LabVIEW
How can I build a dll containing a callback function ,the callback function is used in CVI.
Solved!
We need a lot more information about what you want to do and what you have done so far to be able to give any useful information here.
Most likely you do not want to use callback functions at all.
And why would you want to do the data acquisition in LabVIEW to create a DLL of it to be used in CVI, instead of doing all in CVI directly??
If you can run it in LV then you can use it in CVI. The daq driver is the same, it is just the interface in which it is used. You can use it in LabVIEW, CVI, C++. Whichever you prefer.
coolfire wrote:
I need operate FPGA of PXI-7842. Can CVI do it?
I will receive external data through programming FPGA, then translate data to CVI for other task .
External data will arrive at any time . LV must buffer external data, then tell CVI data ready to take away.
And I do not want to use the query method with CVI always.
Well I'm pretty sure you can't develop the FPGA part in CVI. However in order to access the FPGA from a Windows application it needs to use the NI-RIO API. Technically it should be possible to access the NI-RIO API from CVI, since it is basically a DLL based C AP. LabVIEW uses internally this same API.
Obviously in order to use that API, NI would need to provide the documentation and C header files for that API. In case they don't or can't do that you would indeed have to create a LabVIEW wrapper and compile that into a DLL to be accessed by CVI. However LabVIEW does NOT support callback pointers, so you couldn't do that directly in LabVIEW. Instead you could use Windows events, calling in LabVIEW the apropriate Windows APIs to deal with them. Still most likely you will not be able to avoid some C wrapper on the LabVIEW side too, to provide some bindings to platform APIs. All in all a rather complicated setup, so I would in your case bug the NI repersentative about support for NI-RIO directly for CVI.
