IEC 61784-3-2:2021

IEC 61784-3-2 ®
Edition 4.0 2021-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Industrial communication networks – Profiles –
Part 3-2: Functional safety fieldbuses – Additional specifications for CPF 2

Réseaux de communication industriels – Profils –
Partie 3-2: Bus de terrain de sécurité fonctionnelle – Spécifications
supplémentaires pour CPF 2
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IEC 61784-3-2 ®
Edition 4.0 2021-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Industrial communication networks – Profiles –

Part 3-2: Functional safety fieldbuses – Additional specifications for CPF 2

Réseaux de communication industriels – Profils –

Partie 3-2: Bus de terrain de sécurité fonctionnelle – Spécifications

supplémentaires pour CPF 2
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 25.040.40; 35.100.05 ISBN 978-2-8322-9747-6

– 2 – IEC 61784-3-2:2021  IEC 2021
CONTENTS
FOREWORD . 12
0 Introduction . 14
0.1 General . 14
0.2 Patent declaration . 15
1 Scope . 17
2 Normative references . 17
3 Terms, definitions, symbols, abbreviated terms and conventions . 19
3.1 Terms and definitions . 19
3.1.1 Common terms and definitions . 19
3.1.2 CPF 2: Additional terms and definitions . 24
3.2 Symbols and abbreviated terms . 25
3.2.1 Common symbols and abbreviated terms . 25
3.2.2 CPF 2: Additional symbols and abbreviated terms . 26
3.3 Conventions . 27
4 Overview of FSCP 2/1 (CIP Safety™) . 27
4.1 General . 27
4.2 FSCP 2/1 . 27
5 General . 28
5.1 External documents providing specifications for the profile . 28
5.2 Safety functional requirements . 29
5.3 Safety measures . 29
5.4 Safety communication layer structure . 30
5.5 Relationships with FAL (and DLL, PhL) . 30
5.5.1 General . 30
5.5.2 Data types . 30
6 Safety communication layer services . 31
6.1 General . 31
6.2 Connection object . 31
6.2.1 General . 31
6.2.2 Class attribute extensions . 31
6.2.3 Service extensions . 32
6.2.4 Explicit message response format for SafetyOpen and SafetyClose . 32
6.3 Connection Manager object. 33
6.3.1 General . 33
6.3.2 ForwardOpen for safety . 33
6.3.3 Safety network segment . 35
6.3.4 Originator rules for calculating the connection parameter CRC . 38
6.3.5 SafetyOpen processing flowcharts . 38
6.3.6 Checks required by Multipoint producers with existing connections . 41
6.3.7 Electronic key usage for safety . 42
6.3.8 RPI vs. API in safety connections . 42
6.3.9 Application path construction rules for safety connections . 42
6.3.10 Safety Validator connection types . 44
6.3.11 Application reply data in a successful SafetyOpen response . 48
6.3.12 Unsuccessful SafetyOpen response . 50
6.3.13 ForwardClose for safety . 52

6.4 Identity object . 52
6.4.1 General . 52
6.4.2 Changes to common services . 53
6.4.3 Extensions for CP 16/3 devices . 53
6.5 Link objects . 53
6.5.1 DeviceNet object changes . 53
6.5.2 TCP/IP Interface object changes. 54
6.5.3 SERCOS III Link object. 54
6.6 Safety Supervisor object . 56
6.6.1 General . 56
6.6.2 Safety Supervisor class attributes . 56
6.6.3 Subclasses . 57
6.6.4 Safety Supervisor instance attributes . 57
6.6.5 Semantics. 61
6.6.6 Subclasses . 67
6.6.7 Safety Supervisor common services . 68
6.6.8 Safety Supervisor behavior . 80
6.7 Safety Validator object . 87
6.7.1 General . 87
6.7.2 Class attributes . 87
6.7.3 Instance attributes . 88
6.7.4 Class services . 94
6.7.5 Instance services . 94
6.7.6 Object behavior . 95
6.8 Connection Configuration Object . 98
6.8.1 General . 98
6.8.2 Class attribute extensions . 98
6.8.3 Instance attributes, additions and extensions. . 98
6.8.4 Instance attribute semantics extensions or restrictions for safety . 101
6.8.5 Special Safety Related Parameters – (Attribute 13) . 106
6.8.6 Object-specific services . 112
6.8.7 Common service extensions for safety . 112
6.8.8 Object behavior . 114
7 Safety communication layer protocol . 115
7.1 Safety PDU format . 115
7.1.1 Safety PDU encoding . 115
7.1.2 Safety CRC . 127
7.2 Communication protocol behavior . 128
7.2.1 Sequence of safety checks . 128
7.2.2 Connection termination . 128
7.2.3 Cross checking error. 129
7.3 Time stamp operation . 129
7.4 Rollover counts in the EF . 130
7.5 Protocol sequence diagrams . 130
7.5.1 General . 130
7.5.2 Normal safety transmission . 130
7.5.3 Lost, corrupted and delayed message transmission . 132
7.5.4 Lost, corrupted or delayed message transmission with production
repeated . 134

