ABB AC500 PLC Hardware Manual page 1269

3.
2.6.3.5 Mounting and Demounting the I/O Modules
After mounting the Terminal Unit, mount the I/O Modules.
2019/04/17
The demounting is carried out in a reversed order. Press above and below, then remove
the Processor Module.
3ADR010121, 13, en_US
System Assembly, Construction and Connection
AC500 (Standard) > Mounting and Demounting
1269