Similar Questions

• Reading of the zeros of a DMA FIFO empty

  Hello

  I'm having a problem using the DMA FIFO to communicate between my real-time system and my FPGA. I use two DMA FIFO, one-way to the FPGA of the RT system and then vice versa. I can successfully get data to and from each system; However, before, after and sometimes inbetween my data, I'll get a seemingly random assortment of zeros. In the latest version of my code (which I have provided) I read the number of items stored in the DMA FIFO and read only this number to my RT system to try to get the data that I want and no zeros, but this does not work either.

  I'm new to both in real-time and FPGA and so it certainly feels like I'm missing something very basic. I tried dealing with this problem by myself well and have had absolutely no success and would appreciate any help.

  My equipment includes:
  A Dell laptop (used as a host of the user interface)
  1082 chassis
  Controller of 8133 (running the LabView RT operating system)
  7965R FPGA
  5781 module for FPGA (not currently in use)

  LabView 2014 SP1

  On the side of RT, you need to use a structure of the case so that you have not read of the FIFO if no data is available.

  I would also like to change the flow of network to be inside of your time in a loop until the user interface capturing each data point, as it comes (connect before the loop, close after the loop and write it as the data come from the inside of the loop).  This will save memory (which is VERY important in a RT system) since you don't have to set up the table.

  You write only as an element in the FPGA.  So any sous-suite readings should give you an array of 0 s, causing 0s back upward.  You must maintain the Timed Out in the FPGA so that the data will only until to the RT when there is real data to send.  Your FPGA code could be reduced to this:

  

• Visa read stops execution

  Hi all

  I have a little problem with the control of my power supply E3631A Agilent via Labview:

  I downlaoded all drivers and with the help of you guys I even persuaded that it is running properly.

  At least that's what I thought.

  Turns out he didn't really. At some point the VI just stops.

  Using the execution mode of nail I knew where the problem was:

  The VISA read error query of the configure output has stopped working.

  I have no explanation for it. I get unpredictable and I have not yet managed to influence by changing the different settings.

  (And I tried it for a while now..)

  I built a very simple example VI to show you where the problem lies.

  Explanation:

  I'm basically feeding the output a voltage variable and at the same time measuring how long the vi fonctionnee already has...

  I thank you very much in advance,

  keksbold

  OK it looks like as the time to copy this section of the FAQ: (posted in a place not yet public ~ ~ ~ Hey Jordan? is still FAQ on the right way?)

  "

  In this topic, we will discuss some of the common problems that have been observed using devices with LabVIEW on Windows operating systems.  Many of these points apply also in other environments, but the examples will use the Windows 7 operating system.

  FAQ 1: USB device stops working unexpectedly.

  The first thing to look at is the OS power save options.  There is a global trend towards "Green" electronic development and energy the coast to stars become fairly common.  "If his is used not to turn it off" is not new.  Cave men learned how to Bank a fire in order to preserve the energy that would otherwise be wasted.  Similarly, the Windows operating system has an energy saving function to stop power to the USB hubs when no user activity is present.  In automated systems, this feature can cause problems since remove power USB hub will stop the USB device.   Solution: use Device Manager to change the Power Options USB hub.

  

  FAQ2: I put the power options and my device connection is still not reliable: Don't forget, the USB ports on the computer are often the least expensive that can be mounted on the chassis and system share the PC power supply USB-powered. Most of the uses of USB are temporary connections such as a USB key or a camera.  These connections don't require high reliability because there the user interacts with it.  Mounted sudden power and fault tolerance at worst cause the operator to retry the transfer of data.  Automated systems require a bit more robustness.  Solutions:

  1) ALWAYS use a free external powered hub. Perform your due diligence genius and to inspect devices specifications too - if you do not find them for this device which should clue pick you a product from a vendor who published their specifications.

  2) high noise environments require the use of ferrites on the USB cable- and do not buy the cheapest cable either! The good markets are poorly protected.

