Computer BSOD when reading resistance with PXI-4070

[schelgr]

I have a PXI/SCXI system that is connected to a Windows XP desktop using the MXI-Express 8360 card. I am using the PXI-1045 chassis and a PXI-4070 DMM. The SCXI chassis interfaces through the DMM card. My software makes calls to the nidmm_32.dll. I can initialize the DMM and set it up just fine, but whenever I try to read the card (using niDMM_read()), the desktop computer will get the Blue Screen of Death (IRQL_NOT_LESS_OR_EQUAL). I am also controlling a few SCXI-1127 modules through the DMM and all of those are working fine.

I have had this system up and running with no issues before using the MXI-4 interface (same software). Could there be an issue with the new MXI-Express interface? I noticed a lot of available settings in the desktop BIOS when it comes to PCI-Express (such as 8 bit indexing and what not). Are there recommended settings from NI for the PCI-Express bus?

I have no issues when I call "niDMM_init",  "niDMM_ConfigureMeasurement", or "niDMM_reset". The error only seems to happen when I try to read using "niDMM_Read".

Has anyone else had this happen or know what might be causing it?

[MegaWatts]

Does this problem persist on multiple computers? It also seems strange to me that this only occurs when using the Read function. Does the problem also occur when you use a MAX test panel to preform measurements on the DMM?

[schelgr]

I can open the DMM test panel through Max and press the Read resistance button with no issues. I checked and saw that I was using the niDMM v3.0.1 software, so I updated it to the 3.1 version. That did not solve it. As far as multiple computers, I can't test that since this is the only one we have. The fact that the Max test panel works without issue seems to eliminate the computer (or MXI-express interface) as the culprit. As far as communicating with the DMM, I can initialize and reset the card with no issues. See my code snippet below (It is in Borland Delphi. I converted the niDMM_32.h file to Delphi and call the DLL from within Delphi): {-- Initilize the DMM and get the Handle and store it in "vidmm" --} status := niDMM_init(DMM_NAME, idQuery, reset, @vidmm); checkForError(vidmm); status := niDMM_reset(vidmm); checkForError(vidmm); I get no errors when calling the functions above. Below is the call to the configure and read functions: (* Configures the measurement for 2W resistance *) status := niDMM_ConfigureMeasurement(vidmm,NIDMM_VAL_2_WIRE_RES,range,resolution); checkForError(vidmm); (* Read the Measurement *) status := niDMM_read(vidmm, NIDMM_VAL_TIME_LIMIT_AUTO , reading); checkForError(vidmm); No errors on the Configure call, but when I step into the niDMM_read function (in debug mode), that is where I get the BSOD. The variable "reading" is a pointer to a 64 bit real number. I have had this same software running on an older machine for the last few years. The only difference I can think of is the versions of NI software that I have installed on this one. Here is a quick rundown of what is installed on this machine: NIDMM: v3.1 IVI: 4.5 MAX: 5.5 niFGEN: 2.9 niSwitch: 4.6.5 ni-VISA: 5.4 Traditional NI-DAQ: 7.44 DAQMX: 9.8 Any thoughts?

[schelgr]

Update: My current system has an SCXI chassis (with 9 modules in it) connected to the system through the PXI-4070 card. I have noticed here recently after upgrading to the MXI-Express interface that about 30% of the time the SCXI modules will not initialize when running my program. Normally a computer restart solves this. But, today I noticed that in MAX, the SCXI modules were not responding either. Also, I created a rudimentary program that only initialized, reset, configured, and took a reading from the DMM card (used same Delphi development environment). With nothing connected to the DMM, I received back the Out of range message, which is an open circuit. So, I am starting to wonder if my PXI-4070 card is becoming flaky? It is nearly 10 years old.

[MegaWatts]

Have you tried testing the DMM in a MAX test panel? 

[schelgr]

I have tested the DMM using the Max test panel. It works as expected. Also, my program will run without issues about every 4th or 5th time. The fact that the SCXI modules were not responding when using the Max software seems to indicate an issue with the DMM card. When my program does run, I am taking like 300 separate DMM readings. So, I am not sure what the problem is, but the common casue for the multiple issues seems to point to the DMM card. I might be able to get a hold of another 4070 to try. If so, I will post what happened.

[schelgr]

I figured out the problem. Having the cards in the PXI chassis as I did, too many modules were using the same IRQs. After getting a response about how the PXI chassis uses a set amount of IRQs, I realized that one of the 4 IRQs were not being used. I moved the cards around until I had a good balance between the 4 IRQs and now everything works. Thanks for the responses!