Receive data from serial cable

hello;
i am building a program which recive data from serial port... and to tes it i constructed a circuit where i connect the pin 2 to a power source.
c=inputStream.read();
readBuffer.append( c);
System.out.println("ok "+ readBuffer.toString() );
the prevouse sentence is to print out the result, but the result is numbers ,0,10,255,16,8 collection of numbers at any time i connect the circuit.
so can any one discuss to me what is these results?

I agree with Dennis that the timing characteristics of the USB-6008
would be insufficient to implement a serial interface with, but there
are other issues as well which would prevent you from doing this.
RS-232 has a maximum voltage of +/- 25V, which is higher than the
limits of your device no matter how you connect it. You may be
able to read the incoming data line on the analog lines if you use
differential mode (+/- 20V Range), but you would be unable to output
any data. The analog output range is 0-5V, so you wouldn't have
any way to output the voltage levels needed for a RS-232 interface.
Both the digital lines and the analog output are software timed, so you
would not be able to produce the accurately timed I/O needed for a
RS-232 interface.
You could overcome the voltage issues by using a line converter such as
a MAX232 chip to convert between RS-232 and TTL votlage levels, but you
would still have timing issues which would make it difficult to produce
a working serial interface.
I would recommend that you look into purchasing a USB Serial interface. National Instruments offers a full line of USB Serial Interfaces which allow you to easily interface with RS-232 devices on a computer without a serial port.

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I am using application written in Labview using windows Labview
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Hi Magnetica
Are both of the machines running the same runtime engine,
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Have you had RT applications running on this
machine before?
Is the development computer a 64bit machine?
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Hi
I need some help about rs-232 communication. I want to make a vi witch can do this things:
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I want to use sda6810 to anlyze data from a rs485 bus. So I use Labview to progame the sda6810 with the drivers.Firstly,I intilite the card,then I cofigued an channel to send data from a buffer,and configued another channel to receive data from the first chanel . But unfortunatly the data I received was not equal to the data I sended.And there are not any error messages indicated in Labview
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Hi all,
My scenario is Receiving Data from a third party system and sending it to a R3 system as an IDoc...
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Hello.
Assuming that I send data into PayPal (with the use of "HTML Variables for PayPal Payments Standard"):
var variables:URLVariables = new URLVariables();
variables.cmd = "_xclick";
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My idea is as follow:
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2. After finishing the payment on PayPal, the customer is auto-redirected to your page ("return" variable)
3. Customer returns to your page. PayPal does NOT send any payment data there.
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5. If you receive VERIFIED, you can process payment
This method means that you can easily update for example your MySQL database but unfortunately you have to reload .swf file each time - and that's why it is not a perfect solution in my opinion;
PS:
- variables.return and variables.notify_url must be absolute urls
- notify_url must also allow anonymous access from outside of your network
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- in your business PayPal account:
Auto Return = Enabled in account profile
PDT = Disabled in account profile
IPN = Enabled in account profile
- php file:
<?php
// read the post from PayPal system and add 'cmd'
$req = 'cmd=' . urlencode('_notify-validate');
foreach ($_POST as $key => $value) {
        $value = urlencode(stripslashes($value));
        $req .= "&$key=$value";
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curl_setopt($ch, CURLOPT_URL, 'https://www.paypal.com/cgi-bin/webscr');
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curl_setopt($ch, CURLOPT_POST, 1);
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curl_setopt($ch, CURLOPT_POSTFIELDS, $req);
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$payment_currency = $_POST['mc_currency'];
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I use LabVIEW 7.1 but I have some problem when, I use LabVEW to read the data from serial communication

I use LabVIEW 7.1 but I have some problem when, I use LabVEW to read the data from serial communication.
I use LabVIEW to read the data from serial communication then, i open the example (.vi) from Serial Communication - Advanced Serial Write and Read from LabVIEW Example. BUT it have some error message that : Error - 1073807202 occured at property node in visa configure serial port (instr).vi -> advance serial write and read .vi
this error code is undefined. no one has provide a description for this code, or you might have wired a number that is not an error code to the error code input.
I don't know why? please help me. thank you.