  3) PROTECT connections HUB-if you have a USB 2.0 device and Joe User plugs in a 1.0 device into an open slot, managed by the same hub-Bingo all ports on the rear hub can convert USB1.0.  WORSE, there are a lot of damaged or marginally engineered USB devices out there.  Joe User should cause power fluctuations when it is inserted or removed from the hub just don't let it happen!

  FAQ3: I test USB devices and the operating system can not find more.

  It is a Plug-and-Play feature that deserves exposure.  When you connect a device P - n - P BONE remembers his serial number in an entry in HKEY registry (hive-Key).  This is useful when (for example), you want a specific instrument, say a NOR-USB-6008, to appear as a device DAQmx with VISA Alias "MyDAQ1" whenever it is plugged.  On the other hand, if you want to test a range of USB-serial converters that can be problematic because the pilot of P-n-P will mount the first serial number like "COM3" and the other as "COM4" Add infinitum until the controller of the enumerator in the registry and the VISA recognized alias adjust upward.  Solution: use the Windows registry API and the API of hardware in LabVIEW to clear unused VISA alias and HKEY entered.   Speak with your professional COMPUTING staff structure HKEY and possible side effects before developing a plan to modify registry entries.

• How to change dynamically using visa without stopping the program of baud rate?

  Hello, is there a way I can change the speed of read/write VISA on the fly?

  Please let me know.

  Thank you

  
  

• VISA Read (error BFF0015)

  Hi all

  I use COM VISA library and c# communication with my instrument via TCP/IP.

  I add the reference "VISA COM 3.0 Type Library ' to my c# project and try to establish communication using the following codes:

  *********************************

  Ivi.Visa.Interop.ResourceManager ResMsg = new Ivi.Visa.Interop.ResourceManager ();
  Ivi.Visa.Interop.FormattedIO488Class ioClass = new Ivi.Visa.Interop.FormattedIO488Class ();

  Imsg = Ivi.Visa.Interop.IMessage (ResMsg.Open ("TCPIP0::192.168.0.170::10001:OCKET", Ivi.Visa.Interop.AccessMode.NO_LOCK, 8000, "") as IMessage);
  ioClass.IO = Imsg;

  ioClass.WriteString ("* RST", true);

  ioClass.WriteString ("* IDN?", true);

  String ret = ioClass.ReadString ();

  Console.WriteLine ("ID:" + ret);

  **********************************

  I could write "* RST ' command to the device without errors. And I could see that the device really do a reset of the command.

  But when I send "* IDN?" and read the answer, I still get a TIME_OUT error. Even if I add "\r\n" at the end of the command and increase the value of the time-out period, can I still the same error. Not only "* IDN?" but also another order of reading as "* STB? ', they all can the same timeout error.

  But when I use the VISA-ReadSTB function, it returns the correct data.

  I also tried to use Labview VISA-open, entry VISA, VISA-read for the same test. I also have an error (BFF0015) after VISA-read.

  I also use a programm IO monitor to view the data. I find that I have seen the answer, but I still have a time-out error. Currently, I could only read the answer by Agilent IO control successfully.

  I'm using c# 2008, Labview 8.2.1, VISA 5.0.3

  Any notice will be really appreciated!

  Kind regards

  Please take a look at this KB. Maybe this can help you solve your problem.

  Why should I receive Timeout error-1073807339 on VISA Read or Write?

  http://digital.NI.com/public.nsf/allkb/874B379E24C0A0D686256FCF007A6EA0?OpenDocument

  See you soon

• Stop the VISA to send automatically the characters of endpoints on read

  Is there a way to stop the VISA to send characters to the endpoint on read? The instrument that I'm trying to contact (Olympus IX-81) requires 2 of them and it seems to be quite the hassle to implement both in a single command. I think it would be easier to write just manually with every order.

  Please do what I asked you to do in your other thread. Simply right-click on the control of the chain and it is said Normal display-display or display Hex Codes. Place a probe on the string to write VISA entry and indicate exactly what the probe has. You have the instrument and the code and here is the troubleshooting steps based. You can also turn the tracing OR in MAX and set track or report what he said. You said that he worked with MAX so a comparison with the string sent there and what the VI sends is an important step to isolate the problem.

