PVSS00event - PARAM/WARNING - EvQueryList, doQuery, Too many rows, query aborted

Enclosed you'll find the explanation for a log-message which can occur when a limit for non-historical event-queries is reached. The log-message is written to the PVSS_II.log-file.

PVSS00event (0), 2011.10.06 11:50:08.792, PARAM,WARNING, 54, Unexpected state, EvQueryList, doQuery, Too many rows, query aborted, SELECT '_online.._stime','_online.._user','_online.._manager','_online.._value','_online.._text','_online.._status' FROM '{*}' WHERE _LEAF

Log-message with symbolic names:

PVSS00event (0), <TIMESTAMP>, PARAM,WARNING, 54, Unexpected state, EvQueryList, doQuery, Too many rows, query aborted, <query-string>

This log-message describes that maximum number of lines/rows was reached. The limitation is made with the config-entry maxValueConnectCount (for dpQueryConnect-functions) and/or maxValueRequestCount (for dpQuery-calls) in the [event]-section.

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

PVSS00ui (1), <TIMESTAMP>, PARAM,SEVERE, 54, Unexpected state, Query not successful: Too many values

If this error is reported please 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. 1000000) 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”.