Cable Quality; With Internal Devices; With External Devices - Tandberg Data DAT 160 User Manual

• For single-ended SCSI with Ultra devices the maximum permissible
length is 3 meters for four or fewer devices, and 1.5 meters for more
than four devices.
• For LVD SCSI the maximum length for a single device is 25 meters. For
multiple devices, the maximum combined internal/external length is 12
meters.
• If you have a combination of LVD and SE devices on the bus, the max-
imum cable length reverts to the SE specification. See note on SE and
LVD interfaces for more information.
• For best performance, keep lengths to a minimum, but avoid very short
overall lengths (less than 0.5 meters).

Cable quality

• It is important to use good quality cables. Generally speaking, cable
quality affects performance and reliability. This is particularly true for
external, shielded cables.
• Look after your SCSI cables. In particular, take care when connecting
or disconnecting not to damage the high-density connectors. Avoid putting
excessive twists in external shielded cables, as this can cause premature
failure.

With internal devices

For DAT internal devices, you need a SCSI ribbon cable with the correct
termination. The drives have a 68-pin wide, high-density SCSI connector.
A suitable cable is supplied with the tape drive. If you are using an DAT
drive on an internal bus with other peripherals that run at Ultra160 speeds,
it is important that a 68-pin LVD-compatible ribbon cable is used. Do not
connect your tape drive to lower-rated SCSI or to narrow SCSI.

With external devices

The cable provided with all DAT external tape drives and autoloaders will
attach to a computer with a wide, very high density (VHD), LVDS SCSI
connector.
If your server or host bus adapter is equipped with a high density (HD) wide
SCSI connector, you will need to order a 68-pin VHD-to-HD converter or
68-pin VHD-to-HD cable.
August 2009
SCSI cables
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