SCSI termination ?

[HarryBeanbag]

I have recently Bought a SCSI hard drive set-up, and am now confused about SCSI termination. I have googled on it but am still wondering. Is it neccesary to ALWAYS terminate the scsi bus? I am only planning on using one drive on a single channel so do I need to buy a cable w/ 3 connectors and an active terminator?

If someone could point me towards and understandable scsi explaination I would appreciate it, or for the quick answer here is my paticular Controller card and this drive

 

[alkemyst]

The drive should have a termination jumper....that should suffice.

If you do have problems then a special cable is necessary....usually this is only needed with a lot of drives or a long chain.

 

[HarryBeanbag]

Thanks for the quick, consice response. I'm one step closer to being up and running.

 

[bacillus]

I have googled on it but am still wondering. Is it neccesary to ALWAYS terminate the scsi bus?

the last device on the cable must be terminated.
if you're going to be using a U160 hdd then you'll have to put an active terminator at the end of the cable as the hdd itself will not have a termination jumper!

 

[SCSIRAID]

To be completely correct... both ends of the SCSI bus must be terminated. The 29160 card has auto termination which will terminate the bus at the card end while the other end of the cable (as bacillus said) needs to have an active terminator.

 

[HarryBeanbag]

Ok, I got conflicting responses;
Alkemyst said "The drive should have a termination jumper"

but Bacillus said "using a U160 hdd then you'll have to put an active terminator at the end of the cable as the hdd itself will not have a termination jumper! "

I found this on IBM's site
"Since LVD drives do not provide termination, you will need an active in-line terminator or a device that provides active termination at the end of the chain."

Since the drive I have order is ultra160 and LVD I think I will need an active terminator on the drive end of the cable only, correct?

 

[bacillus]

Since the drive I have order is ultra160 and LVD I think I will need an active terminator on the drive end of the cable only, correct?

yes!

 

[alkemyst]

Yeah I messed up....so much chaos here trying to keep my g/f in the country.

The U160 / LVD drives will need an actively terminated cable. Check out www.cablesgroup.com first, I am not sure if they will have exactly what you need, but they have proven to be cheap on cables. Also get something to 'grow' into, a couple extra bucks now will save you alot of headache down the road.


I believe the U160 / LVD setup you have is not really limited by any realistic cable lengths you can fit into your case like the U2W can be.

Good choices.

 

[eflat]

How about cdrom drives? Will they usually have a built in termination jumper?

 

[bacillus]

Originally posted by: CitizenDoug
How about cdrom drives? Will they usually have a built in termination jumper?

yes, should have a termination jumper at rear of drive!

 

[alkemyst]

All SCSI chains (even if just one drive/device) must be terminated...the built in jumpers on most drives are enough to do this, however, if you are using U160 (or better) drives you need an active terminator.

These can be built-in or plugged into the cable.