DEC AXV11-C analog board
Douglas Taylor
dj.taylor4 at comcast.net
Sun Feb 6 11:43:26 CST 2022
Yes, I am putting 1 into the CSR to start the conversion and I do get a
200(8) indicating that the conversion is complete. I wonder if this
means the A/D chip is OK but something else, like the multiplexer chip
or gain amp is fried.
On 2/6/2022 12:33 PM, Jerry Weiss via cctalk wrote:
> 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
>>
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