Siemens SCALANCE M874-2 Operating Instructions Manual page 38

Connecting up
3.5 Digital input/output
If there is an adequate switching voltage at the digital input, the digital input is active and the
"DI" LED is lit. This means that, for example a local application connected to the in port can
trigger an alarm message by SMS outside the IP data connection.
Digital output
The 2-pin terminal block has the following assignment:
DO+
DO-
38
Relay 24 VDC / 1 A
Relay 24 VDC / 1 A
Operating Instructions, 07/2014, C79000-G89760-C331-03
SCALANCE M874, M876