Difference between active and passive termination?

[phamtastik]

Whats the difference between active and passive termination on an external HPDB 50 pin?

I need to get a terminator. I'm connect a 2910 adaptec card to an external scsi cd-rom exclosure that uses HPDB 50 pin.
Not sure what terminator to get.

 

[bacillus]

the external scsi cd-rom drive should have jumpers at the rear of the drive to terminate the drive if it's to be the last drive on that chain. no need for active termination here as that is usually reserved for drives on the lvd 68 pin connector!

 

[phamtastik]

I have a Yamaha SCSI burner terminated in the exclosure using just the terminated jumper, but when I try to use the drive it seems to keep resetting.
I mean the cd-rw keeps resetting. I would if its the 50 pin cable I'm using.

 

[phamtastik]

^

 

[Pariah]

You always want to use active termination. Passive termination uses a resistor to terminate the bus which was fine in the early days of SCSI. Active termination adds voltage regulators to the resistor making it far more reliable, and a requirement for any current SCSI peripheral SE or LVD. Some cd drives have active termination built in, Plextor's do, I don't know about Yamaha.

 

[CQuinn]

What Pariah said; plus, in my experience, even drives that have built in termination can
benefit from having a real terminator attached.