07-19-2010 10:52 AM
Hi, im going to start using use my compact rio controller and modules soon. But i need a starting block, when i have used compact fieldpoint in the past. It had its own vi's, does compact rio have the same and if so is there any basic read multiple channel i/o examples?? that i can build on.
Stu
07-19-2010 11:09 AM
A good place to start would be to go to help > find examples. Then select Hardware Input and Output > Compact RIO. There are a lot of example VIs on how to work with the cRIO devices.
Knowing if you will be using scan engine, FPGA interface, or some hybrid of the two will tell you how in depth you need to go. I would say the basic IO examples would be a good place to start
07-19-2010 01:12 PM
Hi,
Did you use a RealTime cFP system or just an ethernet cFP?
Anyway: Programming a cRIO system is a little bit more complicated then programming a cFP, especially if you need to program the FPGA yourself. If you use the Scan Mode, then it's easier.
My tipps:
1. Go through the getting started steps.
2. Read the user manuals of your HW.
3. Use the "LV Example Finder". There are a lot of cRIO examples.
4. Read the cRIO Developer Guide.
5. Probably the best option: Attend a LabVIEW Real Time and LabVIEW FPGA course.
07-20-2010 11:51 AM
Hi guys thx for the replies. Think i am going to use scan mode on the rio and use the shared variables. Seems more simple, also i will have 300 inputs so it may be easier to organise in Labview.
07-20-2010 11:59 AM
Stu,
If you are going to have 300 inputs you might want to consider the programmatic api for Scan Mode I/O.
See this white paper for more information. http://decibel.ni.com/content/docs/DOC-6063
Sebastian
07-21-2010 11:10 AM
Also if you have 300 inputs, you may not be able to use scan mode at all, depending on your desired data rate. As you add channels to your scan interface, your highest possible data rate decreases. You can look at the performance benchmark chart for scan engine here: http://zone.ni.com/devzone/cda/tut/p/id/7792
FPGA interface can be quite challenging if you are new to Labview. If you must use it, just be sure to start with example VIs and modify as necessary. Just a tip, each different module type should be in its own acquisition loop in your FPGA program because they have different clock speeds and types.
07-21-2010 12:52 PM
Hmmm..got a dilema. try scan mode or go with FPGA??. Then again i could use queues. The rio i will be using is the NI 9025, also ideally need to scan all channels within one second. Should be doo-able.
07-21-2010 02:13 PM - edited 07-21-2010 02:14 PM
Yea if you only need to scan once per second (1 Hz) I think you will be fine using scan engine. The 9025 is a really sweet controller too, so I seriously doubt you would have a problem.
What modules do you plan to use?
07-22-2010 01:02 PM
I plan to u NI 9208, 9213.
07-22-2010 02:49 PM
Both of those modules have 16 input channels. The maximum number of modules a chassis can hold is 8. So 8 modules at 16 channels each is 128 channels of input. So... how do you come up with having 300 inputs?