compactRIO, CVI, and C series modules

[taft220]

Being used to LabVIEW, not sure how to interface to the C-series modules on my cRIO using CVI.  The project I'm on needs to use CVI, and I have no idea how to interface to my cards -- e.g. writing to my DIO card or reading from an AI channel, etc.  

In LV, it was easy and each I/O channel was simply a variable I could drop over to my block diagram and either read to write from/to.  Any pointers in the right direction for this?  I have the CVI real-time module and I know C, but never messed with CVI much..  I've searched and searched, but maybe I'm not searching right or something 😕

How can I read from my NI-9221 card on, say, channel 0 and get a double back representing the voltage that's on that line??  That's the kind of stuff I'm looking for... in CVI?

Thanks.

[Ryan-C]

Hi there,

LabWindows/CVi actually cannot be used to program cRIO.  CVI uses Pharlap, while cRIO uses VxWorks.  See CVI + RT FAQ and here's another more in-depth document regarding CVI in Real-Time.

Best,

[Ryan-C]

To add to this, while it is true that you must use LabVIEW to program the FPGA itself, you are able to use C to interface the FPGA and acquire data, etc.  Please see the FPGA Interface C API for the download and more information on this.

Hope this helps!

[taft220]

Thanks! I'll look into this ... and probably be back in here......

[Peter_Prinzen]

As far as I know, when using cRIO-Modules, there is a "generic" network variable engine running.

So you can read it's values using the network variable manager.

Peter