connection to RT engine has been lost

[syed]

Hello ,

I am trying to run a VI (Labviews Communication wizard created NPL.vi) for FP 2000  system.

The problem is  some times when I start the Labview targeted to RT-Engine  program I immediately get the message "Connection to RT engine has been lost" .Some times it works fine.

Software :

Labview 7.0 (German Version)

H/W : FP 2000(Labview RT 7.0.0)

OS = Windows XP

Thanks in advance

Syed

[Jochen]

Here are some additional questions:

1. Can you ping the FP-2000 when immediately after you have received the error message?
2. Do you have another FP-2000? Does the problem occurr with that one, too?
3. Do you see the same behavior with another PC?
   
4. How is your network configured (peer-to-peer, company network,...)?
5. Is there the chance of an IP-address conflict?

Best regards,

Jochen Klier
National Instruments Germany

[syed]

Hello Jochen Klier ,

Thank you for your help

questions:

1. Can you ping the FP-2000 when immediately after you have received the error message?
2. Do you have another FP-2000? Does the problem occurr with that one, too?
3. Do you see the same behavior with another PC?
   
4. How is your network configured (peer-to-peer, company network,...)?
5. Is there the chance of an IP-address conflict?

Answers :

    1. Yes i can ping without error

    2. Yes i tried with other FP also it shows same error .

    3.Yes i tried with other PC's

             WindowsXP(Another)  : Same problums

              Windows 2000            : Same problums but less number of times  

   4. company network

    5. NO ,there is no IP-address conflict .

Procedure how i tested:

1.Created new Vi

2.Using communication wizahrd.

3. Shift to labvew   targeting RT    IP(192.168......) 

4.Run the program NPL_....Vi (System Generated)

Some times I get errors like Download fehlgeschlagen Three Buttons Dialog CORE.vi

Regards

Syed

[syed]

Hello Jochen Klier ,

Thank you for your help

questions:

1. Can you ping the FP-2000 when immediately after you have received the error message?
2. Do you have another FP-2000? Does the problem occur with that one, too?
3. Do you see the same behavior with another PC?
   
4. How is your network configured (peer-to-peer, company network,...)?
5. Is there the chance of an IP-address conflict?

Answers :

    1. Yes i can ping without error

    2. Yes i tried with other FP also it shows same error .

    3.Yes i tried with other PC's

             WindowsXP(Another)  : Same problems

              Windows 2000            : Same problems but less number of times  

   4. Company network

    5. NO ,there is no IP-address conflict .

Procedure how i tested:

1.Created new Vi

2.Using communication wizard.

3. Shift to labvew   targeting RT    IP(192.168......) 

4.Run the program NPL_....Vi (System Generated)

Some times I get errors like Download fehlgeschlagen Three Buttons Dialog CORE.vi

Regards

Syed

[Jochen]

Thank you for the information. To narrow down the issue could you please try if the problem persists with a peer to peer connection (using a crossover network cable or a hub/switch)? if this is not the case you should talk to your IT-administrator as there seems to be a network problem.

Other than that there could be several other reasons for the problem.

1. Maybe the vi is too big to fit into the onboard memory. In this case the download could fail or the device may reboot. Please refer to the information from the Real-Time System Manager
2. The vi might use too much CPU load. This could starve the communication process to the PC. Please make sure that your time-critical loop uses a wait function.

If these hints don't help please answer the following questions:

1. Do you loose the connection to the RT target even with no vi running on it?
2. Do you get the same error with a simple vi with low memory and CPU usage?

Best regards,

Jochen Klier
National Instruments Germany

[syed]

Hello Jochen Klier,

I can try with peer to peer connection but for that i should make new setup near testbench.Before that  i would like tell some other information

First time i trying  RT so i am using very simple example just DI read .And  CPU load shows > 95%  and program will hang(some times)

Q.' Please make sure that your time-critical loop uses a wait function. '

I did't find any wait function in my time-critical loop .could you please tell me some thing more about this.

Port numbers are taken randomly ,

Attachments : Test programme
Regards

Syed

[Jochen]

The VI that you have attached already uses a Wait function, timed with 30 ms so this should be ok. On the other hand this vi is not set to trime-critical priority. Is this the time-critical vi you are talking about?

In general wait functions are extremely important (not only) on RT targets. E. g. if you program a while loop without a wait function that generates some random numbers and you turn this vi to time-critical you will see a 100% CPU usage and most probably you will loose the connection between the host and the RT target when you run this program.

Jochen

[syed]

Hello Jochen Klier ,

Thank you very much for your help ,

As you said i tried with another PC and with peer to peer connection.Still i get the same errors .

Could you please advice me which other tests  i should do to narrow down this problum.

Attachments : Errors that i get frequently(.bmp)

Thank you

Regards

syed

[Jochen]

The FP-2000 is the FieldPoint controller with the smallest amount of memory. I'm pretty sure that the size of your vis causes the problem. Please have a look at this link for more information. Please take into account that all vis that are used as a subvi need to be downloaded to the target. That means even if your main vi is pretty small it could use large subvis causing the error.

Jochen

[tst]

Hello syed

I run on some FP2000 an application more than 1mb in size.

I had also rundomal problems traying running the VI from PC to FP target, and solved it in some different ways:

1. Change to FP2015

2. Build an application on the target FP instead of running the VI.

3. Stop all running applications on the FP before building the app.

hope it helps

Shimon