Output board 3/9


This product is available in our web shop: Output board 3/9.


Output board 3/9 is a device primarily intended to interface PlanetCNC Mk3/9 motion controller with external equipment such as spindle routers, spindle drives(VFD, BLDC), solenoid devices.

Features and specification

Single output 3/9 board offers:

  • 8 opto-isolated input channels
  • 1 input channel dedicated for frequency signal with its corresponding 0-10VDC output
  • 2 outputs providing digital output signal with selectable 3.3V or 5V level. Selection is made using solder bridge.
  • 5 relay outputs
  • trimmer resistor for fine tuning of 0-10VDC output voltage
  • Adapter was designed specifically for Mk3/9 controller but it can be used with other controllers (connection adapter might be required in such case)

POWER 12VDC input:

  • External power supply input screw terminal connector, used for powering on-board relays and logic
  • Max voltage value is 12VDC
  • Power supply of 12V/200mA is recommended
Terminal pin Description
+ power supply positive terminal
- power supply negative terminal

Box input header for connecting with Mk3/9 controller

  • Input pins 1 and 2 are opto-isolated. Both signals are avilable at the Output 1 and Output 2 screw terminal.
  • Inputs 3,4,5,7,8 are opto-isolated and control relay outpus 3,4,5,7,8
  • Input 6 is opto-isolated. This input accepts frequency signal from motion controllers output pin dedicated for spindle speed control
Box header pin Description
6 Frequency signal input pin
3,4,5,7,8 Opto-isolated input pin for relay control
1,2 Opto-isolated input for OUT1 and OUT2
+5V +5V pin

Box header pinout is identical to Mk3/9 controller output box header pinout:

Relay 3,4,5,7,8 terminals:

  • Relay screw terminals
  • Each relay output offers Common, NC (normally closed) and NO(normally opened) terminal.
Terminal pin Description
NO NO(normally opened) terminal
3,4,5,7,8 Common terminal
NC NC(normally closed) terminal

Vout6 voltage output:

  • Voltage output screw terminal connector for 0-10V voltage signal
  • This output voltage signal is proportional to frequency signal connected at input 6 of box header for connection of Mk3/9 motion controller.
Terminal pin Description
+ 0-10V voltage output positive terminal
- voltage output negative terminal

O1 and O2 output:

  • Output 1 and output 2 are voltage outputs associated with box header pins 1 and 2.
  • both outputs use solder bridges for voltage level selection: 3.3V or 5V.
Terminal pin Description
O1 Output1 positive terminal
- Output1 negative terminal
O2 Output2 negative terminal
- Output2 negative terminal

Solder bridges:

  • When using inputs 1 and 2 of box header, user needs to solder the corresponding solder bridge. User has two options for voltage level of output pin: 3.3V or 5V.
Solder Bridge OUT1/OUT2 Description
5V output will use 5V level
3.3V output will use 3.3V level


  • Trimmer resistor used for fine tuning of max value of 0-10V voltage output signal

Connection diagrams

Example 1: Connection of VFD, solenoid device and laser module

Bottom diagram describes connection of output board 3/9 with Mk3 controller output pins and VFD.

  • Relay 3 controls solenoid value (e.g. coolant)
  • Relay 4 controls VFD's forward control input
  • Vout output is connected with VFD's analog input for RPM control
  • O1 output is connected with control input of laser module(e.g. PWM signal)

Typical application

PlanetCNC TNG software settings configuration:

Images below describes configuration for 0-10V output signal, relay 3 and 4 and pin configuration for laser power control using the output pin 1 of controller.

Setting configuration for ON/OFF and RPM control, where we set pin 4 as spindle ON/OFF and pin 6 as speed signal:

We set output pin 3 as coolant output:

In NC program, output 4 and speed output 6 will react to gcode e.g. M3 S12000. In this case, relay 4 will activate and voltage at the output board Vout output would be 5V. M8 will activate output 3. In case of M7, mist output will activate(not set in the image above).

In case of using a laser module, we set output pin 1 as spindle speed pin and use the O1 of output board 3/9:

  • when using it with VFD, VFD should use line filter
  • power supply for output board 3/9 should be 12VDC with stable voltage output
  • cable for power supply for output board 3/9 should be as short as possible
  • cable for signal connection between controller and output board 3/9 should be shielded, with shield connected to controller GND terminals only at controllers side
  • spindle motor should use shielded cable
  • when using it with solenoid device:
    • use the output board 3/9 relays only to activate intermediate relay(quality is important) which will actually switch the coil of the valves.
    • on the coil of the valves, try wiring a flyback diode: https://en.wikipedia.org/wiki/Flyback_diode
    • Note that relay coils on the output board 3/9 already have this diode.
hardware/accesories/acces-ob39.txt · Last modified: 2024/05/27 10:37 by andrej

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