> For the complete documentation index, see [llms.txt](https://help.security.gallagher.com/knowledge-hub/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.security.gallagher.com/knowledge-hub/products/cc-hardware/perimeter-solutions/gallagher-fibre-transceiver/fibre-tranceiver-biasing-and-terminati.md).

# Configure HBUS biasing and termination

Learn how to configure HBUS biasing and termination for Gallagher Fibre Transceivers.

{% hint style="info" %}
Read [Gallagher Fibre Transceiver](/knowledge-hub/products/cc-hardware/perimeter-solutions/gallagher-fibre-transceiver.md) if you are new to the product.
{% endhint %}

Configure each HBUS run with one biasing source and termination at both ends. This prevents unreliable communication during commissioning.

### HBUS runs

Each Fibre Transceiver starts a separate HBUS run. Treat each run as an independent entity.

* One biasing source per segment
* Termination at each end of the run

A segment is an HBUS run on one physical electrical path. A fibre section separates segments. Each segment needs its own single biasing source.

### Biasing

Biasing supplies voltage to an HBUS run. Communicating devices pull this voltage down.

More than one biasing source causes signal contention. Configure only one source for each segment.

### Controller 6000 connections

A Controller 6000 is always a biasing source. Turn off biasing on a Fibre Transceiver connected to a Controller 6000.

Use DIP switch 5 for channel 1 or DIP switch 6 for channel 2. Terminate the Controller 6000 and Fibre Transceiver when they sit at opposite ends of the run.

See [Fibre Transceiver specifications](/knowledge-hub/products/cc-hardware/perimeter-solutions/gallagher-fibre-transceiver/fibre-tranceiver-switch-settings.md) for switch positions.

### Incorrect configurations

| Mistake                              | Consequence                                       |
| ------------------------------------ | ------------------------------------------------- |
| No biasing on a segment              | The HBUS section does not work reliably           |
| Two biasing sources on a segment     | Signal contention causes unreliable communication |
| Termination in the middle of the run | The affected section has reduced reliability      |
| Missing termination at the ends      | Reflections cause unreliable communication        |

{% hint style="warning" %}
Terminate at the ends, not the middle. A Fibre Transceiver in the middle of an HBUS run is not terminated.
{% endhint %}

***

🔗 **Related**

* [Fibre Transceiver communication issues](/knowledge-hub/products/cc-hardware/perimeter-solutions/gallagher-fibre-transceiver/fault-finding-biasing-and-termination.md) provides fault-finding diagrams.
* [Fibre Transceiver specifications](/knowledge-hub/products/cc-hardware/perimeter-solutions/gallagher-fibre-transceiver/fibre-tranceiver-switch-settings.md) identifies each switch function.
* [Connect Fibre Transceiver power and ground](/knowledge-hub/products/cc-hardware/perimeter-solutions/gallagher-fibre-transceiver/fibre-tranceiver-power-requirements.md) explains required ground connections.


---

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