Just joined this threadBut my fault units do not connect to ground in a „no error“ scenario. They are simply open - floating. Please correct me if im wrong.
Read through the posts from the OP, and Im less than clear what they want,
Where are the fault indications coming from ? can you share a part number and picture please
Are the outputs of the fault indicators differential i.e. two wire, or single ended referenced to ground
can you clarify please what indicates a fault, a voltage, a current, a ground or what
Are these faults liable to be over long wire s?
are these wires ESD safe ?
What is the part that you want to connect into ?
a part number / picture please
if you signals are from a way away, the voltage will not be 24 v due to voltage drop , and the ground will not be common,
you could also well be having to look at ESD / Voltage offset , such as an opto isolation
If you want to know which input is the fault, and you can't connect them all independently into your receiver
then you need to encode the fault signals
Simple answers, this could be by multi voltage ( the ADC ) , or by time ( the switch selector )
If all you need to do is to detect a fault has happened,
then your into a "wired OR" input
This could be with just resistors, or with diodes / and one resistor,
Depends upon what the fault signla is ( high or low )
Just a last thought
the "Majority" of "fault" indicators I have seen, are "open collector" output
i.e. they have no voltage out, but rely upon a voltage being sent to then, via a pull up resistor