Detector connections on controller

I have connected several Gas detetctors on different Lab locations. I have three controllers and 30 detetctors connected with them.
I have to find out that which detetctor is connected on which controller and its channel. How I can short/ open circuit the detector so it controller should beep. Is there any way not to disconnect the detetctor and detetctor shoul show its position on the controller.???

It might help us help you if you tell us the make and model number of the gas detector you have. And if you have it a link to it's manual.

And how it interfaces with the PLC. ( discrete or analog)