Departure VISA is Looping

Similar Questions

• Session of visa driver looping issue

  Hello

  This is the first time I ever install a loop with a session driver visa in it. I'm trying to recover a table of data flow. The indices of the table correspond to physical locations (x, y) on this point that I measure the flow. This is why I need the data to be read as a 5 x 7 of the stream array. The matrix 5 x 7 is collected 3 times (at 3 different heights z). However, I can't understand why I make three 6 x 7 matrices instead of a 5 x 7. I can't tell if it's my registry setup shift, where my visa session is implemented, etc. I just can't understand it.

  Could someone looking at my code attached (it's quite simple, just 3 nested for loops with the session of visa inside, and that data are sent on to 3 matrices, which is then stripped more which can be ignored)

  Thank you very much

  Chelsea

  First of all, I don't see a point in all the structures of the sequence.  What they do is create clutter.

  Secondly, why you add the second to the last results to results together?  Here comes your additional index.  Get rid of this shift register and table construction.

• Serial port visa and while loop

  Hello

  I am trying to acquire data of a device through serial communication. This is an RS232 interface. I use a port of visa and I know open and close the port of visa again and again while the program is running is bad style. So, I trieed to use a while - excluding the Visa open loop and nearby (see the attachment of a second, program 2). Unfortunately this work of isn´t program and I can´t find the bug. However the first attachment (program 1) works properly (except that the speed is maybe more low). Sombody could me to get the second work programme.

  Thank you!

  Best regards

  Soffi

  What you need to do is to add a register to offset for the name of resource VISA and error. See attachment a screenshot.

  I couldn't find this anywhere in the examples of NEITHER. (This one is based on the basic series example write and read vi.) When I started with LV, I asked tech support how to do this, and they told me. I WISH THEY WOULD SHARE THIS TECHNIQUE WITH USERS IN THE UNITED STATES!

  I hope this helps. (I can reach the vi if you wish.)

  Ed

• Entry VISA to the serial port

  My problem is similar to that in the post titled "Re: read/write using RS232 VISA" posted Sep 2008.

  I want to stream in LabView to an instrument, view data numerically and visually and stream/save each data record long 25 bytes on the disk.   In addition, there are a variety of commands I would like to be able to give the instrument at any point in time (that's why the entry VISA while loop statement - see attachment).  In particular, two commands switch on the lights.  't' turns the LED lights up (they turn on, blinking for 30 seconds then delay).  'p' the lights, magnetometer, and then 'p' it turns off again.

  Question: 't' works very well.  I can press it anytime and it works perfectly.  'p', however, behaves exactly like 't' when you press.  This could be correct, but the mag never turn on either.  When I press the button finish to close everything, everything closes and the mag light - even if I did not press on 'p' for the vi run.  (??)  Then, when I run the vi once again, light mag turns off while I'm working with windows pop up the file - save.

  I tried an order of write buffer flush at the end of the VISA entry orders, but that changed nothing.  Do I have something wrong in my sequence of events?  I'm floundering.  Please please please help me.

  ~ Caught in loop

  p.s. I use a series/USB adapter that connects to my series/RS232 adapter.  Beautiful, I know.

  
  

• How to use visa write in loop for

  Hello

  I'm developing a measurement with labview system. I need to write the entry within the loop and then out of the loop he supposed to read the voltage level of the analog input pin. But the problem is, out of loop is 1 table D, so when I put the entry visa within the loop, exit loop wire VISA is also table 1 d. Please help me. Should I supposed to do?

  Change of your loops of connections to register and you don't build a table or errors or resources from visa.

  /Y

• VISA resources between the loops with the queue

  Hi all

  I am just be familiar with the queues and the producer/consumer model, and I am facing difficulties to pass data between the loops using queues, including data of the type "VISA Resource Name.

  Indeed, it seems impossible to cable "VISA Resource Name" as an entry of the item in the queue, as an output of the Dequeue item.

  These screws can I always try to convert something of this type can accept? Or should I take a different approach and that one?

  Thank you very much for your help.

  Florian

  
  

• VISA series Loopback speed and precision with double loops and a queue

  I'm working on a test of communication between 2 PCs. I test communication series RS-422 ports by using a simple loop. PC2 wrote continuous data at 38400 baud to PC1 (LabVIEW test code is here). PC1 reads the data and writes the data to the same port as soon as possible. PC2, reads the data and compares to what should be returned. I can get the highest speed is a speed of about 37300. Because it is continuous, finally that I get an error because the buffer overruns (read and write buffers are 65KO).

  It seems that VISA writing takes a lot longer than the VISA read. I do read/write asynchronous operations. I've read a fixed amount of data (1024 bytes) and then queued data to write in another loop. My timeout is set to 0.5 seconds, which is much time opf at 38400 baud (4800 bytes/second). I played a bit with these numbers, and they are the best I can get. If I increase the data read to 2 KB, the queue members increase. If I'm going too low, I start getting the data in the input buffer overrun.

