Cabling is one of the most critical issues associated with good data-transfer on the SCSI Bus. For
many years suppliers have been able to sell inexpensive non-shielded cables into the market with
good success. The reason for this is that SCSI was originally very slow, especially in comparison
with today’s blistering SCSI speeds. Since data- transfers were happening so slowly you could get
away with inexpensive non-shielded cables.
Today, with the advances that have taken place in SCSI technology, the quality of the cables has
become one of the most important factors in determining both good reliability and high performance.
The following section will describe how to use the Diagnostic Cables to help increase performance
while maintaining a reliable data-transfer rate.
The Gold Diagnostic Cables have the quality materials and design needed for today’s high
performance specifications. Built into each cable is a diagnostic indicator that tells you if good
connection is being made by all the previous connectors in the SCSI daisy chain. This indicator also
tells you that the SCSI Bus is properly supplying termination power. Termination power is
necessary to guarantee reliable data-transfers.
How To Use The Diagnostic LED
Since this cable is capable of telling you if termination power is being supplied, you can use it as a
diagnostic tool to test both drives and other cables. The testing capabilities are limited. The cable
can only give you a limited amount of information about other products, but it is far better than
nothing and far cheaper than a $12,000.00 SCSI Bus analyzer.
To test cables you must have an external sub-system available and the host computer. Plug the
cable you are testing into the host and into the sub-system. Plug the Diagnostic Cable into the other
connector on the sub-system. Leave the power to the sub-system off. Now, turn on the power to
the host computer. The green LED on the Diagnostic cable should light. If it does, you know that
you are getting both proper termination power and good
conductivity in the cable you are testing.
To test if your drive is supplying proper termination and if the connectors are making good contact,
you simply plug the Diagnostic Cable into the suspect drive, power on the drive and check the green
LED. If the LED is on then the drive is supplying proper termination power and the connectors are
making good contact. If the LED does not come on, you have a problem in the drive. This is usually
a small fuse attached to the drive mechanism. This fuse is not easily removed, and the drive
mechanism should be sent back to the manufacturer for replacement.