Stream Serial Data to Disk

I am looking for a sample .vi that I can use to read in data from my RS-422 port, and stream it straight to disk so I don't have to worry about buffering the incoming data. My incoming data files can be anywhere from 1MB up to about 150MB or so, and it will vary, so I need something, or ideas anyway, how to do this. Any help would be greatly appreciated.
Jimmy

Take a look at the attached VI. It has none of the buffering I mentioned earlier, but you may not need it. Disk transfer will probably be inefficient, but should be able to keep up with the serial port. You may want to put a delay in the loop to keep from sucking up processor resources and to allow some data to come in before the next iteration. This will depend upon your data rates and what else you are doing at the time. I would suggest about 10msec.
This account is no longer active. Contact ShadesOfGray for current posts and information.
Attachments:
StreamToDiskFromSerial.vi ‏65 KB

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Using TDM VI in Lv 7.1 to stream data to disk

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Hi,
The LabVIEW Storage VIs do not yet support streaming data to disk. However, you can benefit from the storage VIs structured approach to saving data by:
Streaming data to disk using standard binary write VIs
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Using Digital I/O to generate serial data stream

Hello All,
I am in need to generate a serial data stream. HW I use is MIO-16E-10.
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Anand,
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Need help streaming data to disk

I have enclosed a simple vi where I'm streaming data to disk and then would like to read the data (analyze it). I'm not a avid user in LV but would like to understand this concept. I'm having problems reading the data. Is anyone experienced in this arena?
Attachments:
streaming to disk.vi ‏146 KB

Hello,
I have taken a look at the vi you attached and have discovered where some problems may be arising. First your For and While loops do not know when to finish. You must give them some sort of termination element whether it be a certain number of iterations or end of file. However, the main problem you are running into is that you are trying to write and read from a file at the same time. The read is actually trying to read from a file that does not yet exist or have data. You must have these be sequential. When the write finishes then you can begin the read. You can do this by using a Sequence Structure from the Structures Palette.
I would also like to suggest using the examples in the Example Finder in the Help menu as a starting point. You can search for read and write to find examples you can incorporate. Also there is one example Read from Binary File that I believe you will find useful in your application.
Thanks,
Caroline
National Instruments
Thanks,
Caroline Tipton
Data Management Product Manager
National Instruments

Why is streaming data to disk necessary?

Does streaming data to disk actually take the burden off the buffer to allow the processing of data after its been acquired? I've seen an example or 2 but unclear to the purpose. Can anyone explain?

Hi,
There's another example called High Speed Data Logger.vi that comes shipped with LabVIEW. This is a more efficient datalogging example than simple data logger.vi. The major difference between the two is that Simple data logger continuously opens and closes the file reference in the while loop and writes in ASCII. High speed data logger.vi only opens the file reference once, and then continuously writes binary data to the file until you tell it to stop. After it stops, it then closes the reference. This is how to efficiently do it without incurring any excess overhead. Hope this helps!
PS - You can find the example in the NI Example Finder. Go to Help >> Find Examples, and then go to the Search Tab and enter "data
logging" as the keyword.
Jeremy L.
National Instruments
Jeremy L.
National Instruments

Streaming data to disk, need help reading data into Power Spectrum/Octave vi

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From your general description, I gather you are streaming to a text based file (comma or tab separated spreadsheet format) and would like to analyse this data with a power spectrum or octave analysis when you finish. Since you are streaming, I assume you have a lot of data. Do you have more than one channel?
In any case, you have two simple options (and lots of complex ones). You can either read the data back from disk and convert it to a 1D array (try the Read From Spreadsheet File.vi - will get a 2D array, take the first column or the column of your choice if you have more than one channel) or you can use the Spreadsheet String to Array primitive to create an array from your text data before you save it to disk.
If your data rate is slow enough, you can analyze as you acquire and store.
Taking your data as text is very inefficient. What you really want to do is read the data as binary, use that for your analysis, and use something like the Write to Spreadsheet File.vi to save text data to disk.
This account is no longer active. Contact ShadesOfGray for current posts and information.

