Application 5.1: Wiring Two Outputs In Parallel For Dark Period Suppression - Siemens S7-300 Installation And Operating Manual

8.7.5

Application 5.1: Wiring two outputs in parallel for dark period suppression

Applications
Parallel operation of two outputs for dark period suppression is possible for all applications in
safety mode (application 5).
Note
In case of parameter setting with SIL3
The signal at the output has to change daily or even more frequently. If this is not the case
with the "0" signal, you will have to activate the light test that meets this condition.
Note for "Keep last valid value" parameter setting:
If a module output is 0 due to a channel/module fault and the redundant module output is 1
due to a communication fault/interruption, the process value 1 will be created.
Also note the table "Reaction of the SM 326; F-DO x DC 24V/2A PP to CPU Stop" in the
chapter "Reactions to Faults in Safety Mode (Page 52)".
Prevent short circuits to L+ at the SM 326; F-DO 10 x DC 24V/2A PP with protected routing
of the signal lines, because the actuator will remain activated otherwise.
In case of a short circuit to L+ it may happen in case of redundant wiring at the output with
configured redundancy operation that the associated output will not be switched off.
Fail-safe signal modules
Installation and Operating Manual, 01/2010, A5E00085586-10
WARNING
WARNING
8.7 SM 326; F-DO 10 x DC 24V/2A PP (6ES7326-2BF10-0AB0)
Digital modules
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