Substitute for Real-time Remote Panel without NPAPI

[Matt_Dennie]

I have an existing Real-time application that runs on a cRIO. Using the traditional LabVIEW Remote Panel VI, I can view the the real-time VI's front panel in a web browser AND I can control the running VI through the remote browser.

With the decreasing availability and support for IE (the only browser still supporting NPAPI), I've been researching NXG WebVIs as LabVIEW Remote Front Panel Alternative Without NPAPI.

So far I'm struggling to understand how I can achieve the same functionality as the old fashioned remote panel:

• Connect to an already running real-time VI on a cRIO
• Receive front panel updates of the current data refreshed automatically at some interval
• Interact / control the real-time VI

Are NXG Web VIs capable of all these things? If not, are there workarounds or other approaches that have these capabilities?

Currently I don't need a separate web server, or system link server, to get this capability. I would prefer to avoid it if possible. The built-in webserver is sufficient for the existing remote panel.

Although the machine running the remote panel VI needs to have LV Runtime Engine (LVRTE), it doesn't require the specific VI or application be installed.

Thanks for looking over my challenge, and I appreciate any suggestions!

-- Matt

[dhardweaterford]

Matt,

NXG Web VIs can do all of the listed. Im currently doing a project where I need to do exactly what you are asking. You can connect to your running VI on the c-RIO with Websockets or Web services (Im doing this), you can use the data from the c-RIO to post the same info as on the front panel to the WebVI and control from the UI using the same methods. 

There is a process to start hosting on the c-RIO here: https://www.ni.com/documentation/en/labview-web-module/latest/manual/hosting-web-application-on-serv...

[Matt_Dennie]

Thanks dhardweaterford for confirmation. Now I just need to understand the methods. Any help is appreciated, or an example if you have one.

Does your NXG WebVI communicate with a current gen LVRT VI using web services? How does the current gen VI publish it's data and controls?

[dhardweaterford]

Matt_Dennie

The methods are mostly the same as you are used to. Move data from the RT code into a data communication scheme as you see fit (Shared variable, FGV, web sockets, etc..) to the web service. The web service Vi handles any transfer from the WebVI located on the browser and vice versa. 

In my current project, I simply created shared variables for the data i wanted to send. I put a write access in the Real time code and a read access in the web service. Connect the inputs and format the web service. Then simply use the HTTP request (usually a GET) to request the data. 

Go here to view examples of webservices and other ways to use the Web vi to move data over.