Small issue and questions about device configurations

[Guest]

Hi,

I've been looking in some detail at the different configurations reported by the FDwfEnum... functions. Looking at the device enumerations of the two devices I have sitting on my desk, I spotted what I think is a small issue.

First, some data as dumped by a script I wrote. These are the configuration numbers reported by my Analog Discovery 2, which reports 8 configurations:

    Configuration:               0       1       2       3       4       5       6       7
    ----------------------  ------  ------  ------  ------  ------  ------  ------  ------
    AnalogInChannelCount         2       2       2       2       2       2       2       2
    AnalogOutChannelCount        2       2       2       2       2       4       2       2
    AnalogIOChannelCount         2       2       2       2       2       2       2       2
    DigitalInChannelCount       16      16       0      16      16      16      16      16
    DigitalOutChannelCount      16       0       0      16      16       8      16      16
    DigitalIOChannelCount       16      16      16      16      16      16      16      16
    AnalogInBufferSize        8192   16384    2048     512    8192    8192     512    8192
    AnalogOutBufferSize       4096    1024   16384     256    4096    4096     256    1024
    DigitalInBufferSize       4096    1024       0   16384    4096    2048   16384   16384
    DigitalOutBufferSize      1024       0       0   16384    1024     256   16384     256

And these are the configuration numbers from my Digital Discovery, which reports 1 configuration:

  Configuration:                 0
  ----------------------  --------
  AnalogInChannelCount           0
  AnalogOutChannelCount          0
  AnalogIOChannelCount           0
  DigitalInChannelCount         24
  DigitalOutChannelCount        16
  DigitalIOChannelCount         16
  AnalogInBufferSize             0
  AnalogOutBufferSize            0
  DigitalInBufferSize     67108864
  DigitalOutBufferSize       32768

The small issue I want to report is that the AnalogIO channel count seems to be incorrect for both devices. Using the FDwfAnalogIOChannelCount function, the AD2 reports 5 channels instead of the 2 as reported above; and the DD reports 3 channels instead of the 2 as reported above. I think the numbers reported by FDwfEnumConfigInfo() with info=AnalogIOChannelCount appear to be wrong, since those channels do in fact appear to exist when queried.

Then, two questions. First, about the AD2, configuration number 5; it reports AnalogOutChannelCount=4 there. Is that a mistake, or does the device in fact support 4 analog output channels in that mode? If the latter, are those outputs available for use?

Then, also for the AD2: based on the reported configurations, it seems as if config #0 is identical to config #4, and #3 is identical to #6. To double-check, I opened with the Waveforms GUI, and I realized that it presents an Other column, where those configurations are different (config #0 and #3 are empty; config #4 and #6 show "1V8 Digital Input"). This suggests that there is some API that the GUI uses that isn't documented, perhaps a DwfEnumConfigInfo value outside of the 10 publicly documented values. Is that the case?

Best, Sidney
 

 

[attila]

Hi @reddish

For Analog Discovery 2 configuration 5th (#4) and 7th (#6) have ~0.5V logic input threshold.
In configuration 6th (#5) the positive and negative supplies can be used as slow Wavegen channels 3/4.

FDwfEnumConfigInfo(idxConfig, -1, char sz[2048]) // detail info text shown in the app as tooltip
FDwfEnumConfigInfo(idxConfig, -2, char sz[256]) // other info text, like: . or 1V8_Digital_Input

For Digital Discovery there should be 3 AIOs

[Guest]

11 hours ago, attila said:

Hi @reddish

In configuration 6th (#5) the positive and negative supplies can be used as slow Wavegen channels 3/4.

 

FDwfEnumConfigInfo(idxConfig, -1, char sz[2048]) // detail info text shown in the app as tooltip
FDwfEnumConfigInfo(idxConfig, -2, char sz[256]) // other info text, like: . or 1V8_Digital_Input

 

 

For Digital Discovery there should be 3 AIOs

 

Hi @attila

Thanks for the info on the Channel 3/4 output. Pretty interesting! I'll play around with it for a bit tomorrow. Can you tell me why it's slow? Different electronics, perhaps an opamp in the output stage?

As to the undocumented functionality of the FDwfEnumConfigInfo -- interesting! I'll add it to my Python binding.

You confirm that for the DD there should be 3 AIOs. Just to make sure we're in agreement -- that means that the FDwfEnumConfigInfo information returned for AnalogIOChannelCount is currently incorrect for both the AD2 and the DD, right?

[attila]

Hi @reddish

I see now.. This FDwfEnumConfigInfo/AnalogIOChannelCount was intended to return the number of power supplies the device has but it not used in the WF app. 
I've corrected it to 1 for Digital Discovery.
For DD 3 AIO channels are exposed with 11 nodes in total.