When I copy that code into "Explain Error" I get: "VISA: (Hex 0xBFFF009E) A code library required by VISA could not be located or loaded."
You may have a bad install of VISA or the wrong version of VISA loaded. Try re-installing VISA. You can get the latest version from the NI support site: http://digital.ni.com/softlib.nsf/webcategories/85256410006C055586256BBB002C0E91?opendocument&node=1....
Also ensure that you are not pointing the example towards a serial port that does not exist.
Please let us know what you find and what gets this working for you.
Rob

Problem while reading data from Serial Port

Hi All,
I am facing some problem while reading data from Serial Port.
As per the requirement I am writing the data on Serial Port and waiting for response of that data.
Notification for data availabilty is checked with method public void serialEvent(SerialPortEvent event) of javax.comm.SerialPortEventListener.
When we are writing data on the port one thread i.e. "main" thread is generated and when data availability event occures another thread "Win32SerialPort Notification thread" is generated. This creates problem for me as we can't control thread processing.
So can anybody pls explain me how to overcome this problem?
Regards,
Neha

My Problem is:-
I am simoultaneouly wrting data on port & reading data from port.
First I write data on port using outputStream.write() method. Now when target side sends me response back for the request on serial port DATA_AVAILABLE of SerialPortEventListner event occured,we are reading data from serial port.Now till the time we didn't get the response from target next command can't be written on the serial port. When we are writing data on port main thread is executed.Now my problem starts when DATA_AVAILABLE event occured.At this point another thread is created.Due to this my program writes data of next command without reading response of previous command.To solve this prob. I have used wait() & notify() methods as follows.But again due to this my pc hangs after execution of 2 commands. (PC hang in while loop in a code provided below.)
From SOPs I could figure it out that after 2 commands we are not able to write data on serial port so DATA_AVAILABLE event doesn't occure n pro. goes in wait state.
Can anybody help me to solve this issue.
Neha.
Code:
public void serialEvent(SerialPortEvent event)
          switch (event.getEventType())
               case SerialPortEvent.BI:
               case SerialPortEvent.OE:
               case SerialPortEvent.FE:
               case SerialPortEvent.PE:
               case SerialPortEvent.CD:
               case SerialPortEvent.CTS:
               case SerialPortEvent.DSR:
               case SerialPortEvent.RI:
               case SerialPortEvent.OUTPUT_BUFFER_EMPTY:
                             break;
               case SerialPortEvent.DATA_AVAILABLE:
                    try
                         dataThread = Thread.currentThread();
                         dataThread.setPriority(10);
                         dataAvailable = true;
                                                                                byte[] tempArray=new byte[availableBytes];
                                    inputStream.read(tempArray);
                                                                   catch (IOException io)
                         SOP(io, "Error in serialEvent callback call for event DATA_AVAILABLE");
public void writetoPort(byte[] data) throws IOException
                         outputStream.write(data);
                          while(finalTimeOut >= actualTime)
                        if( ! dataAvailable)
                                actualTime = System.currentTimeMillis();
                       else
          synchronized (mainThread)
               mainThread = Thread.currentThread();
               mainThread.wait();
public void sendDatatoUser(byte[] b) throws Exception, HWCCSystemFailure
          obj.returnData(b);
          synchronized(mainThread)
               mainThread.notify();

