Strange serial write problem in labview 8.5

I'm having a very strange problem with simple serial port write in labview. I'm running the 'Advanced serial write and read.vi' program from NI examples. I connected a microcontroller board on the device side. The board has been programmed simply to blink an LED fixed number of times. For example if I want my LED to blink 13 times, that is specified in the labview 'string to write' field. I ran the program in hyperterminal window. It runs successfully. But whenever I'm running it in labview it is giving strange response, for example if I give input in 'string to write' field 18/13/15, it blinks 11 times, similarly if I try to run it 21/26/29 times every time it runs 22 times. That is the controller only acknowledges the MSB and duplicates the other bit with it. Since it is running fine in window's hyperterminal, There must be some adjustment need to be done in labview. And that I cannot figure out. Please anybody give some solution.Any suggestion is appreciated.
With Regards,
Tapabrata

Please post your program or a stripped down version (we probably do not need all the signal processing) which shows the problem. Make sure that all the controls for the serial port are set to your default values. Also, provide the exact communication protocol you are using.
When you say you want to write in "real time," please specify what you mean. That term is used in several different ways and is often misinterpretted as a result. How often do you wnat to write? How much timing jitter or error can you tolerate?
Most likely what you want can be done, but without seeing the code it is difficult to say what might be wrong.
Lynn

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In order to work properly I have to manually control the RTS line which isn't a problem using the property node.
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TIA.

Thank you. That solved the problem.
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Ay, perdona, que puse el modelo mal!!
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Attachments:
Mikotron MC 1360_Maite.zip ‏2 KB

Serial VISA problems

Hello,
I keep having problems with VISA serial driver. The problem
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timo
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Timo Miettunen writes:
> Hello,
>
> I keep having problems with VISA serial driver. The problem
> is that VISA seems to reserve the serial port even after the
> VISA session has been closed. Also, if I open COM1 with visa,
> I cannot use hyperterminal with COM2. I have to shut donw LabVIEW
> in order to use _any_ COM ports after I've used one with VISA.
> If i use old serial vi's i don't have to close LV in order to
> use COM ports with terminal hyperterminal or procomm
> etc.
>
> Has anybody else encountered this kind of behaviour with VISA serial?
> I run LabVIEW 5.1f1 in WinNT4.0
Timo,
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in the preferences/Misc tab. Before this option was introduced I used
the
visa sessions.vi in .../Labview/vi.lib/visa.llb .
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sessions not getting closed in your programm.
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Hey.
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bachelor_2013.vi ‏259 KB
Modded Advanced Serial Write and Read_test.vi ‏40 KB

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Unofficial Forum Rules and Guidelines

How do I establish serial communication using LabView to two stepper motors using a motor controller?

I currently use an off the shelf motor controller to run my two stepper motors. It already has integrated a firmware software that sends commands to operate each motor. I would like to create an interface where I can send these commands using LabView. If someone can point me in the right direction I would appreciate it.

Look at the examples for the serial VISA vi. Something like Basic serial write and read.vi is a good starting point.
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Message Edited by Henrik Volkers on 07-13-2009 04:21 PM
Greetings from Germany
Henrik
LV since v3.1
“ground” is a convenient fantasy
'˙˙˙˙uıɐƃɐ lɐıp puɐ °06 ǝuoɥd ɹnoʎ uɹnʇ ǝsɐǝld 'ʎɹɐuıƃɐɯı sı pǝlɐıp ǝʌɐɥ noʎ ɹǝqɯnu ǝɥʇ'

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Hello List,
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Hello,
I apologize for the delay in responding to your post. You are having a timeout issue when using software flow control (XON/XOFF) to transfer data between a PDA and a host computer, right? Are you getting error code 7 when the PDA times out? I was able to duplicate this issue here. This error code is a timeout error and it means that not all bytes have been sent. I spoke with members of the R&D team and they know about the problem. While they were unable to offer a formal solution at this time, they did provide a workaround which I hope works for you.
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Attachments:
Serial_XonXoff_(Host).vi ‏55 KB
Serial_XonXoff_(PDA).vi ‏68 KB

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Strange serial write problem in labview 8.5

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