Q: Re: Q: Acquiring data using two E series devices connected by RTSI and streaming data to disk

<< (My first posting)
I use two E series PCI Cards, connected by RTSI. I'd like to stream the data
from both cards to a binary file and to add a header to it.
I also need to somehow read (plot) the stored data, this with another VI.
The whole should be then integrated into an existing program, that used just
one acquisition card.
Till now I have tried to combine "Two E-series Shared ScanClk.vi" and "High
Speed Data Logger.vi" into another VI, and I have tried to read the stored
data with the "High Speed Data Reader.vi". The problem is that I fight with
one error after another, what prevents me from going further.
I use LabView 6.1, under Windows 2K.
Has somebody by chance already done something similar and would agree to
share with me their experience? TIA for any suggestion.
Regards,
Victor Manta
>>
"Ben" wrote in message
news:[email protected]...
> Hi Victor,
>
> I have done a lot of similar work.
>
> Exactly what did you try and what specific errors did you encounter?
>
> What you are trying is do-able provided the hardware you have suuports
> it.
>
> Please post (both here and to the DAQ group)
> the details of the hardware you are using,
> versions of software being used,
> Examples that you are using,
> error codes that occured,
> posibly post example code showing the problem.
>
> Ben
Hi Ben,
I use two PCI-MIO-16E-1 cards, connected by RTSI. I'd like to stream the
data from both cards in real time to a binary file, after having added a
header to it.
For tests, on the channel 0 of each card is applied the same square wave,
100 Hz.
Yes, the hardware support RTSI. I use LabView 6.1.
Till now I have:
1. Combined the "Two E-series Shared ScanClk.vi" and the "High
Speed Data Logger.vi" into a DAQ VI. To do this, I have "doubled" and
adapted the "High Speed Data Logger.vi". For testing purposes the data are
stored in two files, always the same ones (the old ones being overwritten
after each acquisition).
2. "Doubled" and adapted "High Speed Data Reader.vi" into another VI, for
reading from both files, mentioned earlier.
What already works:
- The headers for both files are correctly stored (VI point 1.)
- The acquired data from the first card (device 1) are correctly stored (VI
point 1.)
- The VI (point 2.) that reads both files and displays the results works
What doesn't work:
- The acquired data from the second card aren't stored at all (VI point 1.)
- An error message says: "Error -10608 occurred at AI Buffer Read. Possible
reason: NI-DAQ LV: No transfer is in progress for the specified resource."
I think that I understand this message, but I don't know how to continue.
The DAQ VI can be downloaded from (please click the link, then the link on
that page; about 100K, zipped):
http://www.swissheartnet.unibe.ch/labview.htm
Thanks a lot in advance.
Regards,
Victor Manta
PS. I don't know which DAQ group you mean.

