IEC 61158-6-2:2007

Industrial communication networks - Fieldbus specifications - Part 6-2: Application layer protocol specification - Type 2 elements

It provides user programs with a means to access the fieldbus communication environment. In this respect, the FAL can be viewed as a "window between corresponding application programs." This standard provides common elements for basic time-critical and non-time-critical messaging communications between application programs in an automation environment and material specific to Type 2 fieldbus. The term "time-critical" is used to represent the presence of a time-window, within which one or more specified actions are required to be completed with some defined level of certainty. Failure to complete specified actions within the time window risks failure of the applications requesting the actions, with attendant risk to equipment, plant and possibly human life. It includes the following significant changes from the previous edition deletion of the former Type 6 fieldbus for lack of market relevance; addition of new types of fieldbuses; partition of part 6 of the third edition into multiple parts numbered.

General Information

• Status: Published
• Publication Date: 13-Dec-2007
• ICS: 25.040.40 - Industrial process measurement and control
• ICS: 35.100.70 - Application layer
• Technical Committee: SC 65C - Industrial networks
• Drafting Committee: WG 9 - TC 65/SC 65C/WG 9
• Current Stage: DELPUB - Deleted Publication
• Start Date: 01-Sep-2010
• Completion Date: 26-Oct-2025

Relations

• Replaces: IEC 61158-6:2003 - Digital data communications for measurement and control - Fieldbus for use in industrial control systems - Part 6: Application layer protocol specification
• Effective Date: 05-Sep-2023
• Replaces: IEC PAS 62413:2005 - Real-time Ethernet - EtherNet/IP(TM) with time synchronization
• Effective Date: 05-Sep-2023
• Replaces: IEC 61158-6:2003/COR1:2004 - Corrigendum 1 - Digital data communications for measurement and control - Fieldbus for use in industrial control systems - Part 6: Application layer protocol specification
• Effective Date: 05-Sep-2023
• Revised: IEC 61158-6-2:2010 - Industrial communication networks - Fieldbus specifications - Part 6-2: Application layer protocol specification - Type 2 elements
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 61158-6-2
Edition 1.0 2007-12
INTERNATIONAL
STANDARD
Industrial communication networks – Fieldbus specifications –
Part 6-2: Application layer protocol specification – Type 2 elements

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IEC 61158-6-2
Edition 1.0 2007-12
INTERNATIONAL
STANDARD
Industrial communication networks – Fieldbus specifications –
Part 6-2: Application layer protocol specification – Type 2 elements

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
XH
ICS 35.100.70; 25.040.40 ISBN 2-8318-9474-3

– 2 – 61158-6-2 © IEC:2007(E)
CONTENTS
FOREWORD.12

INTRODUCTION.14

1 Scope.15

1.1 General .15

1.2 Specifications .15

1.3 Conformance.15

2 Normative references .16

3 Terms, definitions, symbols, abbreviations and conventions .17
3.1 Terms and definitions from other ISO/IEC standards .17
3.2 Terms and definitions from IEC 61158-5-2.18
3.3 Additional terms and definitions.18
3.4 Abbreviations and symbols .24
3.5 Conventions .24
3.6 Conventions used in state machines.28
4 Abstract syntax.30
4.1 FAL PDU abstract syntax.30
4.2 Data abstract syntax specification .110
4.3 Encapsulation abstract syntax .114
5 Transfer syntax.128
5.1 Compact encoding.128
5.2 Data type reporting.136
6 Structure of FAL protocol state machines .141
7 AP-Context state machine .142
7.1 Overview .142
7.2 Connection object state machine .142
8 FAL service protocol machine (FSPM) .151
8.1 General .151
8.2 Primitive definitions .151
8.3 Parameters of primitives.155
8.4 FSPM state machines.156
9 Application relationship protocol machines (ARPMs) .157
9.1 General .157

9.2 Connection-less ARPM (UCMM).157
9.3 Connection-oriented ARPMs (transports).167
10 DLL mapping protocol machine 1 (DMPM 1) .237
10.1 General .237
10.2 Link producer .237
10.3 Link consumer .237
10.4 Primitive definitions .237
10.5 DMPM state machine .239
10.6 Data-link Layer service selection .241
11 DLL mapping protocol machine 2 (DMPM 2) .241
11.1 General .241
11.2 Mapping of UCMM PDUs .241
11.3 Mapping of transport class 0 and class 1 PDUs .246
11.4 Mapping of transport class 2 and class 3 PDU’s .248

