Read/write in a variable using its refnum

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• Can we read/write client side files using UTL_FILE?

  Hi friends,
  
  We have no use in Oracle PL/SQL for file operations (create, read, write, add) on the client side? I have my server DB under GNU / LINUX, but I run my queries through a Windows machine and I want to precess files on my machine (client side) of Windows. Can achieve us through UTL_FILE?
  
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  Deep

  UTL_FILE isn't for treatment side server only.

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• Object LVOOP read/write using the API TestStand

  Is it possible to read/write a LVOOP object to a variable TestStand from LabVIEW using the API of TestStand?

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  Hi jsiegel,

  That's right, it is not quite possible to what I believe, it is your intention. As mentioned, TestStand cannot create the object of LabVIEW. To make and use references of LabVIEW with TestStand, you need LabVIEW out this reference, which may then store it TestStand as an object reference. For VI requiring the obeject LabVIEW as an input, the registered object reference can be passed in. To make calls to LabVIEW classes using the class member call with a step of the VI Action instead of the call to VI for the Type.

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• Effective use of the FPGA read/write

  I am writing an application for a CompactRIO real-time and I am looking for ways to simplify my code and reduce the CPU usage. I use FPGA to do much CAN e-mail and signal processing, then I have a VI running on the real-time processor that reads values in the FPGA, does some processing and outputs data in the FPGA. My code running on real-time parallel uses several loops running in a master/slave architecture. A single loop reads all necessary information in the FPGA in indicators and writes the values of the controls in the FPGA. The other loops read entries and manipulate the outputs via local variables.

  My question if it would be more effective to get rid of the loop which is dedicated to the communication of FPGA and has of each loop to read and write directly on the FPGA. If I use a reference block FPGA open and use the reference of the output in several loops, each read/write operation block others until it's over? Each output is changed only in one place in the code, but there are several entries that are used by multiple loops. It is even more effective for each loop of read/write for the FPGA on request? How will this affect determinism?

  Thank you

  Jon

  Jon,

  Read/write controls is not deterministic, but I think that your previous method should work just fine, as long as you have that unique writers. If you have multiple writers, you start affected by race conditions.

  I don't think you will see a significant improvement in the performance/CPU in the alternative method. You would see big performance gains if your master loop reads more slowly indeed, but it's always a compromise.

• Difficulty using the binary read/write

  Hello

  The binary read/write function somehow not working properly in my application.

  I have one store a 2D strign binary array. When the user closes the application, the application stores the values in table in the Bin file.

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• How to add more variables to a read/write control?

  

  See how the read/write control is connected to global variables? I want to add more variables, I created the globals (some are listed in the table above), but as you can see that they are not available in the read/write control. How can I add them? I also tried to create a new read/write control, but as you can see that didn't help.

  Any help would be appreciated.

  Hi count3r5tr1ke,

  It seems that you are referencing a particular bitfile in open FPGA reference. I think that even when you save your FPGA VI, VI real time still referencing an older bitfile. Have you tried re - compile and referring to the new bitfile once finished compiling? A sure way to make sure that you have the most up-to-date bitfile is to check the VI option when you right-click on the FPGA Open reference and select Configure the reference open FPGA. When this option is checked, if you make changes to the FPGA code, it will force you to re - compile the FPGA VI before you reference it on the real-time side.

  Best regards,

• Am about to buy DW.  2 quick questions before proceeding.  (1) can I associate a DW created an EXTERNAL SQL Express database for the read/write site?  Can be made safe?  (2) am plans to use Contribute to allow non-technical users to end dry change

  Am about to buy DW.  2 quick questions before proceeding.  (1) can I associate a DW created an EXTERNAL SQL Express database for the read/write site?  Can be made safe?  (2) am plans to use Contribute to allow non-technical end users EASILY change the sections of the web site.  Can this work?  Thank you.

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• write a graph in a cluster using a refnum does not?

  Hi all

  A little bit of a weird (I think). I'm trying to update a table that is in a cluster using a refnum.

  See the attached example, Boolean updates correctly, but not the graph (above). Y at - it something I'm doing wrong or can graphics simply can't be updated in this way?

  With the help of LV 8.6 in Win XP (SP3).

