LabView TCP read

Similar Questions

• TCP read bytes to read

  Hello! I have a small question on ports TCP read palett in labview, im trying to send 1 bit from a server to a client. This works when I put 4 digital in the bytes to read TCP entry read client-side. But when I change the value to 1, as it should be efficiant, this work dosent. Any ideas?

  Your number of bytes value is a number of I32 (32 bits, or 4 bytes), so you send 4 bytes followed by 1 byte for the boolean itself.   You can convert the number of bytes in an I8 to make a byte (but I wouldn't bother because the IP header information is the number of bytes, which means 1 to 4 bytes means little).

• How fast can get a TCP read?

  LV 2009 + WIN 7 with 6 GB of Ram.

  I acquire two analog channels as a word of 16 bits each and adding a CRLF at the end example: 1234 567 \r\n

  These data are acquired to 50ms intervals and sent over a link WiFi for my notebook running code LV.

  I know not how fast the "TCP - Read" function can work and which mode (it has four options) to choose if I do not miss any incoming data...

  Now I get some data in French - initially rather quickly and after a few seconds, it slows down the consdierably. I'm running the TCP-read inside a timed loop and I tried various intervals from 10 ms to 500ms. The largest value works OK, but I need the fastest possible. Tips how to handle this?

  My code is attached. (The passage DIO works very well)

  Even if the passage DIO works, it doesn't make sense to use a sequence structure.  It would be better to change the Standard mode and the 100ms Timeout value instead of "wait for next"millisecond"Multiple" as leading to uneven wait times.

  TCP Read should run very quickly, subject to any waiting period that you set.  You should never lose data in any mode, although there is a possibility to receive a partial when you use Standard mode or immediate (unlikely in your case since you read so little data).  The operating system will be buffering of data not read for you.  If you want the fastest possible exchange, divide your code in two while loops, one for EID and the other for the series.  Serial communication can be simply a normal life while loop, with the reading of TCP dictate the timing.  Set a long timeout in buffer mode and the loop will run as quickly as it receives data.

  Also, when the loop ends, you must close TCP connections, not just one of them.

• TCP Read blocks remote Port

  Hello

  I want to read a string of NMEA (1 Hz update rate) of a server. The original NMEA (series, 4800 baud rate) is converted by a MOXA to TCP.

  Here is my minimum program, I normally have a timer "wait until 1000ms" inside.

  

  The problem is that the MOXA closes its other port every minute. I can still read, but everyone else is blocked.

  Other Terminal programs work. The network guy told me that he sees a lot of traffic from my address and he thinks that, at some point, the MOXA is confused and shut its ports.

  Is there a possibility that read TCP sends a string of status or failure?

  azavarsky wrote:

  Hello

  I want to read a string of NMEA (1 Hz update rate) of a server. The original NMEA (series, 4800 baud rate) is converted by a MOXA to TCP.

  Here is my minimum program, I normally have a timer "wait until 1000ms" inside.

  

  The problem is that the MOXA closes its other port every minute. I can still read, but everyone else is blocked.

  Other Terminal programs work. The network guy told me that he sees a lot of traffic from my address and he thinks that, at some point, the MOXA is confused and shut its ports.

  Is there a possibility that read TCP sends a string of status or failure?

  How fast this device sends its strings? -What is simply spit data without any query command to be sent? If so your Moxa can be a problem too, because he doesn't know what to do with the data if there is no client connected to read. Also your Moxa converter can struggle to serve more than one client TCP on port even anyway. What should you do if several clients try to access the same port? Send the same message to everyone? Or send the incoming message randomly to one of them?

  Do you get your TCP read once errors Moxa "closes" the port as you say? If so you should terminate your loop on any error except maybe a timeout error and reopen the port in a second outer loop until your program wants out. Your loop never stopping on the errors will prevent the close TCP to run that will keep open socket and prevent the Moxa to see good handshake that the connection has been properly closed by the customer, which will probably prevent the Moxa device able to accept new connections. Network communication can be tricky and one of the first things you have to learn is the appropriate error handling. No matter what mistake anywhere in the network connection, usually error timeout on reading, with the exception should be managed by closing the connection and tries to reconnect.

• interpretation of TCP read the output string

  What is the right method to interpret the data from the TCP Read function? The output is a string of characters, which are obviously not hexadecimal values. How can I convert the string to a binary table or bytes?

  OK, time wild guess...

  The first four bytes are an indication for SYNCHRONIZATION

  The four bytes 0 4 0 0 is a 32-bit integer, GIS bytes less first. 1024

  Then you have 6 0 0 0, which could be another 32-bit integer, lsb first. 6

  Then your random data

  Rod.

