PVSS00valarch - PARAM/WARNING - ArReadRequestInfo, addGroupResult, Query consumes too much time, allowed maximum: 30 - query interrupted

Enclosed you'll find the explanation for a log-message which occurs when a limit for a historical query is reached. The log-message is written to the PVSS_II.log-file.

PVSS00valarch(7), 2011.10.06 08:47:03.000, PARAM,WARNING, 54, Unexpected state, ArReadRequestInfo, addGroupResult, Query consumes too much time, allowed maximum: 30 - query interrupted

Log-message with symbolic names:

PVSS00valarch(7), < TIMESTAMP>, PARAM,WARNING, 54, Unexpected state, ArReadRequestInfo, addGroupResult, Query consumes too much time, allowed maximum: <timeout> - query interrupted

This log-message describes that the limit queryTimeout (config-entry for the [valarch]-section) was reached. The actual limit is displayed at the log-message.
The query is stopped and the error is reported.

If the function getLastError() is used in the script where the function to read the historical data was started you’ll get the following error. When using the function throwError() the error is written to the PVSS_II.log-file.

E.g. the user-interface with number 1 was trying to read the values:

PVSS00ui (1), < TIMESTAMP>, PARAM,SEVERE, 54, Unexpected state, HistQuery, constructAnswerMsg, archive request returns an error (query error)

If this error is reported please try to find out which historical query was started and afterwards check if this query should be allowed or not. The maximum value has to be defined in discussion with the users operating the plant.

Please do not increase the value for the config-entry to a very high value (e.g. 600) or set it to 0 (no limitation).

The limitation for queries is part of the system stability functions in WinCC OA. For details please have a look at the online-help, search for the keywords “Error tolerance” and “stability”.