WinCC OA-drivers - SYS/WARNING - IOTransCont, outputTrans, Outstanding transaction for “DPE-ID”

Enclosed you'll find the explanation for a log-message which can occur during runtime. The log-message is written to the PVSS_II.log-file.

PVSS00s7 (1), 2012.07.03 06:02:58.522, SYS, WARNING, 54, Unexpected state, IOTransCont, outputTrans, Outstanding transaction for: (Type: 241 Sys: 1 Dp: 22117 El: 21 : _original.._value)

Log-message with symbolic names:

PVSS00<drivername> (1), <TIMESTAMP>, SYS, WARNING, 54, Unexpected state, IOTransCont, outputTrans, Outstanding transaction for: (<DPE-ID> : _original.._value)

This log-message can occur when using _address-configs with an “in/out”-address.

If the datapoint-element is set to send a command to the PLC the transition bit (internal bit used at the driver) is set to 1/true and the WinCC OA-driver is waiting for the response from the PLC.
When the value from the PLC is received the transition bit is set to 0/false.
If the datapoint-element is set again within the timerange “IOTransitionTimeout” (config-entry) before an answer from the PLC for the previous command was received the log-message is written.

When using in/out-adresses and a lowlevel old/new-comparion is configured at the_address-config the answer from the PLC will be discarded, if the PLC sends back the same value. When the next command to the PLC is set within the IOTransitionTimeout the log message will occur.

The given <DPE-ID> information can be converted into a DPE-name using the CTRL-function dpGetName() to get the information which DPE and _address was affected.

To get detailed information for the "_transition"-attribute and the IOTransitionTimeout-config entry please have look at the WinCC OA online-help: "Drivers --> Driver specific functions --> Bidirectional peripheral communication".