Where to run code: FPGA | RT | PC

[bszabo]

Hi,

I have a cRIO (9032) and some analogue measurement cards and I'm trying to measure, process and display the signals. I'm fairly new to the cRIO system and my question is what part of the project should I implement on which environment? 

My idea is to do signal acquisition with FPGA, use DMA FIFO to transfer data to RealTime module and do signal processing there. Is it possible then to display the signals from RT on a connected PC (running LabVIEW on it)? Or do I need to implement a VI on a PC too to display my measurements?

Is there a better way to do this? (I'm measuring vibration with triaxial accelerometers.)

Any advice is appreciated!

Best,

Balázs

[cbutcher · Accepted solution]

For the cRIO-9032, you're probably right to acquire on the FPGA. Depending on the processing you want to do, you might find the FPGA or the RT system more preferable - of course if you can compile it on the FPGA you'll free up resources on the RT system and have things running more smoothly, but it will probably in many cases be more complicated to write on the FPGA than on the RT system.

For visualisation on the host PC side, you'd generally look to something like Network Streams to transmit the data to a VI you write on Windows/Mac/Linux for a non-real-time computer, and then do whatever else you'd like there (perhaps logging, etc).

You don't necessarily have to do this though - it's possible to attach a monitor to the 9032 via a mini Display Port and enable an embedded UI. This will consume quite a bit of the available resources on the RT system, but it is possible and can avoid needing a PC system separately with other VIs. Note in that case you're only able to log to the cRIO disk, which is likely much smaller than a desktop hard drive/SSD.

You can also develop a web interface for the cRIO and use a browser to view the data directly on the cRIO. I suspect (although I haven't tried) that this is intermediate between the two in terms of resource usage, but you probably lose a lot of the convenience you get from directly connecting a monitor.

I suspect the most common is the first - communications with a separate host PC. That's what the system I have set up does, and its one of the main configurations discussed in places like the RT development guide and the online training. I just want to highlight here it isn't the only possibility.

[bszabo]

Perfect, thank you!