User defined M-code "wait"

I created some more M-codes for one of my machines today and I have been unable to find a quick way to make them wait for an input to go high or low.

For instance, I created an M101 to unclamp my rotary table and that part works, but I would like EMC to not execute the next line of the program until the rotary table unclamped switch goes high. Is there a way to hold the M-code from exiting until this happens?

Thanks
Glenn Stewart

Thanks John, I will give that a try.

Glenn Stewart