RS485

[Slade Squire]

I'm trying to simulate using an RS485 cable, through COM ports...
Is there any way to set the DTR in labview 5 (the easier, the better ->
preferably using the Serial port VI's)?


I know that in turbo C/C++, this would work...
if(format == 1) outp(comport+1,(inp(comport+1)&253));
// assert DTR line for Data direction control - Test Set needs that for
// RS485 port direction control

and to release it,
outp(comport+1,(inp(comport+1)|2)); // Release DTR line - ready to receive

but I can't find anything in Labview, that I can get working


--
Slade Squire
Programmer
Rectifier Technologies Pacific
Melbourne, Australia
SladeSquire@rtp.com.au

[C.D.]

You can set DTR with a VISA-Proberty-Node. Open the example-VI in attachment.

[abrause]

Use 'serial line ctrl.vi' in \vi.lib\INSTR\_sersup.llb.
It allows you to control DTR and CTS.


"Slade Squire" wrote in message news:9oom5h$38d$1@perki.connect.com.au...
> I'm trying to simulate using an RS485 cable, through COM ports...
> Is there any way to set the DTR in labview 5 (the easier, the better ->
> preferably using the Serial port VI's)?
>
>
> I know that in turbo C/C++, this would work...
> if(format == 1) outp(comport+1,(inp(comport+1)&253));
> // assert DTR line for Data direction control - Test Set needs that for
> // RS485 port direction control
>
> and to release it,
> outp(comport+1,(inp(comport+1)|2)); // Release DTR line - ready to receive
>
> but I can't find anything in Labview, that I can get working

>
>
> --
> Slade Squire
> Programmer
> Rectifier Technologies Pacific
> Melbourne, Australia
> SladeSquire@rtp.com.au
>
>
>

[adamsjr]

You might try the functions In Port.vi and Out Port.vi under the
Functions-> Advanced -> PortI/O palette. This lets you do something very
similar to the C code inp and outp. If you are running NT, you will need a
different version of these vis than the ones supplied, as well as the
CVIRTE.dll. See the link
http://digital.ni.com/public.nsf/websearch/62790c9621f599cf8625659f0068e6e9?
OpenDocument which talks more about using In Port and Out Port on NT.

Hope this helps.

Jim

Slade Squire wrote in message
news:9oom5h$38d$1@perki.connect.com.au...
> I'm trying to simulate using an RS485 cable, through COM ports...
> Is there any way to set the DTR in labview 5 (the easier, the better ->
> preferably using the Serial port VI's)?
>
>
> I kn
ow that in turbo C/C++, this would work...
> if(format == 1) outp(comport+1,(inp(comport+1)&253));
> // assert DTR line for Data direction control - Test Set needs that for
> // RS485 port direction control
>
> and to release it,
> outp(comport+1,(inp(comport+1)|2)); // Release DTR line - ready to
receive
>
> but I can't find anything in Labview, that I can get working
>
>
> --
> Slade Squire
> Programmer
> Rectifier Technologies Pacific
> Melbourne, Australia
> SladeSquire@rtp.com.au
>
>
>