61158-6-2 © IEC:2007(E) – 3 –
11.5 Mapping of transport classes 4 to 6 .248

11.6 IGMP Usage.248

11.7 Management of an encapsulation session .249

12 DLL mapping protocol machine 3 (DMPM 3) .250

Bibliography.251

Figure 1 – Attribute table format and terms .24

Figure 2 – Service request/response parameter .25

Figure 3 – Example of an STD .29

Figure 4 – Network connection parameters .48
Figure 5 – Time tick .50
Figure 6 – Connection establishment time-out.52
Figure 7 – Transport Class Trigger attribute.76
Figure 8 – CP2/3_initial_comm_characteristics attribute format .79
Figure 9 – Segment type.87
Figure 10 – Port segment.88
Figure 11 – Logical segment encoding .90
Figure 12 – Extended network segment .94
Figure 13 – Encapsulation message.115
Figure 14 – FixedLengthBitString compact encoding bit placement rules .132
Figure 15 – Example compact encoding of a SWORD FixedLengthBitString.133
Figure 16 – Example compact encoding of a WORD FixedLengthBitString .133
Figure 17 – Example compact encoding of a DWORD FixedLengthBitString .133
Figure 18 – Example compact encoding of a LWORD FixedLengthBitString .133
Figure 19 – Example 2 of formal encoding of a structure type specification.138
Figure 20 – Example of abbreviated encoding of a structure type specification .138
Figure 21 – Example 1 of formal encoding of an array type specification.139
Figure 22 – Example 2 of formal encoding of an array type specification.139
Figure 23 – Example 1 of abbreviated encoding of an array type specification .140
Figure 24 – Example 2 of abbreviated encoding of an array type specification .140
Figure 25 – I/O Connection object state transition diagram .142

Figure 26 –Bridged Connection object state transition diagram .146
Figure 27 – Explicit Messaging Connection object state transition diagram .148
Figure 28 – State transition diagram of UCMM client.160
Figure 29 – State transition diagram of high–end UCMM server .161
Figure 30 – State transition diagram of low–end UCMM server .164
Figure 31 – Sequence diagram for a UCMM with one outstanding message.165
Figure 32 – Sequence diagram for a UCMM with multiple outstanding messages.166
Figure 33 – TPDU buffer .167
Figure 34 – Data flow diagram using a client transport class 0 and server transport
class 0 .170
Figure 35 – Sequence diagram of data transfer using transport class 0.170
Figure 36 – Class 0 client STD.171
Figure 37 – Class 0 server STD .172

– 4 – 61158-6-2 © IEC:2007(E)
Figure 38 – Data flow diagram using client transport class 1 and server transport

class 1 .173

Figure 39 – Sequence diagram of data transfer using client transport class 1 and

server transport class 1.174

Figure 40 – Class 1 client STD.176

Figure 41 – Class 1 server STD .177

Figure 42 – Data flow diagram using client transport class 2 and server transport

class 2 .179

Figure 43 – Diagram of data transfer using client transport class 2 and server transport

class 2 without returned data .180

Figure 44 – Sequence diagram of data transfer using client transport class 2 and
server transport class 2 with returned data.181
Figure 45 – Class 2 client STD.182
Figure 46 – Class 2 server STD .184
Figure 47 – Data flow diagram using client transport class 3 and server transport
class 3 .187
Figure 48 – Sequence diagram of data transfer using client transport class 3 and
server transport class 3 without returned data.188
Figure 49 – Sequence diagram of data transfer using client transport class 3 and
server transport class 3 with returned data.189
Figure 50 – Class 3 client STD.191
Figure 51 – Class 3 server STD .194
Figure 52 – Data flow diagram using transport classes 4 and 5.196
Figure 53 – Sequence diagram of message exchange using transport classes 4 and 5 .197
Figure 54 – Sequence diagram of messages overwriting each other .198
Figure 55 – Sequence diagram of queued message exchange using transport classes 4
and 5 .199
Figure 56 – Sequence diagram of retries using transport classes 4 and 5 .199
Figure 57 – Sequence diagram of idle traffic using transport classes 4 and 5.200
Figure 58 – Classes 4 and 5 basic structure.201
Figure 59 – Class 6 basic structure.202
Figure 60 – Classes 4 to 6 general STD.203
Figure 61 – Class 4 sender STD .205
Figure 62 – Class 4 receiver STD .208

