---
title: The backup unit is disconnected from the gateway
description: Steps and instructions to detect the backup unit during the commissioning process
---
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12 October 2026
# The backup unit is disconnected from the gateway
### Issue
During (or sometimes after) commissioning, the backup unit cannot be detected.
### Solution
The backup unit lies on the same CAN bus as the batteries. As such, the same [**instructions**](https://support.atmoce-au.com/knowledge-base/ms-7k-u-batteries-are-not-detected?hsLang=en-gb)need to be followed. It is likely that adding a 2nd resistor will help resolve the backup unit communication issues.
---
*Information in this article was current at the time of publication or last update. Product specifications, software, firmware and procedures may change. Please refer to the latest ATMOCE documentation before proceeding.*
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