wait for Real-Time Target to respond

[FluffyBear]

Hi, guys,

We're using Real-Time target to do car simulations, and it gives all the information back to our host. Now it keeps disconnecting the communiaction between the host and RT target (Wait for Real-Time Target to respond). We saw some threads on the forum, but kind of blur to us. We're using LabView 2011 to do the design. On the target it runs some simulation and real-time communication using a proprietary real-time ethernet. All the computation is in a timed loop. The period is 1ms, and CPU utilization is not that high (just about 10~20%). So could anybody drop some hints that what we should do?

Thank you!

Zhenkai

[Alhern]

Hi. Can you give me some more information about your problem?

What's the RT target you're using?

Have you tried monitoring the target through MAX (Measurement and Automation Explorer)while it's operating? If it's a communication error you won't be able to view it in MAX. Otherwise you probably have an error in your code that's causing the communication to time out.

Can you show me the communication part of your VI?

You might want to try reformatting your RT target and reinstalling the software to solve the issue if it was caused by a faulty installation. However reformatting would erase any partitions that you might have on it (if it's a PXI target).

Regards.

[FluffyBear]

Hi, Aldo,

We are using a four core Desktop that was converted to a Real-Time target. We use a host machine to build the VI and then deploy the VI on the target for execution. MAX sees the real-time target and we've tested it with various other VIs and it works well.

We have a VI that runs on the Real-Time target Labview Real-Time Module. The VI contains an interface to CarSim for executing the simulation of the car. This part is tested and runs well.

We also have another component that essentially retrieves data from a PCIe component on the Target. This data is used as control input to CarSim.

CarSim when executed on a Real-time Target also has a feature for streaming the live video of the car simulation.

We use a timed loop with a period of 1ms to execute the computation and update. The CarSim interface and the component for retrieving information from the PCIe are both in the timed loop. When we run the CarSim interface alone everything works fine and the live video streams as expected. Also, when we run the PCIe component alone without CarSim in a time loop of 1ms, data is retrieved appropriately and everything works fine but then when we combine the two in a single time loop. The issue arises -- "Wait for RT-Target to Respond".

We also tried running each component in distinct timed loops but in the same VI and the issue persists, even each timed loop is assigned to a distinct processor core.

Any ideas to get rid of "Wait for RT-Target to Respond"?

Thank you!

Zhenkai

[FraggerFox]

Would you be able to post the communication part of your application?

What functions are you using to communicate between RT and Host? Are you using shared variables, or are you using TCP/IP functions?

Also, it would be great if you post what you are doing on the host side and what kind of communication is happening between host and RT.

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@FluffyBear wrote:

CarSim when executed on a Real-time Target also has a feature for streaming the live video of the car simulation.

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Does this mean that CarSim runs on RT target and stream video data to host through ethernet? How does the live video streaming work?

[FluffyBear]

What functions are you using to communicate between RT and Host? Are you using shared variables, or are you using TCP/IP functions?

We have a single VI file and deploy the VI file on the RT target and run, and we use the host computer to view and control the parameters. So I'm not sure what you mean by communication functions (we are novices of LabView :-))

Also, it would be great if you post what you are doing on the host side and what kind of communication is happening between host and RT.

The host just receives some data from the target including the video data, some string values and some integers.

Does this mean that CarSim runs on RT target and stream video data to host through ethernet? How does the live video streaming work?

Yes, all the communication between host and RT target is through Ethernet, and the live video streaming has a buffer at the RT target, and the target sends the video stream back to the host.

[Alhern]

Can you post the communication part of your code? That is the part of your code where you send data or video from the target to the host and vice-versa.

If we can take a look at exactly what you're doing to communicate it will help a lot in determining the problem.

[FluffyBear]

Execuse us as LabView novices:

so actually we don't directly use a communication part (they are black boxes for us):

here's our modeling procedure:

in a timed loop, which uses 1 ms period, we add some commercial blocks to do our functions, and these blocks have outputs which will be plotted using some indicators.

then we deploy this VI file on RT target and run it. During its running, the indicators give us the values.

So I guess the communication part is in those commercial blocks? so I want to ask what exactly the target communicates with the host?

Thank you.

[FraggerFox]

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@FluffyBear wrote:

so I want to ask what exactly the target communicates with the host?

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The target communicates/sends video stream data over ethernet to the host. Search for some VIs which might include IP address of your host system wired to some function. That part of your code is the communication VI.