Historical Tag Provider Issues

Ignition
1

I will start with what I am trying to accomplish here first. So I have a dynamic tag history binding using the model from the manual.

  • key [array]
    • [0] {object}
      • aggregate value
      • alias value
      • path value
    • [1]{object}
      • aggregate value
      • alias value
      • path value
    • ...

Now I have done this same thing other places so I know that portion is correct.

But when I have a tag path in there. I get the all mysterious:
"No historical tag information could be found for any of the specified paths"
showing up in my logs.

This is also for any tag I have tried to use in this binding. The one thing I have found out is that if I make it a direct tag binding, it's fine and no logs appearing.

2 areas that I think I have narrowed it down to are:
1- My sqlth_drv table has 2 entries in it both with the same gateway name in the name column and on shows null in the provider column while the other shows my prodier name I am using for these tags.

2 - my tag path in a direct binding looks like:

[Database/gatewayname:provider]path/to/motortag/status/motor amps

While in my dynamic structure my path is:

[Provider]Path/To/MotorTag/Status/Motor Amps

Is this something someone has ran into before, or is there something in this information that I am doing wrong or have issues that look like they need fixed?

Thanks for any advice!

2

When you put just a tag provider name inside the square brackets, the tag provider is asked to expand to the appropriate "driver" and history provider name.

Do note that Perspective generally expects history paths to be in QualifiedPath format, while Vision generally expects history paths to be in enhanced TagPath format. (Scripted queries tolerate all three.)

See these topics for more:

3

Thanks, I will get to reading these!

4

So using @PGriffith's supplied code in that first post.

I am returned the tag path that I was originally supplying but with the prefix of

histprov:provider:/drv:driver:/tag:

So in my tag history binding in Perspective, I tried to use that qualified path being returned, and I get an unable to parse path error. Maybe I am misunderstanding the requirements of paths you referred to there?

I am a little confused as the manual shows this as the example though for dynamic tag paths:

[
{
    "aggregate": "Average",
    "alias": "tank_temp",
    "path": "[default]Tank/03/Temperature"
},
{
    "aggregate": "Average",
    "alias": "setpoint",
    "path": "[default]Tank/03/Setpoint"
}
]
5

Paths in the format histprov:....:/drv:....:/tag:.... are the QualifiedPath format. This is the modern format in Perspective.

Paths in the format [localHistProv/gatewayName:tagProv]path/to/tag are the legacy "expanded" history path within a BasicTagPath format. These translate to the modern format as:

histprov:localHistProv:/drv:gatewayName:tagProv:/tag:path/to/tag

Paths in the format [tagProv]path/to/tag are not historian tag paths at all. When handed to the historian, the historian interrogates that tag provider and the details of the tag to internally construct the QualifiedPath for you. Most of the user manual examples use this short cut, because it is perfectly reasonable to do so in a single-gateway system. Including the example for Perspective indirect history binding.

6

what ‘drv’ does this example tag path from Tag Paths | Ignition User Manual use?

histprov:default:/tag:_Simulator_/Ramp/Ramp0

also - how can a more specific aggregation mode [be] defined on a tag path?

7

I'm not sure that is valid. :man_shrugging:

The aggregation mode is not part of the tag path at all.

1 Like