Configure device redundancy

The OI Server Manager provides the ability to assign redundant device for fail-over protection in the event of device failure. Two devices must be configured in the same Communication Driver having identical item syntax.

Primary and secondary devices will be setup in the REDUNDANT_DEVICE object in the OCMC, along with a common item name (ping item) shared by each device to determine device status.

Note: At present, you cannot configure device redundancy using the PCS scope name. It is recommended to use the SuiteLink protocol while setting up a redundant connection between the Communication Driver and HMI/SCADA client application.

Setup up a REDUNDANT_DEVICE from the configuration branch:

1. Set-up a primary device and hierarchy in the OI Server Manager in the OCMC.

2. Create at least one device item that can be shared between the primary and secondary devices to determine device status.

3. Set up a secondary device on the same Communication Driver. Once again, create an identical device item within the secondary device so that device status can be determined.

4. Right-click on Configuration, and select Add REDUNDANT_DEVICE Connection. An object called New_REDUNDANT_DEVICE_000 is created.

   

5. Rename the newly created object as appropriate. The New_REDUNDANT_DEVICE_000 configuration view is displayed in the Configuration branch of the hierarchy.

6. Enter or use the device browser to select the primary and secondary devices. Save the hierarchy node configuration by selecting on the save icon.

   

   Note: The primary device and secondary device must be a PLC object, and not the Port or Bridge objects.

   Note: Unsolicited message configuration is not supported from the device redundant hierarchy.

   Important: A Ping Item must be specified and be a valid tag in both the primary and secondary controllers to determine the connection status for $SYS$Status. The Ping item can be a static item in the device such as a firmware version or processor type. If the Ping item is invalid or does not exist in the controller, the failover operation may not work correctly as the value of $SYS$Status may continue to stay as FALSE in the standby device.