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Half duplex in LabView?

Hello everyone!

Does anyone no how to communicate with a radio
modem using LabView? The problem is that I have
to communicate using half duplex serial
communication but all the standard VI:s in
LabView are using full duplex. When using full
duplex I can send data to the modem but I can not
recive anything. To recive data I must set the
RTS (Request To Send) line to low but I dont now
how to do that.

I cant be the only one in the world that have
this problem in LabView so please help me!

Regards
/Andreas


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burtrask@my-deja.com wrote:
>
> Hello everyone!
>
> Does anyone no how to communicate with a radio
> modem using LabView? The problem is that I have
> to communicate using half duplex serial
> communication but all the standard VI:s in
> LabView are using full duplex. When using full
> duplex I can send data to the modem but I can not
> recive anything. To recive data I must set the
> RTS (Request To Send) line to low but I dont now
> how to do that.
>
> I cant be the only one in the world that have
> this problem in LabView so please help me!
>
> Regards
> /Andreas

Andreas,
To set the RTS line, use the following VI (which isn't in the
pallette) -
VI.lib\INSTR\_sersup.llb\serial line ctrl.vi
The same thing is possible using VISA serial via the property node.


Regards,
Dave Thomson

-------------------------------------------------------------
David Thomson 303-499-1973 (voice and fax)
Original Code Consulting original.code@technologist.com
National Instruments Alliance Program Member
-------------------------------------------------------------
Research Scientist 303-497-3470 (voice)
NOAA Aeronomy Laboratory 303-497-5373 (fax)
Boulder, Colorado dthomson@al.noaa.gov
-------------------------------------------------------------
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Hi, 

 

I have a similar problem, communicating with an ABB Drive though Modbus Serial (half Duplex). The wiring is correct, but I am unable of receive data.

 

I do not have errors, I just receive a number that does not make sense, and if I ask the value of the next register is that value +128 and so on and so for.

 

I am using Modbus library, anyone know what is the best solution to this problem?

 

I write without problem btw

 

Thanks!

 

Adrian

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