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  It does not work. You must remove the reference for the cluster chart and update it in this way. See attached mod.

• In the target FPGA read/write control function?

  Hi people,

  I learn a lot from the sample project FPGA, including how you can easily retrieve and set controls and indicators in an FPGA using the read/write control function running in an RT target.

  However, I can't find a way to do something similar in a FPGA target.  I've been down this road before - that is, trying to move the data in/out a looping VI FPGA (void) to a (parent) FPGA VI - where my memory points to reach what I needed use.

  So I was happy to see the palette FPGA enabled me to drop the control functions to read/write on a FPGA vi target.  But alas there where tons of errors (not compatible son for target, etc.) and I guess now it's not possible.

  So, just to be sure, I'm not missing something, is there something like control functions to read/write to use in an FPGA for read/write in an another FPGA (looped)?

  In addition, why would I be able to read/write on a FPGA vi control functions if they are not supported?  (Sorry for the n00b question)

  Thank you

  Steve

  maherhome wrote:

  You're right that I don't have this knot in my palette.  However, I also do not seem to have a Refnum Occurrence in the palette is in the FPGA (see below), but I need to synchronize several loops of FPGA and added research using the textfield in the VI editor (and if compiles and runs).  So 6 months to Labview and I'm fuzzy on how the palette is restricted

  I don't know what you're trying to prove here. There is no control of refnum in search in your image. Occurrences are available in FPGA, and for control of refnum for one you just right click on a function of the instance and create a control. If you can create a valid thread of a certain type of data, then you can create a control or the indicator for it, regardless of the question to know if this type of control or indicator appears in the palettes. However, the functions that you can use in the block diagram are limited by what is available in the palettes.

  maherhome wrote:

  Regarding orders read/write for the FPGA/lights, I'm surprised that the infrastructure developed to allow read/write between RT and FPGA has not mobilized to allow read/write between FPGA and FPGA.  The elements of memory function, but they are less convenient.

  You may have noticed that you cannot compile the individual parts of an FPGA VI and combine them later; This is because when you compile an FPGA VI, all its subVIs are essentially merged to create a single block diagram (with additional logic if one not reentrant Subvi is used in multiple locations, this is why it is not recommended on FPGA). The subVIs no longer exist in the FPGA compiled; reading and writing a control on them would make no sense. If you want similar behavior, use global variables - but understand that global variables store values in FPGA logic resources. Using the elements of memory (or FIFO, which can also store in memory) leaves more fabric available FPGA logic by storing data in resources specially designed for this purpose.

• FPGA read/write does not not in cRIO-9073

  Hello.

  I'm stuck with a problem in the use of the FPGA Read/Write control please suggest a solution.

  I use cRIO 9073 and I'm trying to place an order ON / OFF of GUI-> RT-> FPGA host. I use a shared variable of the network to transmit the control GUI form to host RT and I use read/write control to FPGA. I also put a Boolean flag in the FPGA VI to control if the control is transferred to the FPGA.

  When I toggle the button in the GUI, I see the same change in the host of RT (shown as 16 probe in attachment 1). However the FPGA indicator (indicated as probe 19) remains the default false state. The FPGA VI is on attachment 2.

  Thank you

  Guilhem

  Your FPGA only reads the control once before entering the loop.  If you want to read control permanently, you must put it inside the loop.

• under condition of read/write terminals on the side of the connector (basic training 3)

  Hello

  During my practice towards the review of the CLD, I examine the Core 3 online training material too. I just read a few tips of 'best practices' on the forum, for example this post:

  http://forums.NI.com/T5/LabVIEW/Community-Nugget-wired-terminals-in-subdiagrams-clearing-up-the/m-p/...

  It should be noted, that we should not use terminals (which are on the connector pane) to the inside of while loop or condition of the structure. Neither control, nor indicators (read/write terminals): "terminals conditionally read or written on the side of the connector are BAD!"

  I can find many examples in the online training materials, when the indicators and controls are placed inside while loop and the case of structures in a Subvi.

