Digital Input/Output - Siemens SCALANCE M804PB Operating Instructions Manual

5.4

Digital input/output

The digital input/output (relay contact) is a floating switch with which error/fault states can be
signaled by breaking the contact.
Damage due to voltage being too high or too low
The voltage at the digital input/output must not exceed 30 VDC and not fall below -30 VDC,
otherwise the digital input/output will be destroyed.
Note
Interference pulse
Zo avoid evaluating an interference pulse, the pulse for the signal 1 (TRUE / HIGH) must be
at least 200 ms.
Rules for user wiring
● Always wire the digital input/output in pairs-
● The maximum permitted cable length is 30 m.
SCALANCE M804PB
Operating Instructions, 07/2018, C79000-G8976-C496-01
CAUTION
Connecting up
5.4 Digital input/output
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