"Filipe A." wrote in message
news:[email protected]...
> Victor;
>
> You can definitely accomplish that task with the DAQ boards you have
> and Labview.
>
> It would be good if you could be more specific as far as what type of
> errors you are seeing and how you are integrating both VIs.
>
> Regards
> Filipe A.
> Applications Engineer
> National Instruments
Maybe Mr. Filipe A. could help me? Please see below, and TIA.
Regards,
Victor Manta
"Victor Manta" wrote in message
news:[email protected]...
> << (My first posting)
> I use two E series PCI Cards, connected by RTSI. I'd like to stream the
data
> from both cards to a binary file and to add a header to it.
>
> I also need to somehow read (plot) the stored data, this with another VI.
>
> The whole should be then integrated into an existing program, that used
just
> one acquisition card.
>
> Till now I have tried to combine "Two E-series Shared ScanClk.vi" and
"High
> Speed Data Logger.vi" into another VI, and I have tried to read the stored
> data with the "High Speed Data Reader.vi". The problem is that I fight
with
> one error after another, what prevents me from going further.
>
> I use LabView 6.1, under Windows 2K.
>
> Has somebody by chance already done something similar and would agree to
> share with me their experience? TIA for any suggestion.
>
> Regards,
> Victor Manta
> >>
>
> "Ben" wrote in message
> news:[email protected]...
> > Hi Victor,
> >
> > I have done a lot of similar work.
> >
> > Exactly what did you try and what specific errors did you encounter?
> >
> > What you are trying is do-able provided the hardware you have suuports
> > it.
> >
> > Please post (both here and to the DAQ group)
> > the details of the hardware you are using,
> > versions of software being used,
> > Examples that you are using,
> > error codes that occured,
> > posibly post example code showing the problem.
> >
> > Ben
>
> Hi Ben,
>
> I use two PCI-MIO-16E-1 cards, connected by RTSI. I'd like to stream the
> data from both cards in real time to a binary file, after having added a
> header to it.
>
> For tests, on the channel 0 of each card is applied the same square wave,
> 100 Hz.
>
> Yes, the hardware support RTSI. I use LabView 6.1.
>
> Till now I have:
>
> 1. Combined the "Two E-series Shared ScanClk.vi" and the "High
> Speed Data Logger.vi" into a DAQ VI. To do this, I have "doubled" and
> adapted the "High Speed Data Logger.vi". For testing purposes the data are
> stored in two files, always the same ones (the old ones being overwritten
> after each acquisition).
>
> 2. "Doubled" and adapted "High Speed Data Reader.vi" into another VI, for
> reading from both files, mentioned earlier.
>
> What already works:
>
> - The headers for both files are correctly stored (VI point 1.)
> - The acquired data from the first card (device 1) are correctly stored
(VI
> point 1.)
> - The VI (point 2.) that reads both files and displays the results works
>
> What doesn't work:
>
> - The acquired data from the second card aren't stored at all (VI point
1.)
> - An error message says: "Error -10608 occurred at AI Buffer Read.
Possible
> reason: NI-DAQ LV: No transfer is in progress for the specified resource."
>
> I think that I understand this message, but I don't know how to continue.
>
> The DAQ VI can be downloaded from (please click the link, then the link on
> that page; about 100K, zipped):
>
> http://www.swissheartnet.unibe.ch/labview.htm
>
> Thanks a lot in advance.
>
> Regards,
>
> Victor Manta
>
> PS. I don't know which DAQ group you mean.

Q: Acquiring data using two E series devices connected by RTSI and streaming data to disk

I use two E series PCI Cards, connected by RTSI. I'd like to stream the data
from both cards to a binary file and to add a header to it.
I also need to somehow read (plot) the stored data, this with another VI.
The whole should be then integrated into an existing program, that used just
one acquisition card.
Till now I have tried to combine "Two E-series Shared ScanClk.vi" and "High
Speed Data Logger.vi" into another VI, and I have tried to read the stored
data with the "High Speed Data Reader.vi". The problem is that I fight with
one error after another, what prevents me from going further.
I use LabView 6.1, under Windows 2K.
Has somebody by chance already done something simi
lar and would agree to
share with me their experience? TIA for any suggestion.
Regards,
Victor Manta

