PROBLEMS WITH Mac G4 500MHz and Color One Scanner (600/27)

Hello

I am having a problem with my G4 500MHz recognising my color one scanner (600/27). I have tried to use the appropriate card (Adaptec AVA 2906) but cannot seem to get it to function. I keep getting the following message:

“Unable to recognise the Scanner Driver. Either the scanner is not turned on, connected or in use by another application (-30001).”

I suspect that to date, I haven’t ever had the driver recognized at the start-up (Scanner on first), the start-up screen always having a cross through the symbol for the scanner. The SCSI card (Adaptec AVA 2906) WILL run an external Hard Drive and even, when in SCSI series with the scanner, will run a jazz drive.

I have used Scanner driver 4.3, the appropriate driver for the card, have
dragged the file "Adaptec SCSI Card 2906 Driver" v1.1 into the Extensions folder, the SCSIProbe 5.1.1 into the Control Panels folder and have dragged the file "PowerDomain Control" v5.0 onto my HD. None seem to work.

I also have an Adaptec 2940UW card but it features an HD 68 pin outlet so I cannot use it for my Scanner. I have also tried this with an Adaptec AHA 2940U card but no joy. I have been trying this off and on for quite a while now, but cannot work out why this is not working.
I believe the SCSI Manager is 4.3 for my G4 (running System 9.2.2), but have just about given up hope of getting it to work.
I know about ViewScan 7.6.64 which will actually get my scanner to work, but I just cannot work out why I cannot get it to launch under normal conditions. I have tried different daisy-chain termination endings, but no success.
Can somebody please help?