• How to stop the series 'VISA read' the sends packets instead of bytes available.

  Dear Labvillians,

  Highlights:

  How can I stop series "VISA read" send me packages rather bytes?

  Background:

  I have a system which publishes series of 14 bytes on a semi-regular interval packets.

  At busy times, the producer of these these queues of data packets, effectively producing Super-paquets multiple of 14 times larger than 8 packages (112 bytes) bytes.

  My protocol handler is designed to process bytes, packets, or packets Super.

  Now, my request has multiple devices and the order of message processing is essential to the proper functioning.

  My observation is that read VISA waits until the end of a package / super package before moving the data to the application code. (See chart below)

  My expectation is that VISA read should give me bytes available, get too smart for itself and not wait for a package.

  

  .

  

  I noticed this on PXI, PC shipped, PSC and, more recently, cRIO

  I've experimented with Scan interface the cRIO rate, which helps to reduce the backlog of packages but don't decide to package under read byte.

  I understand that a solution is FPGA code write to handle and pass the bytes by R/T-FIFO, and there are some great examples on this site.

  Unfortunately, it does not help with FPGA devices not.

  I have also dabbled in the event based sequential reads, but he is evil on vxWorks devices.

  Any help is appreciated

  It is helpful to sometimes talk to yourself.

  

  

  I hope that is useful for someone sprinkle in the future

• VISA read where you don't know the number of bytes?

  I work with a VISA resource via the USB port that reads in the results of printf (% lu % TSP %d)) of a microcontroller. These results are as ASCII numbers, their length in bytes is unknown. Numbers * should * be not more than 3 digits, but I can't know that for sure. Reading VISA won't let me the number of bytes unwired, so should I join just a high constant let him? Or is there a better way?

  1. do you have the microcontroller send a character to end of line (0xA on the ASCII table) at the end of the printf.

  2. turn the stop of the session VISA character and the value it is 0xA.  You may need to perform this task via the VISA property node.

  3. playback VISA to read more bytes than you tell never expect to get.  VISA playback will stop reading when it detects the termination character (End Of Line).

• How to run vi continuous when the VISA read timeout happens

  Hello

  I'm using LabView 2010 through a series of Agilent 6000 Oscilloscope. The Oscilloscope reads data from another experimental machine which will occasionally fail due to failure of the sample. When the machine breaks down, it ceases to send signals to the oscilloscope and leads to the error timeout of read VISA and the vi It is over.  Is it possible that I can run the vi permanently when the error occurs? For example, when the error occurs, it stores the error in the thread of the error. When the vi read the error code of the wire, it sends a command to stop my experimental machine then stop the vi.

  So far, it stops simply during the execution of the visa, playback function. In that case, why do we mistake in and out? Vi stop just when the error occurs.

  Thank you

  Laurent

  
  

• VISA read lose characters beyond the end of the output string

  Hello

  I wrote a VI to take a string of output data of an ardunio Uno and analysand. I use the vi read Visa to enter the output channel of the unit. In the end I will connect a device that actually gives the value in this type of format string: (#80212164,2289,2292,2296,2300,2328,2289,2297,2290,2300,2308,2292,2295,2298,2289,22,24,0 *).

  So after a large number of loops, the program starts to drop the last characters of the string that it generates. If the string of Visa Read output reads something like (#80212164,2289,2292,2296,2300,2328,2289,2297,2290,2300,2308,2292,2295,2298,2289,22,24,). The only way to solve this problem, once it has occurred must completely close labview (completely). Once I open again and start the program running, all is well in the world.

  Has anyone had this problem? I tried to debug it in different ways and the only weird symptom I have other Visa Read function lose a few characters of the string is the fact that by looking at the bytes to the Port after I read visa, is that she starts showing five bytes instead of zero.

  my last attempt at resolving this issue is attached.

