Siemens SIMATIC ET 200AL, System Manual

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Applications of the F-I/O module
5.2 Digital output applications
Digital I/O module F-DI 4+F-DQ 2x24VDC/2A, 4xM12 (6ES7146-5FF00-0BA0)
Equipment Manual, V1.0, 05/2021, A5E51082342-AA
53
5.2.1 Application 1: Wiring a directly-connected SIL-rated actuator
The module supports application mode 1, where there is a direct connection of a load
between the P and M outputs of one channel. Both switches are opened when de-energizing
the load.
Note
This configuration achieves SIL 3/Cat. 4/PL e if neither channel is configured to disable the
dark test.
Figure 5-13 F-DQ application mode 1
5.2.2 Application 2: Wiring external contactors: Separate P and M controlled
contactors
The module supports application mode 2, where the module controls the load using series-
connected, normally-open contacts of two relays. The coil of one relay connects the P-output
of a channel and M. The coil of the other relay connects the M-output of the same channel
and L+.
Note
This configuration achieves SIL 3/Cat. 4/PL e if you fulfill the following conditions:
•
The CPU checks the relay status (feedback) using a separate digital input.
• You adequately protect the wiring against shorts from the P output to L+ and shorts from
the M output to M. The CPU cannot switch off the actuator if both faults occur.
• You do not disable dark test for either output.