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VISA Serial sends NUL Char even if "Discard NUL Characters" is set TRUE

Hello There!
 
I got a problem with serial Communication. When I write a string to my serial port, there´s added the NUL (0x00) at the begin of the string.
The Windows Hyperterm doesn´t do that. (I logged all data between the communication partners)
 
 My reciever does not interprete the string if there´s a NUL send, so I tried to set that in the VISA Configuration. There you can call in the property node the option Serial Settings: Discard NUL Characters.
 
But it don´t work!
 
What did I do wrong?
 
How can I ensure that all NUL Char (0x00) are discarded /deleted / not transmitted ?
 
Ideas to solve problem are welcome
 
 
Greetings
 
cand. Ing. Sebastian Neumeyer
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Hi,

I'm not shure but maybe that prperty only belongs to the serial read ?

I do a lot of serial communication with VISA and I have never seen an x00 (or any other character) send out at the beginnig without having wired it. 

Have you checked the string you send out? (place  an sring indicator set to hex or \-display or use such an indicator as a custom probe)

 

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!

Thanks for reply, I created a Indicator in Hex for the String in Hex, but there wasn´t a 0x00 (NUL), only the 0x20 (the zero) was showed. I bypassed the serial line and recorded the communication and viewed the logfile in an Hex editor, where I can see the NUL.

 

If I use Hyperterm, then it works in the proper way...(I can see in the logfile of the serial communication a 0x20 at the beginning of the string...)

My Problem is, that my reciever interprete the NUL sign in a wrong way so the whole string seem to contains no numeric values.

What are the reasons for that option with discarding NUL Characters? Is this a newer or older type of Character used for Serial Comm?

How can I force Labview to not send that NUL Character?

I use Labview 7.1 with Win2K SP4 on an AMD Athlon 900Mhz

 

Greetings

 

 

cand. Ing Sebastian Neumeyer

Message Edited by Seppfish on 05-08-2006 06:57 AM

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Hello There!
 
I found the reason for the NUL Char: I send a serial Break, so within the break there is included a NUL Char....
 
Sorry for the work,
thanks for inspiration to find the Problem (NUL Char s are send with break usually in serial Comm)
 
Regards
 
cand. Ing Sebastian Neumeyer
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