Device Status

Calculating device status

The PI Interface for SNMP keeps track of the percentage of hosts (foreign devices) that are Up when multiple tags are set up where the foreign device is designated in the Instrument tag field.

The interface uses the following calculations to determine device status:

• 30 is the first value available for an Interface Specific Device Status

• 70 is the last value available for an Interface Specific Device Status

Calculation 1

devicestatus = 30 + ((devicesOffline / totalDevices) * (70 - 30))

The resulting device status will be between 30 and 70. This prevents clashes with preexisting device statuses such as 0, 10, or 90.

The device status is then sent to UniInt to determine the percentage of devices that are Up.

Calculation 2

percentup = (devicesOffline / totalDevices) * 100

If the percentup value is greater than what is designated in the PERCENTUP parameter, a device status of DeviceStatus=0 is logged.

If the percentup value is less than what is designated in the PERCENTUP parameter, the device status is considered in a bad state (DeviceStatus=[devicestatusfromCalculation1]).

Note: A device status between 30 and 70 is considered Bad.

Device Status Health Monitoring

Use the PI Interface Configuration Utility (PI ICU) to create the device status health monitoring point (shown as type UI_DEVSTAT in the Health Monitoring pane in the PI ICU). The device status health monitoring point stores communication information about the interface and its foreign device (or data source) connection(s). The interface also prints Device Status to the PI message log.

Note: Foreign devices enumerated using the -IgnoreDevice command line option are ignored and not used for determining device status unless all foreign devices are down.