<< (My first posting)
I use two E series PCI Cards, connected by RTSI. I'd like to stream the data
from both cards to a binary file and to add a header to it.
I also need to somehow read (plot) the stored data, this with another VI.
The whole should be then integrated into an existing program, that used just
one acquisition card.
Till now I have tried to combine "Two E-series Shared ScanClk.vi" and "High
Speed Data Logger.vi" into another VI, and I have tried to read the stored
data with the "High Speed Data Reader.vi". The problem is that I fight with
one error after another, what prevents me from going further.
I use LabView 6.1, under Windows 2K.
Has somebody by chance already done something similar and would agree to
share with me their experience? TIA for any suggestion.
Regards,
Victor Manta
>>
"Ben" wrote in message
news:[email protected]...
> Hi Victor,
>
> I have done a lot of similar work.
>
> Exactly what did you try and what specific errors did you encounter?
>
> What you are trying is do-able provided the hardware you have suuports
> it.
>
> Please post (both here and to the DAQ group)
> the details of the hardware you are using,
> versions of software being used,
> Examples that you are using,
> error codes that occured,
> posibly post example code showing the problem.
>
> Ben
Hi Ben,
I use two PCI-MIO-16E-1 cards, connected by RTSI. I'd like to stream the
data from both cards in real time to a binary file, after having added a
header to it.
For tests, on the channel 0 of each card is applied the same square wave,
100 Hz.
Yes, the hardware support RTSI. I use LabView 6.1.
Till now I have:
1. Combined the "Two E-series Shared ScanClk.vi" and the "High
Speed Data Logger.vi" into a DAQ VI. To do this, I have "doubled" and
adapted the "High Speed Data Logger.vi". For testing purposes the data are
stored in two files, always the same ones (the old ones being overwritten
after each acquisition).
2. "Doubled" and adapted "High Speed Data Reader.vi" into another VI, for
reading from both files, mentioned earlier.
What already works:
- The headers for both files are correctly stored (VI point 1.)
- The acquired data from the first card (device 1) are correctly stored (VI
point 1.)
- The VI (point 2.) that reads both files and displays the results works
What doesn't work:
- The acquired data from the second card aren't stored at all (VI point 1.)
- An error message says: "Error -10608 occurred at AI Buffer Read. Possible
reason: NI-DAQ LV: No transfer is in progress for the specified resource."
I think that I understand this message, but I don't know how to continue.
The DAQ VI can be downloaded from (please click the link, then the link on
that page; about 100K, zipped):
http://www.swissheartnet.unibe.ch/labview.htm
Thanks a lot in advance.
Regards,
Victor Manta
PS. I don't know which DAQ group you mean.

PXIe-5122 continuous stream 2 channels to disk with 100MS/s

Hey,
I am currently trying to find a way to stream 2 channels to disk with 100MS/s with my PXIe-5122. According to the product specification, the card should be able to do this.
Unfortunately, I have'nt seen any programs.
What I have are two loops, one for the DAQ and one to empty the onboard memory using a queue and writing the fetched waveform data into a tdms file. I keep obtaining the error, that samples in the onboard memory are overwritten... therefore, the VI doesn't empty the onboard memory in sufficient speed.
Does anybody know how I could solve this problem? Or does anybody have a program?
Thanks for the help!

Hi lehrm,
you are writing about that you didn#t see any application for the 5122. If you mean examples, there are a lot of examples installed on your system when you install the driver sw for the device. eg. there is an example called niScope EX Stream to Disk, that seems to be interesting for your issue
Examples are available in the Example Finder of LabVIEW, in the folder: "Hardware Input and Output" -> "Modular Instruments" -> NI-SCOPE (High Speed Digitizer)" -> "Continious Acquisition".
This can give you first ideas!
Kind regards
Tobias S.

Precise time stamping of serial data

I am having trouble with precise timestamping of incoming serial data recived on 4 ports using 4 separate threads that continually attempt to read a byte.
When the expected frame is recieved the data is tagged with a time stamp.
The issue seems to be windows xp or the serial ports themselves. I am using an xsens serial to usb, 2 lavaport serial cards and the built in serial port.
Any suggestions for precise timing?

