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Quality Assurance Data

12 Apr 2022 08:51 - 12 Apr 2022 08:52 #10803 by support
Replied by support on topic Quality Assurance Data

OPC "Classic" had a concept called Quality.
OPC UA does not have that. I suppose that when you refer to quality, you actually mean StatusCode: .

The StatusCode is usually passed as part of DataValue, i.e. the actual value together with its timestamps, and the status: .

QuickOPC tries not to interfere wit anything inside the DataValue, including the StatusCode. That is, if you read a variable or subscribe to it, the server sends a DataValue, and we just convert it appropriately and deliver to you, but do not change the StatusCode.

OPC UA has guarantees so that whatever gets transferred between the UA server and UA client is not damaged. The StatusCode therefore does not refer to anything that has to do with OPC UA communication. It is determined on the server side (or the PLC).

Given that QuickOPC does not change the StatusCode either intentionally or unintentionally, questions about it should be addressed to whomever that generates the StatusCode - which is the server side.

Best regards
Last edit: 12 Apr 2022 08:52 by support.

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11 Apr 2022 10:22 #10801 by neilcooley
We have been using OPC UA for general data logging but now we are looking at logging more sensitive data and have a few questions.

With regards to OPC UA and the SDK, if the quality is GOOD does this mean that the SDK knows that there has been no corruption in the data value from the PLC?



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