The M codes are passed over the BMI buss to the PMC, they can be seen by looking in the diagnostic BMI-DO, if the sharp unit is a PLC, maybe the M codes are processed externally, but they have to get there via an output, so you really need the PMC I/O diagrams etc for the Fanuc to begin with. If the M code gets to the Sharp then that is where you should be looking maybe. The CNC expects to get a finish signal back when the M codes have completed, otherwise it will hang there also.
Al.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.