_letohs(tvb, offset);
            proto_item_append_text(item, " (%d)", val);
        }
        else if (size == 1)
        {
            val = tvb_get_guint8(tvb, offset);
            proto_item_append_text(item, " (%d)", val);
        }

        offset += size;
    }
    else
    {
        /* response, no payload */
        col_append_str(pinfo->cinfo, COL_INFO, "Response");
    }
    return offset;
}



gint
dissect_epl_sdo_command_read_by_index(proto_tree *epl_tree, tvbuff_t *tvb, packet_info *pinfo, gint offset, guint8 segmented, gboolean response)
{
    gint size;
    guint16 index;
    guint8 subindex;
    guint32 val;
    proto_item* item;

    if (!response)
    {   /* request */
        index = tvb_get_letohs(tvb, offset);
        if (epl_tree)
        {
            proto_tree_add_uint(epl_tree, hf_epl_asnd_sdo_cmd_read_by_index_index, tvb, offset, 2, index);
        }
        offset += 2;

        subindex = tvb_get_guint8(tvb, offset);
        if (epl_tree)
        {
            proto_tree_add_uint(epl_tree, hf_epl_asnd_sdo_cmd_read_by_index_subindex, tvb, offset, 1, subindex);
        }
        offset += 1;

        if (check_col(pinfo->cinfo, COL_INFO))
        {
            col_append_fstr(pinfo->cinfo, COL_INFO, "Read 0x%04X/%d", index, subindex);
        }

    }
    else
    {   /* response */
        if (check_col(pinfo->cinfo, COL_INFO))
        {
            col_append_fstr(pinfo->cinfo, COL_INFO, "Resp. %s",
                            val_to_str(segmented, epl_sdo_asnd_cmd_segmentation, "Unknown (%d)"));
        }

        size = tvb_reported_length_remaining(tvb, offset);
        item = proto_tree_add_item(epl_tree, hf_epl_asnd_sdo_cmd_read_by_index_data, tvb, offset, size, ENC_NA);

        if (size == 4)
        {
            val = tvb_get_letohl(tvb, offset);
            proto_item_append_text(item, " (%d)", val);
        }
        else if (size == 2)
        {
            val = tvb_get_letohs(tvb, offset);
            proto_item_append_text(item, " (%d)", val);
        }
        else if (size == 1)
        {
            val = tvb_get_guint8(tvb, offset);
            proto_item_append_text(item, " (%d)", val);
        }

        offset += size;
    }

    return offset;
}



/* Register the protocol with Wireshark */
void
proto_register_epl(void)
{
static hf_register_info hf[] = {

/* Common data fields (same for all message types) */
{ &hf_epl_mtyp,         { "MessageType",                        "epl.mtyp",             FT_UINT8,   BASE_DEC, VALS(mtyp_vals),      0x7F, NULL, HFILL }},
{ &hf_epl_dest,         { "Destination",                        "epl.dest",             FT_UINT8,   BASE_DEC_HEX, NULL,                 0x00, NULL, HFILL }},
{ &hf_epl_src,          { "Source",                             "epl.src",              FT_UINT8,   BASE_DEC_HEX, NULL,                 0x00, NULL, HFILL }},

/* SoC data fields*/
{ &hf_epl_soc_mc,       { "MC (Multiplexed Cycle Completed)",   "epl.soc.mc",           FT_BOOLEAN,   8, NULL,                 EPL_SOC_MC_MASK, NULL, HFILL }},
{ &hf_epl_soc_ps,       { "PS (Prescaled Slot)",                "epl.soc.ps",           FT_BOOLEAN,   8, NULL,                 EPL_SOC_PS_MASK, NULL, HFILL }},
{ &hf_epl_soc_nettime,  { "NetTime",                            "epl.soc.nettime",      FT_ABSOLUTE_TIME,   ABSOLUTE_TIME_LOCAL, NULL,                 0x0,  NULL, HFILL }},
{ &hf_epl_soc_relativetime,{ "RelativeTime",                    "epl.soc.relativetime", FT_UINT64,  BASE_DEC, NULL,                 0x0,  NULL, HFILL }},

