When an application program reports an error, it can specify a data area containing error information to send to the partner LU. This data area should contain a formatted error log general data stream (GDS) variable as defined by SNA architecture. VTAM® does no error checking, however, to ensure that it does. VTAM treats the error log variable as a normal logical record.

The ability to specify data when reporting an error enables application programs to implement the LU 6.2 option of logging error data in a system log. Because the application program records the data, it receives the error log data. The LU 6.2 architecture does not intend for this data to be passed to a transaction program.

The LOGRCV indicator in the RPL extension is set on when an error is reported to indicate that error log data follows. The application program should check this field when error return codes are received to determine whether such data will follow. Application programs receiving error log data must issue APPCCMD CONTROL=RECEIVE, QUALIFY=SPEC|ISPEC to receive the data. The APPCCMD CONTROL=RECEIVE, QUALIFY=ANY|IANY cannot be used to receive log data.

When an application program is informed that error log data is to follow, it must issue the RECEIVE macroinstruction even if the conversation is being terminated with a deallocation macroinstruction. Errors in receiving this data should be reported as protocol errors and the session terminated with APPCCMD CONTROL=REJECT.