# Wiring Schematic (/docs/v4/reference/wiring-schematic)



This article covers the complete wiring schematic of the Vision Miner 22IDEX V4. Use it as a reference when troubleshooting electrical connections, replacing components, or verifying wiring after maintenance. The printer uses two controller boards: a Duet 3 Mainboard 6HC (Board 0) and a Duet 3 Expansion 3HC (Board 1), connected via CAN-FD bus.

<Callout type="error" title="Before you begin - safety and risk">
  Read the [Safety - Before You Begin](/docs/v4/reference/safety-before-you-begin) article to understand the hazards involved in working on the Vision Miner 22IDEX V4 - including electrical, thermal, mechanical, and chemical risks. All procedures in this wiki are provided as recommendations only. By choosing to follow any procedure, you do so at your own risk.
</Callout>

## HV Wiring Schematic [#hv-wiring-schematic]

High-voltage (mains) wiring between the power supply, SSR (solid-state relay), and the main board. This section is for reference only – do not service mains wiring yourself.

<div style="{backgroundColor: 'white', padding: '1rem', borderRadius: '0.5rem'}">
  <DocImage src="https://pub-e9ada5735e184a34a55b5e8f01a2be68.r2.dev/uploads/v4/diagrams/hv_power_supply_schematic.png" alt="High-voltage wiring schematic showing power supply, SSR, and main board mains connections." size="large" />
</div>

## Heads – Main Board Connections [#heads--main-board-connections]

Hotend heaters, temperature sensors, and extruder motors connect to the Duet 3 MB 6HC (Board 0). Both toolheads (Left / Tool 0 and Right / Tool 1) wire back to this board.

<div style="{backgroundColor: 'white', padding: '1rem', borderRadius: '0.5rem'}">
  <DocImage src="https://pub-e9ada5735e184a34a55b5e8f01a2be68.r2.dev/uploads/v4/diagrams/toolhead_mainboard_connections.png" alt="Toolhead wiring connections to the Duet 3 MB 6HC showing heater, temperature sensor, and extruder motor cables." size="large" />
</div>

## Z Motors – Expansion Board Connections [#z-motors--expansion-board-connections]

The three Z-axis leadscrews are driven by motors connected to the Duet 3 Expansion 3HC (Board 1). The expansion board communicates with the main board over CAN-FD.

<div style="{backgroundColor: 'white', padding: '1rem', borderRadius: '0.5rem'}">
  <DocImage src="https://pub-e9ada5735e184a34a55b5e8f01a2be68.r2.dev/uploads/v4/diagrams/z_motors_expansion_board.png" alt="Z-axis motor wiring to Duet 3 Expansion 3HC showing connections for all three leadscrews." size="large" />
</div>

| Motor     | Driver | Position        |
| --------- | ------ | --------------- |
| Z Motor 1 | 1.0    | Right leadscrew |
| Z Motor 2 | 1.1    | Rear leadscrew  |
| Z Motor 3 | 1.2    | Left leadscrew  |

## X/Y/U Motors [#xyu-motors]

The XY motion system uses four motors on the main board. Two Y-axis motors run in parallel on a shared axis.

<div style="{backgroundColor: 'white', padding: '1rem', borderRadius: '0.5rem'}">
  <DocImage src="https://pub-e9ada5735e184a34a55b5e8f01a2be68.r2.dev/uploads/v4/diagrams/xy_motors_connections.png" alt="X/Y/U motor wiring diagram showing connections to the main board stepper drivers." size="large" />
</div>

| Motor      | Driver | Function                         |
| ---------- | ------ | -------------------------------- |
| X motor    | 0.2    | Tool 0 (left toolhead) movement  |
| U motor    | 0.3    | Tool 1 (right toolhead) movement |
| Y motor #1 | 0.1    | Y-axis (paired)                  |
| Y motor #2 | 0.4    | Y-axis (paired)                  |

## Z-Probe [#z-probe]

The Z-probe is connected to the expansion board (Board 1) via `1.io4.in`. Probe deployment and retraction are controlled by a servo motor driven from `out9` on the main board. An ESD protection output is configured on `1.out4`.