/* PReq data fields*/
{ &hf_epl_preq_ms,      { "MS (Multiplexed Slot)",              "epl.preq.ms",          FT_BOOLEAN,   8, NULL,                 0x20, NULL, HFILL }},
{ &hf_epl_preq_ea,      { "EA (Exception Acknowledge)",         "epl.preq.ea",          FT_BOOLEAN,   8, NULL,                 0x04, NULL, HFILL }},
{ &hf_epl_preq_rd,      { "RD (Ready)",                         "epl.preq.rd",          FT_BOOLEAN,   8, NULL,                 EPL_PDO_RD_MASK, NULL, HFILL }},
{ &hf_epl_preq_pdov,    { "PDOVersion",                         "epl.preq.pdov",        FT_STRING,  BASE_NONE, NULL,                 0x00, NULL, HFILL }},
{ &hf_epl_preq_size,    { "Size",                               "epl.preq.size",        FT_UINT16,  BASE_DEC, NULL,                 0x00, NULL, HFILL }},
{ &hf_epl_preq_pl,      { "Payload",                            "epl.preq.pl",          FT_BYTES,   BASE_NONE, NULL,                 0x00, NULL, HFILL }},

/* PRes data fields*/
{ &hf_epl_pres_stat_ms, { "NMTStatus",                          "epl.pres.stat",        FT_UINT8,   BASE_HEX, VALS(epl_nmt_ms_vals),0x00, NULL, HFILL }},
{ &hf_epl_pres_stat_cs, { "NMTStatus",                          "epl.pres.stat",        FT_UINT8,   BASE_HEX, VALS(epl_nmt_cs_vals),0x00, NULL, HFILL }},
{ &hf_epl_pres_ms,      { "MS (Multiplexed Slot)",              "epl.pres.ms",          FT_BOOLEAN,   8, NULL,                 0x20, NULL, HFILL }},
{ &hf_epl_pres_en,      { "EN (Exception New)",                 "epl.pres.en",          FT_BOOLEAN,   8, NULL,                 0x10, NULL, HFILL }},
{ &hf_epl_pres_rd,      { "RD (Ready)",                         "epl.pres.rd",          FT_BOOLEAN,   8, NULL,                 EPL_PDO_RD_MASK, NULL, HFILL }},
{ &hf_epl_pres_pr,      { "PR (Priority)",                      "epl.pres.pr",          FT_UINT8,   BASE_DEC, VALS(epl_pr_vals),    0x38, NULL, HFILL }},
{ &hf_epl_pres_rs,      { "RS (RequestToSend)",                 "epl.pres.rs",          FT_UINT8,   BASE_DEC, NULL,                 0x07, NULL, HFILL }},
{ &hf_epl_pres_pdov,    { "PDOVersion",                         "epl.pres.pdov",        FT_STRING,  BASE_NONE, NULL,                 0x00, NULL, HFILL }},
{ &hf_epl_pres_size,    { "Size",                               "epl.pres.size",        FT_UINT16,  BASE_DEC, NULL,                 0x00, NULL, HFILL }},
{ &hf_epl_pres_pl,      { "Payload",                            "epl.pres.pl",          FT_BYTES,   BASE_NONE, NULL,                 0x00, NULL, HFILL }},

