If the sense data included (SDI) indicator is on in the user RH field for SEND OPTCD=USERRH, then the associated 4 bytes of sense data are obtained from the SSENSEO, SSENSMO, and USENSEO fields of the RPL. This is applicable to sending requests (exception requests) and responses (negative responses), both FM data and DFC. If the SDI indicator is on for an FM data RU, the RU consists only of those 4 bytes of sense data. For a DFC RU, VTAM® appends the DFC request code to the sense data. If the SDI indicator is on, the data length (RECLEN or the fourth word of the corresponding buffer-list entry) must be 0. If the length is not zero, the SEND operation fails with (RTNCD,FDB2)=(X'14',X'1E'). The data pointer (AREA or the third word of the buffer list entry) is ignored.

When sending a negative response using OPTCD=USERRH, the application program must ensure that both the SDI and response type (RTI) indicators are turned on. For OPTCD=NUSERRH, VTAM automatically turns on the SDI indicator when sending a negative response (for example, SEND STYPE=RESP,RESPOND=(EX,FME)).