| Re: [sparkplug-wg] Does Ignition honor payload/metric is_transient flag? |
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It's possible someone from Cirrus Link may reply directly with more information, but I can confirm that the MQTT Engine module currently ignores the is_transient flag in all cases. From my understanding, any time the MQTT Engine updates a tag's current value
the normal Ignition processes notice a tag change and push it into the historian. I don't think there is a way that MQTT Engine could change the current tag value but tell Ignition to
not record it in history. The only way that a metric flagged is_transient could be kept out of the history would be if MQTT Engine ignored it completely and never updated the Ignition tag value.
The is_historical flag works differently, since MQTT Engine doesn't update the current tag value, and just pushes the metric into the historian directly.
If your primary interest is in recording only specific reports to the historian, you may also want to ask Cirrus Link about their new "DRECORDS" features. It's new enough that I don't totally understand it and it might not actually apply to your use case,
but I think it might.
Justin Brzozoski | Senior Firmware/Systems Engineer 140 Locke Drive, Suite B, Marlborough, MA 01752 o: 978-212-2868 x40222 | e: justin.brzozoski@xxxxxxxxxxxxxxx | www.signal-fire.com ………………………………………………………………………………………………………………………………………………………………………
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