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Hyperterminal vs Labview communication with serial port


I am working on reusing an old prototype. I do not have the BASIC
program initially used to drive the prototype but I do have the
hardware program protocol in hand. Now I'm having troubles initializing
the device. First I need to send "CALL 0D00" to serial port to activate
the prototype, then just commands like "a", "b", "c" etc. But I found
that I can't do the first "CALL 0D00" with Labview. I must use
hyperterminal to send this command, close it, then go back to Labview.
At the point, all the simple commands can go through without a problem.

I wish I made myself clear on this.

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Hi Redoo,

Maybe you have selected some termination character in Hyperterminal (No I don't know where to lookSmiley Happy)? and not set this in LV?
Could you show your code here that doesn't work together with the relevant manual section.

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In Labview, try concatenating a new line character to your command string.  Newline is the standard termination character.
- tbob

Inventor of the WORM Global
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For what it's worth I do a lot of serial comms with LabVIEW.  I've never found anything that HyperTerminal can do that LabVIEW can't.  Okay, the process can be a bit painful while you're developing, mostly due to the flakiness of serial comms, but I always get there in the end.  Biggest problems I have are timing.  Is your DUT ready to receive your initial command when you send it via LV?  As has been said the termination character could be an issue but if your other commands work this might be a red herring.  Personally I ditch termination characters and rely a lot on the serial bytes at port property node to see when a device is/is not ready.  Another one is flushing buffers.  Are you sure you are just sending the initial command and not a lot of garbage with it?  I configure my serial port, flush the Tx and Rx buffers, power up the DUT then start the communication.  This gets rid of anything unwanted left in the buffers from last time (especially if a routine has been aborted mid-communication previously).  I can't believe there's not a LabVIEW solution if the rest of your communications work.  You could do worse than get one of these serial port monitors on it to see what is really going on.  Again as suggested post some of your code.  This might shed some light on it.  Best of luck.



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