Yes, just isolate it from the failed drive control card +24 but do connect the common. Refer to the manual for this. No guarantee that your spare input is not fried until you monitor it and apply external 24vdc in reference to common. I am not 100% sure, but I believe you will have to stop the drive in order to change the start and stop command for the TB, but that is a quick stoppage.
I would look in the manual at the I/O diagram, and test the inputs while monitoring them on the HIM (or via software) to prove that enough of the input board remains functional before pursuing that in favor of replacing the control cassette. You can do this I/O test with the drive running in local control.
I am assuming the I/O you are dealing with is on the side as a plug in cartridge with a removable terminal block? I would get a spare cassette on the way, because swapping it is a five to ten minute job depending on how fast the bus discharges when you power it down. I don't think you want to *******ize it unless you have to, and should plan to put it back to normal, so get the control cassette ordered right away if you haven't already. But for all I know, perhaps you want to make this repair into a permanent modification?
Also do your research before changing the stop input. Is this drive equipped with Safe-Off? If so, don't change the stop input, replace the card...keep it in local control until you can get the new one installed.