How to get data from serial port to GUI textArea

From Serial Port.....
Messages from base (always 5 bytes):
0xAA, 0, 0, 0, 0xBB - IDLE Mode
0xAA, 0, 0x80, 0x80, 0xBB - Question Mode
messages from terminal (always 6 bytes):
0xAA, a, b, c, chksum, 0xBB
where chksum = a+b+c;
a = address (0-250)
the 2 MSB's of b represenet the answer:
0 0 - A
0 1 - B
1 0 - C
1 1 - D
the 6LSB's of b and 8bits of c is the time for answer, in milliseconds.
(0-16384 milliseconds)
I have VB Code for that but I want the same thing in Java ...
Can any one help me?
Here's VB Code..
VERSION 5.00
Object = "{648A5603-2C6E-101B-82B6-000000000014}#1.1#0"; "MSCOMM32.OCX"
Begin VB.Form Form1
   BorderStyle     =   1 'Fixed Single
   Caption         =   "Aakar GUI"
   ClientHeight    =   4665
   ClientLeft      =   60
   ClientTop       =   375
   ClientWidth     =   6105
   LinkTopic       =   "Form1"
   MaxButton       =   0   'False
   MinButton       =   0   'False
   ScaleHeight     =   311
   ScaleMode       =   3 'Pixel
   ScaleWidth      =   407
   StartUpPosition =   3 'Windows Default
   Begin VB.CommandButton cmdPort
      Caption         =   "Open Port"
      Height          =   375
      Left            =   120
      TabIndex        =   4
      Top             =   600
      Width           =   1455
   End
   Begin VB.ComboBox cmbPort
      Height          =   315
      ItemData        =   "Form1.frx":0000
      Left            =   120
      List            =   "Form1.frx":0016
      Style           =   2 'Dropdown List
      TabIndex        =   3
      Top             =   120
      Width           =   2895
   End
   Begin VB.CommandButton cmdEnd
      Caption         =   "End"
      Height          =   495
      Left            =   1560
      TabIndex        =   2
      Top             =   1320
      Width           =   1215
   End
   Begin VB.CommandButton cmdStart
      Caption         =   "Start"
      Height          =   495
      Left            =   120
      TabIndex        =   1
      Top             =   1320
      Width           =   1215
   End
   Begin VB.TextBox txtMessage
      Height          =   2040
      Left            =   119
      MultiLine       =   -1 'True
      ScrollBars      =   3 'Both
      TabIndex        =   0
      Top             =   2475
      Width           =   5848
   End
   Begin VB.Timer tmrRead
      Enabled         =   0   'False
      Interval        =   1
      Left            =   2040
      Top             =   600
   End
   Begin MSCommLib.MSComm MSComm1
      Left            =   3120
      Top             =   360
      _ExtentX        =   1164
      _ExtentY        =   1164
      _Version        =   393216
      DTREnable       =   0   'False
      ParityReplace   =   45
      SThreshold      =   1
   End
   Begin VB.Label Label5
      Caption         =   "Result Data:"
      Height          =   375
      Left            =   120
      TabIndex        =   5
      Top             =   2115
      Width           =   1320
   End
End
Attribute VB_Name = "Form1"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Option Explicit
Dim PortIsOpen As Boolean
Dim Answers(4) As String
Dim RejectKeystroke As Boolean
Private Sub cmbPort_Change()
Debug.Print cmbPort.ListIndex
End Sub
Private Sub cmbPort_Validate(Cancel As Boolean)
'Cancel = True
End Sub
Private Sub cmdEnd_Click()
MSComm1.Output = "e"
txtMessage.Text = ""
End Sub
Private Sub cmdPort_Click()
On Error GoTo ErrorHandler
If cmbPort.ListIndex < 0 Then Exit Sub
If PortIsOpen Then
    cmbPort.Enabled = True
    MSComm1.PortOpen = False
    PortIsOpen = False
    cmdPort.Caption = "Open Port"
    cmdStart.Enabled = False
    cmdEnd.Enabled = False
Else
    MSComm1.CommPort = cmbPort.ListIndex + 1
    cmbPort.Enabled = False
    MSComm1.PortOpen = True
    PortIsOpen = True
    cmdPort.Caption = "Close Port"
    cmdStart.Enabled = True
    cmdEnd.Enabled = True
End If
Exit Sub
ErrorHandler:
Debug.Print Err.Number
Debug.Print Err.Description
MsgBox Err.Description, vbExclamation Or vbOKOnly, "Error opening port"
cmbPort.Enabled = True
PortIsOpen = False
cmdPort.Caption = "Open Port"
cmdStart.Enabled = False
cmdEnd.Enabled = False
End Sub
Private Sub cmdStart_Click()
MSComm1.Output = "s"
txtMessage.Text = ""
End Sub
Private Sub Form_Initialize()
Dim tmp As Variant
tmp = InitCommonControls
End Sub
Private Sub Form_Load()
Answers(0) = "A"
Answers(1) = "B"
Answers(2) = "C"
Answers(3) = "D"
'MSComm1.Settings = "9600,n,8,1"
''MSComm1.Settings = "115200,n,8,1"
'MSComm1.PortOpen = True
On Error GoTo ErrorHandler1
MSComm1.CommPort = 1                    ' comm port 1
MSComm1.RThreshold = 1                  ' use 'on comm' event processing
MSComm1.Settings = "9600,n,8,1"         ' baud, parity, data bits, stop bits
MSComm1.SThreshold = 1                  ' allows us to track Tx LED
MSComm1.InputMode = comInputModeText    'comInputModeBinary ' binary mode, you can also use
                                        ' comInputModeText for text only use
PortIsOpen = False
cmbPort.ListIndex = 0
' open the port
MSComm1.PortOpen = True
