Siemens SIMATIC NET SCALANCE M812 Operating Instructions Manual page 54

Connecting up
5.4 Digital input/output
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
Digital output
The 2-pin terminal block has the following assignment:
54
Assignment
Input
Ground
Status
0
1
Operating Instructions, 11/2023, C79000-G8976-C343-09
SCALANCE M812, M816