there is some hints:
   -for milisecond precise timestamp, you can use GetLocalTime,GetSystemTime or GetTickCount.
But to achieve true milisecond scale, you need use timeBeginPeriod(1)/timeEndPeriod(1) otherwise you get 10-16ms scale depend on system
    (please read help pages on msdn for timeBeginPeriod function)
   - create your program to not use CPU too much(no pooling,just message and/or sync wait),
     or even better, do not run any other apllication which consume lot of CPU/DISK resources on the same PC
   - for serial communication (but this also depend on baud rate) you can try to set send/receive driver buffer to 1 (from windows device manager)
   - try different serial port card/converter(with different drivers)
   - if still need something to try, set higher process and thread priority (SetPriorityClass,SetThreadPriority)
After all of this, on windows, there are no precise timing.Even if you do everything you can do, there is still chance to get time gap, but you can detect it (in milisecond precision)

Serial data input problem

Hi friends.
I have a problem with my java programming. Please don't laugh me if it is simple. I'm new in java.
I want to take data from censor named RFIDreader. It use card like smartcard. When the card approach the censor, it send the ID which consist of 13 bytes of data.
I have search code from the internet. But when I try to my PC, it didn't do very well.
Hopefully, PC would receive all the ID data. But in my case it had to read twice to collect the data. The first trying, it's ok. It can collect data only once loop. But next, it must read 8 byte first and then read the rest on the second loop. Only if i restart my PC so it can be good again. But in the second try next, it screw up again.
I use j2sdk 1.5.0 for windows.
I want to collect the data once, so i can procces it to another task.
this is my code
/* Sample java code to read an RFID tag */
import java.io.*;
import java.util.*;
import javax.comm.*;
public class RFIDTagRead implements Runnable, SerialPortEventListener {
static CommPortIdentifier portId;
static Enumeration portList;
InputStream inputStream;
SerialPort serialPort;
Thread readThread;
//Array consisting of SOH, length, command, data, BCC
static byte[] bytearray = {0x01, 0x02, 0x09, 0x32, 0x39};
static OutputStream outputStream;
static int n =0;
public static void main(String[] args) {
//Enumerate a list of available ports
portList = CommPortIdentifier.getPortIdentifiers();
// Identify the ports. I connected the reader with COM1
while (portList.hasMoreElements()) {
portId = (CommPortIdentifier) portList.nextElement();
if (portId.getPortType() == CommPortIdentifier.PORT_SERIAL) {
if (portId.getName().equals("COM1")) {
System.out.println("The port is: " + portId.getName());
RFIDTagRead reader = new RFIDTagRead();
public RFIDTagRead() {
try {
//Open the COM1 port and name it MicroReader with timeout 2000ms
serialPort = (SerialPort) portId.open("SimpleReadApp", 2000);
} catch (Exception e) {System.out.println("Port Error");}
try {
outputStream = serialPort.getOutputStream();
// Write the stream of data conforming to PC to reader protocol
outputStream.write(bytearray);
outputStream.flush();
System.out.println("The following bytes are being written");
for(int i=0; i<bytearray.length; i++)
System.out.println(bytearray);
System.out.println("Tag will be read when its in the field of the reader");
} catch (IOException e) {}
// Set Serial Port parameter
try {
serialPort.setSerialPortParams(9600,
SerialPort.DATABITS_8,
SerialPort.STOPBITS_1,
SerialPort.PARITY_NONE);
} catch (UnsupportedCommOperationException e) {}
try {
//Register an event listener object to the port
serialPort.addEventListener(this);
} catch (TooManyListenersException e)
{System.out.println("Too Many Listeners");
//Specify an event type. On data availability, triggers serialEvent method
serialPort.notifyOnDataAvailable(true);
try {
//Associate an InputStream object with this port.
inputStream = serialPort.getInputStream();
} catch (IOException e) {}
//Start a thread to handle the time-to-read the tag
readThread = new Thread(this);
readThread.start();
public void run() {
try {
Thread.sleep(56);
} catch (InterruptedException e) {}
//This method is called by notifyOnDataAvailabe()
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:
n++; //to count the number of readings
System.out.println("The reading description of RFID Tag" + " " + n);
//array size must not be less than the number of bytes to be read
byte[] readBuffer = new byte[20]; // to store the read data
int numbyte = 0;
try {
while(inputStream.available() >0) {
// Read the RFID data and store in the byte array
numbyte = inputStream.read(readBuffer);
System.out.println("Number of Bytes read: " + numbyte);
} catch (IOException e) {}
if( readBuffer[0] == 1) /*check if start bit is detected */
int length = readBuffer[1];
// Identify the Transponder type
switch(readBuffer[2]) {
case 12 :
System.out.print("RFID is RO:" + "\t");
break;
case 13 :
System.out.print("RFID is R/W:" + "\t");
break;
case 14:
System.out.print("RFID is MPT/SAMPT:" + "\t");
break;
case 15:
System.out.print("RFID is Other:" + "\t");
break;
// Write the actual tag reading in Hexadecimal
for( int m = length+1; m > 2; m--)
System.out.print(Integer.toHexString(readBuffer[m] & 255));
System.out.println(" ");
System.out.println("\t" + "Read Sucessful");
System.out.println("----------------------------------");
break;
somebody have a suggestion? please help me...
thanx

