External scsi bus on A3311A cabinets

[Robin Bussell]

Hi folks,

I'm trying to connect up an A3311A drive array cabinet to
a PC and need to know if the external bus is HVD or LVD, I have
a manual but it just says it's a "differential" bus... which would
lead me to believe it could be HVD but could anyone confirm or deny this for me?

Thanks,
Robin.

[A. Clay Stephenson]

Those JBOD's (A3311,A3312) could contain either SE-SCSI drives or HVD-SCSI drives (obviously not both of the same bus). If the drives have purple labels they are HVD; if the labels are yellow, they are SE-SCSI.

Your PC is almost certainly LVD but Adaptec (for one) does make an HVD interface.

[Robin Bussell]

Thanks for the info, The drives have purple labels so it looks like they're HVD (though the actual hdd inside the hot swap module is an LVD seagate model I guess the levels get switched by the chips on the ribbon connector to the backplane socket) I'll see if I can find a converter as the scsi card I have is LVD only.

Cheers,
Robin.

[A. Clay Stephenson]

Actually, there is a small interface board inside each module that does the HVD to LVD conversion. People have replaced those drives with varying degrees od success.

I suspect that purchasing an Adaptec AHA-2944UW HBA will be less expensive than an HVD/LVD SCSI bus convertor.