Help Understanding How to Feed Data to openHist

So the RTAC defaulted to 0 which is why I left it at that, and since I only had one tag it was obvious something was not right. After changing the register to 1 it acted a bit funny so I deleted the device and re-added.

The web based trend works, and the OH keeps its connection with the RTAC full time now!

Now the only issue I still see is I can’t select the checkbox in the openHistorian Manager to trend the tag as seen below. Even though now the light next to the device name is green, and its displaying values next to the tag name.

Grafana dosen’t seem to see any points right now either. I’m off to watch the youtube video I saw on this to make sure I’m doing this correctly.

The openHistorian Manager application trending screen will currently only trend Frequency and Phasor quantities - by default Modbus points are marked as Calculated quantities unless you pick another signal type on the “Save Device” dialog screen.

I would expect Grafana to work just fine - on the “Data Source” drop down, try selecting “OHDATA” instead of “default”

Still no data points when I change default to OHDATA. When I look at the data base settings I see OHDATA is set as the default, and when I hit ‘Save and Test’ I get the green ‘Data Source Is Working’ notification.

Maybe Grafana doesn’t see the new points - you can try this from the console window:


How do I type into the console window? When I open it, it just constantly scrolls polling information.

Yeah, there’s that - from the app - you just type with the assurance that it is accepting your input.

You can also type q for quiet and r for resume to make things quiet.

It’s actually easier to hit the console window from the web or manager interfaces - as these have a separate text area from which to type input commands.

On the web page, look for “Monitoring / Remote Console Service”

Oh yeah, the web console is much easier to focus on.

After running the command it looked like the initialization worked, I didn’t see any errors or exceptions come up. It ended with initializing http. Still no data points shown though.

Try changing the time window on the top right of the Grafana screen to the last 5 minutes?

As a last ditch effort, you can try restarting the openHistorian service…

No luck on changing time frame or restarting the service. I restarted the entire machine also.

I’m going to do a fresh install on the server VM that will actually run it and see if I have the same issue. If this is a individual machine issue its probably not worth spending a bunch of time trying to fix on a test install.

Well, getting Grafana to show data is usually the simple part :frowning:

Preformed a fresh install on a new machine yesterday and let it sit collecting data through the night. Grafana will now show data only at the “Last 5 Minuets” mark. All other options show either blank or say ‘No Data Points’. However this time I installed the test device and I can see the test data for any time period chosen. I’m not sure why Grafana has such an issue reading non-test data from the database, the OH ‘Trend / Export’ trend screen has no problem pulling up data from throughout the night.


Perhaps it is an issue with the low resolution of the Modbus data. Try adding the Interval function with a resolution value of zero, this will prevent any down sampling activity.

With any interval value set (including zero) a red exclamation point pops up on the upper left that delivers the following error message:

  "Message": "An error has occurred."

What does your query string look like?

Now something interesting happened, when you suggested the interval change the first time I modified the device settings from the default to a 500ms polling rate, and 150ms inter-sequence group poll delay. Now a little time has gone by and I get data points showing up at different time intervals than before. For example the below shows a last three hour graph, and now it has data where this morning it did not. However, if I float my mouse over the line it only shows three data points.

Also, just encase it has something to do with only having one input into the system I’ve added IA, IB, and IC from the same filter bank. I’ll wait a little bit and take a look at how that data shows in Grafana.

FYI, I ran a test on my end and I’m having issues with the Element List selector in Grafana. I had to change it to a filter expression to get anything to show up. Here’s what my dashboard looks like.

Holy crap it works!

So the functions are finicky. If I close the edit box and then re-open it my functions disappear and the graph returns to just a few sample points. However, if I switch dashboards and then come back the functions are applied again.