Updating value automatically in Data Access View

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JDRL
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Updating value automatically in Data Access View

Post by JDRL »

Good afternoon,

I am new at UAExpert and I was trying to receive a variable from a machine redirected by the server, I can tell that the reception has been successful, the client in UAExpert receives the value of a X Coordinates variable.

However, I realise that if I update the variable in the machine, the value is updated but it is not displayed on the "Data Access View", that is, I have to refresh the value by pressing the two orange arrows on the "Attributes" window and I would be able to see it there at the "Value" field (see attached picture), or drag again the data from the "address space" to the "Data Access View" and get it duplicated with the updated value.

I would like the "X WorkCoordinates" on the "Data Access View" display to be updated automatically in real time, so there is no need of updating it manually. I would be grateful If you could give me a hand.

I attach a picture on the following link:
https://ibb.co/tQXHpNr

Image

Thank you so much in advance :D ,

JD

kemmerichan
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Re: Updating value automatically in Data Access View

Post by kemmerichan »

Hello JD,

If you drag the variable into the Data Acess View window, you can watch the value change without refresh.

JDRL
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Re: Updating value automatically in Data Access View

Post by JDRL »

Hello kemmerichan,

Thank you for your response. I guess it is supposed that when I drag the variable from the Address Space (on the left side) to the Data Access View (window in the middle) y could appreciate de field "value" and that it should to change everytime I change it in the machine. But when I change it in the machine, the "Value" field in the Data Access View is not refreshed automatically, I have to drag the variable manually again with the same procedure to appreciate the change as the value does not change anymore (see link of the picture in my previous post).

I do not know if the normal thing is that it should change automatically, or whether it is necessary to add an event or maybe the "Node Id" field cannot be string type as it is seen in the picture.

Regards,

JD

JDRL
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Re: Updating value automatically in Data Access View

Post by JDRL »

Hi,

I have been observating this X coordinates variable by dragging it to the Data Access View many times. I have found out that the "Source Timestamp" and the "Server Timestamp" are different.

A picture of this situation can be checked by this link:
https://ibb.co/jyF8s3b

As I can see, the "Source Timestamp" is the time when the machine switched on, and the "Server Timestamp" is the time when I dragged the variable to the Data Access View. However, because I saw some tutorial doing all this by python (I am working on C# and C++), I think both times should be equal and change at the same time whenever the value is refreshed (automatically), and that doesn´t happen in my case.

Could this be a possible reason for the data not being refreshed automatically?

Greetings,

JD

kemmerichan
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Re: Updating value automatically in Data Access View

Post by kemmerichan »

On my system the value changes automatically. I have tested this once with a signal that changes with 0.5 Hz. The source timestamp and the server timestamp are always the same and continue to run synchronously.
Maybe, there is something wrong at the Server. My server is an Simatic ET200SP CPU.

JDRL
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Re: Updating value automatically in Data Access View

Post by JDRL »

Hello kemmerichan,

I see that source and server timestamps must be the same, that doesn't happen in my case.

There could be something wrong when programming with source code for the UA Server, that's the most probable, but I still don't know how to fix it.

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Support Team
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Re: Updating value automatically in Data Access View

Post by Support Team »

Hello,

the assumption is correct, just drag&drop the Node into the DAView and it will update automatically.
The "refresh" button in the Attribute-Window on the right side is performing an explicite "Read" on all the attributes of the selceted node (which includes the value attribute).

It seems that the Server is doing wrong with subscription updates. Which implementation is the server based on? An updated value in the UA world means the DataValue is updated, the DataValue is not only the value istself, but includes the timestamp and status.

For analyzes you should check the LogWindow of UaExpert and watch for error trace.
Best regards
Unified Automation Support Team

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