How to get the data from the channel value of OPC UA Server Bytestring data type

Dewesoft OPC UA Server send data to the client by the field "Value" of a channel, but the value is in ByteString format, so the question is how to get the real data from the data type ByteString？Is there any document for it？

Dear Foiray Zhao,

Thank you for contacting us, but we need some more data.

Which version of the OpcUaServer plugin do you have? The latest version does not support ByteString channels. Most scalars are converted to double. The last channel value can be read through the CurrentScaledValue node. Could you specify which node you are trying to read (a screenshot of this node from UA Expert would be best). The node "Value" does not seem to exist. However, there is a node called "Values" that points to the circular buffer of the Dewesoft channel. If you are trying to read this node, it is easier to read the CurrentScaledValue directly.

Best regards

Eva

Dear Eva，

Thanks for your reply.

My  OPC Ua Server plugin version is 3.2.6.

It's my mistake, it should be the node "Values".

Yes, the node "CurrentScaledValue" is more easier to be read for the 3rd OPC UA client, but I think the value is already be "scaled" , we want to read the original values(the data in the circular  buffer), so we try to get the info from the node "Values".

So another question is , does the "CurrentScaledValue" include all the data that the sensor reported to the Dewesoft DAQ(SIRIUS XHS) ?

the detailed information I marked in the attachments.

Best regards

Dear Foiray Zhao,

the best solution to get raw values, is to create Unlinked sensor in Ch. setup - Analog in as shown bellow.

and than set scaling to RAW.

Use Math to create a new scaled channel if you also need it.

Best regards

Eva

Dear Eva,

I will introduce the background of my question first, it may helpful to understanding what we need.

We already deploy the Dewesoft DAQ and dewesoft software on the production system, it works well .

The Dewesoft software deployed in a PC, and if we want obtain the test data for further analysis, the only way for us is export it to a file and copy to another PC manually. It's impossible to get the real time data for analysis based on current solution.

The requirement of us is "Obtain the real time test data from Dewesoft software and transfer to another PC by the network for further analysis."

So we bought the OPC UA server plugin license from Dewesoft and try to get the data by develop our OPC UA client.

Our manager will only allow us to change the OPC UA server configurations, and forbid change any other configurations on the Dewesoft software(any changes on the production system is strict restricted)

After we carefully analysis, we found that dewesoft OPC UA server will send data to the client by the node "CurrentScaledValue" and "Values".

For node "CurrentScakedValue", the data type is "double", and very easy to be understand .But there is no any detailed explain on the "CurrentScakedValue" in the document

"OPC-UA-Server-Manual". if we config the “sampling rate“ to 100HZ (100 test data per second) for a sensor, how many data we can get from the “CurrentScakedValue” per second? 100 data? 10 data or less, could we config it or not, and how to config?

For node “Values”, the format is Bytestring, we think it include all the test data info, but there is still no any document to explain the detailed format of it, no any explain how to obtain the test data from the Bytestring format. The project had blocked by the "Bytestring" for several weeks, so I ask for help in the support forum for solution advise.

Best regards.

Dear Foiray Zhao,

current version of OpcUaServer v4.0.0 no longer supports buffered mode. This means that the 'Values' node does not function and will be removed in the future. However, we have added functionality for OpcUaClient v4.0.0 to read the CurrentScaledValue node via the MonitoredItem mechanism. In this mode, it is possible to sample the CurrentScaledValue node at a sampling frequency of up to 1000 Hz. In this case, it is necessary to update both the OPC UA client and server to v4.0.0. If higher sampling frequencies are required, NET is a better solution than OPC UA.


Best regards
Eva