GPIB & amp; Reading VISA queue

Similar Questions

• Series read, store queue and time-evenly continues treatment, but the data is mixed now

  Hello, all,.

  I send MCU APR data to the PC via a serial interface, 16bytes each time interval of 50 ms, if I donot use queue, the data read visa are the same as sent. But reading and in turn within a while loop is not time efficiently as the multiple loops with queue processing.

  I have a byte (0 x 55) as the first byte of the data transmission, with multiple with queue loops, but now the 0 x 55 position is changed all the time, and most probably present at the 8th byte data.

  Thanks for any help.

  Ted

  Houde, dai wrote:
  [...]

  The data received with VISA read are unstable even without connection to the other party, as the screenshot displayed. [...]

  With best wishes,

  Ted

  Ted,

  What do you mean by 'unstable '? And I saw that in your simple loop VI, you are always empty the buffer after each reading, what you don't do in the loop number VI. Maybe it's the origin of the problem.

  However, IF the rinse, the root cause is not VI, but your connection (or the equivalent of your program). Since removes VISA Read already the amount of reading of data from the buffer, the data must be resent / captured again in the buffer...

  hope this helps,

  Norbert

• Synchronization of read VISA issues

  I use a RS232 to control an older model of power supply (PS 120-10 OXFORD).

  I wrote with success several VI that all the work, the only problem is that reading VISA takes too long. I'm talking about a few tens of seconds to refresh. I need refreshing in milliseconds or less than a few tens of seconds for the measures that we need to have it. All VI, wrote I have the same problem of synchronization.

  The simplest write VI series is attached. Is it possible to improve the reading rate? Or maybe it's a problem of instrumentation. The strange thing is writing commands work almost instantly (I seem to be them on the instrument display).

  Please help if you can, I have only been working with LabVIEW for a few weeks and am very must still in the learning process.

  Thank you!

  Try this minor mod

  

  After Power cycling the device restores the State from "Q0".

• GPIB error message (VISA?) when you access a power meter HP E4419B (double channel)

  Hello

  I used a GPIB-USB-B adapter to access the E4419B meter, via a Calibration of IFR application software. The required initial standard test equipment is an E4418B. During the initialization process, there is always a message:

  "Initialization error: initialization of the HP4418 Power meter, error error: interface type is valid, but the number of specified interface is not configured."

  He was waiting for me that software has always controlled the unit later in some way (i.e., cal sensor, etc.). But that would creat some other comm failure in the race.

  I would like to know, if E4418B and E4419B are compatible with each other insofar as NEITHER Visa is concerned, and it is ' has some sort of screening OR the part number? The software itself is not all flexbility to do.

  Thanks in advance.

  Simon

  Simon,

  For the 19 do not work which suggests that there are no channel selection. Looking at the programming specification for E4418/E4419 (Yes, it the same specification) suggest the same programming codes the only difference is that the E4419 has two channels.

  The other would probably be during initialization and query software maybe be looking for E4418 instead of E441x and ignoring the last character.

• Virtual serial port: no bytes to the serial port before you read visa

  Hi I want to use LabView for data acquisition in real time from my dc servo motors. I'm new to LabView, so I will try to do the same thing with virtual port. I am writing some data (a sinusoidal wave) to the virtual port and can read and display it on the chart. the writing part just works that we see in the hyper terminal. but he's not reading anything. the number of bytes to port is zero. I tried to put the number of bytes in visa read manually, but it does not work. I have attached my code below. any comment is appreciated. Thanks in advance

  This is just the basics of how communication works series. To do a reading without any instrument, you loopback (short) the transmission line to the receiving line. For a connector 9 pins, you short-circuit pins 2 and 3. If you have not done this, I do not understand where you thought you could do a reading of.

  In any case, if you have servos that are controllable of RS - 232, it isn't likely that the series is even close to what you do a closure won't tell you much more that the converter is functional. When you have a real instrument connected, you still need to debug settings com (baud, parity, handshake), type of cable (null-modem or directly through) and the actual orders that you send to the instrument and its answers.

• Problem to run Agilent GPIB with NI-VISA card: recurring at Agilent VISA 32 report of open conflict that all things set correctly...

  Hi developers OR,.

  I have a recurring problem to correct my installation using a labview and Agilent GPIB card.

