Initiate Redundancy Commands with MSG Instructions
For some applications, consider programming the controller to initiate redundancy system commands via the redundancy modules. You can configure an MSG instruction to issue the following redundancy commands:
- Initiate a switchover
- Disqualify the secondary chassis
- Synchronize the secondary chassis
To initiate redundancy commands via an MSG instruction, follow these steps.
- On the Configuration tab of the RMCT, verify that Enable User Program Control is selected for the redundancy module.

- In the program for the redundant controller, create an MSG instruction.
- On the Communication tab of the Message Configuration dialog box, configure the path to the redundancy module and verify that the Connected checkbox is cleared.
Redundancy Command Communication ParametersParameterValuePath1,[slot number of the redundancy module] For example, enter 1,1 for a redundancy module in slot 1 of the chassis.ConnectedLeave the Connected checkbox cleared. - On the Configuration tab of the Message Configuration dialog box, configure the MSG instructions with the following parameters depending on the redundancy command.
Initiate a SwitchoverParameterValueMessage TypeCIP GenericService TypeCustomService Code4eClassbfInstance1AttributeNone - no value neededSource ElementINT tag with a value of 1Source Length2Destination ElementNone - no value neededDisqualify the Secondary ChassisParameterValueMessage TypeCIP GenericService TypeCustomService Code4dClassbfInstance1AttributeNone - no value neededSource ElementINT tag with a value of 1Source Length2Destination ElementNone - no value neededSynchronize the Secondary ChassisParameterValueMessage TypeCIP GenericService TypeCustomService Code4cClassbfInstance1AttributeNone - no value neededSource ElementINT tag with a value of 1Source Length2Destination ElementNone - no value needed
Provide Feedback