S7+ Driver not setting invalid bits when unable to resolve symbolic address

[emaddocks]

Hi,

We are using WinCC OA 3.17 Patch 9 on Linux RHEL 8.2.

When using an invalid reference address for a DPE we don't see the invalid bits get set in the para. We do however see the driver reporting the invalid address:

Code: Select all

WCCOAs7plus  (2), 2021.08.09 13:02:09.781, PARAM,SEVERE,     72/s7plus, Cannot resolve symbolic address DB_AI_HMI.AEN_AHU_01019_PSX_01.ParHmiDs.parHiHiDlyTm for connection _AEN_BMS_PLC
WCCOAs7plus2:WCCOAs7plus  (2), 2021.08.09 13:02:25.003,	conn,	connError check on connection with name "_AEN_BMS_PLC"

If we configure the DPE as In/Out and send a value the S7+ driver then sets the invalid bits as expected. However if the DPE is left as input and polling the invalid bits never get set even though the driver log reports the SEVERE error above.

Is this a known bug or are there some config settings we need to apply? We have selected the 'Set invalid bit' on the relevant S7+ connection.


Cheers
Eric

[leoknipp]

Possibly when using In/Out addresses the invalid bits are set by another function in the driver.
I am not sure if the driver should set all elements invalid which have an invalid/unknown address. As far as I know this is not done in the drivers.

Best Regards
Leopold Knipp
Senior Support Specialist

[emaddocks]

Thanks for your reply.

So should the driver set the invalid bit of a DPE if it has an invalid/unknown address when configured as an Input and Polling every second?
We only see an error come up in the log viewer. The DPE in the para remains 'valid'.

[gruzdev.ds]

Hi,

has anybody solved this problem? We also got this... We tried to check all configs of _addess and _original, but no one shows the wrong symbolic address error, we see it only in Log Viewer.

[leoknipp]

I checked the code again.
For me it looks like only elements with a valid address are set invalid if the PLC connection is lost.
There is no functionality which sets items invalid with an incorrect configuration.

Best Regards
Leopold Knipp
Senior Support Specialist

[emaddocks]

Hi Leopold,

Is this something that ETM plan to fix in a future version of the S7+ driver?

I know that you should ensure your para configuration always matches the PLC but I also know that this is not a perfect world and PLC or para changes will occur in the future. If an address is removed from the PLC there is no immediate knowledge of this as the invalid flag will not be activated. However if the same thing occurs with the standard S7 driver the invalid flag is set.

Should the S7 and S7+ drivers not behave in the same way for the same incident (invalid PLC addresses)?

I'll also raise this with Siemens to see if they plan on updating the driver.

Cheers
Eric

[mplatz]

The invalid bit is not set in the event of configuration errors.
However, efforts are being made to implement this functionality in the future.

[andrea.spinelli]

Hi all,

I found the same issue on 3.17 P028.
I set correctly a S7plus connection to a SIEMENS CPU 1515SP. When I put the CPU in stop mode by TIA portal or by button on board, the operating state ,on the state detail, changes correctly in Stop.
In the para, checking my DPE (DWORD set as input), with the config _default and the checkbox "if original value is invalid...." selected, the original value and the online value are the same of the last value when the connection was up.
No invalid bit is set when I have invalid response from PLC.
I didn't try with a S7 driver because we only use S7plus drivers.
In my mind, I think if the plc is in stop mode, I must have an invalid value of the DPE. So online value and original value must be different.

[leoknipp]

Losing a PLC is connection is different to setting the CPU in stop mode.
This might be the cause why you do not see an _invalid bit set in your case.


Best Regards
Leopold Knipp
Senior Support Specialist