7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
1
Specifies a logical unit number (for bit 4 = 0)
Specifies a process incorporated in the target (for bit = 1)
(Reserved)
(Reserved)
1: Processed by the target alone
0:Processed by the target and logical unit
1:The initiator does not permit disconnect
0:The initiator permits disconnect Bit for distinguishing from other messages
This scanner does not support the target>incorporated process function. Therefore, if a 1 is set in bit 5, the IDENTIFY message is rejected with the MESSAGE REJECT message.
(9)DISCONNECT (X©04) : MESSAGE IN phase (target Æ initiator)
Sent from the target to the initiator, this message indicates that the current link will be disconnected but it will later have to be reconnected to complete the current process.
After successfully sending the DISCONNECT message, the target releases the BSY signal to switch into the BUS FREE phase. The target assumes the message transfer to be successful if it detects that the ATN signal as well as the ACK signal from the DISCONNECT message are false.
This scanner issues the DISCONNECT message if bit 6 (DiscPriv) in the IDENTIFY message from the initiator is 1 and if a long time is expected for processing in the scanner (e.g. , when the scanner receives the READ command and prepares data to be transferred to the initiator).
The link will not be disconnected if bit 6 in the IDENTIFY message is 0. Also, it will not be disconnected if the IDENTIFY message is not issued in a given command sequence. For disconnect to occur therefore, bit 6 in the IDENTIFY message must be set to 1.
When performing the disconnection during data transfer, this scanner sends the SAVE DATA POINTER message before sending the DISCONNECT message so that the data pointer is saved.
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