Changing Parity on Serial Port (VISA) 
Author Message
 Changing Parity on Serial Port (VISA)

Hello all,

I'm having a problem with some parity bits on my serial port. What I
need to do is send the first byte of data with mark parity and then
all remaining bytes with space parity. I have tried using a property
node to do this and it seems to work with one small problem: the
system is changing the parity to space before the first byte (the one
with mark parity) has finished transmission. As a result, the first
byte is ending up with space parity instead of mark. How do I wait
until the first byte is finished transmission so that the parity
change isn't applied to it? I have tried flushing the transmit buffer
on the visa. Is there a way to use the event system to solve my

Sat, 25 Jun 2005 03:51:03 GMT  
 Changing Parity on Serial Port (VISA)
This is just a shot in the dark.

Try right-clicking on the VISA write and select "do I/O syncronously".

If this works, please let me know. I have been trying to figure a good
reason to do serial I/O "syncronously" but was not able to come up
with one until I read your question.



Sat, 25 Jun 2005 04:18:49 GMT  
 Changing Parity on Serial Port (VISA)
I gave it a try and it didn't help. Thanks for trying though. Any
other ideas?

Tony (schellen)

Sat, 25 Jun 2005 08:20:32 GMT  
 Changing Parity on Serial Port (VISA)

Re-post this Q to


Dan Modrik is very good with VISA and prowls the VISA list.

Chris Rake is just plain impresive and lurks in the shadows of the
Serial list.


Sat, 25 Jun 2005 21:27:06 GMT  
 Changing Parity on Serial Port (VISA)
I've researched a little more in the developer forums and there is a
lot of discussion about 9bit serial transmission (my real goal).
However, there doesn't seem to be any really nice resolution. I've
added a 1ms delay after transmission of the first byte then I switch
the parity and it works okay. I waste some time but that's how it is.

Thanks for your efforts to help me and I consider this question to be


Sun, 26 Jun 2005 00:16:17 GMT  
 [ 5 post ] 

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