SCSI Interface Overview Page 9An Initiator that accommodates disconnect/reconnect can indicate this capability tothe tape drive during the Selection phase by asserting both its own Initiator SCSI IDbit as well as the tape drive’s SCSI ID bit (allows the tape drive to know with whichInitiator to reconnect). The Initiator must also assert ATN before exiting the Selectionphase (prior to releasing SEL) and send an Identify message out of C0h to the tapedrive. This sequence causes the drive to enter the Message-Out phase when theSelection phase completes.The first message sent by the host after the Selection phase is an Identify message.Under normal conditions, the first message sent by the tape drive after aReselection phase is also Identify. Under certain exceptional conditions, the hostmay send the Abort message or the Bus Device Reset message instead of Identifyas the first message.2.3.9 Message exception handlingMessage exceptions are handled as described in the following tables. The numbersin the tables identify the actions that the drive takes when an exception under theidentified conditions occurs. The actions are described following the tables.IN Phase during which ATN is raisedMessage Selection Identify Command Data in Data out Status NegotiateAbort (06h) 2 2 2 2 2 2 2BDR (0Ch) 11 11 11 11 11 11 11Identify(80h/C0h)12 7 7 7 7 7 7IDE (05h) 5 2 If Retry, 8,else 5If Retry, 8,else 5If Retry, 8,else 5If Retry, 8, ifStatus, 2, ifNo Status,5If Retry, 4,else 5Reject (07h) 5 2 2 2 2 2 1Parity (09h) 5 2 11 11 11 11 If Retry, 4,else 5NOP (08h) 5 9 9 9 9 9 If EOM, 9,else 4Negotiate 5 10 7 7 7 7 10Unrecognizedor illegal5 6 6 6 6 6 If EOM, 6,else 4IN Phase during which ATN is raisedMessage Save DataPointers(02h)RestorePointers(03h)Disconnect(04h)RejectMessage(07h)Identify(80h)CommandComplete(00h)IgnoreWideResidue(23h)Abort (06h) 2 2 2 2 2 2 2BDR (0Ch) 11 11 11 11 11 11 11Identify(80h/C0h)7 7 7 7 7 2 7IDE (05h) If Retry, 4else 5If Status, 2,if No Status,5If Retry, 4,else 5If Retry, 4,else 13If retry, 4,else 52 If retry, 4,else 5Reject (07h) 2 If Status, 2,if No Status,51 2 2 2 2Parity (09h) If Retry, 4 If Status, 2, If Retry, 4, If Retry, 4, If Retry, 4, 2 If Retry, 4,
