Generate Analog Output Voltage in LabVIEW using USB-6009

[barberk]

Hello:

I am using LabView SignalExpress 3.0. My DAQ is an NI USB-6009. I am trying to generate an analog output voltage. I have already been successful in Aquiring an analog input voltage, but the program says, "MISSING INPUT: One or more of the inputs to this step are not selected.  Insert a step before this step which has an output that matches the type of signal this step requires." Please help. Thanks.

-Kristie

[nayer]

Hello Kristie,

For Analog output you would need to create analog signal first and then "Add Step"of DAQmx Generate Signal and then set generation mode as either Continuous Samples or Finite Samples and select the signal that you want to generate. Have a look at the simple SE project which I have attached.  Also you can look @ link1 and link2.I am sure this will help you .

Good Luck !

NI-khil

[marianok]

Hi,

I´m attempting to perform the same task with Signal express 2012, with an NI USB 6008. However, after downloading and running the proyect, it gives me the following error message, which I cannot solve:

Error -200077 occurred at DAQ Assistant

Possible Reason(s):

Requested value is not a supported value for this property. The property value may be invalid because it conflicts with another property.

Property: SampTimingType
Requested Value: Sample Clock
You Can Select: On Demand

Any suggestions will be welcomed ! 

Thanks in advance,

Mariano

[Dave.C]

Hi Mariano,

Have you checked out our community examples in the Developer Zone.

https://decibel.ni.com/content/docs/DOC-8545

[DFGray]

The USB-6008 does not have a clock for the voltage outputs.  Thus, you cannot set an output frequency.  The best you can do is use the On Demand setting.  You can set a frequency for this output mode, but it will be software timed.  Thus, it may have a fair amount of jitter.

[marianok]

Hi Dave,

Thanks for your help. The example did work to generate an output. Now , can I ask another question? After atempting to add a signal acquisition step in the same programm, I had error messages in this step, including:

Error -200361 occurred at DAQ Assistant

Possible Reason(s):

Onboard device memory overflow. Because of system and/or bus-bandwidth limitations, the driver could not read data from the device fast enough to keep up with the device throughput.

Reduce the sample rate, or reduce the number of programs your computer is executing concurrently.

Error -200284 occurred at DAQ Assistant

Possible Reason(s):

Some or all of the samples requested have not yet been acquired.

To wait for the samples to become available use a longer read timeout or read later in your program. To make the samples available sooner, increase the sample rate. If your task uses a start trigger, make sure that your start trigger is configured correctly. It is also possible that you configured the task for external timing, and no clock was supplied. If this is the case, supply an external clock.

Property: RelativeTo
Corresponding Value: Current Read Position
Property: Offset
Corresponding Value: 0

I´ve attached the example with the acquisition step that gives me this message. Do you have any suggestions on how to alter sample acquisition rate rate so that there is no conflict? Thanks in advance ! 

mariano