Siemens SIMATIC ET 200SP HA Equipment Manual page 16

Wiring
4.2 Pin assignment of the F-DI 16x24VDC HA I/O module
Note
Connection with multicore cables at function status 1 (FS01) of the I/O module
If you use multi-core cables to connect the signals to the inputs of the I/O module, make sure that
any unused cores of this cable are grounded on one side.
This note can be ignored for I/O modules with function status 2 (FS02) and higher.
Note
To prevent wire-break diagnostics in the case of simple encoder contacts, you have the option
of connecting a resistor in parallel to the encoder contact.
Recommended ohmic resistance value: 18 kOhm to 30 kOhm, typically: 26 kOhm
16
Equipment Manual, 08/2021, A5E45647528-AD
F-DI 16x24VDC HA