Erreur 63 : Serial Port receive buffer overflow

Hello
J'ai un problème avec les blocs get.vi dans mon programme
Je fais une boucle for qui compte les heures et après environ 200-300 fois j'ai une erreur qui survient (erreur 63 : Serial Port receive buffer overflow)
A l'intérieur de la boucle j'exécute la commande get.vi plusieurs fois pour différents cas à chaque incrémentation de 1h.
Merci d'avance
En annexe, mon vi principal
Pièces jointes :
regulation.vi ‏462 KB

Du fait de certains vi manquants je ne peux pas executer votre code, Parmis le nombre important de vi GET HTTP, savez-vous lequel est responsable de l'erreur ?, et est-ce toujours le même ?
L'erreur renvoyée concerne le port série, quelle est la configuration de ses buffers d'entrée / sortie (visible dans le gestionnaire de périphérique)
Cordialement,
Vincent.O
National Instruments France
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I want to replicate the entire VB program as Java Program.
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Serial Port Overrun

Hello All,
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Attachments:
Serial Port Error.jpg ‏63 KB

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please use the [ code ]and [code ] tags for code.
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I use PCI-6034E for measurement. After DAQ gets data, I send them to another computer through serial port (com1). I write a Virtual C++ program, which calls NI-DAQ library functions to implement DAQ data sampling (multiple channel scan) and sends measurement data to another computer through serial port under request. DAQ data sampling and serial communication are implemented in two threads. They are running concurrently. They share a global memory for measurement data. The serial communication thread will do infinite wait and send data only when another computer sends a request through serial port.
I met two problems. First, when I reduce the size of DAQ measurement buffers (piBuffer and halfpiBuffer, I us
edouble buffer model), DAQ measurement is often interrupted by the message "[DAQ_DB_HalfReady] returned NI-DAQ warning 10846. Your application was unable to retrive data from the background acquisition buffer fast enough so the unretrieved data was overwritten with new data. ...". I want to get run time data so I need to reduce the buffers as small as possible. How can I solve it ? The second problem is that the serial port gets error data (nothing) from measurement computer sometimes, especially when DAQ initializes itself and finishes work. It looks like that there is a conflict between DAQ and serial port. Does anyone have similar experience about this? Any suggestion?
Thank you in advance.
Le Cai

Le Cai,
You are correct that the number of scans to read is equal to half of the buffer in double buffer mode. I was mistaken and referring to a standard (non double buffered) operation. However, you can increase the size of your buffer without affecting the period of your acquisition. A buffer of 60 is quite small and, as such, will be more prone to overflow errors. The rate is actually set through the DAQ_Rate() and DAQ_Start() functions. For more information on these functions and how to configure the scan rate, please see the NI-DAQ Function Reference Manual.
NI-DAQ Function Reference Manual for PC Compatibles
http://digital.ni.com/manuals.nsf/websearch/1630A0B68738B269862567C1007A2912?OpenDocument&node=132100_US
A good place to start would be the example titled, "DAQdoubleBuf.c" which ships with the NI-DAQ driver. If you installed the examples for Visual C++ when you installed the NI-DAQ driver you should be able to find this example in the \Program Files\National Instruments\NI-DAQ\Examples\VisualC\AI folder on your computer. This example would be a good template as it is very close to what you are trying to do.
If you observe that you only receive the overflow error when you are operating the two threads, thus ruling out the buffer size as being a potential problem, you may want to examine whether or not your second thread is placing a lengthy exclusion on your data buffer during the period when your first thread is trying to move the data. If your first thread has to wait during the half-buffer transfer this could easily cause the overflow, as the acquisition would be running but the transfer would be paused. Instead of placing a mutual exclusion around one piece of global memory you could try using a queue instead. A queue approach will allow you to pass the data from the first thread into a queue to be read, when convenient, by the second thread. In this method the first thread would never have to wait as the transfer would just be a handoff.
Regards,
Justin Britten
Applications Engineer
National Instruments

