Features: 1. Fully supports MACH3 and other computer software that supports parallel port control. 2. USB power supply and peripheral power supply are separated to ensure computer security. 3. 12-24V wide peripheral voltage input, with anti-reverse connection function. 4. All input signals are isolated by optical coupling, and can be connected to emergency stop, tool setting, limit, etc. 5. One-way relay output port can control the spindle switch. The output port is P17. 6. One-way optocoupler isolated 0-10V analog voltage output can control the inverter with the corresponding analog interface to control spindle speed. The output port is P1. 7. Opens all 17 ports, compatible with optocoupler drive, capable of controlling a 5-axis stepper motor. 8. P1 acts as a PWM output and can control the spindle governor with optocoupler input. 9. Can be connected to common cathode/anode drive with input level of 5V. Specification: Input voltage range: 12-24VDC Package weight: Approx. 335g/11.8oz Package list: 1 x Stepper Motor Interface Board 1 x USB Cable 1 x Parallel Port Cable