driver-PingMonitor

This component configures the ping mechanism. The driver network uses the ping monitor to query network and device health by periodically issuing a ping call to the object. The ping monitor provides built-in support to generate alarms when objects that can receive a ping are down. The Ping Monitor is available in the Property Sheet of most networks as Monitor. These properties contain ping and alarm-related parameters that are common to all Niagara video components.

If a device does not respond to the monitor ping, the monitor marks it with a down status and suspends normal communication routines to the device. Upon the next successful monitor ping, device status returns to {ok} and normal communication routines resume.

If a device responds to the monitor ping, device status is {ok}, and normal communication routines to it (proxy-point polling, plus reads of device schedules, trends, etc. if supported by the driver) proceed normally. This applies even if the device returns an error response to the ping. Any response indicates that the device is alive.

A successful ping response updates an object’s Health property with the current time. The network ping Monitor only pings the device if the time of last health verification is older than the ping frequency. Therefore, in normal operation with most drivers, the proxy point polling mechanism actually alleviates the need for the monitor ping, provided that the ping frequency is long enough. Also, in most drivers, if a point poll request receives no response (not even a null) from a device, the monitor immediately notes a ping fail condition without waiting for the monitor ping interval.

Figure 42. Ping Monitor properties

To access ping monitor properties under the NiagaraNetwork, expand Config > Drivers, right-click NiagaraNetwork, click Views > AX Property Sheet and click Monitor.

Property	Value	Description
Ping Enabled	`true` (default) or `false`	Turns the monitor ping on and off. `true` each network device receives a ping, as needed. `false` no network device receives a ping. Device status remains as recorded the last time this property was `true`. Recommendation: leave `Ping Enabled` as `true` in almost all cases.
Ping Frequency	hours, minutes, seconds (defaults to 05m 00s)	Specifies the interval between periodic pings of all devices. Typical default value is every 5 minutes (05m 00s), you can adjust differently if needed.
Alarm On Failure	`true` (default) or `false`	Controls the recording of ping failure alarms. `true` records an alarm in the station’s AlarmHistory for each ping-detected device event (down or subsequent up). `false` ignores device down and up events.
Startup Alarm Delay	hours, minutes, seconds	Specifies how long a station waits at startup before generating a device down or up alarm. Applies only if the Monitor’s `Alarm On Failure` property is `true`.
Num Retries Until Ping Fail	number	Sets up a counter. A ping does not fail until it exhausts this number of tries.

driver-PingMonitor

Figure 42. Ping Monitor properties

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