RT: Dynamic Event possible without polling?

[tomker]

RT Targets only support dynamic events as seen in this demo:

http://digital.ni.com/public.nsf/allkb/42B70D2D0C4B568586256E2F0051441D?OpenDocument 

the example uses: "Generate User Event" to fire an event.

The event is fired within an While Loop where two inputs are compared (polling the input all the time....)

I would like to generate an Event on a change of a variable without having to poll.

Is this possible?

thanks a lot

thomas

[Suse]

Hi Thomas,

you can use shared variables and LabVIEW DSC on your RT target without polling but otherwise there's no possibility to avoid polling completely.

Here are some interesting links on this issue:

"Installing LabVIEW DSC, SQL, or MSDE on a Real-Time Target": http://digital.ni.com/public.nsf/allkb/52CC76196A480C6C86256F8900592A25  

This page contains also other interesting links on this issue!

https://www.ni.com/en/support/documentation/release-notes/product.labview-datalogging-and-supervisor... 

"Using the LabVIEW Shared Variable": https://www.ni.com/en/support/documentation/supplemental/06/using-the-labview-shared-variable.html 

"Using Shared Variable Events on Real-Time Targets": http://digital.ni.com/public.nsf/websearch/3AE325EECD9A17AD862570BA00625088?OpenDocument  

The DSC features of the shared variable are limited to use on Windows targets, however you can host variables on a Windows machine and reference them on a real-time target. Another option is to create two sets of shared variables, one set hosted on the Windows side and one on the RT side, with each variable on the Windows set bound to the corresponding variable on the RT side. This would allow you for example to log data on a variable, but have it hosted on the RT side with no network dependency on the RT side to the Windows side.

I hope these informations help you!

Best regards

Suse

[viScience]

Unfortunately, the only blocking method to read NSV's is with Data Socket where you can check for a timeout condition on a read.

[tomker]

Thanks for your help,

I now understand that there is no reasonable dynamic event possible in RT.

DSC doesnt help at all, cause its not working on RT.

I need relyable events on RT for some emergency stops within process.

So I will poll the boolean inputs for that

tom