01-28-2019 02:41 PM
Hi,
I'm trying to setup a NI USB 6212.
NI-MAX and Labview (DAQ Assistant) appear to recognize the device just fine. I need to read the voltage on all 8 of the device's analog inputs. I tried setting the device up accordingly with the DAQ Assistant in labview (DAQ Assist > Acquire Signals > Analog Input > Voltage > ai0 thru ai7), but upon testing it appears that all 8 channels are reading the same voltage.
E.g., If I put 1V across ai0, the device behaves as though 1V has been put across the other 7 channels (ai1 through ai7). This goes for any channel.
This is unexpected and undesirable behavior. Could I get some assistance setting up this device such that the analog input channels are "separated", i.e. don't all read the same voltage?
Thanks. Happy to provide any additional information.
01-28-2019 03:20 PM
How is your task configured? What do you see when you run the task from inside Max? Are you sure that you are not configuring a simulated device (simulated devices always output the same waveform)?
01-28-2019 03:54 PM
I don't know - I'm pretty new to this. I don't even have a task assigned to the DAQ Assist object.
I switched over to the DAQmx read voltage, etc. sub-vi's instead of using DAQ assist and it's working now, I think.
Thank you.
01-28-2019 03:57 PM
@midnightminer wrote:
I switched over to the DAQmx read voltage, etc. sub-vi's instead of using DAQ assist and it's working now, I think.
Good answer.
01-28-2019 05:20 PM
So I can't actually really tell if it's working. It seems as though it might be, but I'm unable to separate the channels the way I'm doing it now?
I've attached the VI I built to test this to this question. What I would like is a numeric indicator for each channel (ai0,ai1,ai2,ai3), which I can't get working. It's like I can only see one channel at a time?
01-28-2019 06:02 PM
What sensors do you have hooked up to each of the channels? What values should each of them be showing you and what values are you actually seeing?
01-28-2019 06:43 PM
If you have nothing connected to channels 1-3, then due to the muti-plexing, you will get an almost identical signal read on those channels to what is connected to channel 0.