IEC PAS 61784-3-18:2009

IEC/PAS 61784-3-18 ®
Edition 1.0 2009-08
PUBLICLY AVAILABLE
SPECIFICATION
PRE-STANDARD
colour
inside
Industrial communication networks – Profiles –
Part 3-18: Functional safety fieldbuses – Additional specifications for CPF
SNpFAMILY
IEC/PAS 61784-3-18:2009(E)
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IEC/PAS 61784-3-18 ®
Edition 1.0 2009-08
PUBLICLY AVAILABLE
SPECIFICATION
PRE-STANDARD
colour
inside
Industrial communication networks – Profiles –
Part 3-18: Functional safety fieldbuses – Additional specifications for CPF
SNpFAMILY
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
XA
ICS 13.110; 25.040.40; 35.100.05 ISBN 978-2-88910-807-7
– 2 – PAS 61784-3-18 © IEC:2009(E)
CONTENTS
FOREWORD.5
INTRODUCTION.7
1 Scope.8
2 Normative references .8
3 Terms, definitions, symbols, abbreviated terms and conventions .9
3.1 Terms and definitions .9
3.1.1 Common terms and definitions .9
3.1.2 CPF X: Additional terms and definitions.13
3.2 Symbols and abbreviated terms.14
3.2.1 Common symbols and abbreviated terms .14
3.2.2 CPF SNpFAMILY: Additional abbreviated terms .15
3.2.3 CPF SNpFAMILY: Additional symbols.16
3.3 Conventions .16
4 Overview of FSCP SNpFAMILY/1 (SafetyNET p™).17
5 General .18
5.1 External documents providing specifications for the profile.18
5.2 Safety functional requirements .19
5.3 Safety measures .19
5.4 Safety communication layer structure .20
5.5 Relationships with FAL (and DLL, PhL) .20
5.5.1 General .20
5.5.2 Data Types .20
6 Safety communication layer services .21
6.1 General elements .21
6.1.1 General .21
6.1.2 Safe object dictionary .21
6.1.3 Safe process data object (SPDO) .21
6.1.4 Safe heartbeat (SHB) .21
6.1.5 Safe delay monitoring (SDM) .21
6.2 Communication relation.21
7 Safety communication layer protocol .23
7.1 Safety PDU formats.23
7.1.1 Safe process data objects (SPDO) .23
7.1.2 Safe heartbeat (SHB) .24
7.1.3 Safety PDUs embedded in a Type SNpTYPE PDU.26
7.2 Safe application layer management (SALMT) .27
7.3 Safe process data communication .28
7.4 Safe heartbeat.29
7.5 Delay monitoring .30
8 Safety communication layer management.31
8.1 Parameter handling .31
8.2 Object dictionary .31
8.2.1 General .31
8.2.2 Communication profile section.32
8.2.3 Standardized device profile section .47
8.3 Device description.47

PAS 61784-3-18 © IEC:2009(E) – 3 –
9 System requirements.47
9.1 Indicators and switches .47
9.1.1 Indicator states and flash rates.47
9.1.2 Indicators .48
9.1.3 Switches.48
9.2 Installation guidelines.48
9.3 Safety function response time .48
9.3.1 General .48
9.3.2 Determination of FSCP SNpFAMILY time expectation behavior .50
9.3.3 Calculation of the worst case safety function response time .50
9.4 Duration of demands .51
9.5 Constraints for calculation of system characteristics.51
9.5.1 Safety related constraints .51
9.5.2 Probabilistic considerations .52
9.6 Maintenance.52
9.7 Safety manual .53
10 Certification.53
Bibliography.54

Figure 1 – FSCP SNpFAMILY/1 system .18
Figure 2 – FSCP SNpFAMILY/1 software architecture.20
Figure 3 – SPDO interaction model.22
Figure 4 – SHB interaction model .22
Figure 5 – Safe process data object frame.23
Figure 6 – Safe heartbeat request PDU .24
Figure 7 – Safe heartbeat response PDU.25
Figure 8 – Safety PDU for FSCP SNpFAMILY embedded in a Type SNpTYPE CDC
data section .27
Figure 9 – Safe application layer management state machine .28
Figure 10 – RxSPDO state machine.29
Figure 11 – Heartbeat procedure .30
Figure 12 – Delay measurement principle .30
Figure 13 – Parameter handling.31
Figure 14 – Safety response time components.49
Figure 15 – Considered data fields for message size calculation.52
Figure 16 – Residual error rate .52

Table 1 – Object definition .17
Table 2 – Safety PDU element definition.17
Table 3 – Communication errors and detection measures .19
Table 4 – SPDO PDU structure.23
Table 5 – SHB request PDU structure.25
Table 6 – SHB response PDU structure .25
Table 7 – Safe heartbeat FS AL state encoding .26
Table 8 – Safe application layer management commands .27

– 4 – PAS 61784-3-18 © IEC:2009(E)
Table 9 – State transitions SALMT state machine .28
Table 10 – State transitions RxSPDO state machine.29
Table 11 – Object dictionary structure.32
Table 12 – Objects of communication section .33
Table 13 – Device type .34
Table 14 – Safe ID.34
Table 15 – Fail-safe consumer heartbeat list entry encoding.35
Table 16 – Fail-safe consumer heartbeat .36
Table 17 – Fail-safe producer heartbeat parameter.36
Table 18 – Fail-safe bus cycle times .39
Table 19 – SPDO timeout tolerance .
...