/* SoA data fields*/
{ &hf_epl_soa_stat_ms,  { "NMTStatus",                          "epl.soa.stat",         FT_UINT8,   BASE_HEX, VALS(epl_nmt_ms_vals),0x00, NULL, HFILL }},
{ &hf_epl_soa_stat_cs,  { "NMTStatus",                          "epl.soa.stat",         FT_UINT8,   BASE_HEX, VALS(epl_nmt_cs_vals),0x00, NULL, HFILL }},
{ &hf_epl_soa_ea,       { "EA (Exception Acknowledge)",         "epl.soa.ea",           FT_BOOLEAN,        8, NULL,                 0x04, NULL, HFILL }},
{ &hf_epl_soa_er,       { "ER (Exception Reset)",               "epl.soa.er",           FT_BOOLEAN,        8, NULL,                 0x02, NULL, HFILL }},
{ &hf_epl_soa_svid,     { "RequestedServiceID",                 "epl.soa.svid",         FT_UINT8,   BASE_DEC, VALS(soa_svid_vals),  0x00, NULL, HFILL }},
{ &hf_epl_soa_svtg,     { "RequestedServiceTarget",             "epl.soa.svtg",         FT_UINT8,   BASE_DEC, NULL,                 0x00, NULL, HFILL }},
{ &hf_epl_soa_eplv,     { "EPLVersion",                         "epl.soa.eplv",         FT_STRING,  BASE_NONE, NULL,                 0x00, NULL, HFILL }},

/* ASnd header */
{ &hf_epl_asnd_svid,    { "ServiceID",                          "epl.asnd.svid",    FT_UINT8, BASE_DEC, VALS(asnd_svid_vals),   0x00,NULL, HFILL }},
{ &hf_epl_asnd_data,    { "Data",                               "epl.asnd.data",    FT_BYTES, BASE_NONE, NULL,                   0x00,NULL, HFILL }},

