Versions Compared

Old Version 15

changes.mady.by.user Gill Houghton

Saved on

compared with

New Version 16

changes.mady.by.user Gill Houghton

Saved on

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

...

Note
The reference tag must be a Reference tag only.  Derived, Expression and OPC tags (expose MQTT Engine tag provider through OPCUA server) will not properly store history when MQTT Engine tags are updated with historical data at a high rate of speed. This is a limitation within the Ignition platform and may be addressed in a future release.

Back-fill support

Historical back-fill support was added in Ignition 8.1.4 which allows Reference Tags in Ignition to be updated even if history arrives out of order. See the following document for details : MQTT History Back-Fill with Reference Tags

If using an Ignition release before v8.1.4, in order for the historical tag changes at the MQTT Engine tag to propagate to the referencing tag, MQTT Engine must be configured to write historical data directly to its tags. See the Writing historical events directly to tag section for configuration details.Historical back-fill support was added in Ignition 8.1.4 which allows Reference Tags in Ignition to be updated even if history arrives out of order. See the following document for details : MQTT History Back-Fill with Reference Tags

Scripting

Use Ignition scripting to reapply history configuration directly on MQTT Engine tags on demand.

...