Does the program have a "M3" or "M03" command somewhere in the first few lines of code? That's what's supposed to turn the spindle on, normally, followed by an "S" command that sets the feed rate.. It stops with a "M5" or "M05" You can test if this function is working by going into MDI and giving it a command like "M3 S3000". The spindle should turn on, and if your machine is set up to vary the speed from software, should start turning at 1000 RPM. See LEARNING CNC STRATERGIES AND TIPS: "What is M-CODES M03, M04 & M05 (Spindle motion codes) used in CNC PROGAMMING "