1. Fully support MACH3 and other computer software that supports parallel port control. The USB power supply and the peripheral power supply are separated to the safety of the computer. 2. Peripheral wide voltage input, 12-24V, and anti-reverse connection function. All input signals are isolated by optical coupling, which can be connected to emergency stop, tool setting, limit, etc. to computer security. 3. One relay output port can control the spindle switch. The output port is P17 port. One channel of 0-10V analog voltage output isolated by optocoupler can control the inverter with corresponding analog interface and control the spindle speed. The output port is P1 port. 4. Open all 17 ports, can connect to the driver with optocoupler, can control 5-axis . 5. P1 is used as PWM output, which can control the spindle speed governor with optocoupler input. Can be connected to common cathode Product name: engraving board Type: optocoupler isolation board Model: MACH3 Product size: 91 x 63mm color:Green Material:ABS Package Contents: 1 x MACH3 engraving board 1 x USB cable (1m) Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.