/* ASnd-->IdentResponse */
{ &hf_epl_asnd_identresponse_en,      { "EN (Exception New)",       "epl.asnd.ires.en",             FT_BOOLEAN,        8, NULL,                 0x10, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_ec,      { "EC (Exception Clear)",     "epl.asnd.ires.ec",             FT_BOOLEAN,        8, NULL,                 0x08, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_pr,      { "PR (Priority)",            "epl.asnd.ires.pr",             FT_UINT8,   BASE_DEC, VALS(epl_pr_vals),    0x38, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_rs,      { "RS (RequestToSend)",       "epl.asnd.ires.rs",             FT_UINT8,   BASE_DEC, NULL,                 0x07, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_stat_ms, { "NMTStatus",                "epl.asnd.ires.state",          FT_UINT8,   BASE_HEX, VALS(epl_nmt_ms_vals),0x00, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_stat_cs, { "NMTStatus",                "epl.asnd.ires.state",          FT_UINT8,   BASE_HEX, VALS(epl_nmt_cs_vals),0x00, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_ever,    { "EPLVersion",               "epl.asnd.ires.eplver",         FT_STRING,  BASE_NONE, NULL,                 0x00, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_feat,    { "FeatureFlags",             "epl.asnd.ires.features",       FT_UINT32,  BASE_HEX, NULL,                 0x00, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_feat_bit0,   { "Isochronous",              "epl.asnd.ires.features.bit0",  FT_BOOLEAN,  32, NULL,           0x0001, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_feat_bit1,   { "SDO by UDP/IP",            "epl.asnd.ires.features.bit1",  FT_BOOLEAN,  32, NULL,           0x0002, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_feat_bit2,   { "SDO by ASnd",              "epl.asnd.ires.features.bit2",  FT_BOOLEAN,  32, NULL,           0x0004, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_feat_bit3,   { "SDO by PDO",               "epl.asnd.ires.features.bit3",  FT_BOOLEAN,  32, NULL,           0x0008, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_feat_bit4,   { "NMT Info Services",        "epl.asnd.ires.features.bit4",  FT_BOOLEAN,  32, NULL,           0x0010, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_feat_bit5,   { "Ext. NMT State Commands",  "epl.asnd.ires.features.bit5",  FT_BOOLEAN,  32, NULL,           0x0020, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_feat_bit6,   { "Dynamic PDO Mapping",      "epl.asnd.ires.features.bit6",  FT_BOOLEAN,  32, NULL,           0x0040, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_feat_bit7,   { "NMT Service by UDP/IP",    "epl.asnd.ires.features.bit7",  FT_BOOLEAN,  32, NULL,           0x0080, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_feat_bit8,   { "Configuration Manager",    "epl.asnd.ires.features.bit8",  FT_BOOLEAN,  32, NULL,           0x0100, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_feat_bit9,   { "Multiplexed Access",       "epl.asnd.ires.features.bit9",  FT_BOOLEAN,  32, NULL,           0x0200, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_feat_bitA,   { "NodeID setup by SW",       "epl.asnd.ires.features.bitA",  FT_BOOLEAN,  32, NULL,           0x0400, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_feat_bitB,   { "MN Basic Ethernet Mode",   "epl.asnd.ires.features.bitB",  FT_BOOLEAN,  32, NULL,           0x0800, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_feat_bitC,   { "Routing Type 1 Support",   "epl.asnd.ires.features.bitC",  FT_BOOLEAN,  32, NULL,           0x1000, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_feat_bitD,   { "Routing Type 2 Support",   "epl.asnd.ires.features.bitD",  FT_BOOLEAN,  32, NULL,           0x2000, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_mtu,     { "MTU",                      "epl.asnd.ires.mtu",            FT_UINT16,  BASE_DEC, NULL,                 0x00, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_pis,     { "PollInSize",               "epl.asnd.ires.pollinsize",     FT_UINT16,  BASE_DEC, NULL,                 0x00, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_pos,     { "PollOutSize",              "epl.asnd.ires.polloutsizes",   FT_UINT16,  BASE_DEC, NULL,                 0x00, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_rst,     { "ResponseTime",             "epl.asnd.ires.resptime",       FT_UINT32,  BASE_DEC, NULL,                 0x00, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_dt,      { "DeviceType",               "epl.asnd.ires.devicetype",     FT_STRING,  BASE_NONE, NULL,                 0x00, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_profile, { "Profile",                  "epl.asnd.ires.profile",        FT_UINT16,  BASE_DEC, NULL,                 0x00, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_vid,     { "VendorId",                 "epl.asnd.ires.vendorid",       FT_UINT32,  BASE_DEC_HEX, NULL,                 0x00, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_productcode,{ "ProductCode",           "epl.asnd.ires.productcode",    FT_UINT32,  BASE_DEC_HEX, NULL,                 0x00, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_rno,     { "RevisionNumber",           "epl.asnd.ires.revisionno",     FT_UINT32,  BASE_DEC_HEX, NULL,                 0x00, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_sno,     { "SerialNumber",             "epl.asnd.ires.serialno",       FT_UINT32,  BASE_DEC_HEX, NULL,                 0x00, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_vex1,    { "VendorSpecificExtension1", "epl.asnd.ires.vendorext1",     FT_UINT64,  BASE_DEC_HEX, NULL,                 0x00, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_vcd,     { "VerifyConfigurationDate",  "epl.asnd.ires.confdate",       FT_UINT32,  BASE_DEC_HEX, NULL,                 0x00, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_vct,     { "VerifyConfigurationTime",  "epl.asnd.ires.conftime",       FT_UINT32,  BASE_DEC_HEX, NULL,                 0x00, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_ad,      { "applicationSwDate",        "epl.asnd.ires.appswdate",      FT_UINT32,  BASE_DEC_HEX, NULL,                 0x00, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_at,      { "applicationSwTime",        "epl.asnd.ires.appswtime",      FT_UINT32,  BASE_DEC_HEX, NULL,                 0x00, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_ipa,     { "IPAddress",                "epl.asnd.ires.ip",             FT_IPv4,    BASE_NONE, NULL,                 0x00, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_snm,     { "SubnetMask",               "epl.asnd.ires.subnet",         FT_IPv4,    BASE_NONE, NULL,                 0x00, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_gtw,     { "DefaultGateway",           "epl.asnd.ires.gateway",        FT_IPv4,    BASE_NONE, NULL,                 0x00, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_hn,      { "HostName",                 "epl.asnd.ires.hostname",       FT_STRING,  BASE_NONE, NULL,                 0x00, NULL, HFILL }},
{ &hf_epl_asnd_identresponse_vex2,    { "VendorSpecificExtension2", "epl.asnd.ires.vendorext2",     FT_BYTES,   BASE_NONE, NULL,                 0x00, NULL, HFILL }},