– 4 – IEC 61784-3-2:2021  IEC 2021
7.5.5 Point-to-point ping . 136
7.5.6 Multipoint ping on CP 2/3 Safety . 137
7.5.7 Multipoint ping on CP 2/2 safety networks . 139
7.5.8 Multipoint ping – retry with success . 139
7.5.9 Multipoint ping – retry with timeout . 140
7.6 Safety protocol definition . 141
7.6.1 General . 141
7.6.2 High level view of a safety device . 141
7.6.3 Safety Validator object . 142
7.6.4 Relationship between SafetyValidatorServer and SafetyValidatorClient . 142
7.6.5 Extended Format time stamp rollover handling . 143
7.6.6 SafetyValidatorClient function definition . 149
7.6.7 SafetyValidatorServer function definition . 157
7.7 Safety message and protocol data specifications . 170
7.7.1 Mode octet . 170
7.7.2 Time Stamp Section . 171
7.7.3 Time Coordination Message . 171
7.7.4 Time correction message . 172
7.7.5 Safety data production . 172
7.7.6 Producer dynamic variables . 180
7.7.7 Producer per consumer dynamic variables . 182
7.7.8 Consumer data variables . 183
7.7.9 Consumer input static variables . 185
7.7.10 Consumer dynamic variables . 186
8 Safety communication layer management . 188
8.1 Overview. 188
8.2 Definition of the measures used during connection establishment . 188
8.3 Originator-Target relationship validation. 192
8.4 Detection of mis-routed connection requests . 193
8.5 SafetyOpen processing . 193
8.6 Ownership management . 193
8.7 Bridging different physical layers . 194
8.8 Safety connection establishment . 196
8.8.1 Overview . 196
8.8.2 Basic facts for connection establishment . 196
8.8.3 Configuring safety connections . 197
8.8.4 Network time expectation multiplier . 198
8.8.5 Establishing connections . 200
8.8.6 Recommendations for consumer number allocation . 203
8.8.7 Recommendations for connection establishment . 203
8.8.8 Ownership establishment . 204
8.8.9 Ownership use cases . 204
8.8.10 PID/CID usage and establishment . 207
8.8.11 Proper PID/CID usage in multipoint and point-to-point connections . 208
8.8.12 Network supported services . 210
8.8.13 FSCP 2/1 safety device type . 211
8.9 Safety configuration process . 215
8.9.1 Introduction to safety configuration . 215
8.9.2 Configuration goals . 215

8.9.3 Configuration overview . 216
8.9.4 User configuration guidelines . 217
8.9.5 Configuration process justification . 218
8.9.6 Device functions for tool configuration . 219
8.9.7 Password security . 219
8.9.8 SNCT interface services . 219
8.9.9 Configuration lock . 220
8.9.10 Effect of configuration lock on device behavior . 220
8.9.11 Configuration ownership . 222
8.9.12 Configuration mode . 222
8.9.13 Measures used to ensure integrity of configuration process . 222
8.9.14 Download process . 224
8.9.15 Verification process . 227
8.9.16 Configuration error analysis . 230
8.10 Electronic Data Sheets extensions for safety . 234
8.10.1 General rules for EDS based safety devices . 234
8.10.2 EDS extensions for safety . 235
8.11 Requirements for CP 2/2 . 240
8.11.1 EPI rules for safety messages that travel over CP 2/2 . 240
8.11.2 Default safety I/O service . 240
8.11.3 Duplicate IP detection . 241
8.11.4 Priority for safety connections . 241
8.12 Requirements for CP 2/3 . 241
8.12.1 Allocation of CP 2/3 identifiers . 241
8.12.2 Additional requirements . 244
8.13 CP 16/3 requirements . 244
8.13.1 General architecture for CPF 2 on CP 16/3 . 244
8.13.2 Baseline FSCP 2/1 on CP 16/3 device . 244
8.13.3 Supported objects and services in CP 16/3 devices . 245
8.13.4 Transport layer requirements . 246
8.13.5 FSCP 2/1 and the CP 16/3 device model . 248
8.13.6 UNID assignment on CP 16/3 . 249
9 System requirements . 252
9.1 Indicators and switches . 252
9.1.1 General indicator requirements . 252
9.1.2 LED indications for setting the device UNID . 252
9.1.3 Module Status LED . 252
9.1.4 Indicator warning . 253
9.1.5 Network Status LED . 253
9.1.6 Switches . 254
9.2 Installation guidelines . 256
9.3 Safety function response time . 257
9.3.1 Overview . 257
9.3.2 Network time expectation . 257
9.3.3 Equations for calculating network reaction times . 258
9.4 Duration of demands . 260
9.5 Constraints for calculation of system characteristics . 260
9.5.1 Number of nodes . 260
9.5.2 Network PFH of Extended Format . 260