• little binary string in array (of TCP read) to the table of Boolean LV (and back)

  I would like to ask what is the easiest way for the next conversion? We use aTCP Read function to read an incoming binary string to a S7 API using LabVIEW. We know that LabVIEW stores a Boolean value to 8 bits. The incoming binary string contains 14 bits (representing 14 indicators of status). What is the best way to convert these values of 14-bit LabVIEW Boolean table?

  In addition, we send a LAbVIEW Boolean table in the PLC data (to write a TCP) string containing status bits.

  Thank you very much!

  Martins wrote:

  This 30 bytes contains some data more, including 14 bit flags (size is 14 bits). Since the PLC cannot put 'together' (16-bit) words at his side before sending data TCP, 14 bits is padded with 2 bits holding no valueable info.

  Then the solution is simple.  Take your 2 bytes and unflatten in a U16.  Then use Boolean table number.

• TCP Read and Write at the same time

  Hello everyone,

  I have a question about parallelism in TCP connections.

  I know that it is possible to read and write on the same connection ID.

  So, if you ReadTCP and WriteTCP block each other, if you use the same TCP connection ID?

  Or to request more precise if I run two while loops, in parallel, with one end by calling WriteTCP and the other called ReadTCP.

  one of the delay of loops (or block) will be the other if both loops call their VI TCP at the same time right?

  The system is Windows 7 and Labview 2012.

  Kind regards

  Sebastian

  They are perfectly parallel.  Just write in one and read it from the other.  There is no conflict.

  See My TCP articles for more details.

• LabVIEW TCP/IP Client and server, I need to send commands and receive comments side server from the client regarding the command sent.

  Hi all

  I can configure my two PCs, one as a client and a server very well. I am able to send commands from the server to the client. However, I am trying to determine how I can get feedback from the client to the server that something has changed, or a CQI that the command has been received. How I can do this in LabVIEW with the box to TCP/IP tools, or is there a better way to do it?

  Thanks for your help!

  Best regards

  -Gmac

  Once the connection is established, TCP does not care which end is the 'server' and the 'customer '. Data can be sent in both directions using the same read and write functions. So, if you are already able to send data to the client and read on the server, you should be able to do the same to send data from the server to the client, using the same TCP connection.

  If this is not clear, please your postal code so that we can provide more specific advice.

• Writing TCP TCP read of the same VI.

  Hello

  I want to write data to a c program and also read data from it just after grace to a TCP connection. How can I implement both options in a single VI.

  I send you pictures of pixels values - program, then technology will send the berries to me. I made a suggestion, but I don't know if it is correct or not.

  The VI is downloaded and shown in the image below

  

  Yes, you can read and write to the same connection. Why would it be possible? I do not understand why you ask the question. Did you try and have a problem? If you don't try it, you might at least have opened one of the many TCP examples delivered with LabVIEW and illustrate this, you have not even need to write new code to see. If you have a problem, then ask for it specifically on this issue.

• Modbus tcp read holding registers return not requested quantity

  Background: I have a client using ELAU motion system - they record data with records they want to be able to read on a cRIO match with some analog FPGA data (I have digital handshaking going on for this).

  LabVIEW 2010 SP1

  cRIO-9074

  With the help of the library of VI of MOdbus.llb OR communicate with the other system.  I can open the TCP communication without problem and actually get SOME records, but not ALL registry data, I want to read.

  I want to do is read the registers individual operating 330 U16 values.  I know how the data are split to represent different lengths (i.e. most of the data items use 2 records number represent a 32 bit).  I want just to read all of the individual records and analyze the data in another VI to convert it to other data types.

  I provided the .vi MB Ethernet Master Query (poly) with the starting address for the first register, then the amount of 330.  The polymorphic instance selected is "reading record keeping.  The array returned by this VI via 'Holding Registers' is only 74 elements and not requested 330.  I have no exception code and no error in LV.  Is there some intrinsic limit, i.e. the number of Holding Registers that can be read?

  I do not use the (not sure if necessary) MBAP header entry.

  Thank you.

  Simple solution once I dug in the series MODBUS/TCP protocol protocol documentation out there via Google.

  History of the modbus function series is the limitation that carried over TCP - the maximum amount of bytes in the pack a data can be only 256 bytes.  So I was limited to approximately 125 ~ records at a time.

  256 bytes is 2048 bits.  The use of the 16-bit registers which gives maximum 128 registers.  I went with 125 followed making easier totals.

• wait on tcp read

  I'm sure this is a total noob question, but here it goes.

  I have a test machine that spits out data on a serial line after each test (about 1 or 2 minutes).  This unit is not near my pc, so it has a serial number to ethernet connected to it.  Everything is fine with the data to my pc but I don't know when the test is finished.

