> 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-switch-settings.md).

# Configuring a Fibre Transceiver

Reference Gallagher Fibre Transceiver variants, distance limits, and DIP switch settings.

This reference lists Fibre Transceiver variants, distance limits, and DIP switch settings.

### Variants

| Variant         | Part # | Fibre type            | Max distance between units |
| --------------- | ------ | --------------------- | -------------------------- |
| N11 Single-Mode | G28811 | 9/125 um              | 40 km                      |
| N12 Multi-Mode  | G28812 | 50/125 or 62.5/125 um | 4 km                       |

### DIP switch location

The dual in-line package (DIP) switches are on the right side of the transceiver. All switches default to OFF. Push a switch down to set it to ON.

![DIP switch layout on N11/N12](https://328339335-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F6bM8WhlBE9BYizPWJaPN%2Fuploads%2Fgit-blob-96f5bac9330415715170d8beb9236bff808d115d%2FSECHUB-FIBRE-10-dip-switch-layout.png?alt=media)

<img src="https://328339335-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F6bM8WhlBE9BYizPWJaPN%2Fuploads%2Fgit-blob-dd5efa98bcf5b185f09dfa12e8f035f881c48d49%2FSECHUB-FIBRE-11-side-view.jpg?alt=media" alt="Transceiver side view showing DIP switch position" width="320">

### DIP switch functions

<table><thead><tr><th width="97.60009765625">DIP switch</th><th width="530">Function</th><th>Default</th></tr></thead><tbody><tr><td>1</td><td>Alarm relay mode. OFF is local, this transceiver only. ON is global, all transceivers alarm</td><td>OFF</td></tr><tr><td>2</td><td>Self Healing Ring distance</td><td>OFF</td></tr><tr><td>3</td><td>Self Healing Ring distance</td><td>OFF</td></tr><tr><td>4</td><td>Master/Slave. ON is Slave, OFF is Master</td><td>OFF</td></tr><tr><td>5</td><td>Channel 1 biasing, RS485 680 ohm</td><td>OFF</td></tr><tr><td>6</td><td>Channel 2 biasing, RS485 680 ohm</td><td>OFF</td></tr><tr><td>7</td><td>Channel 1 termination, RS485 120 ohm</td><td>OFF</td></tr><tr><td>8</td><td>Channel 2 termination, RS485 120 ohm</td><td>OFF</td></tr></tbody></table>

Leave DIP switches 2, 3, and 4 OFF when not using Self Healing Ring.

{% hint style="warning" %}
Set one transceiver as Master with DIP switch 4 OFF. Set every other transceiver as Slave with DIP switch 4 ON.
{% endhint %}

### Self Healing Ring distance

<table><thead><tr><th width="312.800048828125">Total Ring Length</th><th>DIP Switch 2</th><th>DIP Switch 3</th></tr></thead><tbody><tr><td>&#x3C; 1 km or not a Self Healing Ring</td><td>OFF</td><td>OFF</td></tr><tr><td>1 km to 2 km</td><td>OFF</td><td>ON</td></tr><tr><td>2 km to 5 km</td><td>ON</td><td>OFF</td></tr><tr><td>5 km to 50 km</td><td>ON</td><td>ON</td></tr></tbody></table>

***

🔗 **Related**

* [Configure HBUS biasing and termination](/knowledge-hub/products/cc-hardware/perimeter-solutions/gallagher-fibre-transceiver/fibre-tranceiver-biasing-and-terminati.md) identifies when to set DIP switches 5 to 8.
* [Gallagher Fibre Transceiver](/knowledge-hub/products/cc-hardware/perimeter-solutions/gallagher-fibre-transceiver.md) describes supported topologies.
* [Connect Fibre Transceiver power and ground](/knowledge-hub/products/cc-hardware/perimeter-solutions/gallagher-fibre-transceiver/fibre-tranceiver-power-requirements.md) covers power and isolation.


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