/* ASnd-->StatusResponse */
{ &hf_epl_asnd_statusresponse_en,                               { "EN (Exception New)",         "epl.asnd.sres.en",                     FT_BOOLEAN,      8, NULL,                   0x10, NULL, HFILL }},
{ &hf_epl_asnd_statusresponse_ec,                               { "EC (Exception Clear)",       "epl.asnd.sres.ec",                     FT_BOOLEAN,      8, NULL,                   0x08, NULL, HFILL }},
{ &hf_epl_asnd_statusresponse_pr,                               { "PR (Priority)",              "epl.asnd.sres.pr",                     FT_UINT8, BASE_DEC, VALS(epl_pr_vals),      0x38, NULL, HFILL }},
{ &hf_epl_asnd_statusresponse_rs,                               { "RS (RequestToSend)",         "epl.asnd.sres.rs",                     FT_UINT8, BASE_DEC, NULL,                   0x07, NULL, HFILL }},
{ &hf_epl_asnd_statusresponse_stat_ms,                          { "NMTStatus",                  "epl.asnd.sres.stat",                   FT_UINT8, BASE_HEX, VALS(epl_nmt_ms_vals),  0x00, NULL, HFILL }},
{ &hf_epl_asnd_statusresponse_stat_cs,                          { "NMTStatus",                  "epl.asnd.sres.stat",                   FT_UINT8, BASE_HEX, VALS(epl_nmt_cs_vals),  0x00, NULL, HFILL }},
{ &hf_epl_asnd_statusresponse_seb,                              { "StaticErrorBitField",        "epl.asnd.sres.seb",                    FT_BYTES, BASE_NONE, NULL,                   0x00, NULL, HFILL }},

/*StaticErrorBitField */
{ &hf_epl_asnd_statusresponse_seb_err_errorregister_u8_bit0,    { "Generic error",              "epl.asnd.res.seb.bit0",                FT_UINT8, BASE_DEC, NULL, 0x01, NULL, HFILL }},
{ &hf_epl_asnd_statusresponse_seb_err_errorregister_u8_bit1,    { "Current",                    "epl.asnd.res.seb.bit1",                FT_UINT8, BASE_DEC, NULL, 0x02, NULL, HFILL }},
{ &hf_epl_asnd_statusresponse_seb_err_errorregister_u8_bit2,    { "Voltage",                    "epl.asnd.res.seb.bit2",                FT_UINT8, BASE_DEC, NULL, 0x04, NULL, HFILL }},
{ &hf_epl_asnd_statusresponse_seb_err_errorregister_u8_bit3,    { "Temperature",                "epl.asnd.res.seb.bit3",                FT_UINT8, BASE_DEC, NULL, 0x08, NULL, HFILL }},
{ &hf_epl_asnd_statusresponse_seb_err_errorregister_u8_bit4,    { "Communication error",        "epl.asnd.res.seb.bit4",                FT_UINT8, BASE_DEC, NULL, 0x10, NULL, HFILL }},
{ &hf_epl_asnd_statusresponse_seb_err_errorregister_u8_bit5,    { "Device profile specific",    "epl.asnd.res.seb.bit5",                FT_UINT8, BASE_DEC, NULL, 0x20, NULL, HFILL }},
{ &hf_epl_asnd_statusresponse_seb_err_errorregister_u8_bit7,    { "Manufacturer specific",      "epl.asnd.res.seb.bit7",                FT_UINT8, BASE_DEC, NULL, 0x80, NULL, HFILL }},
{ &hf_epl_asnd_statusresponse_seb_devicespecific_err,           { "Device profile specific",    "epl.asnd.res.seb.devicespecific_err",FT_BYTES, BASE_NONE,NULL, 0x00, NULL, HFILL }},