  My only solution is to stay connected while is Read.vi of TCP in a loop and ignoring the timeout error (56).  I don't want the entry timeout to be set to infinity, because if, for some reason, the test never ends, my program is stuck.

  Any ideas?  Your contribution is greatly appreciated.

  programmindragon wrote:

  My only solution is to stay connected while is Read.vi of TCP in a loop and ignoring the timeout error (56).  I don't want the entry timeout to be set to infinity, because if, for some reason, the test never ends, my program is stuck.

  Any ideas?  Your contribution is greatly appreciated.

  I have an idea... it's the same as your idea . Set a time-out and clear errors if you get the error 56. I wouldn't set up in 2 minutes, because, as you say, in this case, your program could potentially take 2 minutes to stop. I would have put something like 200 ms (random value I took.).

• How do I program labview to read a full bridge strain gauge placed at an angle of 45 degrees to measure the torsional deformation?

  Hello

  Currently, I'm trying to convert the reading of the strain gauge allows to get readings of the strain of a game of strain gauges of configuration of full-bridge at an angle of 45 degrees on a hollow cyllinder. It is set at 45 degrees, because we are trying to get traction and compression strains resulting from the application of the twist, or a moment of torsion, to the cyllinder hollow. Finally, we want to convert these readings of strain in order to get the couple. Our problem is that full-bridge options to convert the strain gauges appear only apply to configurations 0 or 90 degrees. My question is how can I take my current VI and set it to take readings of the strain of an alignment of 45 degrees. Also suggestions on how to add couple of this VI measures would be appreciated. We have scoured the site, but we are very new to Labview.

  Thank you!

  

  This is not a very good example, they show.  Full-bridge 1 will also read the constraint of torsion.  Full-bridge 1 is for any configuration where you get 2 gauges of tensile and compression 2 meters and you expect roughly equal magnitudes.  With a twisting bridge, the only thing you need to do is to make sure that the wiring and pay attention to the numbering of gage.  Think just mentally on what measurers are in tension and in compression as you twist the stem or tube.

  If you're wrong, you pretty much know immediately because you will see very little change in the output when you go to the torsion of the shaft because the templates of traction and compression will liquidate cancel each other in the bridge rather than expand their effects.  To fix it, all you will need to exchange a few threads to effectively rewire the bridge correctly.

  Good luck in your project.

• Stop listening tcp and tcp read

  Hi all

  If I use tcp and tcp listening read blocks with a time of judgment-1, how to prevent their execution if they are waiting for incoming connection or data?

  The read block tcp is in a while loop and the State of the stop button is not evaluated, because the reading block is pending.

  can someone tell me a solution compatible with the S-RIO target device problem?

  Thank you

  Hi giac82,

  I know you want to just close the server. You can create your own connection to the listener. You need another loop for it.

  See the attached picture. This is only a small example. You can do more complex to react on the different statuses.

  Mike

• LabVIEW can read data Excel with Excel installed Starter?

  I'm reading an Excel file, but I get the error-2147221164 try to read an Excel file and I think it's because of starting Excel. Is this the case?

  You probably found this:

  http://digital.NI.com/public.nsf/allkb/B7F980D169474D568625760E0055D55E?OpenDocument

  Who said Excel is not installed, but I think the problem is that Excel Starter (and the word by the way) is a not the component ActiveX.  This is what is used behind the scenes to talk to Excel, and without it, you will get several errors.

  EDIT: I can't seem to find where it says ActiveX is not included, but I remember having read - it somewhere.  Here is the wiki on this topic page.

  http://en.Wikipedia.org/wiki/Microsoft_Office_2010#Starter_Edition

• How do I program labview to read all 8 compact fieldpoint modules?

  I am new to fieldpoint and I my set-up block diagram to read 8 strain gauges using a SG-140 module.  My basket is filled with strain gauge modules 8 SG-140, and I need to know how to fix my diagram to read all 8 modules of SG - 140.  So, I need a total of 64 strain gauge readings 8 modules of SG - 140.  Can I do this without really copying what I've already done 8 times more?  Is it possible to use a loop or something to read the 7 other modules?  I appreciate any help I can get.

  My opinion about not having to duplicate the table of index based on what your VI was showing at the time.  Once you have the VI implemented with multiple modules, then you will need to implement an array of unique Index stretched far enough to get all the channels of interest.  From a 2D array, you need to connect both the row index and column index for a single scalar element.  So first channel would be 0 and 1, then 0 and 4, canal next 0 and 7.  The next module would be 1 and 1, 1 and 4, 1 and 7.