Reference Guide

Chapter 4 SCSI Commands

READ Command (08h)

DLT-S4 Interface Reference Guide 233

Table 128 PREVENT /

ALLOW MEDIUM REMOVAL

Command Descriptor Block —

Field Descriptions

READ Command (08h) 4

The READ command transfers one or more data blocks from the medium

to the initiator starting with the next block on the tape.

Figure 117 READ Command

Descriptor Block — Data

Format

Field Value Description

Preven

0 Clears the Prevent state corresponding to the initiator. When all initiators have

cleared their Prevent states, the Eject button and

UNLOAD commands are enabled

both for the drive and for any attached tape automation system, library, or loader.

By default after power-on or a logical unit reset, the

PREVENT MEDIUM REMOVAL

function is cleared.

1 Effectively disables the Eject button on the drive’s front panel or a

LOAD UNLOAD

command from unloading the medium. If the drive is in a tape automation system,

any

MOVE MEDIUM command is prevented from removing a data cartridge.

Bit

7 6 5 4 3 2 1 0

Byte

0 Operation Code (08h)

1 Reserved SILI Fixed

2 — 4

(MSB)

Transfer Length

(LSB)