Problem Labview receiving data continuously

[syanitaa]

thanx...i have doing the received string connected to the shift register to keep the previous msg..

however, the previous msg is still not appear and replace by the new word..

here i attach what i have done.

[RavensFan]

Use the concatenation function in the string palette to concatenate the contents of the shift register to the new data read in that iteration and feed that back into the shift register.  That is what Gerd meant by "adding strings".  You may also want to wire the shift register through the false case of the case structure.

[syanitaa]

ok..i have put the concatenate string in my block.

when i running continuously, 

example:

When the program is run continuously and never press stop :-,

i send "BOOK", the receiver will received "BOOK",

if i write the other word "PENCIL", the receiver will still received word "BOOK".

When the program is running continuously, then i press the "stop":-

i send "BOOK", the receiver will received "BOOK",

if i write the other word "PENCIL", then, i press  stop button, then i run back continuously, the receiver will received word "PENCILBOOK".

Why this happen?i attach what i am doing here. i put two read buffer just to see the output, its that same..

[Dennis_Knutson]

Your concantanate string is wired backwards. You are appending new data to the beginning of the shift register. Swap the wires to the inputs of the function. You should also wire the shift register through the false state of the case statement.

You also mention running the VI continuously. The run continuous button on the toolbar should only be used for occassional debug purposes. Don't use this mode for regular operation.

[RavensFan]

One thing, it is generally a bad idea to use the "Run continuously" and the "Abort VI" buttons.  It's okay when you are first trying to get some code running and to try out, but now that you are moving beyond the basic serial read write example into a bit more of an application, you should start setting up some master program loops and your own program stop buttons.  With the code you have right now if you run it, it writes a value once, then reads the serial port continuously until you hit the abort button (because of the false constant wired to the while loop stop node that is the only way to stop the program!)

The reason you get pencil before book is that I think you have your concatenation wired backwards.  You are putting the newly read value in front of the previous value coming out of the shift register.  It should go after.  So you need to swap the inputs to the concatenation functions.  Quick tip. Hold down control and hover over those input wires.  The cursor will get a kind of curly circle appearance.  Click on the inputs.  They will swap automatically without having to delete the wires and rewire.  This only works on certain functions, basically the ones that have two inputs like the math functions.

Beyond that, I'm not really sure what you are trying to do with this application.  Some details about the other end of the communication are missing.  What is the end result of all this programming supposed to do or look like?  Is this a homework assignment?  I'm having a hard time visualizing how your description of the communication scheme fits into a real world application.

[syanitaa]

hye...

ok...i really appreciate that you help me..this is not a assignment. this is the project.

its hard for me because i never used the LABVIEW software before. im a new. i never have basic about this labview software. Im sory.

actually, my project is about wireless receiver using the Maxtream. im not doing the transmitter part.

my objective is collect and recognize data from the transmitter. And express it into spread sheet.

i donno how to make it send once, and at the read buffer appear many times even though send only once.

[syanitaa]

hello, thanx to raven and all people that help me alot..

finally i get what i want. To maintain the previous msg..like maintain word BOOK before PENCIl..

you are right, that the  post one word can then received once at time.

its can maintain the previous word only..

thanx alot...

this what i get.i have post it here.

[nisa^k]

Hi everyone,

Actually i have a problem little bit like her problem..i try to post new topic but i don't know how..so i just post it here..

My project is to collect data from 3 sensor and display it using Labview..But it will be using wireless module to transmit and receive the data ( connect by usng serial port)

I have no idea how to do it because i never use labview before....So, can any one help me with this problem..URGENT

[RavensFan]

If you have never used LabVIEW before, you are going to need to start with some tutorials.

I would recommend looking at the online LabVIEW tutorials
LabVIEW Introduction Course - Three Hours
LabVIEW Introduction Course - Six Hours

If you are planning to use the serial port, look at the examples in Example Finder such as Basic Write Read Serial.

Start with those. Come up with a plan on precisely what you want your program to do.  (e.g. read the serial port and display data, or log to file, do something else).  Begin with some basic VI.  Post any questions you have in a new thread when they arise. 

[Ymahardh]

Hi Nisa,

For additional info, you can read below interesting links that will give you a fundamental on measurement by using Labview. I think this will be very helpful for you.

1. Interesting forum thread, will give you step by step doing multiple measurement 

http://forums.ni.com/ni/board/message?board.id=170&thread.id=325072

2. Introduction to DAQ
http://zone.ni.com/devzone/cda/tut/p/id/3536

Furthermore, you may explain to us about your project. Perhaps, I can advise what hardware that NI can provide.

Please let me know if you face any further problem. Good luck for your trial.

Regards

Yasrof

NI ASEAN