Quantum Instruments DLT 7000 manual Reset Condition, Drive Message OUT Phase Response, SELECTION1

Models: DLT 7000

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SCSI Description

Table 3–7 Drive MESSAGE OUT Phase Response

 

 

 

ATN Signal True in Phase...

The Drive Enters MESSAGE OUT…

 

 

 

COMMAND

After transferring part or all of the command descriptor block

 

bytes.

DATA

At the drive’s earliest convenience (often on a logical block

 

boundary). The initiator continues REQ/ACK handshakes until it

 

detects the phase change.

STATUS

After the status byte has been acknowledged by the initiator.

MESSAGE IN

Before it sends another message. This permits a MESSAGE

 

PARITY ERROR message from the initiator to be associated with

 

the appropriate message.

SELECTION1

Immediately after that SELECTION phase.

RESELECTION2

After the drive has sent its IDENTIFY message for that

 

RESELECTION phase.

1Before the initiator releases BSY, provided the initiator asserted ATN

2The initiator should only assert the ATN signal during a RESELECTION phase to transmit a BUS DEVICE RESET or DISCONNECT message.

The initiator keeps the ATN signal asserted if more than one byte is to be transferred. The initiator can negate the ATN signal at any time, except it does not negate the ATN signal while the ACK signal is asserted during a MESSAGE OUT phase. Normally, the initiator negates the ATN signal while the REQ signal is true and the ACK signal is false during the last REQ/ACK handshake of the MESSAGE OUT phase.

3.6.2 Reset Condition

The tape drive responds to power-on and/or bus reset conditions as described:

All tape drive SCSI lines assert high impedance when the tape drive is powered off.

The drive does not generate any spurious signals on the SCSI bus when the drive is powered on.

Within five (5) seconds of power-on, and within 250 milliseconds (typically under 4 milliseconds) after a bus reset, the tape drive responds to SCSI bus selections and returns the appropriate normal responses. Tape motion commands are returned with Check Condition status, Sense Key of Not Ready, until the medium has been made ready.

Quantum DLT 7000 Tape System

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Quantum Instruments DLT 7000 manual Reset Condition, Drive Message OUT Phase Response, SELECTION1, RESELECTION2