Wiring Guide
Connection diagrams and wiring examples for ISOBUS Block
Wiring Guide
Terminal Layout
The ISOBUS Block has screw terminals for all connections. Refer to the labels on the enclosure.
Power Supply
The module is powered through the ISOBUS connection itself — CAN and module power arrive over the same connector. The relay loads draw from a supply you provide (the tractor battery or another 12/24V source). The BAT+/BAT- screw terminals are available for bench testing or for feeding the module directly when not wiring through ISOBUS.
| Terminal | Connection |
|---|---|
| BAT+ | Positive supply (7-36V DC) |
| BAT- | Ground / Negative |
Important: Verify polarity before connecting power.
Digital Inputs (IN1-IN8)
The module has 8 optocoupler-isolated inputs, each accepting 5-36V. They are not part of normal operation — outputs are switched from the tractor's Virtual Terminal buttons, AUX-N armrest/joystick buttons, or the web interface TEST function. You do not need to wire the inputs to control the relays. The terminal details below are for reference only.
Switch Input (Dry Contact)
BAT+ ----[Switch]---- INx
When switch closes, input activates.
Voltage Signal (Wet Contact)
Signal+ (5-36V) ---- INx Signal- ---- BAT-
When voltage is present, input activates.
Sensor with Open Collector (NPN)
Sensor Output ---- INx BAT+ ---- Sensor Power BAT- ---- Sensor Ground
Relay Outputs (CH1-CH8)
Each relay has three terminals:
| Terminal | Function |
|---|---|
| COM | Common (connect to power source) |
| NO | Normally Open (closed when relay ON) |
| NC | Normally Closed (open when relay ON) |
Typical Load Wiring (Normally Open)
Power+ ---- COM NO ---- Load+ Load- ---- Power-
Load turns ON when relay activates.
Typical Load Wiring (Normally Closed)
Power+ ---- COM NC ---- Load+ Load- ---- Power-
Load turns OFF when relay activates.
CAN Bus (ISOBUS)
| Terminal | Connection |
|---|---|
| CAN_H | CAN High (to ISOBUS CAN_H) |
| CAN_L | CAN Low (to ISOBUS CAN_L) |
| CAN_GND | CAN Ground (optional shield) |
ISOBUS In-Cab Connector Pinout
The in-cab ISOBUS connector is a 9-pin socket. ISOBUS Block connects to four of its pins:
- Pin 2: CAN_L
- Pin 4: CAN_H
- Pin 7: BAT+ (12V or 24V)
- Pin 9: GND
The remaining pins carry the tractor's internal CAN bus, cable shield, and grounds, and are not used by the module.
CAN Termination
If the ISOBUS Block is at the end of the CAN bus, enable the 120Ω termination resistor via the onboard jumper/solder bridge. Check your tractor's ISOBUS documentation for termination requirements.
Wiring Best Practices
1. Use appropriate wire gauge
- Power supply: 1.5mm² or larger for main power
- Relay loads: Size according to load current
- Inputs/CAN: 0.5-1.0mm² is typically sufficient
2. Protect with fuses
- Fuse the main power supply
- Fuse high-current relay loads individually
3. Route cables properly
- Keep CAN bus cables away from high-current/noisy wiring
- Use twisted pair for CAN_H and CAN_L
- Avoid routing near ignition systems or PWM controllers
4. Use proper connectors
- Crimp terminals for screw terminals
- Weatherproof connectors for external connections
- Secure all connections against vibration
Example: Work Light Control
Work Light Load (12V): +12V ---- CH1 COM CH1 NO ---- Light+ Light- ---- GND
Assign a VT button to CH1. When you press the button (on the screen or an AUX-N armrest button), the CH1 relay closes and the light turns on. The load's +12V comes from your own supply; the relay only switches it.
Example: ISOBUS Connection
Tractor ISOBUS (in-cab connector): Pin 2 (CAN_L) ---- CAN_L terminal Pin 4 (CAN_H) ---- CAN_H terminal Pin 7 (BAT+) ---- BAT+ terminal Pin 9 (GND) ---- BAT- terminal
CAN and module power both arrive over the ISOBUS connection — no separate power wiring is needed for the module.