cRio controling AI/AO for Actuators/Motors without FPGA (Scan Interface Mode)

[MarMo]

Hello Folks,

As an beginner, here my Question about the programming of a Project i´m realising.

As read in the "Getting started" Tutorial by NI,:
"if an alarm condition occurs, you may want to 

monitor a physical process in more detail or observe changes in data over a
period of time. In order to do waveform acquisition of analog input data,
you need to use LabVIEW FPGA"

i try to build an Project in "Scan Interface Mode" (means without FPGA)
Only Using simple AO and AI Modules in my cRio Chassis.

The AI / AO variables / CHannels are then specified as simple DBL, and that´s the problem i Think.....

For measurement and control i would need to generate "continuous Signals" for the Actuators and Motors

So do i now have to get some FPGA Modules?

Thanks a lot.

[FelixDürnberger]

Hello MarMo,

First of all: Yes, you can generate a PWM without an FPGA module.

BUT the signal you're generating will be slower and less accurate than if you were using an FPGA.

If you want to generate a PWM with a frequency of less than 500Hz it will work just fine.

Have a look at this example. I think it will answer your questions:

https://decibel.ni.com/content/docs/DOC-11079

If you still have any questions feel free to post again!

Best Regards

[MarMo]

Thanks a lot, for helping.

And indeed i have another Question about the RT-cRio SetUp.

I´m tryiing to pass an simple Boolean-Trigger via my PC, throgh Network to my RT.cRio Module. 
More detailed, to my Statemachine, that gets called by the Top.vi.

on cRio i tryed to estabish an Statemachine, controled by the Rio Modul, but configurated by the User-Interface on my PC.

getting huge issues, with the Variables in My Project.

Modified them as RTFIFO Elements. But no Use ?!

Maybe some specialist 😉 could find the problem.

[FelixDürnberger]

What are the problems with the variables? Are the other variables working?

They should be working.

Please check the NI-DSM (Distributed System Manager) and check unter Network Objects if the variables are being sent to your cRio correctly.

If they dont change please try removing the variable and putting it back in.

If that doesnt work either try to deploy an empty VI with just a while loop and the variable and check the DSM again.

On A sidenote I also noticed that you are using Windows timers on a RT system, which you shouldnt use. There are special RT timers in LabVIEW.

Also you are displaying a message box on a RT system, which has no screen.

You might want to think about visiting a LabVIEW RT course.