# 1-Wire interface

BBO gateways use 1-Wire interface to communicate with the sensors and interfaces.

1-Wire interface has +5V, GND and 1-Wire data lines.

There are typically 4 pins with the following markings and functions:

<table><thead><tr><th width="143.66666666666666">Marking</th><th width="273">Signal</th></tr></thead><tbody><tr><td>OW</td><td>1-Wire data</td></tr><tr><td>GND</td><td>Power ground</td></tr><tr><td>GND</td><td>Power ground</td></tr><tr><td>PWR</td><td>Power supply +5V</td></tr></tbody></table>

The GND pins are shorted together in the module.

+5V and GND supply sensors and interfaces, 1 Wire is a common communication line. These lines are connected in parallel to all the units using the interface.

Every 1-Wire bus is controlled by a single 1-Wire master that communicates with multiple 1-Wire slave modules like sensors and interfaces.

In BBO installation, BBO gateway is a 1-Wire master.

The 1-Wire interfaces’ connectors have duplicated all three interface lines to enable easy pass-through connection. Using this method provides a simple way to connect remote groups of sensors using a single 1-Wire cable.

![Pass-through connection](https://1398263718-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2Fe49zOmJ9qgXRcOoMVIir%2Fuploads%2FH2OOGeKwBN2IavauWr62%2F1.png?alt=media)