{ &hf_epl_asnd_statusresponse_el,                               { "ErrorCodesList",             "epl.asnd.sres.el",                     FT_BYTES, BASE_NONE, NULL, 0x00, NULL, HFILL }},
{ &hf_epl_asnd_statusresponse_el_entry,                         { "Entry",                      "epl.asnd.sres.el.entry",               FT_BYTES, BASE_NONE, NULL, 0x00, NULL, HFILL }},

/*List of Errors/Events*/
{ &hf_epl_asnd_statusresponse_el_entry_type,                    { "Entry Type",                 "epl.asnd.sres.el.entry.type",          FT_UINT16, BASE_HEX, NULL, 0x00,    NULL, HFILL }},
{ &hf_epl_asnd_statusresponse_el_entry_type_profile,            { "Profile",                    "epl.asnd.sres.el.entry.type.profile",  FT_UINT16, BASE_DEC, NULL, 0x0FFF,  NULL, HFILL }},
{ &hf_epl_asnd_statusresponse_el_entry_type_mode,               { "Mode",                       "epl.asnd.sres.el.entry.type.mode",     FT_UINT16, BASE_DEC, NULL, 0x3000,  NULL, HFILL }},
{ &hf_epl_asnd_statusresponse_el_entry_type_bit14,              { "Bit14",                      "epl.asnd.sres.el.entry.type.bit14",    FT_UINT16, BASE_DEC, NULL, 0x4000,  NULL, HFILL }},
{ &hf_epl_asnd_statusresponse_el_entry_type_bit15,              { "Bit15",                      "epl.asnd.sres.el.entry.type.bit15",    FT_UINT16, BASE_DEC, NULL, 0x8000,  NULL, HFILL }},
{ &hf_epl_asnd_statusresponse_el_entry_code,                    { "Error Code",                 "epl.asnd.sres.el.entry.code",          FT_UINT16, BASE_DEC, NULL, 0x00,    NULL, HFILL }},
{ &hf_epl_asnd_statusresponse_el_entry_time,                    { "Time Stamp",                 "epl.asnd.sres.el.entry.time",          FT_UINT64, BASE_DEC, NULL, 0x00,    NULL, HFILL }},
{ &hf_epl_asnd_statusresponse_el_entry_add,                     { "Additional Information",     "epl.asnd.sres.el.entry.add",           FT_UINT64, BASE_DEC, NULL, 0x00,    NULL, HFILL }},


/* ASnd-->NMTRequest */
{ &hf_epl_asnd_nmtrequest_rcid,                     { "NMTRequestedCommandID",      "epl.asnd.nmtrequest.rcid",                     FT_UINT8,   BASE_HEX_DEC, NULL,                 0x00, NULL, HFILL }},
{ &hf_epl_asnd_nmtrequest_rct,                      { "NMTRequestedCommandTarget",  "epl.asnd.nmtrequest.rct",                      FT_UINT8,   BASE_DEC_HEX, NULL,                 0x00, NULL, HFILL }},
{ &hf_epl_asnd_nmtrequest_rcd,                      { "NMTRequestedCommandData",    "epl.asnd.nmtrequest.rcd",                      FT_BYTES,   BASE_NONE, NULL,                 0x00, NULL, HFILL }},

