Modbus reading on request

Is there a way to read only a modbus on request? I want to be able to click a button 'Get Data of the controller.

Also related, I just want it write on command. I currently have a trigger/relay for writing data, but I can't tell if modbus is always send the "write" command (using the previous value of the line) or not.

I'm reading through the modbus test data. It seems that additional orders would limit the sampling frequency, leading to lost data. If I read that data registers, the data have no recurrence. With other commands, I get up to 10 blocks of the same value.

Thank you.

You take the input module in a relay with option of data block.  Only when you raise the output of the command, you will be allowing the flow of the module.

This average thagt unless you trigger the relay, the module will not process and ask for value

Tags: NI Products

Similar Questions

  • mod_plsql read the request header

    I've been Googling for more than a week now, but I can't seem to find...

    Is there a way to read the request (raw) of a query headers web mod_plsql hollow coming?

    Thank you!

    Maybe this can help: reading HTTP header in

  • Modbus read

    I'm reading three registers of a Modbus slave unit operating from inside a timed loop. The timed loop is configured to run at 250ms intervals in the original application and that's why I won't be able to wait until playback is completed. So, I read every one registry, which allows a 250ms gap between each reading.

    I just want to know if the VI that I coded will do the job? (Reading of a single register in a VI with Timed loop works fine)  I'm particularly curious about whether referring to how I opened the VISA and using it is correct.

    Thank you

    Salvation of the crows and CC,

    Thanks for your interesting alternatives in the treatment of the data conversion. Of course in this case the maximum is taken by scripture - reading for the Modbus and so this calendar conversion is not too critical.

    But good course compared to the original way of stripping - reorganization and concaneting alternatives are very elegant.

    Thanks again.

  • Using NI MODBUS - reading of several distinct registers

    I'm using LabVIEW 8.6, with the NI MODBUS 1.2 VI library. I have a device which serves up to 50 records, all keeping the same format. I want to read about 20 of them, however they are not consecutive.  (40010, 40015, 40017, etc.)  Read Holding Registers VI gives me the opportunity to read consecutive registers beginning at a given address.   On the other hand, writing several registers VI seems to me to write in an array of distinct registers. Is it possible to do it for the reading of records?

    AZZOAutomation wrote:

    I'm using LabVIEW 8.6, with the NI MODBUS 1.2 VI library. I have a device which serves up to 50 records, all keeping the same format. I want to read about 20 of them, however they are not consecutive.  (40010, 40015, 40017, etc.)  Read Holding Registers VI gives me the opportunity to read consecutive registers beginning at a given address.   On the other hand, writing several registers VI seems to me to write in an array of distinct registers. Is it possible to do it for the reading of records?

  • MODBUS RTU multiple request & response (OR VISA)

    Hello

    I would like to ask how many request and response on MODBUS RTU using VISA? I tried 2 camera digital surveillance, I did a Labview program to connect this device alternately using stacked sequence Structure, but it can communicate with 1 device and the answer, I think that there is an error, the number of bytes does not match what I ask (0 A 04 0000 0002 B 70-0)

    It's my screenshot

    any suggestion? or maybe use other way to many request and response use NI VISA?

    Thank you ~.

    It was pretty hard to see this video.

    Of course, as part of the 2nd, lower comparison was coming to True, which means the false cases where things was spent could not run.  (Seems like the reverse logic to me.)

    Well, you check the first two bytes to see if they were not equal to 010 a.  They were good because it is the response to the command you send who left 010 a.

    In the first picture, it worked because you send the command from 0A 04 and compare to see that's not equal to 0404, which of course is not.  What is the point of this?  It makes sense to mixed.  You want to confirm it is the correct slave address and the correct command (so that they would be equal) to run the code of decoding.

    The other comparison is also useless because you try to check if the first two bytes are equal to 0 a, (any image you're in) which they will never because a string of bytes 2 can never be equal to a 1 byte string.

    Through execution of high point, you should have been able to understand what was or wasn't running and why.

    In addition, you only need a VISA close because you open just a resource of VISA.

    Really, you'd be better off using the Modbus Library.

    This is a much cleaner version of your code using the Modbus Library.

  • Mail only handed to me with read receipt requested.

    Messages sent from a particular recipient are not distributed in my Live Mail Inbox, unless they request a read receipt.

    No idea why?

    I can return to the sender without problem. When they replicate another cc recipients would receive the response.

    The mail is not in my junk mail.

    The recipient in question is in my contacts.

    If I use the default Office Outlook 2007 e-mail client. The mail is not present if I have access to the Inbox via a browser or by using the Windows Live Mail client.

    I am running Windows Vista.

    Thank you very much in advance for your suggestions.

    Submit all Live queries on the forum right here:

    Windows Live Solution Center
    http://windowslivehelp.com/

  • Read value request chart

    I've searched for this idea for a long time.

    Right now I use a manufacturing build .exe created in labview. I downloaded the .llb file to change the program to my goal, but I can't find a way to do as I want.

    Basically, this program measures and updates the data in a chart, I want to know the value of a specific point in this chart. I want to go with my cursor on this point see the value. But I can't find a way to do it in labview

    Is there a way to do what I want? Just as the cursor to go to the specific point and then read the value? The graphic can be found under 5015_measure with RS232.vi

    In the attachments you will find the .llb and a picture of a point that I want to read the value of.

    Thank you!

    I am not sure if you already have a cursor and are looking for a way to better control it or you want to add a mobile cursor to your chart, but if the second is your question:

    1. right click on the chart and go to the-> legend of slider check the visible items

    2. right click on the legend of cursor and add a cursor of your choice.

