Mitsubishi Electric MELSEC iQ-R Series User Manual page 184

4.
Set the master/local module for the slot No.1.
5.
Click the [OK] button to add the module labels of the master/local module.
6.
Set the items in "Required Settings" as follows.
[Navigation window]  [Parameter]  [Module Information]  [RJ61BT11]  [Required setting]
APPX
182
Appendix 8 How to Use Standby Master Function in Redundant System