You may want to try the 'Java Technology Forums - Socket Programming' forum for issues like this:
http://forum.java.sun.com/forum.jspa?forumID=11
btw, i did a search on that forum and found a thread that discusses a problem similar to the one you have:
http://forum.java.sun.com/thread.jspa?forumID=11&threadID=555379
The suggestion on that thread is:
try to use
serialPort.disableReceiveFraming();
serialPort.disableReceiveTimeout();
serialPort.enableReceiveThreshold(length);
with lenght as the preferred size of the dataset. (e.g. 16 bytes instead of 8)You may want to read that thread to see if it helps...

Program to decode serialized data?

Is there a program around which displays the contents of a serialized data stream? Because I'm having a bit of difficulty in serializing some highly interlinked objects, and I suspect that a class is being serialized which shouldn't be. It would be good just to have a quick look at what objects are in the output file.
I've seen the spec, and should obviously write a one-off program to do the decoding, but if there's something out there already it would save a lot of time.
I tried doing a loop with
Object o=objectInputStream.readObject();but it complained that the UIDs were wrong. Which of course was true.

If you were to System.out.println(objectInputStream.readObject(); in your loop instead of assigning it to an object, does/will it still generate the UID error?
I don't know of a program to do what you want, but I do know a tedious way to get around the UID error. When it gives you the error, copy down the UID number of the file, then go over to the class and declare private static final long serialVersionUID = /*the UID of the file followed by an L*/ I feel like it's almost a hack, but it will stop the UID mismatch, and you won't have to worry about it again. (I think. It worked for me when I had UID issues and realized it was because I wasn't declaring serialVersionUID like I should have been.)

Direct Streaming of data from onboard memory to Host memory in PXI 5122

Hey All,
I have a small query about PXI 5122. In Data Sheet its written that " The PXI-5122 also can stream data continuously from onboard memory to host memory for longer acquisitions and streaming to disk. "
So do we have to write some code for streaming the data on hard disk or when drivers of this card is installed then some VI's will appear in control panel through which we can stream data on hard disk ??
I hope you all understood what my query is. Please let me know for further details
Thank you.
Regards,
Sarang Dhananjay Jaiswal
Satyam Development Center, Banglore, INDIA

hi sarang,
u have to write some code for streaming the data on hard disk,
for any applications using labview u need to do coding........
here is a vi which will do streaming of data on to hard disk
to know more about digitizers (C:\Program Files\National Instruments\LabVIEW 7.1\examples\instr\niScope\niScope EX Getting Started.vi)
or in labview goto
find examples \hardware input output \modular instruments\ NI-scope(high speed digitizers)
regards
ak
Attachments:
Stream data to Disk1.vi ‏172 KB

What's the fastest C function for writing binary data to disk?

I'm acquiring data at high speeds across multiple boards and I'm having a hard time writing the data to disk fast enough to keep up. I'm programming in C in Visual Studios and I'm currently using fwrite. I have a similar system set up in LabView and my C code can't perform as well. Is there a better or faster way to write to disk in C?