– 6 – IEC 61784-3-2:2021  IEC 2021
9.5.3 Bit Error Rate (BER) . 261
9.6 Maintenance . 262
9.7 Safety manual . 262
10 Assessment . 262
Annex A (informative) Additional information for functional safety communication
profiles of CPF 2 . 263
A.1 Hash function example code . 263
A.2 Void . 277
Annex B (informative) Information for assessment of the functional safety
communication profiles of CPF 2. 278
Bibliography . 279

Figure 1 – Relationships of IEC 61784-3 with other standards (machinery) . 14
Figure 2 – Relationships of IEC 61784-3 with other standards (process) . 15
Figure 3 – Relationship of Safety Validators. 28
Figure 4 – Communication layers . 30
Figure 5 – ForwardOpen with safety network segment . 34
Figure 6 – Safety network target format . 36
Figure 7 – Target Processing SafetyOpen with no configuration data (Type 2

SafetyOpen) . 39
Figure 8 – Target Processing for SafetyOpen with configuration data (Type 1
SafetyOpen) . 40
Figure 9 – Originator logic to determine which format to use . 41
Figure 10 – Applying device configuration . 72
Figure 11 – Configure and Validate processing flowcharts . 73
Figure 12 – UNID handling during "Waiting for TUNID" . 79
Figure 13 – Safety Supervisor state diagram . 81
Figure 14 – Configuration, testing and locked relationships . 85
Figure 15 – Safety connection types . 92
Figure 16 – Safety Validator state transition diagram . 96
Figure 17 – Logic for Auto-detecting format type . 111
Figure 18 – Connection Configuration Object state diagram . 114
Figure 19 – Connection Configuration Object data flow . 115
Figure 20 – Format of the mode octet . 117
Figure 21 – 1 or 2 octet data section, Base Format . 117
Figure 22 – 1 or 2 octet data section, Extended Format . 118
Figure 23 – 3 to 250 octet data section format, Base Format . 118
Figure 24 – 3 to 250 octet data section format, Extended Format . 119
Figure 25 – Time Stamp section format, Base Format . 120
Figure 26 – BF Time Coordination message encoding . 121
Figure 27 – EF Time Coordination message encoding . 121
Figure 28 – BF Time Correction message encoding . 122
Figure 29 – EF Time Correction message encoding . 122
Figure 30 – 1 or 2 octet point-to-point PDU encoding . 124
Figure 31 – 1 or 2 Octet multipoint PDU encoding . 124

Figure 32 – 1 or 2 Octet, multipoint, Format 2 safety connection format . 125
Figure 33 – 3 to 250 Octet Point-to-point PDU encoding . 125
Figure 34 – 3 to 248 Octet Multipoint PDU encoding . 126
Figure 35 – 3 to 248 Octet, Multipoint, safety connection format . 126
Figure 36 – CRC Calculation order for Extended Format messages . 127
Figure 37 – Time stamp sequence . 129
Figure 38 – Sequence diagram of a normal producer/consumer safety sequence . 130
Figure 39 – Sequence diagram of a normal producer/consumer safety sequence
(production repeated) . 131
Figure 40 – Sequence diagram of a corrupted producer to consumer message . 132
Figure 41 – Sequence diagram of a lost producer to consumer message . 133
Figure 42 – Sequence diagram of a delayed message . 134
Figure 43 – Sequence diagram of a corrupted producer to consumer message with