  I guess I should not do this during my review of the CLD, as they will run benchmark on my project? Should not be the core training materials updated some time? Or it's just not too important to have terminals on the outside? I would lose points during the CLD Exam my project as in the Core 3 screws?

  example 1: Core 3, exercise 4-6 design of an error-handling strategy:

  

  EDIT:

  What's even more ugly in this project, is that, in the case of 'Get empty Cue', the Cue output indicator is updated via a local variable, because the indicator is not accessible via 'outside ': wire

  

  Nice catch on the training material.  that the application would take an if subject to a review of the CLD test graders.

  As noted in the nugget: sentencing of perfomance for conditionally reached terminals is a function of the size of the data.  So, it is sometimes acceptable for simple data.  The larger point being to learn about compromise and make the right choice for your code.

  Preping for the CLD on other means of hand knowing that VI Analyzer will run on your project.  Like any other code review you walk in - know the guidelines for the review and code to ' review ' as well as 'reply spec.'

  I've not seen an instance where an example of shipping (2013 and later versions) would fail this test VIA (there are a few screws deep inside the vi.lib which can date back to before the adoption of this recommendation from style)

• Synchronization with Serial read/write problems. can not get the functionality of the terminal emulator

  Hello

  I am writing a VI to control PWM with a microcontroller via a serial port. I wrote a simple code for the microcontroller that allows me to set the ratio of duty cycle on a scale of 0-65535. It works very well with Termite of Compuphase (RS-232 plug); The microcontroller invited me to an entry, expected that I would one, updates and expected another entry when I decided to send him. Now, I'm trying to get the same functionality on a LabVIEW vi but hit a snag.

  When I tried to send my orders with a series read base and an example of writing, everything worked fine. I could see the prompt entry, write an entry and if I was quick enough, check out the update message. Even when I was not fast enough, I was able to check the update by monitoring the PWM pin with a Logic Analyzer. The problem with the basic example, however, is that I need to update the report to aura cyclical ratio, so I went for an example of reading continues writing. The problem I've met; is that I have to switch between reading and writing to make it work. When I do that, either I don't hold write it down long enough and nothing happens, or I get several updates when I switch to reading. Some of these updates don't even match and produce updates to defective upgrades for example; 16000 16000, 16000, 16000, 6000, 600, 60, 16000, 1600, 60, 0, 0, 0, 16000, 60, 0, 0 etc.

  I tried which allows characters of endpoint in the hope that the writing would end at the end and go to reading where he would receive a termination character and wait for me allow writing once again, but nothing helped. I still have to alternate between the two and either get no response on reading several updates of variable accuracy. I tried to remove her allows read/write and their structures of matter in the hope that the loop flow, associated with the characters of endpoint would the case, but then the updates don't register at all. The funny thing is I did a VI like this before with an Arduino and that there not even no need to switch between writing and reading (I'm now using a Board of Freescale FRDM).

  I was also the frequency of timeout errors; Error-1073807339 at VISA Read, reason Possible: VISA Hex 0xBFFF0015. I removed the option to stop the while loop if there is an error so I can run but always pops up an error on the judgment occasionally. Could the problem of synchronization always cause me problems?

  Would appreciate all advice really, I am providing my slightly modified example screws and can provide the code for microcontroller on request, even if it's very simple.

  Thanks in advance, it is
  Yusif Nurizade

  In other words, frankly, a good bad example you according to your code. Also, you have the order of writing and read upside down in your amendment if the instrument requires a command to return something. It should really be using a structure of the event. The structure of the event around a write and read and use a value change event. I have attached a quick change. This mod is still a reading after writing. If necessary, you may have two separate events to write and read.

• Read/write function reads a bad value?

  HY,

  I'm using on my FPGA OR Quadrature encoder.

  (http://www.ni.com/white-paper/6608/en/)

  I add a few entries, so that its possible to set an offset value.

  

  In all the VI on the FPGA, works very well with my encoder.

  If I start the VI on my FPGA, the position value is 0, because of the "first round"? Element.

  Now, I used the command of read/write in a while loop on my host VI to get the current value of the encoder.

  After I start my host vi the defiler position always shows the value "2".

  If I use the highlight function, the value remains at '0 '.

  This is a really strange behavior, I don't know what can be the cause of this problem.

  All positionsoffset values are 0 and encoders on my 9401 module entries are tied to the land.

  The position value is only written on the fpga, nowhere else.

  Anyone have any idea why?

  Thank you very much.

  

  
  

• 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.

