Hello,
I am using up a bunch of our CR1000 control ports reading wet/dry contacts and I'm running out. I looked at expanding the control ports with a SDM-CDXX module but budgets killed that idea. Anyway, is there a way to use an SE port to do the same thing? Maybe excite the channel and if it's > 0 it's closed etc?
Yes but you will need to bias the input to ground using a resistor. The control ports have a built-in pull down resistor, whilst there is not one on the analogue inputs.