# Deleting a Modbus RTU master

A Modbus RTU master can only be deleted by deleting the associated UR20-1COM-232-485-422 I/O module.

## NOTICE

Deleting a Modbus RTU master deletes all subordinate slaves as well. It also deletes all data items associated with these slaves including their mapping to global variables.

1. Open the device view.
2. Delete the UR20-1COM-232-485-422 u-remote I/O module that contains the master.