/* ASnd-->NMTCommand */
{ &hf_epl_asnd_nmtcommand_cid,                      { "NMTCommandId",               "epl.asnd.nmtcommand.cid",                      FT_UINT8,   BASE_HEX_DEC, VALS(asnd_cid_vals),  0x00, NULL, HFILL }},
{ &hf_epl_asnd_nmtcommand_cdat,                     { "NMTCommandData",             "epl.asnd.nmtcommand.cdat",                     FT_BYTES,   BASE_NONE, NULL,                 0x00, NULL, HFILL }},

{ &hf_epl_asnd_nmtcommand_nmtnethostnameset_hn,     { "HostName",                   "epl.asnd.nmtcommand.nmtnethostnameset.hn",     FT_BYTES,   BASE_NONE, NULL,                 0x00, NULL, HFILL }},
{ &hf_epl_asnd_nmtcommand_nmtflusharpentry_nid,     { "NodeID",                     "epl.asnd.nmtcommand.nmtflusharpentry.nid",     FT_UINT8,   BASE_DEC_HEX, NULL,                 0x00, NULL, HFILL }},
{ &hf_epl_asnd_nmtcommand_nmtpublishtime_dt,        { "DateTime",                   "epl.asnd.nmtcommand.nmtpublishtime.dt",        FT_BYTES,   BASE_NONE, NULL,                 0x00, NULL, HFILL }},

/* ASnd-->SDO */
{ &hf_epl_asnd_sdo_seq_receive_sequence_number, { "ReceiveSequenceNumber",          "epl.asnd.sdo.seq.receive.sequence.number", FT_UINT8,   BASE_DEC, NULL,                             0xfc, NULL, HFILL }},
{ &hf_epl_asnd_sdo_seq_receive_con,             { "ReceiveCon",                     "epl.asnd.sdo.seq.receive.con",             FT_UINT8,   BASE_DEC, VALS(epl_sdo_receive_con_vals),   0x03, NULL, HFILL }},
{ &hf_epl_asnd_sdo_seq_send_sequence_number,    { "SendSequenceNumber",             "epl.asnd.sdo.seq.send.sequence.number",    FT_UINT8,   BASE_DEC, NULL,                             0xfc, NULL, HFILL }},
{ &hf_epl_asnd_sdo_seq_send_con,                { "SendCon",                        "epl.asnd.sdo.seq.send.con",                FT_UINT8,   BASE_DEC, VALS(epl_sdo_send_con_vals),      0x03, NULL, HFILL }},

