Error -200576 using thermocouple with SCB-68

[AndrewO_nyc]

I am having problems using the SCB-68 in conjunction with PCI-6221 and Labview 8.0. I am making  making thermocouple (TC) measurements with the built-in CJC. I had previously used a setup with PCI-6221 and SCB-68  for almost 2 years without any problems. I then installed an additional SCB-68 which is connected to a second DAQ card, PCI-6281, and am getting an intermittent error message. . The error message that I am getting in labview reads :

Error -200576 occurred at DAQmx Create Channel (AI-Temperature-Thermocouple).vi:2

Possible reason(s):

CJC Source cannot be set to Built-In for the specified thermocouple channel. The physical

channel does not support a built-in CJC temperature sensor.

If your hardware contains a CJC temperature sensor on the physical channel corresponding to

the built-in CJC source, make sure that the hardware configuration (including any

accessories and/or terminal blocks) is correct. Alternatively, specify a different CJC

Source, or use hardware with a built-in CJC temperature sensor.

Channel Name: Dev1/ai1

Task Name: _unnamedTask<51>

Currently it is setup so that 8 voltage measurements are on  Dev3(PCI6281), and 7 TCs are installed on Dev1(PCI6221). Everything works ok in MAX, The CJC is enabled  in the software and also through the the switches in the SCB-68. I am measuring the correct temperatures when I create a task in MAX, this problem is only showing up in labivew. There have also been a few times where if I restart labview or the pc the problem goes away only to return later on.

[John_P1]

Hi Andrew,

Intermittent error messages like this can sometimes be difficult to troubleshoot.  Just to confirm, you are not changing any settings at all between successful and unsuccessful runs?  The CJC must be enabled both through the switch on-board the SCB-68 as well as through software, but it sounds like you have this covered already.  Is there any way that you can force the error to happen, or any discernable circumstances under which it occurs?

It looks like the error is coming from the task that contains the PCI-6221.  I suggest that you switch SCB-68s between your devices to see if the error message comes from the 6221 or from the particular SCB-68.  Also, could you attach your code so I can see how you have your task configured?

The above steps should be valuable in helping us get to the bottom of this.  I hope to hear from you soon so we can continue looking into the issue.  Thanks for posting and have a great evening!

-John 

Message Edited by John P on 02-12-2009 08:30 PM

[AndrewO_nyc]

Hi John,

Thank you for the response. I would have replied sooner but I thought that I had solved the problem. I replaced all "Daqmx stop tasks" with "Daqmx clear tasks" thinking that maybe there was an error message which just kept getting passed through the program This resolved the problem all day yesterday. However today I turned the PC back on and tried it again, and the same problem has returned. I am unable to locate any repeatable method for making the error appear or not appear. Sometimes it is not present for numerous program starts, and then suddenly it appears. Or sometimes when I close labview or restart the computer it will go away. 

I switched the SCB-68s, I switched the connectors cords, and I tried running the SCB-68 with the TCs on the PCI-6281. In all configurations there was an error in Labview on the SCB-68 with the TC, while there was no problem in NI-MAX. 

I am uploading my labview code. Here is a brief description of the code. It is used simply for measuring 7channels of voltage, and 6 channels of TCs. There are 3 measurement modes controlled via tab:

1)Timed Mode (samples  all 13 CH for a specified period of time and then graphs and scales data, and writes to file)

2)Continuous Mode (samples all 13CH for a specified period of time  and then graphs and samples again

3) Very long mode (samples 7voltage channels while plotting and optionally writes data to file)

Thanks for your help,

Andrew O'Grady

[jakkefire]

Hi,

i encountered this error message when the SCB-68 CJC wasn't turned on in NI-max.

For me the sollution was to right click my DAQcard in  NI-MAX devices and interfaces, then chose properties, then chose tab accessory and fill in SCB-68 and enable CJC.

After this it worked for me.

Regards 

Jan

[AndrewO_nyc]

---

jakkefire wrote:

Hi,

i encountered this error message when the SCB-68 CJC wasn't turned on in NI-max.