<div style="{backgroundColor: 'white', padding: '1rem', borderRadius: '0.5rem'}">
  <DocImage src="https://pub-e9ada5735e184a34a55b5e8f01a2be68.r2.dev/uploads/v4/diagrams/z_probe_wiring.png" alt="Z-probe wiring showing connections to expansion board IO and servo control from main board." size="large" />
</div>

## Switches [#switches]

Endstop switch wiring for all axes. All endstop switches connect to IO headers on the main board.

<div style="{backgroundColor: 'white', padding: '1rem', borderRadius: '0.5rem'}">
  <DocImage src="https://pub-e9ada5735e184a34a55b5e8f01a2be68.r2.dev/uploads/v4/diagrams/endstop_switches_wiring.png" alt="Endstop switch wiring diagram showing all axis limit switches connected to main board IO headers." size="large" />
</div>

| Switch       | Pin      | Type                 |
| ------------ | -------- | -------------------- |
| X endstop    | `io4.in` | Min endstop (S1)     |
| U endstop    | `io5.in` | Max endstop (S1)     |
| Y endstop #1 | `io1.in` | Min endstop (paired) |
| Y endstop #2 | `io2.in` | Min endstop (paired) |

## Toolhead Wiring [#toolhead-wiring]

Terminal block connections for both toolheads, including heater wires, temperature sensor wires, fan wires, and extruder motor cables.

<div style="{backgroundColor: 'white', padding: '1rem', borderRadius: '0.5rem'}">
  <DocImage src="https://pub-e9ada5735e184a34a55b5e8f01a2be68.r2.dev/uploads/v4/diagrams/toolhead_terminal_block_wiring.png" alt="Toolhead terminal block wiring showing heater, sensor, fan, and motor cable connections." size="large" />
</div>

## Main Board Pinout – Duet 3 MB 6HC (Board 0) [#main-board-pinout--duet-3-mb-6hc-board-0]

Complete pin assignment table for the main board. All pin names use RepRapFirmware notation.

<DocImage src="https://pub-e9ada5735e184a34a55b5e8f01a2be68.r2.dev/uploads/v4/diagrams/duet3_mb_6hc_pinout.png" alt="Duet 3 Mainboard 6HC pinout diagram showing all stepper drivers, outputs, temperature sensors, and IO connections." size="large" />

### Stepper Drivers [#stepper-drivers]

| Connector | RRF Pin | Axis | Function              |
| --------- | ------- | ---- | --------------------- |
| DRIVER\_0 | 0.0     | E0   | Left extruder motor   |
| DRIVER\_1 | 0.1     | Y    | Y-axis motor #1       |
| DRIVER\_2 | 0.2     | X    | X-axis motor (Tool 0) |
| DRIVER\_3 | 0.3     | U    | U-axis motor (Tool 1) |
| DRIVER\_4 | 0.4     | Y    | Y-axis motor #2       |
| DRIVER\_5 | 0.5     | E1   | Right extruder motor  |

### High / Medium Current Outputs [#high--medium-current-outputs]

| Connector | RRF Pin | Function                      | Details                          |
| --------- | ------- | ----------------------------- | -------------------------------- |
| OUT1      | out1    | Left hotend heater (H0)       | PT1000 sensor on TEMP\_0         |
| OUT2      | out2    | Right hotend heater (H1)      | PT1000 sensor on TEMP\_1         |
| OUT4      | out4    | Left hotend cooling fan (F2)  | Thermostatic, activates at 70 °C |
| OUT5      | out5    | X print cooling fan (F3)      | User-controlled                  |
| OUT7      | out7    | Right hotend cooling fan (F0) | Thermostatic, activates at 70 °C |
| OUT8      | out8    | U print cooling fan (F1)      | User-controlled                  |
| OUT9      | out9    | Z-probe servo (S0)            | 50 Hz PWM                        |

