Application programs can issue APPCCMD CONTROL=SEND, QUALIFY=ERROR when either sending or receiving data on half-duplex conversations. Application programs can issue this macroinstruction only when allowed to send data on full-duplex conversations. If an application program is sending data, and a complete logical record has not been sent, a return code of PROGRAM_ERROR_TRUNCATING (X'0038' in RCPRI) or SERVICE_ERROR_TRUNCATING (X'0044' in RCPRI) is reported to the partner LU. The partner LU will not receive the remainder of the record being sent. Reporting this error is the orderly way for an application program to stop sending a logical record.

If a complete logical record has been sent, return codes of PROGRAM_ERROR_NO_TRUNC (X'0030' in RCPRI) or SERVICE_ERROR_NO_TRUNC (X'003C'in RCPRI) are reported to the partner.