Larry, heres the specs from Peters site
G540 Specifications:
- Four 10-Microstep motor drives
- 0 to 3.5A rated phase current
- 18VDC to 50VDC supply voltage
- Mid-band resonance compensation
- Auto standby current (70% current)
- Short-circuit protected
- Optoisolation on all LPT signal pins
- Two 1A at 0 to 50VDC rated outputs
- Four SPST to GND inputs
- FAULT indicator LED,signal to PC
- POWER indicator LED
- I-SET resistor on motor connector
- TRIM adjust for motor smoothness
- Panel mount (5.7” by2.4” hole dim.)
- Anodized aluminum package
- No heatsink needed below 40C ambient
- Easy to service, removable drives
- Modular PCB design with no internal wires
- 10kHz watchdog timer (charge pump)
- Optoisolated analog output for a VFD drive
- Conservative ratings, premium components
- Comes with four backshells and four DB9 solder cup connectors