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ERROR->1073807339 occured at VISA read in Labview->

I'm using LabView7.0 profesional edition and a begineer in LabView.
I'm using PIC18F4520 microcontroller to communicate with the serial port RS232 and transmit the data whatevr it is receiveing immediately using asynchronous EUSART , but everytime i run provided in examples i get the error - 1073807339 occured at VISA read in LabView.
I have preformed the loopback test in Labview and it is doing well and other configurations of COMM1 port are correct to my knowledge..
I'm attatching the code written in MPLAB IDE for PIC and the i'm using present in the installaiton examplesfor the same.
Please help me in debugging this problem as i'm out of ideas now
hoping for a helpful hand asap...........
Message 1 of 19
Have you already checked the baudatm, parity, start, stop bit. We are using also PIC's and never had a problem to make any communication to LABView.
Message 2 of 19
I tried using my code in hyper terminal it is able to send and receive data but in labview it is continuously creating such problems and giving the same error i have checked the baud rate parity bits and stop bits etc.
but nothig seems to wrktillnow
please help as im getting stuck
Message 3 of 19

Here is the definition of the error code:

"VISA:  (Hex 0xBFFF0015) Timeout expired before operation completed."

How did you implement the serial read in Labview?  You mentionned that you are using the example.  I'm assuming it is the one that came with LV.  The first thought would be to simply extend the timeout duration...  however...

The code shows that REGisters are set for Tx & Rx.  However, I do not see how the data / info is sent to the serial buffer.   What value are you wiring to the Serial Read input (bytes available at serial port)?  and how do you determine the value?   One example with LV7.1 uses the Property Node to read the number of bytes available at the serial port.  If you are using something similar, what is the value for the no. of bytes at the port? 

There is an advanced example that forces to read a certain amount of data or timeout.  It also indicates how many bytes it actually read.  If it is not able to read the number of bytes requested, then it will generate a timeout error.  See images below:



Basic Example


Advanced Example:

Message Edited by JoeLabView on 05-11-2006 08:32 AM

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Message 4 of 19
And double check to see if you are sending the correct termination character. In the shipping example called Basic Serial Write and Read, the last two characters in the default string to write is \r\n which are carriage return\line feed. You probably need to include these in the actual  commands you send.
Message 5 of 19
Thanks a lot
 for the support providid any way i figured out my problem and have modified  my vi i'm atttatcing it...which can be of help to someone else............
thanks once again
Message 6 of 19
hI, Rohit
i'm also facing a same problem what should i do . see attach.
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Message 7 of 19

Why are you posting to such an old thread?

The error you have is common and numerous solutions have posted. Did you search the forums for that error code? A common mistake is not using the correct termination character. Since all you posted was an image and not the actual VI, it's hard to say if you have set the write buffer control correctly as mentioned above but it's definite that no termination character is visible. Another common error is using the wrong type of serial cable.

Did you do any basic troubleshooting like checking communication with a program like Hyperterminal?

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Message 8 of 19

Hai, Mr Dennis

Thanks for your reply and comment.

actually my comm serial cable is ok through checking with hyper terminal and what you mean by 'not using the correct termination character'. sorry for this question?



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Message 9 of 19
I have a device that measures the blood pressures. I've writed the following vi. When the device finishes the measurement it sends a string "\02999\03" when I recieve it I send the command to request the measurements from the device. 2 questions?

1)Is my vi correct?
2)I want the measurements stay on the screen till I press a boolean. How can I do that?

Message Edited by treadagon on 06-09-2008 03:38 AM
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Message 10 of 19