• CD / dvd drives will not read / write to any disk

  Hi, can someone help (first timer) I have two cd/dvd drives will read / write to disk get them all is a window pops up asking me to insert the disc. all my drivers are up to date, my Device Manager shows two active drives and works correctly, I use service pack 2 and I have installed a new software/hardware. my computer is a dell XPS 420 that is now three years old and this is the first time that I had any problem that I have not been able to solve. Help!

  Hello

  Its not unusual for the same problem have an impact on both drives, in fact its very common.

  Step 1: Please do all the same underneath if you did some before as is often total
  a process that solves the problem.

  Try this - Panel - Device Manager - CD/DVD - double click on the device - driver tab.
  Click on update drivers (this will probably do nothing) - RIGHT click ON the drive - uninstall.
  RESTART this will refresh the default driver stack. Even if the reader does not appear to continue
  below.
  
  Then, work your way through these - don't forget the drive might be bad, could be a coward
  cable or slight corrosion on the contacts (usually for a laptop) and other issues.

  Your CD or DVD drive is missing or is not recognized by Windows or other programs
  http://support.microsoft.com/kb/314060 - a Mr Fixit

  Try this fix manually if the Fixit 314060 does not work
  http://www.pchell.com/hardware/cd_drive_error_code_39.shtml

  Your CD or DVD drive is missing or is not recognized by Windows or other programs-
  a Mr Fixit
  http://support.Microsoft.com/kb/982116

  The CD drive or the DVD drive does not work as expected on a computer that you upgraded to
  for Windows Vista
  http://support.Microsoft.com/kb/929461

  When you insert a CD or a DVD, Windows Vista may not recognize the disc
  http://support.Microsoft.com/kb/939052

  Your CD or DVD drive cannot read or write media - A Mr Fixit
  http://support.Microsoft.com/GP/cd_dvd_drive_problems

  CD/DVD drive does not appear in Windows Vista, or you receive this error in Windows
  Vista installation after booting from the DVD (AHCI)
  http://support.Microsoft.com/kb/952951
  Drive CD - R or CD - RW Drive is not recognized as a recordable device
  http://support.Microsoft.com/kb/316529/

  Hardware devices not detected or not working - A Mr Fixit
  http://support.Microsoft.com/GP/hardware_device_problems

  Another possibility is that the cables are loose. Remove ALL power, then make sure that the cables in both
  ends. Remove and replace, do not just tight. For laptops, you can often clean power and
  contacts data with a pencil eraser.

  Some DVD players do not use the Windows default drivers so check with the manufacturer of system and
  manufacturer of device to see if there is a firmware or drivers for your drive if necessary.

  ===============================

  Step 2: You have disc problems as the CD/DVD is actually 4 discs in 1 case (CD & DVD
  Burn and CD and DVD read). So it is not unusual for 1 or 2 operational so that other parts
  do it right.

  Did you follow the Troubleshooting Guide for the reader who still does not work? There are
  the entries in registry that the troubleshooter does not solve and those who "might" be the cause.

  Check with your Maker system and a device for the two possible firmware updates and
  the correct registry entries for your car.

  Here are the keys that I of course are those in question - for the subkeys of the CD/DVD drive
  as there will be other subkeys in these keys. Do not forget to ask specific keys involved as well as
  the parameters.

  HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\IDE

  HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Hardware Profiles\0001\System\CurrentControlSet\Enum\IDE

  HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\ {4D36E965-E325-11CE-BFC1-08002BE10318}

  -----------------------------------------------------------------------

  You can probably find more info here and maybe even the exact registry for your CD/DVD settings
  drive from someone with the same model.

  Forums - a lot of expert real help
  http://Club.myce.com/

  CD/DVD units
  http://www.myce.com/storage/

  Use DevManView to locate the CD/DVD in the registry (be careful and do a prior Restore Point)
  nothing change) - find the DevManView device and then make a right click on it free in RegEdit.

  DevManView - free - an alternative to the standard Windows Device Manager, which displays all the
  devices and their properties in flat table, instead of the tree viewer
  http://www.NirSoft.NET/utils/device_manager_view.html

  I hope this helps and happy holidays!

  Rob Brown - MS MVP - Windows Desktop Experience: Bike - Mark Twain said it right.