trouble with queryPropertyHistory

[MA_10062204]

Hello, i need to get a single value and timestamp from the service, and i have trouble understanding the documentation - as in I can't seem to get it to work.

The properties the service gets are as following:

The output should be an infotable containing "timestamp" and "Modbus_Demobox2_kW", which is defined in a datashape.

My main Problem is filtering right -- what do I have to do?

[nmutter · Accepted solution]

I think you are searching the service called "QueryNumberPropertyHistory" where you can pass in the propertyname "Modbus_Demobox2_kW" and maxItems set to "1." and oldestFirst "false"

[MA_10062204]

Well, it worked. It wasn't really what I was asking for, but I made it work. So, thanks I guess

[nmutter]

Maybe I did not understand the question correctly then. I understood you wanted a service which will return "timestamp" and "value" of a property.

There is also service GetPropertyValuesVTQ (returns Value Time Quality for ALL properties of the thing), or GetNamedPropertyValuesVTQ where you can specify which properties you want.

I was searching for a GetPropertyVTQ(propertyName) but such a service does not seem to exist. So I thought the proposed solution with maxItems=1 would be easiest.

What were you searching for? Maybe you can add some code and what you would expect it to do so I can better understand.