Contactor Monitoring (Edm); Extended Restart Delay Time - Siemens SIMATIC FS400 Anleitung

4.2.3 Contactor monitoring (EDM)

The SIMATIC FS400 3RG7845 contactor monitoring can be activated with the
corresponding wiring and parametering (see, Chapter 8.3.4)!
The "Contactor monitoring" function dynamically monitors contactors, relays or valves
downstream from the SIMATIC FS400 3RG7845. Precondition here are switching
elements with positive-guided feedback contacts (normally closed).
Fig. 4.2-3: Contact monitoring function, combined in this example with a start/restart
interlock
You can implement the contactor monitoring function,
➢ with the corresponding wiring and parametering of the SIMATIC FS400 3RG7845
receiver (see, Chapter 8.3.4)
➢ or the external contactor monitoring of the downstream safety interface
➢ or the contactor monitoring of the downstream safety PLC (optionally connected
via a safety bus).
If the internal contactor monitoring is activated (see Chapter 8.3.4), it works
dynamically, i.e. the system also checks whether the feedback circuit has opened
within 500 ms of being enabled and whether it has closed again within 500 ms after
turning off the OSSDs. If this is not the case, the OSSDs return to the OFF state again
after being briefly switched on. An error code appears on the 7-segment display (F34)
and the receiver goes to the error locking status, from which it can only be returned to
normal operation by switching the supply voltage off and back on again.

4.2.4 Extended restart delay time

The restart delay time is the minimum period between switching off the OSSDs and
their restarting. The default time for restarting with SIMATIC FS400 3RG7845 light
curtains and SIMATIC FS400 3RG7845 light grids is 100ms. The restart delay time can
be extended by parametering to 500 ms (see, Chapter 8.3.1).
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