It creeps as long as power is applied.
We inherited this line from a sister company that we shut down in Mexico and I do not have the original copy of the RSLogix 500 program that runs the machine; which means I don't have the rung comment file, so I do not know if there is a Stop Motion bit. I have simulated a 500 part run and everything functioned, but if the line is paused, or stopped, the feed rolls creep. A funny thing is that we discovered the resolver was bad on the motor when we were installing the line and even with the motor leads removed, the drive indicated that it was creeping...with no motor and no resolver.
I uploaded the parameters and loaded them into another FX 455 we bought and it does the same thing. I am assuming that it is a programming issue since this is the first one I ever had to deal with.