Analog Output to Oscilloscope

[Quincy123]

Hi all,

I have PCI-6731 analog output board in my pc. I'm trying to generate a sine wave in a .vi and view the waveform on an oscilloscope. I have the i/o board hooked up to an scb-68 connector block. On the block, i have a wire hooked up to ground and another hooked to port 9, or the output（1）. The code looks fine to me, I configured the daq assistant to generate a voltage signal to dev3/a01, which corresponds to the port on the connector block. However, when I hook everything up and run the vi, I'm seeing nothing on the oscilloscope. Any tips?

[apok]

you are outputting an error( Error -200220 occurred at DAQmx Create Channel (AO-Voltage-Basic).vi:2 

Possible reason(s):

Device identifier is invalid.

Device Specified: Dev3
Suggested Device(s): Dev2, PXI1Slot2

Task Name: _unnamedTask<31>

)

which stops your loop....

[Quincy123]

My bad, I uploaded the wrong vi. Delete everything which isn't already in the while loop. You should be left with the daq assistant, the funciton generator, and the waveform graph.

[Dennis_Knutson]

Your message says ao1 but the DAQ Assistant is set for ao0. You say port 9 and the use of "port" is meaningless. For the 6731 ao0 is pin 22 and for ao1, it's pin 21.

[Quincy123]

Okay forget about the software. I know I have that fixed. I just want to know how to hook up the oscilloscpe to the connector board. Right now I have a wire in ground and another in pin 9 on the scb-68, which corresponds to ao1. Do I need a power supply hooked up to the 5V? 

[Dennis_Knutson]

According to the documentation for the 6731, ao1 is pin 21 as I already said. What makes you think it's pin 9? The SCB-68 is a dumb terminal block so you better pay attention to the pin out of an actual DAQ device.

Do not connect a dc source to the dc output of the board unless you feel a need to savage the board. That question does not make any sense.

[Quincy123]

Pin 9 on the scb board is the output(1) is it not?

I have the 6731 outputting a waveform at a01. The 68 pin connector runs between the 6731 and the scb. I assume that one wire from the oscilloscope is put into pin 9 on the scb, which I am guessing carries data from a01 in 6731. I hope this clears things up, I should have made a distinction between the hardware.

[Dennis_Knutson]

The scb board has no inputs or outputs. The inputs and outputs are on the DAQ board.

There is a one to one correspondence between the DAQ board and the scb. So, to repeat myself, find the pin number on the DAQ board. Use that pin number on the scb board. I already did that but you don't seem to believe me. I don't get your insistence about the pin numbers of the scb. Are there labels on there? If so, someone labeled it for a different board.

[Quincy123]

There are labels. My grad student insisted that I follow that, but I will look into what you said. Thanks for putting up with me, I'll let you know what happens

[Dennis_Knutson]

Find a different grad student and study the DAQ hardware manuals you have. Another simple check is to right click on the device in MAX and select 'Device Pinouts'.