Where get my application (LV, LW/CVI) the configuration of my PXI-system?

[Joerg]

Somtimes I have trouble with my MAX. The config that is shown is not the config from the aktual system. Where take LV or LW/CVI the config? Take them from MAX or get them from the niconfig.daq file directly?

It´s very important for me to known. So I can give response of the stability of my system.

Thanks for helping!

[Claudia]

Joerg,

LabVIEW and LabWindows/CVI take the configuration from MAX. MAX reads the DAQ configuration from the file niconfig.daq, but if you are using other type of boards, MAX also reads other configuration files.
You can save the niconfig.daq in MAX by going to the menu Tools>>NI-DAQ Configuration>>Save Configuration As. Later on you can load a configuration in MAX by going to the menu Tools>>NI-DAQ Configuration>>Set Active Configuration.
The DAQ configuration file is very useful to store the characteristics of VIRTUAL CHANNELS and SCALES. However, it will not store the logical device number of a board (in MAX, this is the Device Number).
The Device Number of a board is assign by NI-DAQ at start-up and it depends on how the PCI bus is enumerated. The architecture fo the PCI bus changes from manufacturer to manufacturer, so the way the PCI bus will be enumerated will change from one computer to another.
A PXI chassis uses a PCI bus too. For every combination of National Instruments PXI chassis and PXI controllers, we provide a PXI Configuration File (PXISYS.INI) that describes the architecture of the PCI bus. NI-DAQ reads this file and assigns a Device Number that corresponds to the Slot number in the PXI chassis where the DAQ board is installed.
So in the case of a PXI system, if you are interested in having a stable configuration, make sure the appropriate PXISYS.INI file is saved in the System directory of your computer and that the DAQ boards are always installed in the same slot. This way, you can save and load the DAQ configuration (a *.daq file) that you want.
You will find more detailed information in the links below.
Hope this helps,

Claudia Lorente
Applications Engineer
National Instruments

KnowledgeBase 1EGB71UI: What Are PXISYS.INI and CHASSIS.INI?
KnowledgeBase 2CFE965P: Slot Detection of PXI Modules
KnowledgeBase 2E1AJUQI: Correlation of PXI DAQ Device Number to PXI Slot Number
KnowledgeBase 2MDFG2WD: Programmatic PXI Slot Detection

[Joerg]

Hello Claudia,

many thanks for helping!
Bevor you answers I have make some tests.
One of my testing´s was, that I write two different daq-files with one PXI system. And if I change the link of the daq-file in the registry, my application takes the changes form the new daq-file. But if I started MAX, sometimes the shown configuration in MAX was the old config.
As example: in file1 the device of my DMM is 3 and in file2 ist is 4. I load the file1 in MAX, close MAX an change the registrylink from file1 to file2. after this my CVI can write/read data only from device 4 (my DMM) and if I start MAX, he shows that my DMM is lokated as device 3. If I pess [F5] MAX changes his configuration and my DMM is device 4

Of your answer, I checked all the pxisys.ini files
I can reached to lock for the pxi configuration, but I can´t find diferent settings in different pxi systems.

I hope you can give me some help to sate my thirst for knowledge