DI 880 Line Monitoring
I didn't found something in the Datasheet.
It should be possible to analyse current issues on security parts like emergency stop buttons.
See --> Bartec: 1 kOhm/10 kOhm Resistive coupling element
Look in the manual e.g. 3BSE020924-510 B
It is described there, that each channel of DI880 has own current limited power supply. But you should use the corresponding MTU (from the manual):
"It is recommended to feed all sensors connected to DI880 from the current limited sensor power supplies that are supplied by DI880, to fulfill this TU830, TU833, TU842, TU843 or TU852 should be used"
Using of this option, you will have specific channel supervision (open circuit, short circuit etc), reported as internal channel error.
Source: 3BSE020924-510 B