  Note: The Ardunio outputs a string of this format every 2 seconds with the values being incrimental on a specified range. (80212164,2289,2292,2296,2300,2328,2289,2297,2290,2300,2308,2292,2295,2298,2289,22,24,0 # *)

  You can configure the * your character of termination if your Arduino does not send the carriage return or line feed.  Use the configure a Serial Port to ensure that your settings are correct.  You can also use this VI to increase your timeout so that you no longer need your waiting.

• PCI-6601 reading pulse without stop the meter

  Hi, the problem seems to be simple, just for the moment that I did not came up with a reasonable solution. I'm programming the meter 6601 for the following using my own routines of driver (in visual studio 2008 C++) for read/write registers. I follow carefully the DDK examples. I started with the example 1 and 4, and it works very well and now I have to somehow come up with the following code:

  1. I use the signal specific to 10 MHZ external H. MAser as input to the meter.

  2. I start the meter with arm software and am constantly read the values of the counter.

  3. I want everything just to read a single pulse (1PPS) and make the absolute time of the counter in time synchronization UTC. He should simply give me the meter reading of the rising edge of the PPS signal but after that it should be possible to read the counter as usual by reading the save save values, so read pps without stopping, nor anything in the registers of meter loading or b, simply give a pulse reading and continue even as 2...

  Any suggestions?

  Hello

  problem solved, but anyway, to all those who might have a similar task, here are the raw extract of what I've done (code names and function are similar to the DDK, but has nothing to do with the DDK)

  Sub yourclass::yourppscountfunction()
  {

  m_stopPPS = false;
   
  first reset internal values
  card1. Write_G01_Joint_Reset_Register_G0Reset(); reset the counter 0
  card1. G0_Reset_Registers_Values (); Reset internal values
  Disarm
  card1. Write_G0_Command_Register_Disarm (true);
  load the initial value of 0
  card1. Write_G0_Load_A_Register (0x00000000); counter should start with 0
  card1. Write_G0_Command_Register_G0_Load (); tells to load the initial counter of a register value
  Set the source to time external base
  card1. Write_G0_Input_SelectRegister_SourceSellect (1);
  Select the axis dedicated to door sellect (default value in this case, PFI_38)
  card1. Write_G0_Input_SelectRegister_GateSellect (1);
  card1. Write_G0_Mode_Register_Gating_Mode (2); rising edge Gate
  card1. WriteIO_Config_Reg_Pin36_Select_out(); Configure the PFI_36 PIN to drive the output
  card1. Write_G0_Mode_Register_Output_Mode (1); We're out the TC, connect to a counter2 to count the animated buttons
  Configure the PFI_36 PIN to drive the output (not made here)
  card1. Write_G0_Mode_Register_Trigger_Mode_For_Edge_Gate (3); Gate not used to start or stop
  card1. Write_G1_Command_Register_Synchronized_Gate (true);
  card1. Write_G0_Command_Register_Up_Down (1); counting direction up
   
  card1. Write_G0_DMA_Config_Register_DMA_Enable (true);
  card1. Write_G0_DMA_Config_Register_DMA_Int_Enable (true);
   
  arm the meter
  card1. Write_G0_Command_Register_Disarm (false);
  card1. Write_G0_Command_Register_Arm (true);
  WRITE THE COUNTER VALUES
    
  card1. G0_Write_Mode_Registers();
  card1. G0_Write_G0_Input_Sellect_Registers();
  card1. G0_Write_G0_DMA_Config_Registers();
  card1. G0_Write_Command_Registers();
  while(!m_stopPPS)
  {
  PeekAndPump();
  now loop to see if measures available PPS, if yes, read them and display
  If (card1. Read_DMA_Status_Register_G0_DRQ_Status()) //if that something saved
  {
  unsigned long int counterValue1.
    
  int HWSaveorSWSave;
  HWSaveorSWSave = card1. Read_DMA_Status_Register_G0_DMA_Readbank();
  if(HWSaveorSWSave==1)
  {
  counterValue1 = card1. Read_Save_Register();
  m_editPPSreading = counterValue1 * 1.E-7;
  }
  on the other
  {
  counterValue1 = card1. Read_HW_Save_Register();
  m_editPPSreading = counterValue1 * 1.E-7;
  }

