Larnitech CAN Bus: Topology and Wiring Practice for Panel Builders
A working Larnitech installation stands or falls on how the CAN bus is routed and terminated. This is the wiring discipline behind it — for panel builders and installers, not a product pitch.
How the bus is laid out
Plan a linear trunk
Route the CAN bus as a single line from module to module — no star branches, no ring. Larnitech's Main Gateway gives you the two connection points that mark the physical ends of that line.
Run CAN High / CAN Low as a twisted pair
The two data conductors carry a differential signal, which is what gives CAN its noise immunity. Twist them together along the full run; in electrically noisy panels or trays, use shielded twisted-pair cable.
Terminate both physical ends
A CAN bus needs a terminating resistor at each end of the trunk, not in the middle and not on a stub. The Main Gateway's two bus connections mark where that termination belongs.
Tap modules with WAGO-type connectors, keep stubs short
Each DIN-rail module taps into the trunk via a WAGO-type terminal. Keep the tap short — long stubs off the main line invite signal reflection on a CAN bus.
What the wiring practice covers
One trunk, two ends
Larnitech's Main Gateway exposes exactly two CAN-bus connection points — the two ends of a linear trunk, terminated as standard CAN engineering practice requires.
Linear, not star
CAN doesn't tolerate star or ring wiring well; the trunk runs point-to-point through the installation, module to module.
Differential pair
CAN High and CAN Low run twisted together end to end, carrying the differential signal that rejects electrical noise.
Termination at the ends
Both physical ends of the trunk get terminated — at the Main Gateway's two bus connections — never mid-run.
Separated from 230V
CAN cabling is routed apart from mains wiring in the panel and along cable trays, to keep low-voltage data clean.
Shielded cable where needed
In electrically noisy locations, shielded twisted-pair cable is used for the CAN run instead of unshielded pair.
What we check on-site
A wiring review before or during panel build, not a Larnitech sales pitch.
- Trunk topology walkthrough (no star branches, no long stubs)
- Termination check at both physical bus ends
- CAN High/Low twisted-pair routing and 230V separation review
- WAGO-type connector tap points at each DIN module
- Panel assembly to IEC 61439 around the finished bus wiring
Frequently asked questions
Is the Larnitech CAN bus the same protocol as KNX?
No. Larnitech runs its own manufacturer CAN-bus system, configured through its own app rather than an ETS-style design tool. Larnitech devices are not KNX-certified and don't interoperate with KNX actuators/sensors the way certified KNX devices do with each other.
Can I wire the bus as a star instead of a line?
It's not standard CAN practice. A linear trunk with termination at both physical ends is how Larnitech's Main Gateway is designed to be connected, and it's the topology that keeps CAN's differential signalling reliable.
What cable should I use for CAN High/CAN Low?
A twisted pair for the two data conductors, run separate from 230V wiring. In electrically noisy panels or trays, use shielded twisted-pair cable rather than unshielded.
Where does termination go, and how many points?
At the two physical ends of the trunk. Larnitech's Main Gateway provides two CAN-bus connections for exactly this purpose — one at each end of the line.
Is this the same as CANopen?
No. Larnitech uses the CAN physical layer with its own manufacturer protocol on top, not CANopen. We don't compare or certify Larnitech against CANopen on this page.
Get your CAN bus wiring reviewed before it's closed up
Send us your panel layout or ask a specific wiring question — our engineers will look at topology, termination and cable routing before the panel goes into the field.