Emerson Exchange 365

Re: Value not updating in deltaV reporter

Any idea on this....
In deltaV reporter/sytech, if we try to update values of certain tags within  RECENT 2 hours back  it is getting "#N/A" as logged value. But in trend the value is actually logged.

2. If we try to update the values of same tag after TWO hours ,it is picking the values perfectly. And again  if we try to update the tag with RECENT 2 hours back again,the values after 2 hours are showing #N/A.

We have done the following and found the observations as:

1. Downloaded the module: 
The value is getting updated
In reporter without #N/A,but after some time same the problem came again. It started showing #N/A .

2. We have COPIED the module and assigned to same controller and checked in the reporter,the value is updating perfectly with no #N/A.

3. We  have unassigned,deleted and assigned the module with same name again, the  problem was not got resolved.

4. We have checked the value in OPCWATCHIT,there was no error logged and is updating perfectly.

5. The problem we found is with pressure modules only.

Regards
Mithun Dan Thomas

On May 12, 2016 3:13 PM, "Mithun Dan Thomas" <mithohm@gmail.com> wrote:

Dear all,
We are facing a problem in our plant that, the value is logging continously in Continous Historian but it is not updating in DeltaV reporter,instead it is showing #N/A.
If we update the same time interval after 2 hours, the values are coming perfectly.
We have found that value is updating in deltav reporter after every 2 hours. Pl find the attached screen shots.
Advanced thanks for your help.

Regards
Mithun Dan Thomas

Mithun Dan Thomas

• 18 May 2016 12:00 PM
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2 Replies

• Steve Linehan

  

  • 18 May 2016 12:14 PM

  Have you reached out to sytech technical support. I have always found their tech support first class. You have to call the US office during their business hours but they have always been willing to support.
  
  It sounds like an issue with OPC timing out. The OPCWACHIT uses the same calls as the DeltaV graphics but WACHIT will use standard OPC calls as if it was an external system. Some please correct me if I am wrong but this has been my experience.

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• Andre Dicaire

  

  • 18 May 2016 4:04 PM

  It appears that your report is calling for historical data (Recent 2 Hours). If that is the case, then the status of current OPCWatchit values is not relevant as your data request, since you have to pull this past data from the historian.
  
  It would be useful to share the specific call you use in the report (syntax ) and to look at the actual data that should be returned, based on what you see in PHV. It would also be useful as a matter of course to share the historian configuration settings for the affected tags.
  
  Speculation section----
  
  What if you are over compressing this data in the historian and there is actually no value stored for a couple of hours, resulting in the call returning no data for up to 2 hours. Then, a value is stored and the report uses this to extrapolate (or interpolate) the data? The historian compression value may be too large for the variable and so all data is discarded, except for maybe the max time values that force a value to be stored. Providing the above information would answer this, and might reveal another explanation.

  Andre Dicaire

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