production repeated . 135
Figure 44 – Sequence diagram of a connection terminated due to delays . 135
Figure 45 – Sequence diagram of a failure of safety CRC check . 136
Figure 46 – Sequence diagram of a point-to-point ping – normal response . 136
Figure 47 – Sequence diagram of a successful multipoint ping, CP 2/3 safety. 138
Figure 48 – Sequence diagram of a successful multipoint ping, CP 2/2 safety. 139
Figure 49 – Sequence diagram of a multipoint ping retry . 140
Figure 50 – Sequence diagram of a multipoint ping timeout . 140
Figure 51 – Possible safety architectures for FSCP 2/1 . 141
Figure 52 – Safety device reference model entity relation diagram . 142
Figure 53 – Two devices interchanging safety data via a SafetyValidatorClient and a
SafetyValidatorServer . 143
Figure 54 – Point-to-point, originating consumer. target producer . 144
Figure 55 – Point-to-point, originator producer, target consumer . 146
Figure 56 – Multi-point, originator consumer, target producer . 147
Figure 57 – Safety production data flow . 149
Figure 58 – Consumer safety data monitoring . 158
Figure 59 – SafetyValidatorServer – application triggered . 159
Figure 60 – Target ownership . 192
Figure 61 – SafetyOpen forms . 193
Figure 62 – Connection ownership state chart. 194
Figure 63 – SafetyOpen UNID mapping . 194
Figure 64 – Common CPF 2 application layer . 195
Figure 65 – End-to-End routing example . 195
Figure 66 – Sources for safety related connection parameters . 199
Figure 67 – Parameter mapping between originator and target . 200
Figure 68 – CP 2/3 Safety connection establishment in targets for Type 2a SafetyOpen . 202
Figure 69 – General sequence to detect configuration is required . 202
Figure 70 – PID/CID exchanges for two originator scenarios . 208
Figure 71 – Seed generation for multipoint connections . 209
Figure 72 – PID/CID runtime handling . 210

– 8 – IEC 61784-3-2:2021  IEC 2021
Figure 73 – Connection categories and supported services . 213
Figure 74 – Recommended connection types . 214
Figure 75 – Logic-to-logic supported services . 214
Figure 76 – Recommended connection types for logic to logic . 215
Figure 77 – Configuration data transfers . 216
Figure 78 – Protection measures in safety devices . 218
Figure 79 – Configuration, testing and locked relationships . 221
Figure 80 – Originator's configuration data. 223
Figure 81 – SNCT to device download process . 225
Figure 82 – SNCT Downloads to originators that perform Type 1 configuration . 226
Figure 83 – Protection from locking and ownership . 228
Figure 84 – Verification process including all alternatives . 230
Figure 85 – Baseline FSCP 2/1 on CP 16/3 device. 245
Figure 86 – FSCP 2/1 Adaptation Layer and SMP interaction . 247
Figure 87 – FSCP 2/1 Adaptation . 248
Figure 88 – CP 16/3 device model . 249
Figure 89 – Adding a standard module to a modular device . 251
Figure 90 – Safety device NodeID processing logic . 256
Figure 91 – Safety function response time . 257
Figure 92 – Safety function response time components . 259
Figure 93 – Network protocol reliability block diagram (RBD) . 260

Table 1 – Communications errors and detection measures matrix . 29
Table 2 – New class attributes . 31
Table 3 – Service extensions . 32
Table 4 – SafetyOpen and SafetyClose response format. 32
Table 5 – Safety network segment identifier . 35
Table 6 – Safety network segment definition . 35
Table 7 – Safety network segment router format . 37
Table 8 – Safety Network Segment Extended Format . 37
Table 9 – Multipoint producer parameter evaluation rules . 42
Table 10 – ForwardOpen setting options for safety connections with object-based
application paths . 45
Table 11 – ForwardOpen setting options for safety connections with ANSI Extended
symbol segment application path . 47
Table 12 – Network connection parameters for safety connections . 48
Table 13 – SafetyOpen target application reply (size: 10 octets) . 48
Table 14 – EF CP 2/2 or CP 16/3 SafetyOpen target application reply (size: 14 octets) . 49
Table 15 – BF CP 2/3 SafetyOpen target application reply (size: 18 octets) . 49
Table 16 – EF CP 2/3 SafetyOpen target application reply (size: 22 octets) . 50
Table 17 – New and extended error codes for safety. 50
Table 18 – SafetyOpen error event guidance table . 51
Table 19 – Identity object common service changes . 53
Table 20 – Identity object extensions for CP 16/3 devices . 53

Table 21 – New DeviceNet object instance attribute. 54
Table 22 – New TCP/IP Interface object instance attribute . 54
Table 23 – SERCOS III Link object class attributes . 55
Table 24 – SERCOS III Link object instance attributes . 55
Table 25 – SERCOS III Link Object Common Services . 56
Table 26 – Safety Supervisor class attributes . 57
Table 27 – Safety Supervisor instance attributes . 57
Table 28 – Device status attribute state values . 62
Table 29 – Exception status attribute format . 62
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