I have some DO relay type outputs working at 24VDC and I need to monitor the outputs. I am looking for a module that'll do that for me without having to change my control system hardware (it's a very primitive piece of hardware, line monitoring is not available in it.)

I have about 200 DOs and I am looking for somethign that takes in at least 8 and maybe 16 channels at a time and monitor them individually. An output (for each or a group of channels) from that unit will be the best but if it provides only an LED indication that'll be good enough.

 

One way to do this is to use some I/O modules such as: http://www.power-io.com/products/iac.htm
or equivalent. You can gang them in any combination. Google on "din rail io" for additional suppliers.

Cheers;
Bob