trouble with serial communication (serial port init.vi) 
Author Message
 trouble with serial communication (serial port init.vi)

hi,

I have a little problem with the usage of the 'serial port init' vi.

I want to talk to a serial device who wants the following settings:
baudrate 9600
1 stopbit
no parity
8 databits.
buffersize 1024

The serial device gets its power from the serial port of the PC. (-3 to -12V
from the DTS line and +3 to +12V from the RTS line). The problem with
labview is that it initialises these two lines bouth to the negative voltage
(-3 to -12V). When I measure the DTS and RTS line (pin 4 and 7), both lines
are -11V

What can I do to make one of these lines +3 to +12V (+11V) so that the
serial device has -11 and +11V?
The communication is OK in Visual Basic. There i have +11V and -11V but I
want to do this in a labview program.

thank u

greetings...

Marino



Sun, 18 Apr 2004 03:21:31 GMT  
 trouble with serial communication (serial port init.vi)
Those pins are for hankshaking. Did you configure the flow control
correctly?


Sun, 18 Apr 2004 03:52:25 GMT  
 trouble with serial communication (serial port init.vi)
You can assert DTS and RTS with LabVIEW. With VISA use a property
node; the settings are under Modem Line Settings. For standard serial
driver use the VI vi.lib\platform\_sersup.llb\serial line ctrl.vi

Jean-Pierre Drolet



Sun, 18 Apr 2004 04:25:42 GMT  
 trouble with serial communication (serial port init.vi)
Thank you for your answer.
I tried to do as you told (i used the serial line ctrl vi) and I
measure correct voltages but i still have no serial communiction with
the device (wich is a fluke 89 IV multimeter).How can I combine this
vi with te serial comport init vi (where i can set the baudrate,
parity, ect...)? Because when i run this serial init vi, the voltages
on the serial port are wrong again.
the Fluke multimeter needs following settings:
9600 baud
no parity
8 bits
1 stop bit
and the IR adapter (which enables you to read out the measured result
though the serial port) gets its power from the DTR and RTS line.

thank you,

greetings,
Marino



Sun, 18 Apr 2004 22:56:16 GMT  
 trouble with serial communication (serial port init.vi)
First you initialyze the port and after you call "serial ctrl line.vi"
to set the controls lines. Serial VIs lack the error in/out clusters
to chain the VIs in the right order so use a sequence structure or
wrap serial VIs in caller VIs with errors clusters.

Jean-Pierre



Sun, 18 Apr 2004 23:26:02 GMT  
 
 [ 5 post ] 

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