Siemens SIMATIC NET SCALANCE M874 Operating Instructions Manual page 62

Connecting up
5.4 Digital input/output
Digital input
The 2-pin terminal block has the following assignment:
Contact
+DI
-DI
If there is an adequate switching voltage at the digital input, the digital input is active and
the "DI" LED is lit.
The voltage applied to the "DI" contact is converted to a digital status by the device as follows:
Voltage
-30 to +3 V DC
+13 to +30 V DC
62
Assignment
Input
Ground
Status
0
1
Operating Instructions, 02/2023, C79000-G8976-C331-12
SCALANCE M874, M876