Operating instructions

3-2

SCSI REFERENCE 1012975

CHAPTER 3—IMPLEMENTING SCSI OPERATIONS

3.2 RESETTING THE AUTOLOADER AND TAPE DRIVE

You can use any of the following methods to reset the autoloader and its tape

drive.

 Power-on reset. Power the autoloader off and back on again to reset the

autoloader and its tape drive.

 Operator panel reset. When you select Reset autoloader from the

Diagnostics menu and press , a confirmation screen appears. Press to

begin the reset (or to cancel the reset). The autoloader resets and

performs a cartridge inventory. When the reset is complete, the Home

screen appears.

 SCSI bus reset. Send a RST pulse on the SCSI bus for a minimum of 25 µsec.

A SCSI bus reset immediately clears all devices from the bus, resets their

associated equipment, and terminates all pending I/O processes.

 SCSI Target Reset message. Issue a Target Reset (0Ch) message to the

autoloader or a tape drive to reset the individual device. A Target Reset

message clears the device from the bus, causes all commands sent to it to be

cleared, and terminates all pending I/O processes. Note that a Target Reset

message received by the autoloader does not reset the tape drive or the SCSI

bus.

Note: If the autoloader is performing a cartridge move operation when it is reset,

it completes the move operation during POST.

3.2.1 EFFECT OF POWER-ON RESETS

The power-on reset has the following effects:

 The checksum of the flash code is validated.

 All autoloader parameters are reset to their default or saved values.

 The autoloader performs its power-on self-test.

 A power-on reset of the autoloader also resets the tape drive and causes

them to perform their power-on self tests.

After a power-on reset, the autoloader will respond on the SCSI bus within

15 seconds.

! !

! Important

When active termination of the SCSI bus is used, powering off the

device that supplies terminator power for the SCSI bus leaves the

RST line in an indeterminate state (either reset or not, depending

on the voltages). In this situation, it may be impossible to

communicate with the autoloader.