0 bytes at serial port after Visa Write

Hi,
I'm having problems communicating with a Pollux box controlling a stepper motor (both from Micos). The Pollux box has an RS232/485 connection to the computer.
I have tried adaptations of LV's Basic Serial Read and Write example. Even for the basic example there has never been any bytes at the serial port after the write.
I have attached some sample code for LV 10.0.1(64bit) and the OS is Windows Server Enterprise 2008.
The Visa drivers have just been installed.
After some research I have added a 'Set I/O buffer size' as advised by http://digital.ni.com/public.nsf/allkb/60DDFED7EFEFE7188625705700750821?OpenDocument
The time-out is set to 10s, I have a wait of 1s before read and 0.5s between each write (the characters are written individually incase that was the problem).
The write command getaxisno_ should reply with the default axis no which is 1. However, there is never any reply.
The termination character for Venus2 is a space for transmitting commands and ASCII CR LF at the end of received data.
I'm not sure what else could be wrong. According to MAX the device is working properly. Although, when I try to open a Visa test panel in MAX the program crashes. I'm not sure if this is a related problem.
I'd be really grateful for any advice, have been trying to fix this for a few days now.
Thanks in advance!
Ciara
Attachments:
Getaxisno test.vi ‏18 KB

Thanks, I'll search those now.
When I click the test panel button, the Max window disappears and the program is closed. Next time I open it an Unexpected Error box opens with a message saying there was an unexpected error and I should search Info Code MAXKnownException.
'The exception occurred in the NIMax process in the function (Unknown).'
I have searched this and the info advised me to send a report with log files etc to NI which I have done. Just waiting on the reply.
I copied the Visa resource name from MAX and the termination character is the same as what a previous owner of the equipment used in Visual Basic.

Serial port prob

Hi,
I'm testing some application using javax.comm.* serial communication package.
Problem some data is missing after some time connection, any one have any clue?
Below is the code snippet.
====================
Open Connection
=============
public void openConnection() throws SerialConnectionException {
          // Obtain a CommPortIdentifier object for the port you want to open.
          try {
               portId = CommPortIdentifier.getPortIdentifier(parameters
                         .getPortName());
          } catch (NoSuchPortException e) {
               throw new SerialConnectionException(e.getMessage());
          // Open the port represented by the CommPortIdentifier object. Give
          // the open call a relatively long timeout of 30 seconds to allow
          // a different application to reliquish the port if the user
          // wants to.
          try {
               sPort = (SerialPort) portId.open("SerialDemo", 30000);
          } catch (PortInUseException e) {
               throw new SerialConnectionException(e.getMessage());
          // Set the parameters of the connection. If they won't set, close the
          // port before throwing an exception.
          try {
               setConnectionParameters();
          } catch (SerialConnectionException e) {
               sPort.close();
               throw e;
          // Open the input and output streams for the connection. If they won't
          // open, close the port before throwing an exception.
          try {
               sPort.setInputBufferSize(999999999);
               os = sPort.getOutputStream();
               is = sPort.getInputStream();
               dis = new DataInputStream(is);
          } catch (IOException e) {
               sPort.close();
               throw new SerialConnectionException("Error opening i/o streams");
          // Create a new KeyHandler to respond to key strokes in the
          // messageAreaOut. Add the KeyHandler as a keyListener to the
          // messageAreaOut.
          keyHandler = new KeyHandler(os);
          messageAreaOut.addKeyListener(keyHandler);
          // Add this object as an event listener for the serial port.
          try {
               sPort.addEventListener(this);
          } catch (TooManyListenersException e) {
               sPort.close();
               throw new SerialConnectionException("too many listeners added");
          // Set notifyOnDataAvailable to true to allow event driven input.
          sPort.notifyOnDataAvailable(true);
          // Set notifyOnBreakInterrup to allow event driven break handling.
          sPort.notifyOnBreakInterrupt(true);
          // Set receive timeout to allow breaking out of polling loop during
          // input handling.
          try {
          sPort.enableReceiveTimeout(30);
          } catch (UnsupportedCommOperationException e) {
          // Add ownership listener to allow ownership event handling.
          portId.addPortOwnershipListener(this);

Placing a delay is not the solution.
Have a look at the code snippet that I posted here:
http://forums.ni.com/t5/LabVIEW/Reading-time-interval-of-serial-port/m-p/1529140#M568806
The modified code is also attached in that post.
The solution is to place the serial read inside a loop which continues to read until there is no more data in the buffer.

Erreur 63 : Serial Port receive buffer overflow

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