Figure 63 – Sequence diagram of three fragments using transport class 5 .211
Figure 64 – Sequence diagram of fragmentation with retries using transport class 5 .212
Figure 65 – Sequence diagram of two fragments using transport class 5.212
Figure 66 – Sequence diagram of aborted message using transport class 5.213
Figure 67 – Class 5 sender STD .214
Figure 68 – Class 5 receiver STD .217
Figure 69 – Data flow diagram for transport class 6 .221
Figure 70 – Sequence diagram of message exchange using transport class 6 .223
Figure 71 – Sequence diagram of retries using transport class 6 .223
Figure 72 – Sequence diagram of idle traffic using transport class 6 .224
Figure 73 – Sequence diagram of request overwriting null .225
Figure 74 – Sequence diagram of response overwriting ACK of null.225

61158-6-2 © IEC:2007(E) – 5 –
Figure 75 – Sequence diagram of three fragments using transport class 6 .226

Figure 76 – Sequence diagram of fragmentation with retries using transport class 6 .227

Figure 77 – Sequence diagram of two fragments using transport class 6.227

Figure 78 – Sequence diagram of aborted fragmented sequence using transport

class 6 .228

Figure 79 – Class 6 client STD.229

Figure 80 – Class 6 server STD .232

Figure 81 – Data flow diagram for a link producer and consumer .237

Figure 82 – State transition diagram for a link producer .240

Figure 83 – State transition diagram for a link consumer.240

Table 1 – Get_Attribute_All response service rules .26
Table 2 – Example class level object/service specific response data of
Get_Attribute_All .26
Table 3 – Example Get_Attribute_All data array method .26
Table 4 – Set_Attribute_All request service rules .27
Table 5 – Example Set_Attribute_All attribute ordering method.27
Table 6 – Example Set_Attribute_All data array method.28
Table 7 – State event matrix format .29
Table 8 – Example state event matrix .30
Table 9 – UCMM_PDU header format .33
Table 10 – UCMM command codes.33
Table 11 – Transport class 0 header .34
Table 12 – Transport class 1 header .34
Table 13 – Transport class 2 header .34
Table 14 – Transport class 3 header .35
Table 15 – Classes 4 to 6 header format.35
Table 16 – Real-time data header – exclusive owner .36
Table 17 – Real-time data header– redundant owner .36
Table 18 – Forward_Open request format .39
Table 19 – Forward_Open_Good response format .39
Table 20 – Forward_Open_Bad response format .40

Table 21 – Large_Forward_Open request format .41
Table 22 – Large_Forward_Open_Good response format .41
Table 23 – Large_Forward_Open_Bad response format.42
Table 24 – Forward_Close request format.43
Table 25 – Forward_Close_Good response format.43
Table 26 – Forward_Close_Bad response format .43
Table 27 – Unconnected_Send request format.44
Table 28 – Unconnected_Send_Good response format.45
Table 29 – Unconnected_Send_Bad response format .45
Table 30 – Get_Connection_Data request format.46
Table 31 – Get_Connection_Data response format .46
Table 32 – Search_Connection_Data request format .47

– 6 – 61158-6-2 © IEC:2007(E)
Table 33 – Get_Object_Owner request format .47

Table 34 – Forward_Open_Good response format .47

Table 35 – Time-out multiplier.50

Table 36 – Time tick units .51

Table 37 – Selection of connection ID.54

Table 38 – Transport class, trigger and Is_Server format .55

Table 39 – MR_Request_Header format .55

Table 40 – MR_Response_Header format.55

Table 41 – Structure of Get_Attribute_All_ResponsePDU body.56
Table 42 – Structure of Set_Attribute_All_RequestPDU body.56
Table 43 – Structure of Get_Attribute_List_RequestPDU body .56
Table 44 – Structure of Get_Attribute_List_ResponsePDU body .56
Table 45 – Structure of Set_Attribute_List_RequestPDU body .57
Table 46 – Structure of Set_Attribute_List_ResponsePDU body.57
Table 47 – Structure of Reset_RequestPDU body.57
Table 48 – Structure of Reset_ResponsePDU body .57
Table 49 – Structure of Start_RequestPDU body.57
Table 50 – Structure of Start_ResponsePDU body.58
Table 51 – Structure of Stop_RequestPDU body.58
Table 52 – Structure of Stop_ResponsePDU body .58
Table 53 – Structure of Create_RequestPDU body.58
Table 54 – Structure of Create_ResponsePDU body .58
Table 55 – Structure of Delete_RequestPDU body.59
Table 56 – Structure of Delete_ResponsePDU body .59
Table 57 – Structure of Get_Attribute_Single_ResponsePDU body .59
Table 58 – Structure of Set_Attribute_Single_RequestPDU body .59
Table 59 – Structure of Set_Attribute_Single_ResponsePDU body.59
Table 60 – Structure of Find_Next_Object_Instance_RequestPDU body .59
Table 61 – Structure of Find_Next_Object_Instance_ResponsePDU body.60
Table 62 – Structure of Apply_Attributes_RequestPDU body.60
Table 63 – Structure of Apply_Attributes_ResponsePDU body.60

