Regarding HDA Data and Timestamp values viewed in UA Expert Client does not match with the PYTHON OPC UA Client Response fetched from Siemens WinCC SCADA

[rajnishnationfirst]

Hi ,

I have developed a PYTHON OPCUA client to get data from Siemens WinCC SCADA .

The above Python OPCUA client fetched data for a TAG ( Archived ) for the below snapshot.

I queried using the above time and gets the data in the form of list having value , status and timestamp.

Also i used the UA Expert OPCUA client to view the same interval HDA data .

But the values doesn't gets mached against the timestamp values .

Response of Python OPCUA HDA cleint :

The same interval data viewed from UA expert doesn;t match .

Also is there any other OPC UA HDA Software based client to view the OPCUA HDA data ?

&

How to view the HDA Data from a OPC UA clients ?

Help from anyone from this group will be really appreciable for me to learn something new.

Thanks Rajnish Vishwakarma

[brubbel]

It seems there is an off-by-one shift between source timestamp and values in one of the two clients. That or the server does not send consistent results in those two history requests.

Most interesting, it would be useful to find which is the origin of that error.

1. Retest to see if the results are consistent between requests.
2. Look at the database of the server itself.
3. Run wireshark with opcua plugin to see which is the expected result. Disable encryption of course.

[duduyoyo]

See if this can help you.