SCSI cable minimum bend radius?

[jimkberry]

I've got an Ultrium 960 that is working just fine and I'm able to send data to at 75MB/sec uncompressed continuously, but...

I have it and the host computer in an acoustical enclosure and I take occasional data errors that L&TT reports as possible cabling problems and it sure seems to me that when I leave the enclosure door open and unbend the SCSI cable (an HP-C2362B) things get better.

In the closed enclosure the cable takes a pretty tight - say, 1.5" radius - 180 degree bend.

Can anyone point me to a "minimum bend radius" spec for this or any similar cable? If I'm gonna modify the enclosure I'd like to have some target in mind.

Thanks,
-jim berry

P.S. This thread has been moved from general to Tape Libraries and Drives. - Hp forum moderatro

[Torsten.]

Not really a spec, but often said the radius for cables in general should be a "can of cola".

[jimkberry]

Thanks for the reply.

Personally, though, I have to say I'm not real comfortable with the idea of "one size fits all" cabling in general - the signals and signal levels are just way too different from cable to cable.

Although I'm still unable to find a bend spec for the sort of SCSI cable I've got here, I've changed my mind and am currently going under the impression that the problem is not the bend radius at all, but that the cable is kinking at the connector, since the bend is right up next to it. Kinks seem to be a much worse things than smooth but tight bends. So I've actually gone the opposite route, and built a wooden form to ensure a smooth 90 degree bend that is small enough that no force is exerted on the cable near the connector. So far it seems to be working fine.

As an aside, I have to point out how disappointed I am that there's no bend strain relief built into to either of the connectors on this cable. I mean, for a cable that lists for US$175 you'd think HP would have gone to a little more trouble.

-jim berry

[jimkberry]

So I'm going to take back sorta dissing the "can of cola" answer. :)

Even if I'm not sure I buy that a general case cable bend radius makes sense, being able to say "can of cola" when discussing the issue with others is really, really handy and immediately understood.

Here's what I heard back from HP support:

"We don't see any specification for how much you can bend a SCSI Cable. The basic care that needs to be taken when bending a SCSI cable is that it should not be bent more than its natural ability to bend. In short please don't force the cable to bend specially at the connection ends and certainly do not bend it to flatten it."

I'm not convinced, tho... I'll look around a while more and if I don't find anything I'll just mark the thread "answered"

-jim berry