Monitor Items
The user-defined monitor item identifies a single item to poll while the active device is in use. This periodic item poll ensures that the inactive device's error state is updated so that it can be switched to when needed. The default setting is 300 seconds; however, when the active device is in an error state, the default setting is accelerated to a fixed rate of 30 seconds.
When there is no monitor item defined, the first available client item that requires device communications is used for polling if the secondary device is active. When the secondary is communicating successfully, the monitored item interval is 300 seconds; however, when the secondary device is in an error state, the monitored item interval is 30 seconds (regardless of the setting in the property editor).
1. A poll is not issued unless a minimum of one client item that requires device communications exists on the primary device.
2. The default setting is not accelerated in Switch On Trigger Mode.
Important: An explicitly defined monitor item must require device communication: this ensures that the poll updates the error state.