Corrected from:
Controller 3200C V3.19
Panel Controller p500 V3.19
Response of the new version
When using the function block L_SMC_Multiturn, the homing information is not reset.
However, it can still happen in case of a slave error that the process input image is not valid (correct). In this case, it may be necessary to check the validity of the process image of the EtherCAT slave in the PLC logic using the 'WcState' property.
What happens?
- The process input image of an EtherCAT slave corresponds to the process output image of the EtherCAT master for the corresponding slave. The process input image is therefore invalid.
- The WorkingCounterError (the output oDiagnostic.udiCycWorkingCounterErrorCounter of the function block L_ETC_GetMasterDiagnostic) increases. The EtherCAT slave concerned leaves the EtherCAT status 'Operational' a few cycles later due to an error or is no longer available.
- When using the function block L_SMC_Multiturn, the homing information is reset.
When does this behaviour occur?If the EtherCAT master setting 'LRW' is set (master tab, option Use LRW instead of LWR/LRD active), the output data and the input data of an EtherCAT slave are packed into one telegram. If a slave cannot process the process data - due to a slave error or when the slave is switched off - the output data of the slave are sent back to the master as input data (the slave does not insert its data into the telegram). The EtherCAT master copies the data originally sent to the slave into the process input image. This means that the process input image contains invalid values.
Which products are affected?
Controller 3200C from V3.6
Panel Controller p500 from V3.6
Short-term measures:
Deactivate the option Use LRW instead of LWR/LRD (Master tab in EtherCAT_Master) or
Check in the PLC project whether the WorkingCounterError (WKC error) increases. To do this, evaluate the output oDiagnostic.udiCycWorkingCounterErrorCounter of the function block L_ETC_GetMasterDiagnostic. If the output increases, there is a WKC error and the input process image of the EtherCAT slave must not be used.
- Always evaluate the EtherCAT status of all EtherCAT slaves.
Evaluation/recommendations:
If the default setting of the EtherCAT master is used, then the option Use LRW instead of LWR/LRD is active and in the event of an error of an EtherCAT slave this function restriction may occur. In this case, the process input image of this slave is invalid in the controller. The evaluation of the EtherCAT status of the slaves alone is not sufficient to check the validity of the process image, since the status is only updated a few PLC cycles after the occurrence of the function restriction.
Apply the short-term measures described above.
Automatic Translation
