Device Polling

When the Polling checkbox is enabled on a device, Supervisor 9 (Svr9) will periodically send a P command to the unit, then update the data fields on the Monitor dialog with appropriate data. The length of the polling period is determined by the Odu Polling Period field in the CommPort Options dialog.

The Polling LED on the Summary dialog provides confirmation that polling is active; the LED is GREEN when polling is enabled, then turns BLUE when the device is actually being accessed.

Response to communications failures

If the P command fails, which indicates a communications problem of some sort, the polling LED will change to RED, and the Alarms field in the Summary dialog will display the number of seconds since the last successful access.

Long-term communications faults (Polling-Fault Cutoff)

In the CommPort Options dialog, there is a field called Polling-Fault Cutoff. If this field is greater than 0, and if the number of consecutive polling failures is equal to this value, then the device will be marked as FAULTED; the Connection LEDs on the Summary and Monitor dialogs will change to RED, the Summary dialog Alarms field will display Device Lost, and polling will be suspended on the device.

Once the communications issue with the ODU is resolved, the connection to the device can be restored by pressing either the Connect or ReScan buttons on the CommPort dialog. If the Device-Lost retry (mins) field contains a non-zero entry, Svr9 will attempt to recover lost devices automatically after the specified amount of time.

Poll LED states

BLACK - polling is disabled on this device

GREEN - polling is enabled on this device

BLUE - polling is enabled, and the device is currently being polled

YELLOW - polling is suspended temporarily

RED - device did not respond to polling command