Features The stepper motor interface board fully supports MACH3 and other computer software that supports parallel port control. The USB power supply is separated from the peripheral power supply to ensure the safety of the computer. 12-24V wide peripheral voltage input, the stepper motor interface board has anti-reverse connection function. All input signals of the USB interface distribution board are isolated by optocouplers, which can be connected to emergency stop, tool setting, limit, etc. 1 relay output port can control the spindle switch. The output port is the P17 port. Features:1. Fully support for 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 port.6. One-way optocoupler isolated 0-10V analog voltage output can control the inverter with the corresponding analog interface to control the spindle speed. The output port is the P1 port.  Specification:Input voltage range: 12-24VDCPackage weight: Approx. 335g/11.8oz Packagelist:1 * Stepper Motor Interface Board1 * USB Cable1 * Parallel Port Cable Package List