  Of course, the well-known configuration tips are generally defined:

  -Agilent VISA a VISA secondary (by-side mode)

  -the passport for tulip is enabled in NOR-MAX

  -OR-488 support active in Agilent librabry suite 16.1

  I uninstalled and reinstalled any component twice, but still get the same error message when I want to talk to a Keithley 2400 EMS:

  -Firstly, the agilent GPIB interface is correctly recognized expert Agilent connection and NOR-MAX

  -Then the instrument of 2400 keitjley initially works correctly in Agilent connection Expert and NOR-MAX

  BUT: when I try to send a command to the device (whether through the wizard or VISA using the Labview instrument driver), the tool returns an error (error "Application incomplete" punch followed immediately by a second "Invalid while in the local" error code)

  At the same time, the Manager (32 open report VISA) conflict in expert Agilent connection says "NI-VISA has returned an error. "There is a conflict of interface between NI-VISA and VISA Agilent". He suggested that the conflict occurs when different interfaces receive the same number of interface in the two VISA.

  Therefore, aware of the conflict that can occurs in a side-by-side installation, I tried to change the ID of Interface CLCL's Board of Directors in the Agilent connection Expert (from gpib0 to gpib9) and restart, but it did not help.

  So can you help me solve this recurring problem?

  Is it necessary to also change the VISA interface ID, or address of the GPIB Board Agilent GPIB in connection Expert? Wouldn't be the same address (9 for example)?

  I really do not understand.

  Sorry for this new message on the configuration of this topics, but I found no useful advice in the forums.

  See you soon,.

  Yoyo87.

  Finally, I got my system running after several tests, although I couldn't use NI-VISA as first VISA (allowing the tulip passport) with agilent VISA (permit for programs OR-488) at the same time.

  I uninstalled it all components of NOR and the agilent and re - install in the correct order (OR first, followed by agilent): nothing has changed.

  I check for updates of agilent and NOR and use several different versions of VISA at the same time: nothing has changed and I still communication errors when you try to send the order through NI-VISA Interactive control or labview (although it worked well by expert agilent of connection).

  I don't really know why, but I solved my problem by installing Agilent VISA primary visa. In this way, even if I do not see the Council of Agilent in NOR-MAX, I can always send control of GPIB instruments by labview using their VISA address or aliases defined in connection expert Agilent...

  I am always interested to understand why I was not able to run the two VISAs on my system with agiulent only one card PCI GPIB... so if one of you sees a clear reason for this...

  Thanks in any case, even if I don't have a lot of response on this topic...

  Yoyo87

• Problem reading visa

  I have a series vi communication that works very well.  I need to go to the Visa and created a vi.  My problem is that I get data that are not logical at all with the VISA program.

  For example:

  Byte 1: Leading byte 0D

  Byte 2: Bit 0,1,2 define the decimal and only one of them can be 1.

  Byte 3: Different data

  Byte 4: What are the units and only at 1 bit 0-6 may be 1.

  The Hex data is now invalid.  I can run the old communication vi series and I get the correct data without changing any installation.

  Any ideas?  There is no stop character.

  Thank you

  The Subvi did what I thought he could. You will need to apply the same logic in your new program. Like the old driver, there is no built-in function to search for a main character then return the rest. Your reading with the new chain will be incorrect until you synchronize the flow of data, as did former program.

  p.s. If you hadn't cheated a bit and used a law degree to keep the old level series features low, your VI 7.1 would have used VISA. The conversion was (and is) automatic.

• County to return read VISA does not match number of bytes

  I encounter an error with a VISA reading.  I ask 8 bytes (in number of bytes), but get only 7 return (return number), which causes errors in my code downstream.  Curiously, the VISA Read block does not return an error.  Any ideas on how to debug this?

  Data sheet:

  LabVIEW RT 8.2

  VISA 4.3

  Series OR 3.3.0

  PXI-8431/4

  Parameters: 1843200 Baud, 8N1.

  Is VISA reading set to put an end to the reception of a termination character?  I think that it does not have the stop in the output string character, which could make your short back counter.

  Lynn

• Difficulty communicating with a GPIB instrument using VISA

  Hi all

  I am trying to create a Subvi allowing communication between a computer and a spectrometer to MS260i. This is an old spectrometer and can only be interfaced via GPIB or RS232. I chose to use a GPIB-USB-HS adapter to connect it to the computer. The following parameters in the NOT-MAX I would easily send commands to the spectrometer when you use the Communicator of NOR-488. 2. I have also attached a picture of a wavelength successfully query.

