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.
| 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. |