Table 64 – Structure of Save_RequestPDU body .60
Table 65 – Structure of Save_ResponsePDU body.60
Table 66 – Structure of Restore_RequestPDU body.61
Table 67 – Structure of Restore_ResponsePDU body .61
Table 68 – Structure of Group_Sync_RequestPDU body.61
Table 69 – Structure of Group_Sync_ResponsePDU body .61
Table 70 – Identity object class attributes .61
Table 71 – Identity object instance attributes .62
Table 72 – Identity object bit definitions for status instance attribute.63
Table 73 – Bits 4 – 7 of status instance attribute.63
Table 74 – Class level object/service specific response data of Get_Attribute_All .64
Table 75 – Instance level object/service specific response data of Get_Attribute_All.64

61158-6-2 © IEC:2007(E) – 7 –
Table 76 – Modified instance level object/service specific response data of

Get_Attribute_All .65

Table 77 – Object-specific parameter for Reset.65

Table 78 – Message Router object class attributes .65

Table 79 – Message Router object instance attributes .66

Table 80 – Class level object/service specific response data of Get_Attribute_All .66

Table 81 – Instance level object/service specific response data of Get_Attribute_All.66

Table 82 – Assembly object class attributes.66

Table 83 – Assembly object instance attributes.67

Table 84 – Acknowledge Handler object class attributes .67
Table 85 – Acknowledge Handler object instance attributes .68
Table 86 – Structure of Add_AckData_Path_RequestPDU body.68
Table 87 – Structure of Remove_AckData_Path_RequestPDU body .68
Table 88 – Time Sync object instance attributes .69
Table 89 – Structure of Management_Message_RequestPDU body .71
Table 90 – Structure of Management_Message_ResponsePDU body.71
Table 91 – Management Message Command values.71
Table 92 – Connection Manager object class attributes.72
Table 93 – Connection Manager object instance attributes.72
Table 94 – Connection object class attributes .73
Table 95 – Connection object instance attributes .74
Table 96 – Values assigned to the state attribute.75
Table 97 – Values assigned to the instance_type attribute .75
Table 98 – Possible values within Direction Bit .76
Table 99 – Possible values within Production Trigger Bits.76
Table 100 – Possible values within Transport Class Bits .77
Table 101 – Transport Class_Trigger attribute .78
Table 102 – Values defined for the CP2/3_produced_connection_id attribute.78
Table 103 – Values defined for the CP2/3_consumed_connection_id attribute .79
Table 104 – Values for the Initial Production Characteristics nibble .80
Table 105 – Values for the Initial Consumption Characteristics nibble.81

Table 106 – Values for the watchdog_timeout_action.84
Table 107 – Structure of Connection_Bind_RequestPDU body.85
Table 108 – Object specific status for Connection_Bind service.86
Table 109 – Structure of Producing_Application_Lookup_RequestPDU body .86
Table 110 – Structure of Producing_Application_Lookup_ResponsePDU body.86
Table 111 – Producing_Application_Lookup Service status codes.86
Table 112 – Possible port segment examples .88
Table 113 – TCP/IP link address examples .89
Table 114 – Electronic key segment format.91
Table 115 – Logical segments examples.92
Table 116 – Network segments .92
Table 117 – Extended subtype definitions .94