Some speculated a few years ago that there would be
no reason to use Fortran too. :)Are you saying there's a reason to use Fortran? Help me lord!
Anyway, they were right! The industry may be stalling, but the vision is not. The economy and many other factors are to blame for why we haven't been able to break out of the computing paradigm we're stuck in. It's like the automobile, it hasn't changed in a century. Why? $$$
Oh, people said we'd have flying cars by now, where are they? Well we do have them! But we're too busy spending that 400 billion a year on war instead of evolving as a species.
Anyway, when we take the next step and have true distributed computing with multi-core processors everywhere, Java will run, Java will scale, and Java will outperform ANYTHING available.
And speaking of game programming, the PS3 developers are having a hell of a time doing the 3 CPUs. Why? Because all they've ever done is single & double processor systems. It's time to think out of the box. When a game console hits the market with 512 CPU cores, do you REALLY think C/C++ will run on that? But, Java was designed for it.
Java = the future
C++ = the past

Searching Incoming Serial Data

Greetings!
I was trying to get visual studio to filter through the incoming serial data it is receiving from an Arduino. The program shows the incoming data, so I know the serial port is working, but I'm not sure how to get it to look through that data ( I was thinking
I could use StreamReader to do this). My goal is this: When certain data is received, change the background color of a textbox. I am very new at this and any direction would be appreciated! I feel like i'm throwing spaghetti at a wall...
Here is my current code:
Imports System
Imports System.Threading
Imports System.IO.Ports
Imports System.ComponentModel
Imports System.IO
Public Class Form1
Dim myPort As Array
Delegate Sub SetTextCallBack(ByVal [TEXT] As String)
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
myPort = IO.Ports.SerialPort.GetPortNames()
portCmbo.Items.AddRange(myPort)
End Sub
Private Sub startBtn_Click(sender As Object, e As EventArgs) Handles startBtn.Click
SerialPort1.PortName = portCmbo.Text
SerialPort1.BaudRate = baudCmbo.Text
SerialPort1.Open()
startBtn.Enabled = False
closeBtn.Enabled = True
End Sub
Private Sub closeBtn_Click(sender As Object, e As EventArgs) Handles closeBtn.Click
SerialPort1.Close()
startBtn.Enabled = True
closeBtn.Enabled = False
End Sub
Private Sub SerialPort1_DataReceived(sender As Object, e As SerialDataReceivedEventArgs) Handles SerialPort1.DataReceived
ReceivedText(SerialPort1.ReadExisting())
End Sub
Private Sub ReceivedText(ByVal [text] As String)
If Me.inputTxtBox.InvokeRequired Then
Dim x As New SetTextCallBack(AddressOf ReceivedText)
Me.Invoke(x, New Object() {(text)})
Else
Me.inputTxtBox.Text &= [text]
End If
End Sub
Private Sub outputTxtBx_TextChanged(sender As Object, e As EventArgs) Handles outputTxtBx.TextChanged
Dim myReader As StreamReader = New StreamReader("Me.inputTxtBox")
Dim line As String = ""
End Sub
End Class
ps: If there is an easier way of doing this, please let me know!

You should read a good book on "Communications". When processing received data (from any device) you need to wait until you get the end of message before parsing the data. The data will be received in chunks that can contain from 1
to a million bytes. When you get the word "Hello" you could get "H" then "ello" or "Hel" and then "lo". You can't start looking through the data until you get the entire word "Hello".
So you first have to define a protocol for sending commands to the device and the amount of data that gets returned. So normally you have to terminate a message using one of the following methods
1) Ascii : Terminate a message with a fix character like a return or EOM.
2) Ascii or binary : Includes a bytes count at the beginning of the message.
3) Ascii or binary : Each type message is a fixed length.
You can use combination of the 3 methods above.
jdweng

Stream Serial Data to Disk

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