OPC UA Historical Access

Ignition Early Access
1

Hey,

Was wondering if historical access to OPC tags would be supported in v8. Would be huge if we didn’t have to backfill data into our OSISoft/PI corporate historian – and just leverage the functionality that is planned for OPC UA directly.

Thanks in advance!

-Paul

2

It won’t be part of Ignition 8.0 and I doubt this will be implemented any time soon.

There’s very little demand (although I’m counting your request) and it’s a significant amount of effort to implement.

1 Like
3

Thanks Kevin for the (amazingly) quick reply. Yes – please count this as a request :slight_smile: I imagine there will be much more demand for this as UA becomes more widely adopted. Would be great to see…

4

Kevin,

Is this the kind of thing that should be posted on the Ignition Features and Ideas page?

5

Never hurts to post it there.

6

yep – I posted there too a while back :slight_smile: – was just curious what was in the works with the beta

https://inductiveautomation.canny.io/ignition-features-and-ideas/p/opc-ua-historical-access

7

Paul. How are you currently backfilling the data into Osisoft PI?

8

Hi Mark,

It can be done manually by inspecting a combination of the sql tables managed by the historian module – I would suggest taking a quick look at the SDK reference for these tables to better understand how they function: https://docs.inductiveautomation.com/display/SE/Tag+History+Tables+Reference

Generally – you will need to inspect the following (names/etc may not be exact – going from memory here…)

  • sqlth_te (find the id of the tag based on it’s TagPath within the historian db)
  • sqlth_partitions (find the data table(s) for the time-range you’re after)
  • sqlt_data_x_x_x (this is the table returned for your time-range in question…use the “WHERE” clause to filter entries pertaining to your specific tag id)

Hope this helps!

-Paul

PS – I think there is a more elegant way of doing this via the PI RDBMS interface – but I’m assuming you’re trying to fill the missing data that may have been captured via OPC-UA connector?)

1 Like