4-16
Menu Operations
500300 Rev. U
4.5.6.1
Write Ident Function
The
WRITE 6250 (3200, 1600) IDENT
functions allow you to initialize a blank tape (or to
reinitialize prerecorded tapes) to a recording density of his choice. These functions
will write the selected ID burst, erase 50 feet of tape, and rewind the tape back to
BOT. The tape will then appear as a blank tape with an ID burst, and the ID burst
will cause the tape drive to set the desired operating density when the tape is read
from BOT. Drives will not write ID bursts for unsupported densities.
4.5.6.2
Security Erase Function
The
SECURITY ERASE
function will completely erase a tape from BOT to a point
sixteen feet beyond EOT, including the ID burst. The tape must be at BOT before
invoking the function. The function takes less than 3 1/2 minutes for a 2400-foot reel
of tape and may be aborted at any time by pressing or EXIT.
4.5.6.3
Verify Media Function(341X only)
The
VERIFY MEDIA
function allows you to verify the suitability of any reel of tape for
use on the drive by writing the maximum density on all nine tracks of the tape from
BOT to EOT without any gaps. While writing, it monitors the amplitude of the
signals of all nine read channels and when one or more channels fall below the
normal threshold, a dropout is counted. Single-channel and multiple-channel
dropouts are counted separately. Multiple-channel dropouts indicate a larger defect.
When writing a normal data tape, the host is responsible for rewriting a block
whenever a dropout is detected (you may configure your SCSI drive in the Menu
mode to perform the rewrite automatically.) Therefore, almost any number of defects
can be tolerated; however, the quality of the tape and its suitability for long-term
storage is indicated by the number of dropouts detected during this test. More than
ten dropouts indicates considerable wear or dirt on the tape, and will also cause
more rewrite operations, resulting in tape repositioning and a lower data throughput
rate.
The dropout counters stop counting at 255, but the function continues until EOT:
1.
While the function is running, the display will indicate the number of dropouts
detected.
2.
When EOT is detected, the tape will be rewound, but the dropout counts will
remain displayed until any switch is pressed.
When display line two is cleared, the operation is complete and you may scroll the
menu with the and switches. The function takes about five minutes for a 2400-
foot reel of tape and may be aborted at any time by pressing .
The Verify Media function is not available on the 3402/3404 tape drives.
