Error -200077 occurred at DAQ Assistant

[sam B]

I want to generate a digital signal using NI USB 6218. Therefore, I'm using the DAQ Assistant. When I try to select "N samples" or "Continuous samples" in the "Generation mode" setting, I always get the following error:

Error -200077 occurred at DAQ Assistant

Possible Reason(s):

Measurements: Requested value is not a supported value for this property.

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

Does anyone know why I get this message?

[Dennis_Knutson]

According to the specs, your board only has software timing for the digital I/O and thus you can't select anything that requires a sample clock.

[cuthbert]

According to the error message "The requested value is not a supported value for this property. The property value may be invalid because it conflicts with another property.

Property: Sample Timing Type

Requested Value: Sample Clock

You Can Select: On Demand, Handshake

This error message is really strange since I had this task working for both DI & DO for this device and the signals all displayed in Amplitude display for both N Samples and Continuous Samples!  After a little monkeying around I suddenly got this error message but the task still ran the 1 Sample mode even though I did not see any values in the display.  The error dialog box says you can select On Demand or Handshake, but I don't see any place where this can be selected.

Any ideas?

[ThiCop]

Hello cuthbert,

You can change this the following way:

- Open your DAQ Assistant

- Go to the Configuration Tab

- Go to the Timing Settings subdivision.

- Change the selected Generation Mode to "1 Sample (On Demand)"

This should make the error disappear.

[cuthbert]

I'm sorry that you go the idea that I am using the Data Assistant: I am using sub VIs throughout this code. So lets start over. One of the VIs that I am fooling around with is fairly simple. There is a Create Virtual Channel . a DAQmx Timing, a DAQmx Write, & a DAQmx Stop VI on the block diagram. It couldn't be much simpler than that!  On the physical channel input I have selected Dev2/ai3 and on the task input I have VoltageOutTask_Dev2_ao3 and the names of these inputs should make things clear as to how they are configured in MAX.  Also the Create Virtual Channel VI is configured for AO Voltage. When I run this VI the following error dialog box appears:

    Error - 200855 occurred at DAQmx Create Channel.vi
    Possible reasons:
    Devices cannot be added to a task after configuring timing, triggering, buffers, and /or exported signals
    Add all devices to the task before configuring other aspects of the task
    Task Name: VoltageOutTask_Dev2_ao3

This I find rather strange since when I go into MAX and look at Dev2, I find it is a PCI-6259 device which from the test panel display is both an input and an output device so there should be no problem creating a virtual channel as far as I can see as far as MAX is concerned.  When I go into MAX and look at the test panel display for the task that I selected, I can see that the physical channel selected in the configuration display is Dev2/ao3 and the test signal is a sine wave in the graph display.

How can the error dialog box ask me to add all devices to the task before configuring other aspects of the task?  The device is in the task according to MAX!

Incidentally, there was some more code in this VI that was disabled to make the VI as simple as possible.  This code had a Create Task VI wired up to the input of the Create Virtual Channel VI as I have done before in some of my other example VIs where I was working with inputs, and these VIs for the most part, seem to work so far. Anyway, the Create Task VI has MyVoltageOutTask_Dev2_ao3 attached to the Create Virtual Channel VI.  And when I run this VI with the Create Task VI enabled I now get the following error out of the Create Virtual Channel VI, but not the Create Task Vi:

    Error - 200371 at DAQmx Create Channel vi:
    Possible reasons:
    Requested multiple virtual channels that correspond to the same physical channel within a task. A task cannnot
    contain multiple physical channels for each virtual channel.

    Use different physical channels for each virtual channel
    physical channel name: ao3
    virtual channel name: chan1
    Device: Dev2
    Task name: myNewOutputTask

I have only one task created and from that the create virtual channel uses the task that is associated with Dev2 to create a new virtual channel using the physical selected from the list for the physical channel input!  Why would I need to use a different physical channel than the one I need to run this virtual channel?

Again I have included a MAX configuration report so you can see how I have MAX configured.

[Dennis_Knutson]

Stop asking the same question over and over again and pay attention to the answers given in all of those other threads. You obviously cannot add an analog input to a task that is already defined as an analog output. You MUST use different tasks for inputs and outputs. It's also pretty obvious that if you have a defined task such as VoltageOutTask_Dev2_ao3, you cannot use Dev2/ao3 as a phsical channel input since that would be adding the same channel to your existing task.

[cuthbert]

I did create a seperate task for input and output!  Even the examples that I have seen obviously do this and I also do not create identical tasks even in MAX which are both configure to do the same functionality. As a matter of fact when I create a task in MAX I create one for a device that is capable of I/O and one task would be configured to use this device for input and anothe task would be configured to use outputs for the same device!  How then are these tasks conflicting?

[ThiCop]

Hello Cuthbert,

Based on the error posted I indeed assumed you were using DAQ Assistant.

Can you upload you MAX configuration report again (because I don't see  it attached your post)?

Can you also upload an example VI that illustrates the error?

[Dennis_Knutson]

---

@cuthbert wrote:

I did create a seperate task for input and output!  Even the examples that I have seen obviously do this and I also do not create identical tasks even in MAX which are both configure to do the same functionality. As a matter of fact when I create a task in MAX I create one for a device that is capable of I/O and one task would be configured to use this device for input and anothe task would be configured to use outputs for the same device!  How then are these tasks conflicting?

---

The only VI you have posted is below and it is clearly wrong since you have duplicate channels in both the analog in and analog out tasks. If you have written other code, you need to post that since it is silly to attempt to answer without it. 

[cuthbert]

I am sorry, and I feel rather stupid over not getting this. From the diagram I see two different tasks each configured for the same device,
Dev3 in this case, but the device is being used as an input in one case and an output in the other case, so where am I cuplicating channels? Are you saying that in one VI I can't create two virtual channels off the same device?

I have included a MAX report along with two VIs for you to peruse.
"Cont AI Mult Chs DAQ VIs" is an example that creates a task and then a virtual channel and then starts timing. This VI works OK.

The other VI, Cont AO with DAQmx API, is a similar example code but for analog output instead of input.  When the create task VI is diabled the code runs OK. But on this case what task is being used to run this program: a voltage, current, thermistor, or whatever? There is no task in the code anymore that selects a  task.  When I enable the creae task  subVI I now generate error 200371.  How is this VI so different than my other VI?