– 8 – 61158-6-2 © IEC:2007(E)
Table 118 – Data segment .94

Table 119 – ANSI_Extended_Symbol segment .95

Table 120 – Addressing categories .95

Table 121 – Class code ID ranges .96

Table 122 – Attribute ID ranges .96

Table 123 – Service code ranges .96

Table 124 – Class codes.97

Table 125 – Reserved class attributes for all object class definitions .97

Table 126 – Common services list.98
Table 127 – Acknowledge Handler object specific services list.99
Table 128 – Time Sync object specific services list .99
Table 129 – Services specific to Connection Manager .99
Table 130 – Services specific to Connection object.99
Table 131 – Device type numbering .100
Table 132 – Connection Manager service request error codes .101
Table 133 – General status codes.106
Table 134 – Identity object status codes .108
Table 135 – Encapsulation header .115
Table 136 – Encapsulation command codes.116
Table 137 – Encapsulation status codes .117
Table 138 – Options flags .117
Table 139 – Nop request encapsulation header .117
Table 140 – RegisterSession request encapsulation header .118
Table 141 – RegisterSession request data portion .118
Table 142 – Options flags .118
Table 143 – RegisterSession reply encapsulation header .118
Table 144 – RegisterSession reply data portion .119
Table 145 – UnRegisterSession request encapsulation header .119
Table 146 – ListServices request encapsulation header .120
Table 147 – ListServices reply encapsulation header .120
Table 148 – ListServices reply data portion.120

Table 149 – Service type codes .121
Table 150 – Communications capability flags.121
Table 151 – ListIdentity request encapsulation header .121
Table 152 – ListIdentity reply encapsulation header.122
Table 153 – ListIdentity reply data portion.122
Table 154 – ListInterfaces request encapsulation header.123
Table 155 – ListInterfaces reply encapsulation header.123
Table 156 – SendRRData request encapsulation header.124
Table 157 – SendRRData request data portion .124
Table 158 – SendRRData reply encapsulation header.124
Table 159 – SendUnitData request encapsulation header .125
Table 160 – SendUnitData request data portion .125

61158-6-2 © IEC:2007(E) – 9 –
Table 161 – Common packet format.125

Table 162 – Address and data item structure .126

Table 163 – Address type ID’s .126

Table 164 – Data type ID’s.126

Table 165 – Null address type.126

Table 166 – Connected address type .127

Table 167 – Sequenced address type .127

Table 168 – UCMM data type.127

Table 169 – Connected data type.127
Table 170 – Sockaddr info items .128
Table 171 – BOOLEAN encoding .129
Table 172 – Example compact encoding of a BOOL value .129
Table 173 – Encoding of SignedInteger values .129
Table 174 – Example compact encoding of a SignedInteger value .129
Table 175 – UnsignedInteger values .130
Table 176 – Example compact encoding of an UnsignedInteger.130
Table 177 – FixedLengthReal values .130
Table 178 – Example compact encoding of a REAL value .130
Table 179 – Example compact encoding of a LREAL value .130
Table 180 – FixedLengthReal values .131
Table 181 – STRING value .131
Table 182 – STRING2 value .131
Table 183 – STRINGN value .131
Table 184 – SHORT_STRING value.131
Table 185 – Example compact encoding of a STRING value .132
Table 186 – Example compact encoding of STRING2 value .132
Table 187 – SHORT_STRING type .132
Table 188 – Example compact encoding of a single dimensional ARRAY.134
Table 189 – Example compact encoding of a multi-dimensional ARRAY .134
Table 190 – Example compact encoding of a STRUCTURE .135
Table 191 – Identification codes and descriptions of elementary data types .136

Table 192 – Example 1 of formal encoding of a structure type specification .137
Table 193 – I/O Connection state event matrix.143
Table 194 – Bridged Connection state event matrix .147
Table 195 – Explicit Messaging Connection state event matrix.149
Table 196 – Primitives issued by FAL user to FSPM .152
Table 197 – Primitives issued by FAL user to FSPM .153
Table 198 – Primitives issued by FSPM to FAL user .155
Table 199 – Parameters used with primitives exchanged between FAL user and FSPM .156
Table 200 – Primitives issued by FSPM to ARPM .158
Table 201 – Primitives issued by ARPM to FSPM .158
Table 202 – Parameters used with primitives exchanged between FSPM and ARPM .159
Table 203 – UCMM client states .159

– 10 – 61158-6-2 © IEC:2007(E)

Table 204 – State event matrix of UCMM client.160

Table 205 – High-end UCMM server states .161

Table 206 – State event matrix of high-end UCMM server.163

Table 207 – Low-end UCMM server states.164

Table 208 – State event matrix of low–end UCMM server .164

Table 209 – Notification .167

Table 210 – Transport classes .168

Table 211 – Primit
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