DEC AXV11-C analog board

[Jerry Weiss]

Are you triggering an A/D conversion via the CSR or external signal?  
Then check the A/D done bit.

See  EK-AXV11-UG-02 Chapter 4.

    Jerry

On 2/6/22 11:20 AM, Douglas Taylor via cctalk wrote:
> I have one of these and would like to use it, however it appears to 
> only partially work.  Here is what I have found that works and what 
> doesn't:
>
> 1. CSR and DBR are present and operational.
>
> 2. Jumpers set to 'factory'.
>
> 3. D/A portion works, can deposit codes in ODT and see voltages out on 
> DAC pins that change depending on the octal value deposited in CSR+4 
> or +6.
>
> 4. A/D portion returns full scale code, either 3777 (2's compliment) 
> or 7777 (offset binary) whether in the input is open or shorted to gnd.
>
> I think the problem is that the A/D inputs are not exactly protected 
> and damage has occurred to this portion in the past.
>
> Does anyone have any info on the A/D module?  Who made it?  Can you 
> open it up?  Does XXDP have a test for this?
>
> Doug
>