A5838A Dual SCSI Dual 10/100 Card Terminators

[Frank Fitch_1]

I have a system with an A5838A combo card. The two SCSI adapters on the card are unused. I seem to vaguely recall reading somewhere that these adapters are self terminating. Is this right or do I need to terminate?

I realize that if I attach SCSI devices to either adapter, then the last device in the chain requires termination, but what if there are no devices.

Thanks in advance....... Frank

[Jeff Schussele · Accepted solution]

Hi Frank,

IF there are no external devices, no terminators are required on the external nor internal ports. I *think* there are jumpers on the board that define this & I'll check one of mine tomorrow. But the default is generally to self-terminate the side w/o devices attached.
Rule of thumb is that IF there are devices on *just* one end, i.e. either internal OR external - not both - then you terminate the side with devices & not the other. OR if devices are on both sides - you terminate both sides.
I'll get back to you.

Rgds,
Jeff

[Alexander M. Ermes]

Hi there.
If the SCSI card is not connected to a device,
there is no need to terminate. As soon as you plug in devices, you have to terminate either the devices or the cable.
Rgds
Alexander M. Ermes

[Frank Fitch_1]

Thanks for the fast responses --- much appreciated !!! Frank

[Jeff Schussele]

Hi Frank,

OK - I dug up my docs on the 5838 & there are indeed jumpers on the board for the SCSI.
Labeled JA1 (SCSI B) & JA2 (SCSI A).
Jumper ON => autotermination is OFF

You *only* need to disable autotermination when the HBA is in the middle of the bus - i.e. there are *both* internal and external devices attached.

BTW - the part # for the doc is A5838-90001

HTH,
Jeff