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SCSI Interface Overview
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only power on situations, but also how cleaning tapes, incompatible tapes and
firmware tapes are handled.
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Powering on or power cycling while the tape is inside the drive.
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Cleaning tape has finished the cleaning cycle.
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Unsupported data tape has been loaded.
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Unsupported cleaning tape has been loaded.
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Microcode download from a firmware tape.
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Microcode download via the SCSI WRITE BUFFER command while a tape is
loaded.
2.7.10.2
Host Unload Override
The LTO drive has a Host Unload Override mode that may be accessed via a Mode
command to Mode Page 21h. The purpose of the Host Unload Override mode is to
allow the Library system to set the drive into a mode where the drive will not eject
the cartridge should the host issue a SCSI Unload command. A SCSI Unload
command from the host will cause the tape to be unthreaded but the cartridge will
remain in the drive. The Library Unload command will cause the cartridge to be
ejected.
2.7.10.3
Primary Port Control
When a tape drive is installed in a library, it may be desirable for the primary port to
be disabled when the drive first powers on. This prevents any hosts from sending
the drive commands before it has been configured by the library. The power-on
state of the primary port can be configured via the Port A Power On Disabled bit in
the Interface Control mode page (22h). If the bit is set at power on, the primary port
will be disabled until the library enables it via the ADC device server presented on
the ADT port. If no cable is attached to the ADT port connector, then the primary
port will be enabled regardless of the setting of this bit.
2.7.10.4
ID Modification
Tape libraries require the ability to change the primary port selection ID of installed
tape drives without opening the library and changing address jumpers. The
automation device configures the ID via the ADC device server presented on the
ADT port.
If the address jumpers are changed and the drive’s power is cycled, the drive will
respond to the new address on the jumpers.
2.7.10.5
ADI Bridging
An automation device (tape library or autoloader) containing an LTO drive can
receive its SCSI commands via the LTO drive. This function is called “ADI Bridging”
Summary of Contents for LTO 4
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