  Anyone had experience with this type of test? The code is attached. Please take a look and see if I'm doing things correctly.

  Michael

  I do not know if this explains a gap between what you expect and what you found in 0.8 seconds, but you have added another level of complication in using the digiboard.  You don't have a real serial port, but a simulated serial port which is hung at the end of a USB bus.  The digiboard software creates a virtual experiences, and so its driver software and firmware on the side of the Board of Directors of the USB bus must manage some translations to go a number of compote, transfer on the bus and decode the Compote number so that it knows which 8 physical ports that it must send the message to.  You can see delays in translation at each end so something in the USB itself Protocol where it needs group information.

  If you have another, a different brand of the serial ports, you can use, you might want to try one of these to see if you get similar or different results.  But I don't think it's a good idea to try to test the limits of a serial communication device using hardware that adds the other layers of the communication protocol and therefore complicated results.

• How I WRITE VISA to 2 devices of a while loop?

  Hello

  I have developed a fairly complex vi that reads data from two sensors and controls SERIES written to two engine controllers.  The idea is to send the engine controls more or less "simultaneously", and they are generally not the same commands.  The two motor controls are determined by the sensor input with each iteration of the WHILE loop and subsequently sent to the VISA WRITE motor controller.  I was getting an errors and failures with the vi, then, we decided to break up and test the components individually.  In the original vi, I had two sets of VISA OPEN, WRITE, NEAR wired inside the WHILE loop and he sent two orders for both engines successfully.

  The test code I have attached here, "simple VISA speed controller rev1.vi" has the VISA sequence configured around the loop according to the advice of OR.  He suggested that the VISA OPEN and CLOSE while loop and wiring outside the VISA two WRITE such as shown.  However, in this configuration, only the command of the CHANNEL 3 runs.  The CHAIN 1 command does not run.  The string ' / 1V...» "engine controls 1, and" / 3V... " "engine controls 3.  So, by changing the 1 and 3, I order two this vi engines, but only, the chain is the first VISA WRITE running effectively, regardless of the engine is selected in the order of the string.  There is no malfunction of the motor or wiring, and I order the two motors separately using the software provided with the manufacturer of the motor controller, therefore, the hardware has been confirmed to work properly.  I use NI USB-RS232 to send the string on the motors controllers.  Motor controllers are connected in Garland, and each has a switch address so 1 engine knows how to respond to ' / 1V...» «and the engine with the value '3' address switch responds to ' / 3V...» "etc.

  The other code attached here, "simple VISA speed controller 2 motors.vi" sends the two commands at the same time.

  So, why the second VISA WRITE does not work the '... rev1.vi '?

  Thank you

  Dave

  Hello Dave,

  In accordance with our telephone conversation, that give a try.

  Joel C

  National Instruments

  Engineering applications

• With the help of VISA Write in parallel loops (multithreading)

  Hello

  I got the idea to set up four parallel loops on a quad core with four EHR via serial port independently. I use the PXI-8430/8 and I was told that an independent operation of ports is possible.

  What I did was simply to put in place four parallel for loops consisting only of a single entry VISA. With the help of the Tools > profile > find parallelizable loops, they gave me the following warning

  This loop For may or may not be safe to parallelize. Warning (s):
  -A node in the loop For can have side effects.

  This means, that the pilot VISA screws are not suitable for multithreading? With the help of LV2010

  Thanks for your comments!

  See you soon

  Oli

  Here's some good reading on paralleled for loops.

  Regarding the caveat, it's just that - a warning. If you write commands on a device and orders must be received in the order then you cannot parallelize the loop. If the order does not matter then go ahead. But in the case of VISA wrote that a parallelized loop going not buy you anything. They are intended for operations of calculation intnesive.

  Just stick to four loops.

• Timed loops with visa

  Hi, I'm new in labview and I need help.

  I have a microscope shutter which is controlled by VISA.

  I want this component to open for X milliseconds (eg. 100 milliseconds) and then close, wait W dry (eg. 3 seconds) until it opens again expect the same milliseconds X so that it closes and wait W dry again and so on. And I want to repeat this cycle Z time (eg. 100 times). I use the shift operators in a time loop, but I can't stop the loop in the middle of the operation.

  Thank you

  Carlos

  Hi Carlos,

  Under the name of Raven suggested would be the way to go.  I have attached a first draft of this thing with the necessary documentation.  If something is not clear, feel free to ask.

  

• Possible timeout in VISA read/write in While loop

  As the title says, I have a while loop that is constantly written followed by reading using VISA read/write.  I'm waiting for buffer correspond to a certain one, which the true value would end the loop.  In this loop, I have an indicator showing how many times he runs. All of this is repeated in another while loop.

  My problem comes the counter arrives at 10, then stops at the "write" command.  Do not know why.  I tried to increase the time-out of the instruments, but nothing has changed.  I added a delay of 10ms in loop, which also has not changed anything.

  For reference, I use a tektronix scope series 3000 of the MDGS and checking its state of relaxation.

  You said chill to read earlier!

