Command Disconnection; Scsi Reset - Fujitsu M2488 Product Manual

M2488 PRODUCT GUIDE
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COMMAND DISCONNECTION

After receiving any command, the controller disconnects if disconnection is not inhibited by the IDEN-
TIFY message and the controller requires device activity to complete the request.
The controller reconnects to perform parameter or data transfers or to present command completion sta-
tus as required.
Multiple disconnect and reconnect sequences may be performed for a single READ or WRITE com-
mand as space or data becomes available in the buffer.
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SCSI RESET

The SCSI Reset is performed in response to a SCSI BUS RESET or a BUS DEVICE RESET Message.
The M2488 supports the SCSI hard reset alternative as follows:
• All SCSI I/O processes are cleared; i.e., the SCSI I/O process ends with the BUS FREE phase.
• Any back-end (tape motion or medium changer motion) operation in progress (rewind, synchronize,
erase, locate, space, unload, or write filemarks, etc.) is allowed to complete after all of the SCSI I/O
processes are cleared.
• Buffered write data is synchronized to tape.
• Buffered write data error is discarded.
• All SCSI device reservations are released.
• Power-on/Reset Unit Attention is generated.
April 1997 CG00000-011503 REV. A
TAPE UNIT SCSI COMMANDS
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