cmbPort.Enabled = False
PortIsOpen = True
cmdPort.Caption = "Close Port"
cmdStart.Enabled = True
cmdEnd.Enabled = True
Exit Sub
ErrorHandler1:
Debug.Print Err.Description
PortIsOpen = False
cmbPort.Enabled = True
cmdPort.Caption = "Open Port"
cmdStart.Enabled = False
cmdEnd.Enabled = False
End Sub
Private Sub Form_QueryUnload(Cancel As Integer, UnloadMode As Integer)
If MSComm1.PortOpen Then MSComm1.PortOpen = False
End Sub
Private Sub lblOption_Click()
End Sub
Private Sub MSComm1_OnComm()
' Synopsis:     Handle incoming characters, 'On Comm' Event
' Description: By setting MSComm1.RThreshold = 1, this event will fire for
'               each character that arrives in the comm controls input buffer.
'               Set MSComm1.RThreshold = 0 if you want to poll the control
'               yourself, either via a TImer or within program execution loop.
'               In most cases, OnComm Event processing shown here is the prefered
'               method of processing incoming characters.
    Dim i As Long
    Dim sBuff    As String           ' buffer for holding incoming characters
    Const MTC       As String = vbCrLf ' message terminator characters (ususally vbCrLf)
    Const LenMTC    As Long = 2         ' number of terminator characters, must match MTC
    Dim iPtr        As Long             ' pointer to terminatior character
    ' OnComm fires for multiple Events
    ' so get the Event ID & process
    Select Case MSComm1.CommEvent
        ' Received RThreshold # of chars, in our case 1.
        Case comEvReceive
            ' read all of the characters from the input buffer
            ' StrConv() is required when using MSComm in binary mode,
            ' if you set MSComm1.InputMode = comInputModeText, it's not required
            'sBuff = sBuff & StrConv(MSComm1.Input, vbUnicode)
            'If Len(txtMessage.Text) > 4096 Then txtMessage.Text = ""
            sBuff = MSComm1.Input
            Dim ch As String
            Dim PacketStart As Boolean
            Dim PacketLength As Integer
            Dim Packet() As String
            PacketStart = False
            PacketLength = 0
            While (Len(sBuff) > 0)
                ch = Left(sBuff, 1)
                If (ch = Chr(&HAA)) Then PacketStart = True
                If (ch = Chr(&HBB)) Then PacketStart = False
                If (ch <> Chr(&HAA) And ch <> Chr(&HBB)) Then
                    PacketLength = PacketLength + 1
                    ReDim Preserve Packet(PacketLength)
                    Packet(PacketLength) = ch
                End If
                'txtMessage.Text = txtMessage.Text + Format(Hex(Asc(ch)), " @@")
                sBuff = Right(sBuff, Len(sBuff) - 1)
            Wend
            If (PacketLength = 3) Then
                Debug.Print "Command packet recieved"
                'txtMessage.Text = txtMessage.Text + vbCrLf + "Address =" + Str(Asc(Packet(1)))
                'txtMessage.Text = txtMessage.Text + vbCrLf + "Address =" + Str(Asc(Packet(2)))
            End If
            If (PacketLength = 4) Then
                Debug.Print "Response packet recieved"
                txtMessage.Text = txtMessage.Text + "Address =" + Str(Asc(Packet(1))) + _
                    " Answer = " + Answers((Asc(Packet(2)) And &HC0) / 64) + _
                    " Time =" + Str((Asc(Packet(2)) And &H3F) * 256 + (Asc(Packet(3)))) + "mS" + vbCrLf
                'txtMessage.Text = txtMessage.Text + vbCrLf + "Address =" + Str(Asc(Packet(1)))
                'txtMessage.Text = txtMessage.Text + vbCrLf + "Option =" + Str((Asc(Packet(2)) And &HC0) / 64)
                'txtMessage.Text = txtMessage.Text + vbCrLf + "Time =" + Str((Asc(Packet(2)) And &H3F) * 256 + (Asc(Packet(3))))
            End If
            If (PacketLength <> 4 And PacketLength <> 3) Then Debug.Print "Unknown packet of length" + Str(PacketLength) + " recieved"
            txtMessage.Text = txtMessage.Text + vbCrLf
        ' An EOF charater was found in the input stream
        Case comEvEOF
            DoEvents
        ' There are SThreshold number of characters in the transmit buffer.
        Case comEvSend
            DoEvents
        ' A Break was received.
        Case comEventBreak
            DoEvents
        ' Framing Error
        Case comEventFrame
            DoEvents
        ' Data Lost.
        Case comEventOverrun
            DoEvents
        ' Receive buffer overflow.
        Case comEventRxOver
            DoEvents
        ' Parity Error.
        Case comEventRxParity
            DoEvents
        ' Transmit buffer full.
        Case comEventTxFull
        ' Unexpected error retrieving DCB]
        Case comEventDCB
            DoEvents
    End Select
End Sub
Private Sub tmrRead_Timer()
'MSComm1.Output = vbCrLf + vbCrLf
'MSComm1.Output = Chr(128)
End Sub
Private Sub txtMessage_KeyDown(KeyCode As Integer, Shift As Integer)
If Shift = 2 Or Shift = 4 Then RejectKeystroke = False Else RejectKeystroke = True
End Sub
Private Sub txtMessage_KeyPress(KeyAscii As Integer)
If RejectKeystroke Then
    KeyAscii = 0
End If
End SubThanks in advance..

