A POU is called from many locations in the project. If there is an error detected, you must determine which program location the function block was called from.
A program must be able to detect the error. If an error is detected, the function FC_SysUserCallStack() is to be called up. An optional parameter, i_diValue, can be transferred. The diagnostic message 026 "User exception" is triggered for the message logger. The parameter i_diValue is logged in the ext. diagnostic. In addition, an exception error is created that contains the IEC 6-1131 tasks. The call up task is stopped exactly at the call-up point and displayed in EcoStruxure Machine Expert. The call-up interlacing is indicated via the call-up list. The exception error of the type 'VendorException' is also entered into the message logger and the diagnostic parameters as diagnostic message (DiagClass = 4; DiagCode 1073746179 = 16#40001103; DiagExtMsg = 8192).