Contents
Cirrus Link Resources
Cirrus Link Website
Contact Us (Sales/Support)
Forum
Cirrus Link Modules Docs for Ignition 7.9.x
Inductive Resources
Ignition User Manual
Knowledge Base Articles
Inductive University
Forum
PLC > Edge > MQTT Server > MQTT Engine module
The timestamp for an Edge tag read from a PLC will be the timestamp assigned by the PLC and associated Ignition driver.
The timestamp for any other Edge tag will be the Ignition server OS time for change in Qualified Value (Value, Quality or Timestamp)
All timestamps published on the wire are in UTC and displayed converted to local time.
In general, the Edge is the source of truth for tag timestamps although there are several events that will cause the timestamps to differ across the system:
In a Transmission/Injector BIRTH message
OPC Tag Disabled
OPC Tag Enabled
OPC Restart Tag
Time at PLC is older than Transmission or Engine leading to tag change events being ignored as the new event time is before current time for the tag at Engine