MQTT edge node tag history not being pulled up

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1

Configured MQTT Engine edge nodes tags to save history to database. Database shows tag values being written to database with timestamp. Tag values also show being updated on the tag bowser. However dragging the tag into table comes up blank. The log shows “No historical tag information could be found for any of the specified paths. Check that paths are correct. Paths: [edge nodes/xx/xx/xx]”

Non MQTT Engine tags configured to store in db work fine when dragged to table.

However I can query the database to view tag data using tag id. I use Postgres as db. Not sure if missing any setting specific to MQTT tags.

Also if I created derived tag off an mqtt engine edge node tag and enable historian on it the historical values from derived tag show up in a table. This doesn’t make sense since whats the point of enabling history on a MQTT engine edge node tag if history doesnt show. Also creating derived tag for each MQTT engine tag is not feasible as MQTT engine tags are constantly updated.

2

Did you ever find a solution for this?

I’ve found that you have to use this type of tag path to retrieve MQTT Engine tag history:
[historian-tag-provider/.realtime-tag-provider]tagpath

3

Hi All,

I have the same setup but with MYSQL as my DB. Drag the tag and no linking in charts, but browse to the tag and it works well. The path change to the tag history provider also worked for me but this will make it a much longer process than just dragging and dropping the tag onto the graph. I was wondering if either of you found a quicker way to get this done?

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4

I am seeing this same issue. I have some MQTT tags and I actually use a reference tag that looks at them with history set up on the reference tag. That reference tag is in the [default] tag area.

I can look in the database and see that the data is recording properly in the history table, but when I try to use a tag history binding it will not find the data. I am using Perspective 8.1.0rc3 (MQTT engine is v.4.0.5). If it matters the MQTT tags are being published by a project in 8.0.7 (MQTT transmission v4.0.3).

5

After doing some more testing, the tag history “works” but the data is delayed (at least for Float tags). You an see from the trend if I expand the time range that it is lagging about 2 minutes. Is this typical of MQTT tags?

image

An example from querying the database right after I knew the tagid = 12 event would appear. You can see the float tags are lagging:
image

6

That might mean that your source device for those float values has a clock off by two minutes.

7

Dangit - I was coming to update my post and say that… but you beat me to it.

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