"Waiting for RT tartget to Respond'"- how to prevent this message.

[hema]

Hello.

I have cRIO 9014 and am using NI 9215 modules on LabVIEW 8.6

When I run my RT program , i get a message "Waiting for RT tartget to Respond. Stop Waiting and Disconnect"

Why is this message  appearing. Then after few seconds, i get message failed to connect to RT target.

If i see in Max,  connection status would be disconnected even if there is no problem with physical connection. I have to switch off and ON the controller, and then the status becomes "connected".

Sometimes, after getting the message, when i see in MAX, the status would be still connected and running. Then ,i have to again run the VI.

Please let me know how to get over this problem. In my Real time VI, i have RT FIFO , TCP Listen ,TCP Write to transfer data to windows and FPGA reference going to multiple parallel loops within the VI.

Thank you.

[AdnanZ]

Is it possible for you to post your RT and Host applications? I am sure this is more a case of assigning priorities and putting some Waits inside the loops that are based on the RT side. This is all a guess right now; if possible, post your applications and we can help you out better. Also, have a look at some of the examples that are provided with LabVIEW and try to run them and see if you are getting any problems.

[hema]

Hi Adnan,

I was getting FPGA error as "Transfer did not complete within the specified amount of time or within specified retries" when i was reading 100000 elements from the DMA FIFO . I found out (if i am correct) that this is causing problems and showing status as disconnected. I made elements as 48000 and depth of FIFO also as 48000. now the message does not come up.

Thank you.

[AdnanZ]

Is it possible for you to post a screenshot of your read method? I think you could use a more efficient way to get the data values which could prevent the error.

[hema]

Hi Adnan,

I hav attached the pictures of the RT and windows VI, In the RT VI, i have depth of FIFO as 40000. I place the data read from FIFO into the RT FIFO write. Then in another VI, i read RT FIFO and place data into TCP Write.vi

I do not have any back log that is no. of elements remaining comes as zero in FIFO read.

I have attached the winodws VI where i do TCP Read and decimate the array to get the 8 channels plot . i have 8 channels of 9215 to be read in windows. I have used 8 build arrays because the user needs to see every second log of data on the waveform graph.

For every iteration, i get 5000 samples on each channel. ( that is 40000/8) . but i have to get 50,000 samples per second on each channel.

I give i value as 10 , to get 50000 samples( i am measuring 50 HZ signal). Now the problem is that the waveform graph plot is very slow.

It becomes more delayed if i have to see 9 seonds of plot. when i give no. of iterations as 90.The waveform graph should plot 9 * 50000 samples.  So what should have plotted in 9 seconds take around 18 seconds to plot.

In the RT VI , i have count in microsecs as 20 micro sec assigned to NI 9215.

How to get over the delay in the waveform plot on windows.

Thanks.

[Fercho8]

Hi I have exactly the same issue.

I verified and the CPU is in approx 60%. But for some reason while I'm running the VI, it gets disconected.

Attached the 2 VIs (working the cRIO as Scan Engine)