### Temperature Sensors [#temperature-sensors]

| Connector | RRF Pin | Function     | Sensor Type |
| --------- | ------- | ------------ | ----------- |
| TEMP\_0   | temp0   | Left hotend  | PT1000      |
| TEMP\_1   | temp1   | Right hotend | PT1000      |

### Input / Output [#input--output]

| Connector | RRF Pin  | Function     |
| --------- | -------- | ------------ |
| IO\_1     | `io1.in` | Y endstop #1 |
| IO\_2     | `io2.in` | Y endstop #2 |
| IO\_4     | `io4.in` | X endstop    |
| IO\_5     | `io5.in` | U endstop    |

### Power Control [#power-control]

| Connector | RRF Pin | Function                      |
| --------- | ------- | ----------------------------- |
| EXT 5V    | pson    | Power supply on/off (M80/M81) |

## Expansion Board Pinout – Duet 3 EXP3HC (Board 1) [#expansion-board-pinout--duet-3-exp3hc-board-1]

Complete pin assignment table for the expansion board, connected to the main board via CAN-FD (address 1).

<DocImage src="https://pub-e9ada5735e184a34a55b5e8f01a2be68.r2.dev/uploads/v4/diagrams/duet3_expansion_3hc_pinout.png" alt="Duet 3 Expansion 3HC pinout diagram showing stepper drivers, outputs, temperature sensors, and IO connections." size="large" />

### Stepper Drivers [#stepper-drivers-1]

| Connector | RRF Pin | Axis | Function                  |
| --------- | ------- | ---- | ------------------------- |
| DRIVER\_0 | 1.0     | Z    | Z motor – right leadscrew |
| DRIVER\_1 | 1.1     | Z    | Z motor – rear leadscrew  |
| DRIVER\_2 | 1.2     | Z    | Z motor – left leadscrew  |

### Outputs [#outputs]

| Connector | RRF Pin | Function                                                                       | Details                          |
| --------- | ------- | ------------------------------------------------------------------------------ | -------------------------------- |
| OUT0      | 1.out0  | Bed heater (H2)                                                                | 10 Hz PWM                        |
| OUT1      | 1.out1  | Chamber heater (H3)                                                            | 10 Hz PWM                        |
| OUT2      | 1.out2  | Chamber heater fan (F4)                                                        | Thermostatic, activates at 80 °C |
| OUT3      | 1.out3  | White LEDs (F6)                                                                | User-controlled                  |
| OUT4      | 1.out4  | Z-probe ESD protection                                                         | –                                |
| OUT5      | 1.out5  | [HEPA filter fan](https://visionminer.com/products/hepa-filter-fan-rev-2) (F7) | Thermostatic on chamber temp     |
| OUT6      | 1.out6  | Red LEDs                                                                       | PWM, 5 kHz                       |
| OUT7      | 1.out7  | Green LEDs                                                                     | PWM, 5 kHz                       |
| OUT8      | 1.out8  | Blue LEDs                                                                      | PWM, 5 kHz                       |

### Temperature Sensors [#temperature-sensors-1]

| Connector | RRF Pin | Function       | Sensor Type | Parameters     |
| --------- | ------- | -------------- | ----------- | -------------- |
| TEMP\_0   | 1.temp0 | Chamber air    | Thermistor  | 200 kΩ, B=3950 |
| TEMP\_1   | 1.temp1 | Bed heater     | Thermistor  | 100 kΩ, B=3950 |
| TEMP\_2   | 1.temp2 | Chamber heater | Thermistor  | 100 kΩ, B=3950 |

### Input / Output [#input--output-1]

| Connector | RRF Pin    | Function      |
| --------- | ---------- | ------------- |
| IO\_4     | `1.io4.in` | Z-probe input |

## Support [#support]

If you could not find an answer here, reach out to our [support team](/support).