#805 Pull setpoint values of configured control points

Ramamurthi Iyer Tue 21 Apr


I would like to know if we can pull setpoint values of configured points using the NHaystack API. These are explicitly configured setpoint in Niagara for a control point.

Thank you, Ram Iyer

Ramamurthi Iyer Wed 22 Apr

Hi Chris,

Would you know if this is possible and how using NHaystack API?

Thank you, Ram Iyer

Paul Quinn Wed 22 Apr

You would need to do a live watch on the point and collect histories in SkySpark or add a history in Niagara and sync with SkySpark. Basically, you would treat it like any other Niagara control point.

Ramamurthi Iyer Thu 23 Apr

Hi Paul,

Thanks for the reply. Can I tag the point as a sp and use it as his? I was reading your blog. https://project-haystack.org/tag/sp

If I have a point setup as his how can I invoke it using the REST API? I am looking for the exact filter condition? Could you please share that?

Regards, Ram Iyer

Ramamurthi Iyer Thu 23 Apr

Hi Paul,

I am trying to invoke the hisRead op using rest API.Could you give me an example of how I can invoke this on a control point that is defined with his tag?


How do I give the id and hisStart and hisEnd in the query parameter?

Ramamurthi Iyer Thu 23 Apr

Just another update: I am pretty close but getting the following error.


How do I give the range now?

"dis": "s:org.projecthaystack.UnknownNameException: range",

"errTrace": "s:org.projecthaystack.UnknownNameException: range\n  at org.projecthaystack.HRow.get(HRow.java:46)\n  at org.projecthaystack.HDict.get(HDict.java:49)\n  at org.projecthaystack.HDict.getStr(HDict.java:82)\n  at org.projecthaystack.server.HisReadOp.onService(HStdOps.java:314)\n  at org.projecthaystack.server.HOp.onService(HOp.java:48)\n  at 

Brian Frank Thu 23 Apr

The documentation the hisRead operation is here

If using a GET, it would be ?id={id}&range={range}

Ramamurthi Iyer Thu 23 Apr

Hi Brian,

I was able to use the it the same way earlier today and able to do run the get successfully? Thanks for update.

Thank you!

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