serial communication in labview

[craigc]

HI

As Dennis Says we are all unclear as to how far you have got.  We need to break the problem down into bits.

Q1 - Does the Serial Read Actually Read Data Back

Q2 - If it does is it clean data, i.e no missing bits, reads are terminated properly, The data is just reading random No of Bytes etc?.

Q3 - If it isnt clean data, what format are you expecting the serial data?  Terminated by CR / LF, ASCII, Binary?

Q3 - If Data is clean, what format is it in, so that it can be converted to the graph properly.

Some actual data on the read String OP would be usefull, a probe or write to txt file maybey?

Otherwise all we can see is a string with some conversion on it at the moment, which doesnt tell us a lot as to what the problem might be.

Just trying to help

Craig

[Dennis_Knutson]

Yes, start from square one. Have you even tried to do something as basic as using Hyperterminal to read/write to your serial device? Before writing any LabVIEW code, you should verify that you are actually getting data.

[Coq_Rouge]

Hi samatha.k

First of all. Serial communication is sometimes very hard get working. That is if you do not have attention to all details. You must be 100% sure that the cable you are using is correct. Just using a cable you found in some drawer, may be disastrous even if the connectors fit.  Then you are sure the cable is correct, it is time to concentrate on the serial port settings in both end. Are you sure you have all details like handshake signals, start/stop bit, bit transferred etc correct. Also pay some attention to the signals level. You say you are using a PCB board. Is the signal output from this board correct? In serial communication there are about a infinite number of settings. But only one will be correct

As a starter do you have any documentation about your PCB board you can post here

Message Edited by Coq rouge on 05-06-2009 01:49 PM

[RavensFan]

One recommendation I have based on your VI in reply #4 (this is the one you should be working with since it uses the VISA functions), is to get rid of the shift registers on the error wires and just make them normal tunnels.  An error would prevent most if not all of those functions from running.  Then the error would get carried to the next loop iteration.  So one small sporadic error would wind up preventing all future code from running unless you put in special code to clear the error.  You should put an error indicator in at the end of the line but inside the loop so you can see any errors that might be occuring while you are still debuggin your code.

[samtha]

hi everyone i have got the solution thank you for trying to help me if there are any further questions i'll let you know.