  

  

  However, I am unable to do a Subvi with the same settings. For example, the following VI

  

  Returns the following error

  

  Is there something that I forget? I also noticed that even if I saved the GPIB interface properties, these do come up not by default when you use the Communicator of NOR-488. 2. Indeed, I have to manually configure EOS settings every time that I reopen it tool.

  Any help would be greatly appreciated.

  Did you do a right-click on the control of the chain and select ' \'Codes display? If you do not, the stop character is not sent.

• error timeout on write and read VISA

  I'm having problems of error timeout with a VI who just writes and reads the necessary data and will be eventually added as a Subvi. Everything is set up the same as my camera. I tried to increase the timeout for the session, but it does not work and I don't know what else to try.

  Any help would be appreciated!

  The \r is the termination character (carriage return) and YOU set the constant/control channel for------display Codes. It is a right click option.

  The driver is located by help > find the instrument Drivers. The driver page main has links on what makes a driver is and how to use a.

  http://www.NI.com/downloads/instrument-drivers/

• Read visa does not read as specified in bytes read

  
  

  Karine says:

  Thank you Jeff Bohrer

  say that I have to wait frame sequence delete and replace with delay?

  Best regards

  That and stop playing with hardware flow control RTS - CTS will do it for you

• VISA, GPIB read all device settings values

  Hello

  Y at - it a specific order of VISA or GPIB to read the current state of a device? I don't know the status byte.

  What I'd like to see is the present value of all parameters of the device, in order to be able to reproduce the same situation, other times.

  Is this possible with a standard command? Or is it related to a specific order of devices?

  Thank you

  This is something that is totally dependent on the device.

• Keithley 2601 - VISA READ 0xBFFF0015 (VI_ERROR_TMO)

  Dear people,

  I hope you can help me with this problem which has been haunting me for days. Please excuse me if it's a rookie mistake, as I have no experience with LabVIEW.

  I'm trying to control a 2601 Keithley uses LabVIEW drivers provided by the manufacturer (http://www.tek.com/source-measure-units/2635-software/keithley-series-2600-2600a-2600b-native-labvie...).

  The connector I use is a NI GPIB/USB and communication seems to work well with interactive control of NI-VISA, writing and reading the output of "* IDN? "\n" perfectly:

  1: write operation (* IDN? \n)
  
  Back County: 6 bytes
  2: read operation
  
  Back County: 54 bytes
  
  Keithley\sInstruments\sInc.,\sModel\s2601,\s1078308,\S1.1.1\n

  When you try to run the example 'KE26XX factory Pulse Usage.vi' However, after having managed the initialization of the device and to write a series of settings, it still shows error 0xBFFF0015 (VI_ERROR_TMO) in the CITATION READ in 'Config Pulse V measure I.vi':

  

  I had that before with a serial cable, so I changed the thought of GPIB/USB it re-establishes a possible problem of TermChar. Does not work, the error is still the same. I tried to add a wait function with up to 5 after the WRITE VISA, without success. Tried to increase the number of bytes to READ VISA, without success. Tried to manually add "\n" to the string of Scripture, without success.

  Using Windows 7 Enterprise, LabVIEW 2014 SP1 f3, NI-VISA 15.5, OR-488. 2 15.5.

  Thanks in advance for any help!

  Diego

  It looks like to, this is caused by something else. The other cause of VISA time-out for a tester is usuaully when you call a VI to do certain things which need more steps to take before calling them. For example, you may need to call one another VI Keithly to initialize the device and then put it in a certain mode, configure something using an another VI then call the Subvi. If you do not follow such a sequence, you can ask something that the instrument is not able to do and so he will not respond and will trigger a timeout. To do this, you will need to consult the manual of the instrument, Keithly examples or try to contact their support.

• Error reading misaligned GPIB

  Under Instrumeent i / o-> GPIB, are read are writing functions.  The error inside and out for these functions are not aligned.  Why is this?

  Should I still use the GPIB functions?  Can I use the VISA fucnctions instead?  I like the features of GPIB, because I only need to enter a number of GPIB address to a string for the address, and I think that it is convenient.

  Using GPIB functions has not recommended for quite a few years and certified instrument drivers need VISA. Using GPIB is, in my opinion, being short-sighted. They rope you up materials and you belay GPIB. With VISA, you can use other providers GPIB controller and you can easily use VISA with USB, Ethernet, RS-232, etc. with little or no code changes. The extent of comfort and control of resources VISA, you just select the correct resource from the drop - no need to try to remember addresses and you have support for aliases (i.e. "DMM"). I also have the VISA Resource Name Out makes for a neater wiring.

• 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