It would help if you supplied some info regrading specific machine and host software.
The typical motor used on diode laser etchers is called a NEMA 17 stepper motor. There are three signals from the CPU to invoke motion Enable, Step & Direction. The motors are typically driven by little stepper motor driver boards although the chips may be embedded on the main board. These driver boards include a current limiting circuit that needs to be tuned to the job. Too much current and things overheat, too little and they stall. There is usually and adjustable trim pot used to set the limit. Each specific driver chip has a different tuning scheme. For a chip driving 1 motor you might want to set for 1A, for a chip driving 2 motors perhaps 1.5A.