For me the sollution was to right click my DAQcard in  NI-MAX devices and interfaces, then chose properties, then chose tab accessory and fill in SCB-68 and enable CJC.

After this it worked for me.

Regards 

Jan

---

Hi Jan, thank you for your input. I definitely had the CJC enabled in NI-MAX because I was able to create tasks in NI-MAX and to measure temperatures using the built-in CJC and the TCs. 

I have also been getting a new error message which comes up periodically. This is not a labview error cluster message but rather in a windows pop-up message box. It crashes labview and I have to use task manager to end it. Here is the error message:

An exception occured within the external code called by a Call Library Function Node. This might have corrupted Labview's memory. Save any work to a new location and restart Labview. VI "01_23_09DuctFlow_PandT_2DAQ_rev6.vi" was stopped at node 0x0 of subVI "DAQmx Create AIChannel (sub).vi:3"

Thanks,

Andrew

[John_P1]

Thanks for posting: not configuring the CJC is the common cause of error -200576.  I am inclined to believe Andrew has his CJC configured in MAX because the error only shows up intermittently, but to double check here is a screenshot of how your configuration should look in MAX:

 

After you verify that this box is checked in MAX, I have the following questions/suggestions::

1. What version of DAQmx are you running?  I suggest you upgrade to the most current version--DAQmx 8.9.  Given your most recent error message, it sounds like you might have a corrupt driver installation.  If you are already running on 8.9, try repairing the driver.
2. Which version of LabVIEW are you running?
3. Do you receive the same error when running a shipping example?  For example, try the Cont Acq Thermocouple Samples-Int Clk.vi located at:  Help >> Find Examples... >> Hardware Input and Output >> DAQmx >> Analog Measurements >> Temperature.  If this example results in the same error, we can disregard your code as the source of the problem.
4. If the example does not result in an error, which mode of your code is resulting in an error?  Any additional information about where the error is coming from would be helpful--if the problem is specific to your code and not the example then we need to further investigate how your tasks are being created and cleared.  

Let me know the results.  I am hoping that a simple driver upgrade/repair will fix the problem.  If not, I'd be very interested in finding out if the shiping example returns an error as well, and if not, more details about where the error occurs in your code.

-John 

Message Edited by John P on 02-16-2009 11:36 AM

[AndrewO_nyc]

Hi John,

I definitely have the CJC temperature reference enabled in NI-MAX. In response to your questions:

1. and 2.  am running DAQmx 8.0 and Labview 8.0. I downloaded DAQmx 8.9, but when I try to install it says that it is not compatible with labview 8.0. Do you know what version of labview or DAQmx I can update to? I have the full version of Labview

3. The shipping example did not cause an error. 

4. I have not received the built-in CJC error (Error -200576) after numerous program openings and closing, although I received the 2nd error (An exception occured within the external code called by a Call Library Function Node.... "   a couple of times recently. It's possible that unchecking and checking the CJC box in NI-max made part of the problem go away.

Thanks,

Andrew

[John_P1]

Hi Andrew,

Sorry about the assumption, the most recent version of DAQmx that is compatible with LabVIEW 8.0 is DAQmx 8.7.1.  The compatibility information can be found in the DAQmx readme, but for a consolidated list of which versions of DAQmx are compatible with which versions of LabVIEW, you can reference the NI-DAQ & LabVIEW Version Compatibility (for Windows).

I think upgrading your DAQmx would be a good step at this point--it sounds like there is something fishy with your current installation.  Let me know how everything goes, hopefully this will resolve the issue!

-John

[AndrewO_nyc]

Hi John ,

Thanks for all of your help with this. I didn't get around to updating DAQmx yet, however, the problem has mysteriously returned to wherever it came from. I have been running tests for a few weeks without any CJC error messages.  I'm convinced that I had a labview program error in my .vi which kept getting rerouted through my program. I will return if the problem returns.

Thanks,

Andrew