ADCs don't work on NI7342

[f_g]

I am using a using an NI7342 motion controller, trying to read an analog signal using Analog input 1 or Analog input 2 (and ADC1 or ADC2).  The result, using  flex_read_adc16_rtn () in CVI is always between 523 and 526, regardless of the actual input voltage.  When I read ADC5, ADC7 and ADC8, all internally connected to known voltages, I get the correct outputs.  When I read ADC3 and ADC4 (unavailable) or ADC 6 (NC), I get between 523 and 526.  The return status is always OK (0).

I’ve tried this using both UMI7764 and CB68LP interfaces.

f_g

[Luke H]

f_g,

The first thing I would do is make sure that the axes you are trying to read are not mapped to the feedback of any axis.  What do you mean when you say that ADC3 and ADC4 are unavailable and ADC6 is NC?  What voltage range are you using?  I would also try it with another card to see if you experience the same behavior.

Regards,
Luke H

[f_g]

By default, the ADCs aren't mapped and I didn't change that.
On the 7342, ADCs 3 and 4 are not available, presumably not connected internally.  They are available on the 4-axis 7340.  ADC 6 has no connection according to the documentation.  I'm using the +/- 5 volt range, though I've also used the default +/- 10 V with the same results.  Since the output of ADCs 1 and 2 look like the outputs of unconnected DACs 3, 4 and 6, it looks like this card may be defective.  Unfortunately, I don't have another one to try.

FG

[Luke H]

f_g,

That is interesting.  The only other thing you could try would be a different PC just to ensure that its not something weird in the driver installation.  If not, I would call in for support so that you can setup an RMA on the card.

Regards,
Luke H