I want to replicate the entire VB program as Java Program.
This has to be included in my project which i am doing in java.

Problem in reading data from serial port continuously- application hangs after sometimes

I need to read data from two COM port and order of data appearance from COM port is not fixed.
I have used small timeout and reading data in while loop continously . If my application is steady for sometime it gets hangs and afterwards it doesnt receive any data again.
Then I need to restart my application again to make it work.
I am attaching VI. Let me know any issue.
Kudos are always welcome if you got solution to some extent.
I need my difficulties because they are necessary to enjoy my success.
--Ranjeet
Attachments:
Scanning.vi ‏39 KB

billko wrote:
Ranjeet_Singh wrote:
I need to read data from two COM port and order of data appearance from COM port is not fixed.
I have used small timeout and reading data in while loop continously . If my application is steady for sometime it gets hangs and afterwards it doesnt receive any data again.
Then I need to restart my application again to make it work.
I am attaching VI. Let me know any issue.
What do you mean, "not fixed?" If there is no termination character, no start/stop character(s) or even a consistent data length, then how can you really be sure when the data starts and stops?
I probably misunderstood you though. Assuming the last case is not ture - there is a certain length to the data - then you should use the bytes at port, like in the otherwise disastrous serial port read example. In this case, it's NOT disastrous. You have to make sure that you read all the data that came through. Right now you have no idea how much data you just read. Also, if this is streaming data, you might want to break it out into a producer/consumer design pattern.
Not fixed means order is not fixed, data from any com port can come anytime. lenght is fixed, one com port have 14 byte and other 8 byte fixed..
Reading data is not an issue for me as it works nice but I have a query that why my application hangs after sometime and stops reading data from COM PORT.
Kudos are always welcome if you got solution to some extent.
I need my difficulties because they are necessary to enjoy my success.
--Ranjeet