  But it is not supposed to have to write it either.  Experimentally, access all VISA nodes, right-click and choose the Mode of synchronous i/o.  Make it synchronous instead of asynchronous.  The watch symbol will disappear from the top right corner.  See if that changes anything.

  What kind of serial port are you using?  What is an integrated in the PC?  A USB to serial port adapter?  Makes the chips on that, Prolific and FTDI?  You can try with a different serial port or a brand of adapter?  A lot of people have had problems with prolific chips.  And I have also heard of people having problems using adapters who had fake chips in them.

• Baudrate configuration change VISA inside a loop

  Hello

  In my application, I read a value of load cell using the serial port. I use VISA configuration serial port to initialize the port (9600. 8, none, 1, None).

  Last week, I changed my computer and since then, I have problems with the configuration of VISA. In a few lines, the baud rate change to 1200, so I can't get the value of the cell.

  I already checked COM1 configuration in my OS and everything seems fine.

  I have no idea what happening, someone could help me. Thank you

  Ignacio

  Thanks for your reply. I understand that it seems poitnless but I prefer to keep VISA configuration inside the loop to allow a user to reconfigure the handle during execution. In any case, I'll look for other ways to do better.

  The solution was to remove the block 'VISA close' as you suggest. Thanks again

• Leak memory in real time caused by VISA Read and timed loop of data nodes? Is not supposed.

  In collaboration with LV 8.2.1 in real time to develop applications that monitor or emulate computers on bus RS-422.   The following screenshots have been taken an application that monitors a transmission of 200 Hz.  After a few hours, the PXI station would break a range impressive messages angry... most involving something about memory loss.  After much hair pulling and passing money, my partner has discovered while looking at the available memory on the controller of loss of memory occurred at each loop containing a VISA read and propagation of error using the data nodes (see Leak.jpg of memory).  He concluded that if he went to the propagation of the error to the regular old shift registers, then the available memory was rock-solid.  (has the Leak.jpg of No memory)

  Any ideas of what could be the cause?  Do you see not any problem with the way that we code these kinds of loops?  We always strive to optimize the way in which we use the memory on our urgent requests and VISA readings and DAQmx bed give us the heartache more than ever, we are able to allocate memory for these screws some tips?

  Dan Marlow

  GDLS

  Hi thisisnotadream,

  This problem has been reported, and you seem to be exactly reproduce the conditions required to see this problem. This was reported to R & D (# 134314) for further investigations. There are several possible solutions, of which one is the one you have already found the wiring error directly in the loop. Other situations which give rise to no memory leak are:

  1 if the bytes of the property node port is not there and has read lies in each iteration and time-outs resulting are ignored.

  2. If the structure of the deal is gone and just blindly check the bytes to the port and read each iteration.

  3. If the timed loop is transformed into a while loop.

  Thanks for the comments!

  Kind regards

  Stephen S.

• How to eliminate the audio loop "police Siren" in firefox?

  I picked up an audio loop "police Siren" when I went to youtube.com , which is now integrated into Firefox and comes every time I open the browser

  This has happened

  Each time Firefox opened

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  OR

  If you have seen cool so that disable

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• How to read the Serial Arduino data using labview VISA?

  Hi =). Im a beginner work reading data series from an arduino but im facing... Lets do it step by step

  I built a voltage divider circuit which gives from output
  from 0 to 5V. The output of this circuit is sent to a 0 analog input pin
  of a Committee of Arduino Duemilanove.

  (1) Firstly, I connected the cable to connect to my laptop USB the Arduino.

  (2) I went to start-> control
  Control Panel-> system-> hardware-> Device Manager. Check the Ports (COM
  & LPT). In my laptop I can see USB Serial Port (COM4). Now I know only in
  LabVIEW that I must read the data series COM 4.

  (3) to the side of the arduino, here's the code to read changes in voltage
  entered to analog pin 0. The last line of 'delay' determines the sampling
  Rate of how we want to taste the output of the voltage divider:

  int potPin = 0;    Select the input pin for the output of the voltage divider
  int val = 0;       variable to store the value from the probe

  void setup()
  {
  Serial.begin(9600) (9600);    Opens the serial port, establishes the rate of 9600 bps data
  }

  void loop() {}
  Val = analogRead (potPin); read the value of the voltage divider
  Serial.println (Val);
  Delay (10);
  }

  I slightly modified the basis series reading writing VI... I have
  attached the block schema used with comments. Basically, I tried to read
  data series, divide by 1023 and multiply by 5 to graphic voltage
  variations of the voltage divider circuit.  But Im not getting
  the correct voltage output values. The value of the tension just keeps go
  0 and coming again, as shown in the photo.

  Could you guys please guide me on what went wrong?

  Thank you!

  -you read the data, even if there is no data on the port. If 0 bytes are read => «»

  -in the case of false, you resources VISA wired for the output of channel tunnel?

  -There is no close VISA at the end of the VI resources

  -you're not a loop this VI reading bytes

  I added an addaption of your VI that you should give a try maybe