Requests received from the 3270 LU always specify no response, RESPOND=(NEX,NFME,NRRN). Requests sent to the 3270 LU can specify exception response, RESPOND=(EX,FME,NRRN), or definite response, RESPOND=(NEX,FME,NRRN). However, when sending data to a printer, or when sending a begin-bracket or end-bracket indicator, the application program must ask for a definite response. For all requests sent to the LU, only response type 1 is allowed; thus, NRRN must always be specified. The queued-response indicator is not supported by the PU 3270 PU type 1. You should specify it as RESPOND=(NQRESP) for the application program to work with all LU type 0 3270s.