  This-> UpdateData (FALSE);
  } //if something red

  } //while
  card1. Write_G0_Mode_Register_Gating_Mode (0); gating disabled
  card1. Write_G0_DMA_Config_Register_DMA_Enable (false); Disable dma
  card1. Write_G0_DMA_Config_Register_DMA_Int_Enable (false); Disable interrupts
  card1. G0_Write_G0_DMA_Config_Registers();
  card1. G0_Write_Mode_Registers();

  } //after you might normally read the meter (PPS values are added to playback as UTC offset-> not done here)

  to stop playback PPS and continue as normal counter where the values are simply red of the SW save registers
  Sub yourclass::yourstopppscount()
  {
  m_stopPPS = true;
  }

• Visa reading reads all bytes to the port

  I have a camera that I communicate via the Serial Port. I have a standard communications protocol. For a particular command, I know that the exact number of bytes expected in return. I send my order. I see the correct number and exepcted to bytes in the port. I then read the number of bytes in the port. However, the VISA read returns only the first two bytes.

  I contacted success with this camera and this Protocol for more than 130 commands unique and different. There are only about 6 orders in which the read visa does not read all the bytes in the port. Anyone know why that would happen?  I expect to see 6 bytes. I see 6 bytes. I have visa read the command with 6 bytes. The visa read returns only the first 2 bytes. It's very very frustrating. I can do this exact process even with a different command. I expect 45 bytes of this command. I see 45 bytes with this command and I read 45 bytes with this command.

  I don't think that it is device connected as I can converse with success with the same camera on the same computer with the same cable of connector using non-LabView. It seems to be a problem strictly related to labview and VISA read the order. If someone could help that would be greatly apprecicated.

  Thank you.

  What is the exact byte stream that await you in return with this command?

  Instead of opening VISA, use the configuration Serial Port VI.  In this way, you can override the default values.  It looks that your instrument using all the defaults VISA of speed in baud rate, start and stop bits, etc.  However, in the VISA software, there is a failure to use a termination character, and this character is 10 (0x0A).  If you use the configure Serial Port, you can tell the pilot VISA do not use the stop character.

• No VISA Read reading all the bytes available and ordered

  Hi all

  I use Write.vi VISA and VISA Read.vi to send and receive packets of bytes to and from a processor.  Generally, everything works fine.  I put a loop repeats until he sees at least 20 bytes to the port, then I VISA Read to read 20 bytes.   However, when I receive some packets of bytes, my property node indicates 20 bytes to the port, I ask VISA Read to read 20 bytes, but it reads 13 bytes and leaves seven bytes to the port.  If I run the read operation again, it will read their remaining 13 bytes.

  Any ideas on what might materialize this project?

  Thank you

  Forbes

  OK, I thought about it.  I put 'Stop character activate' in 'VISA configure Serial Port' to 'False', and all my problems disappeared.

  It's fun to talk to myself.

  See you soon,.

  Forbes

• want to use visa read only when the pieces is in port

  Hi all

  I do a lot of serial data communications and visa read doesn't have an undo feature.  Heres so the question.  If I'm in the middle of the read visa, set up the picture picture and block, and I press the stop button, I have to wait for the visa reading for timeout, in this case 2 seconds, before I can move to the next step in the shutdown sequence.  Now, I know, there is a way to use the events of specefic bus, but I have yet to find a good example.  Any help or advice for a workarond for that matter?

  

  Thank you

  Matt

  
  

• Visa read byte at the port

  My visa to read, I feed in the bytes in the property node port as input for the number of bytes to read (it's 4 bytes).  However, the output of the read visa give only 2 bytes.  It seems that a few bytes have been lost during the read operation?  Why is this?  It is an easy to see what is in the buffer of the serial port?  Thank you!

  Yik

  You likely the session VISA set to end readings when he sees a stop character and VISA reading is to see the stop character, and ending the reading, regardless of the number of bytes you told to read. If you want that it explicitly read that much then you must disable the option "Activate the stop character" in VISA set up a Serial Port.