Siemens SIMATIC Operating Instructions Manual page 90

Fail-Safe Electronic Modules
8.2 4 /8 F-DI/4 F-DO DC24V/2A PROFIsafe Digital Electronic Module
Circular connector view
3-, 4- or 5-core copper cable
1
Only relevant for 1oo2 evaluation via a connecting cable
2
90
Terminal Assignment of X1 to X12
5 Connectors X1 to X4: 24 V sensor supply 2 (Vs2)
Connectors X5 to X8: Not assigned
Connectors X9 to X12: Functional ground (FG)
ET 200pro Distributed I/O System - Fail-Safe Modules
Operating Instructions, 05/2007, A5E00394073-02