NI 3100RT and display

[JChec]

Hi,

I am required to develop a real time application, but to display a front panel on a 40in screen. User interaction would be through a mouse.

Initially I would think to use a RT controller and a PC for the front panel... maybe even the 3100 with hypervisor, but is there anyway to use just the NI 3100RT without having to communicate to windows?

Is there USB support on the RT controller? So I could get USB mouse input.

And are there limitations to the display from this controller when using just the RT version?

Thanks,

Jevon

[Logan_H.]

Hey Jevon,

So, I want to address your last question first:

"And are there limitations to the display from this controller when using just the RT version?"

Yes. The limitation of a Real-Time operating system is that there is not a user interface. This is because UI's (and especially Graphical User Interfaces) are very processor intensive, and detract from the deterministic goal of Real Time.

In fact, when a VI is deployed to an RT target, only the block diagram is sent, not the front panel.

Now, there are ways to interact with a Real Time application once it is deployed. The most common method is to host a Shared Variable on the RT target and building an application on a development machine running a General-Purpose OS (Like Windows) that reads these Shared Variables and maybe writes some of its own to be used to control the RT Application. This Developer Zone article is a great resource on Shared Variables and their use in an RT Application.

Another method would be to host a Remote Front Panel on the RT Target which is saved as an HTML file that can be accessed in a web browser on any computer in the subnet. This, in essence, gives the RT Application a Front Panel that can be used to interact with the block diagram code behind it. The process for creating a Remote Front Panel for an RT Application can be found on this Knowledge Base article.

I completely support your idea to use Hypervisor as it allows for the two machines necessary to run and interact with an RT Application to coexist inthe same machine.

[JChec]

Hi Logan

Thanks for your explanations! I've used the methods with an OS like windows and also the html before, but thank you for explaining those options.

So now for the questions of  USB and display limitations... I'm asking about usb support not just for an input like for a mouse (which is no longer needed tho), but just generally. Using it for other usb devices, flash sticks etc.

Display limitations.... my understanding is that I'd be able to display images from an RT. In a previous app, we used a CVS and displayed images to a screen. On the NI 3100RT there is the DVI port, would I be able to display images to screen through that port using my RT app?

Thanks,

Jevon

[Logan_H. · Accepted solution]

Hey Jevon,

When it comes to the USB ports on the NI 3100RT, they do support a keyboard and a mouse. However, these are only really used to set the BIOS and don't do anything during execution of an RT Application as user interfaces are not deterministic. LabVIEW RT supports USB storage devices for data logging and will show up as another drive on the RT Controller. Some great info on the caveats of using USB on an RT Target can be found on this Knowledge Base. Flash drives is about where the USB support ends for RT OS's so plugging in a USB Printer, wifi card, blinder (maybe?), it probably won't work.

On to the display. The VGA and DVI outputs on the controller are usually just used to show the Terminal or BIOS screen of the controller but can also be used to display images using the IMAQ drivers. Probably the most common use would be using the monitor to display the video coming from a real-time camera.

Attached is a piece of code using the IMAQ RT Video Out.vi to create an RT Screensaver!!

Logan H