  • Modbus reading

    Hello

    In the Advanced_Serial_Write_and_Read.vi we can find in the Labview example, in the part "reading" of the program, I have to put the right number of bytes I have to read in the memory buffer, and if I don't I always get a time-out error.

    I want to read the buffer without putting the number of bytes that I read before. Any idea to solve this problem?

    I have attached the VI.

    Thank you

    Peter.

    Hello

    What do you think is impossible, because the instrument you control needs to know the number of bytes, it must go back.

    In addition, the entry "bytes read" is a necessary input.

    Normally, when you send a command to your instrument, in the documentation of the instrument, you have all the information to determine the number of bytes to read.

    Sincerely

  • Volume mixer can read a request.

    I have a request that I don't want to hear playing in my speakers. How to make it my default speakers to the other mixer I activated?

    I want to spend the Hauppauge Capture of this mixer application.

    To that used.

    Had the same problem, Anshul directions did not help.

    What worked for me is as follows

    Click Start, click Control Panel, and then double-click sounds.   [Or, better yet, just press the Windows key, type 'sound' and click on the sound icon, NOT "change the system volume"]

    In the sound dialog box, click the playback tab, click the speaker device and then click on "Set as default" to the bottom.

  • Help - I don't have any on my dialog toolbar "to write" a new message so I can't select a read receipt request file or attach

    Before the two latest versions of THunderbird, I've always had a toolbar on my screen to write a new Message, but no more. So I can't select an application approval on an individual basis. I don't know how to recover my toolbar on the screen of my writing

    The universal key for hidden menus features are the alt or F10 key. One of them will be the convening of menu bar. The menu bar select View-Toolbars and rekindle the missing toolbars.

  • How can I disable cookiies for other computor can read my request

    I filled out an online application and it says to disable cookies I don't know what to do

    Post your question in the forum for whatever browser you use.

    Use your browsers as helper function find the answer.

  • How do you know if your email has been read in Windows Live Mail, after choosing the option "request receipt reading"?

    Ok. It of stupid, but how do I know if my Windows Live Mail has been read after requesting a read receipt?

    Thank you again you wonderful people!

    LindaSView

    You do not have. You ask the recipient sends the receipt for you, but they are under no obligation to do so. Send a message to yourself to see what they see.
     
     
  • Tool to read the response and request ksoap?

    Hello

    Does anyone know of a 3rd third party tool that can be used to read the request and response using ksoap2.

    I am aware of httptransport, .requestdump and responsedump. But these do not work in all scenarios.

    What I want is something that will trace the whole process and give me the details of the calls made in preference to the xml format.

    Thanks in advance!

    Saket

    I use tcpmon for this.

    can be downloaded for free and is also part of soapUI I recommend for webservice tests as well.

    Another tip:

    ksoap2 httptransportSE to test your webservices with JUnit (in java desktop). If your Web service is wrapped properly you should not use any bb specific code and can run all your webservices in JUnit (I do).

  • Update of Adobe Reader for El Capitan

    I received a notice to update Adobe Reader and requested he return later. He never appeared again - will someone please tell me what version I need for El Capitan and also PLEASE send me a link to the correct site? Thanx

    https://get.Adobe.com/reader/

    You can download the current version it.

  • Modbus communication with a piezoelectric dynamometer

    Hello..!

    I am a new user of LV and I try to communicate with a piezoelectric dynamometer in modbus RS232.

    After you install NI Modbus Library, I created a master VI with labview 8.6 using these libraries and I can get communication with scale, these values are added in the registry U32Bit 1 and it's good, if I press a load cell, I can see the values exceed. (from 0 to 65535). Now, I want to show on the front the weight in KG, as the decimal separator, for a proper interpretation of the value for my client, so I added a block table to unbundle that I convert a value with I32Bit (-32768 a 32768) with a flag, but I don't see not all values...

    I guess I did something wrong (conversion), I read a few KB, but I do not see a solution...

    Can someone give me a link or information to show me an example to convert this value... ?

    Thanks in advance for any help to...

    Configuration of master VI:

    Read now register

    Address starting 2012 (query to get the net value of the load cell)

    Quantity 1

    Slave address: 1

    RTU

    9600

    3 com

    parity none

    Can you post some examples of bytes you receive from the Modbus read and you expect that these values are?  It's probably just a matter of the right of casting, or the number endianism, or operation of scale that must be done.

Maybe you are looking for

  • System sounds & his browser = Yes, sound Media = NO!

    Hey guys! First post here so I hope that I give all the info as I should. Basically, I got an update from HP. I was sport to music until I restarted so I put everything on the update being responsible for the problems that I'm having now. I restarted

  • My iPhone was stuck

    My Iphone was blocked by someone else (not me) with its ICloud. Application for iPhone to "Activate the Iphone", but I don't know his Apple ID. This person claims the money to unlock my Iphone. What should I do? Help!

  • OfficeJet 6600 Fax confirmation date and time fields zeros

    When I send a fax directly from the printer that prints the confirmation record has a field for the date and time, but it shows all zeros (see below) Is it possible to fix these so that they are accurate? If I need to prove that a fax has been sent,

  • OfficeJet 4500 wireless: Scanner Errror

    I get an erroe as below when I try to scan. No problem with printing. "The program didn't find any available destinations to which the scans can be sent. Reinstall the Hp photosmart software supplied with the unit. I had updated my windows 7 to 10 wi

  • Windows 8.1 does not speak for Color Laserjet CM1312

    After you have installed windows 8.1 my Color Laserjet CM1312 printer and pc are not communicating.  Tried several drivers update. They do not install. What can I do more? PS this post and his response were separated from the other thread and edited