{ &hf_epl_asnd_sdo_cmd_transaction_id,          { "SDO Transaction ID",             "epl.asnd.sdo.cmd.transaction.id",          FT_UINT8,   BASE_DEC, NULL,                             0x00, NULL, HFILL }},
{ &hf_epl_asnd_sdo_cmd_response,                { "SDO Response",                   "epl.asnd.sdo.cmd.response",                FT_UINT8,   BASE_DEC, VALS(epl_sdo_asnd_cmd_response),  0x80, NULL, HFILL }},
{ &hf_epl_asnd_sdo_cmd_abort,                   { "SDO Abort",                      "epl.asnd.sdo.cmd.abort",                   FT_UINT8,   BASE_DEC, VALS(epl_sdo_asnd_cmd_abort),     0x40, NULL, HFILL }},
{ &hf_epl_asnd_sdo_cmd_segmentation,            { "SDO Segmentation",               "epl.asnd.sdo.cmd.segmentation",            FT_UINT8,   BASE_DEC, VALS(epl_sdo_asnd_cmd_segmentation), 0x30, NULL, HFILL }},
{ &hf_epl_asnd_sdo_cmd_command_id,              { "SDO Command ID",                 "epl.asnd.sdo.cmd.command.id",              FT_UINT8,   BASE_DEC, VALS(epl_sdo_asnd_commands),      0x00, NULL, HFILL }},
{ &hf_epl_asnd_sdo_cmd_segment_size,            { "SDO Segment size",               "epl.asnd.sdo.cmd.segment.size",            FT_UINT8,   BASE_DEC, NULL,                             0x00, NULL, HFILL }},
{ &hf_epl_asnd_sdo_cmd_data_size,               { "SDO Data size",                  "epl.asnd.sdo.cmd.data.size",               FT_UINT8,   BASE_DEC, NULL,                             0x00, NULL, HFILL } },
{ &hf_epl_asnd_sdo_cmd_abort_code,              { "SDO Transfer Abort",             "epl.asnd.sdo.cmd.abort.code",              FT_UINT8,   BASE_HEX, VALS(sdo_cmd_abort_code),         0x00, NULL, HFILL }},
{ &hf_epl_asnd_sdo_cmd_write_by_index_index,    { "SDO Write by Index, Index",      "epl.asnd.sdo.cmd.write.by.index.index",    FT_UINT16,  BASE_HEX, NULL,                             0x00, NULL, HFILL }},
{ &hf_epl_asnd_sdo_cmd_write_by_index_subindex, { "SDO Write by Index, SubIndex",   "epl.asnd.sdo.cmd.write.by.index.subindex", FT_UINT8,   BASE_HEX, NULL,                             0x00, NULL, HFILL }},
{ &hf_epl_asnd_sdo_cmd_read_by_index_index,     { "SDO Read by Index, Index",       "epl.asnd.sdo.cmd.read.by.index.index",     FT_UINT16,  BASE_HEX, NULL,                             0x00, NULL, HFILL }},
{ &hf_epl_asnd_sdo_cmd_read_by_index_subindex,  { "SDO Read by Index, SubIndex",    "epl.asnd.sdo.cmd.read.by.index.subindex",  FT_UINT8,   BASE_HEX, NULL,                             0x00, NULL, HFILL }},
{ &hf_epl_asnd_sdo_cmd_write_by_index_data,     { "Payload",                        "epl.asnd.sdo.cmd.write.by.index.data",     FT_BYTES,   BASE_NONE, NULL,                             0x00, NULL, HFILL }},
{ &hf_epl_asnd_sdo_cmd_read_by_index_data,      { "Payload",                        "epl.asnd.sdo.cmd.read.by.index.data",      FT_BYTES,   BASE_NONE, NULL,                             0x00, NULL, HFILL }},
};


    /* Setup protocol subtree array */
    static gint *ett[] = {
        &ett_epl,
        &ett_epl_feat,
        &ett_epl_seb,
        &ett_epl_el,
        &ett_epl_el_entry,
        &ett_epl_el_entry_type,
        &ett_epl_sdo_entry_type,
    };

    module_t *epl_module;

    /* Register the protocol name and description */
    proto_epl = proto_register_protocol("Ethernet POWERLINK", "EPL", "epl");

   /* subdissector code */
   register_heur_dissector_list("epl", &heur_epl_subdissector_list);

   /* Registering protocol to be called by another dissector */
    new_register_dissector("epl", dissect_epl, proto_epl);

    /* Required function calls to register the header fields and subtrees used */
    proto_register_field_array(proto_epl, hf, array_length(hf));
    proto_register_subtree_array(ett, array_length(ett));

    /* register preferences */
    epl_module = prefs_register_protocol(proto_epl, NULL);

    prefs_register_bool_preference(epl_module, "show_soc_flags", "Show flags of SoC frame in Info column",
        "If you are capturing in networks with multiplexed or slow nodes, this can be useful", &show_soc_flags);

    /* tap-registration */
    /*  epl_tap = register_tap("epl");*/
}



void
proto_reg_handoff_epl(void)
{
    dissector_handle_t epl_handle;

    epl_handle = new_create_dissector_handle(dissect_epl, proto_epl);
    dissector_add_uint("ethertype", ETHERTYPE_EPL_V2, epl_handle);
    dissector_add_uint("udp.port", UDP_PORT_EPL, epl_handle);
}