VISA Read gets incorrect data from serial connection

I am having difficulty using the VISA functions in LabVIEW to read data from a virtual COM port. Data is being sent from a serial to USB chip via a USB connection using OpenSDA drivers. I have a python program written to read from this chip as well, and it never has an issue. However, when trying to achieve the same read in LabVIEW I am running into the problem of getting incorrect data in the read buffer using the VISA Read function.
I have a VISA Configure Serial Port function set up with a control to select the COM port that the device is plugged into. Baud rate is default at 9600. Termination char of my data is a newline, which is also default. Enable termination char is set to true. A VISA Open function follows this configuration, and then feeds the VISA Resource Name Out into a while loop where a VISA Read function displays the data in read buffer. Byte count for the VISA Read is set to 20 so I can read more of the erroneous datat, however actual data will only be 6-12 bytes. The while loop has a wait function, and no matter how much I slow down the readings I still get incorrect data (I have tried 20ms thru 1000ms).
The data I expect to receive in the read buffer from VISA Read is in the form of "0-255,0-255,0-255\n", like the following:
51,93,31\n
or
51,193,128\n
And occasionally I receive this data correctly, however I intermittently (sometimes every couple reads, sometimes a couple times in a row) get incorrect readings like this:
51,1\n
51,193739\n
\n
51,1933,191\n
51,,193,196\n
51,1933,252
51,203,116203,186\n
Where it seems like the read data is truncated, missing characters, or has additional characters. Looking at these values, however, it seems like the read was done incorrectly because the bytes seem partially correct (51 is the first number even in incorrect reads).
I have search but haven't found a similar issue and I am not sure what to try from here on. Any help is appreciated. Thanks!
Attachments:
Serial_Read_debugging.vi ‏13 KB

The first thing is that none of the error clusters are connected so you could be getting errors that you are not seeing. Are you sure about the comm parameters? Finally, I have never had a lot of luck looking for termination characters. You might want to just capture data and append each read into one long string just to see if you are still seeing this strangeness.
What sort of device is returning the data? How often does it spit out the data? How much distance is there between it and your computer? Can you configure it append something like a checksum or crc to the data?
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How do you receive data from multiple people on a single port?

I am trying to make a server where it receives the data from multiple users and then send it back to them all- multicasting audio to be exact. I tried setting it up but when i open the RTP session i get "can't open local data port" if i have more than one used connected to me. Does anyone have a solution? I didnt find much on the samples page and the multicast example from http://java.sun.com/products/java-media/jmf/2.1.1/apidocs/javax/media/rtp/RTPManager.html
didnt help either- i used the same ipaddress for the initialize and addtarget but i get "Local Data AddressDoes not belong to any of this hosts local interfaces". I am really in a pickle... If anyone can help me out that would be great!
EX: If A,B,C want to multicast they will all send to Server S using port 3000. Server S will create listeners for each of them using port 3000 and when received data it will send back to all of them at 4000. This is what i am trying to do... should i make multiple threads? would that help? thanks and please help!

To send to everyone, you can send to a multicast address (choose one from 224.0.0.0 to 239.255.255.255), on a given port (2000). I don't have any code example here but it should very similar to unicast. As you said, you just have to register the Session and add a target with this same address.
I don't have any example myself, but you should find code example of both server and client around. It is a very common usage of jmf rtp.
I don't know how to mix several audio streams together (never had to do this), so I'm afraid I can't answer your other questions, sorry... The only way to know if it will slow down the transmission is to try. :)

Port number on which SAP receives data from extrernal systems

Hi,
We have an external application which sends/receives data to/from SAP. I am trying to figure out the port on which SAP server getting/sending data. Every time on SAP server side, the port opened is sapgw01( sapgw<system number>). Can anyone tell how to figure out the correct port on which SAP is operating in this case ?

Hi
check the following link
https://www.sdn.sap.com/irj/sdn/go/portal/prtroot/docs/library/uuid/4e515a43-0e01-0010-2da1-9bcc452c280b

Stoping VI inbetween when program seeking data from serial port.

I have an application in which I need to read data from two serial port one after other.
One read will read 14 byte and other 08 bytes(Just info).
Now in between if user need to stop the VI then how to stop it?
Kudos are always welcome if you got solution to some extent.
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A state machine could do this easily. Just have a state to check for the stop (or any other events).
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Receive data from serial cable

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