How much programming do cRIO or cDAQ need?

[XebeXUC]

So for a school project we will be controlling pumps that pump liquids into an oven, the temperature will be the main input here.

Now we were wondering wether to use cDAQ or cRIO, which we still haven't decided, so help on this would be great too.

However, my main concerns are: how much of either one do you have to program?

I found that cRIO uses FPGA and cDAQ uses ASIC. In my understanding they both need to be programmed? (I'm not very into programming, so I have no understanding of either one or how to program these.) 

Also, what are the main differences between FPGA and ASIC?

[crossrulz · Accepted solution]

To answer your initial question, cDAQ uses DAQmx while cRIO uses RealTime and FPGA.  Depending on your requirements, you can avoid writing FPGA code.

Now let's talk requirements.  What is your control rate? What are the safety concerns?  Are you logging any data?  If so, at what rate?

My general advice is any control systems should be done with a cRIO or an FPGA expansion chassis, mostly for reliability.

[XebeXUC]

Thanks for your quick respond crossrulz.

The project is still in quite an early stage. Also I'm pretty new to the entire control theory. So not everything is clear to me.

Could you enlighten me with what control rate exactly is? I suppose the rate at which your control loop runs?

The plan on safety is to shut down the oven, stop the pumps and close certain valves, of course depending on the severity of the problem.

I don't think data logging is neccesary, however for the early stage, in which we want to test the system (without using chemicals) it is probably a good idea to actually log/store the data. The rate doesn't have to be very fast probably (I'd say once per few seconds or even per minute maybe).

[crossrulz]

Again, I would go with a cRIO.  All of the control and safety logic should be in the FPGA.  I do this because if the RT decides to crash for some unknown reason (doesn't happen often unless people are stupid with the memory), the FPGA can still run on its own.  And since safety is the first priority for any control system, that FPGA has to be able to perform shutdowns when things go wrong.

You might also want to look at DCAF, which is a bunch of libraries NI Systems Engineering have been working on as an open source project.  It should be able to handle most of what you want for the RealTime part of the cRIO.

[XebeXUC]

Alright, thanks for the help, it's worth a lot.

One more question, just for the info, can both systems run without a pc connected to it? (after all the programming/installation is done)

[crossrulz]

A cRIO can run off on its own (I have done this many times).  In fact, you can get a cRIO-903X with embedded UI (haven't done this yet).

[XebeXUC]

and what about cDAQ, can that run on it's own?

[crossrulz]

I would never trust cDAQ in a control application.  There are cDAQ chassis with embedded OS (Windows or RT).  Last I looked, they tended to be more expensive than the cRIOs and you still do not have that hardware level of safety.

[XebeXUC]

Alright, well thanks a lot for your help