ReadADC.flx output

[CaterMatt]

I have attached the image of the block diagram, front panel, and error message.  I have the wires connected as specified and the 5 V power confirmed.  It says the Load DAC command is not supported.  I couldn't find anything in the PCI 7332 manual describing the function.

[Paul_M.]

Hi CaterMatt,

What version of NI-Motion are you using? And you're sure that you have the Motion I/O connected to the UMI and not the Digital I/O?

Paul M

[CaterMatt]

NI Motion 8.1. We definitely have the motion I/O connected to the UMI.  What would be the expected output of the loop back code?  I appreciate your patience and continued support.

[Paul_M.]

Hi CaterMatt,

The loop back code was something that we generated here and were able to get correct readings from the Read ADC.VI. However, I realized today that we were using a 7340 rather than 7330! That is why you were getting the error you were seeing in the code, sorry for the confusion. We're going to set up the 7330 here, verify that we're getting the appropriate readings, and then I'll post the updated code and connection diagram. Sorry for the delay and thanks for your patience!

Paul M

[Paul_M.]

Hi CaterMatt,

So we were able to test it out over here with a 7330 this time and we were able to read the appropriate value. Go ahead and construct a VI like the one shown below.

Then all you need to do is to make sure that you have a 5V power supply connected to the required inputs on the UMI. Once you've done that you just need to connect the +5V output from the top left of the UMI to the AIN1 input from the top right. Then connect the GND output from the top left of the UMI to the AIGND. This should provide a 5V voltage which should be read by the Read ADC.VI as about 1026 when set on the default range of +-10V.

[CaterMatt]

The analog value is 1006 when conducting the test.  However, the voltage from the function generator is still much smaller than it should be (+-4V on function generator is -6 15 on the card).  A steady 4.96V was supplied from a power source to the same analog inputs as the loop back test and produced a value of 125.  The voltage is verified to be 5 V when connected to the UMI.  Is there some sort of voltage drop internal to the card?  We can't imagine why the card would read correctly when connected to itself but not an external source (the same one that powers the UMI) of the same voltage.

[Paul_M.]

Hi CaterMatt,

I just tested out the UMI 7764 with an external function generator and I was able to read the correct analog values. I also tested out the same power supply that I used to power the UMI 7764 and it came back as 1020.

Is there anyway you could post a picture of your connection with the external power source and function generator to the UMI 7764?

Can we also try the hardware on another machine?

The only other difference that I can see between our two set ups is that I'm using NI-Motion 8.2 and you have NI-Motion 8.1.

If you have a DAQ device on this machine you can also output a sine wave and test that signal on the UMI.

Paul M

[CaterMatt]

Paul,

We continued testing with other voltage sources and determined that the function generator was spotty.  We have managed to connect an alternate dc power supply and produce a calibration curve for the ADC.  It seems everything is in working order.  We extend are deepest gratitude for all of the help you have provided.  We are very pleased with our decision to go with NI.

Thanks,

Matt

[dg_lbe]

Though I know you posted this some time ago but I have the same issue.  I am reading about 0.488 Vdc lower then the actual value.  This is consistant with several other voltage sources.  Have any clues I can use?

Thanks,

Dave