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Author RS232 connection
Emanuele

2007-03-30, 7:11 pm

Hi !
First, thanks for your attention, second thanks for your eventual
support.

I got a problem: I am reading an USB encoders (Gurley Precision
Instr) with Matlab - the USB works as a COM port, I am able to read
the encoder with:

load GPI_encoder; obj1 = GPI_encoder;
fopen(obj1);
% data = query(obj1, 'A', '%c', '%s')
tic,
fprintf(obj1, '%c', 'A');
data = fscanf(obj1, '%s'),
toc

I can send to you more details on the port, etc.
PROBLEM: it takes 15-50 ms (variable) to have the data back (too long
!). I need to be faster (at least 10 ms), with Labview it takes 6-7
ms.

Any suggestion, help ? Probably some setting on obj1 is wrnog, we
looked at every attribute of obj1 but we don't know where we can put
our hands...
Any suggestion and/or check to do, and/or auto-config and/or tool to
reduce the time ?
Thanks a lot !!
Emanuele Secco
<http://www3.deis.unibo.it/Staff/Fel...ueleLindoSecco/>
dave

2007-03-30, 7:11 pm

Emanuele wrote:
>
>
> Hi !
> First, thanks for your attention, second thanks for your eventual
> support.
>
> I got a problem: I am reading an USB encoders (Gurley Precision
> Instr) with Matlab - the USB works as a COM port, I am able to read
> the encoder with:
>
> load GPI_encoder; obj1 = GPI_encoder;
> fopen(obj1);
> % data = query(obj1, 'A', '%c', '%s')
> tic,
> fprintf(obj1, '%c', 'A');
> data = fscanf(obj1, '%s'),
> toc
>
> I can send to you more details on the port, etc.
> PROBLEM: it takes 15-50 ms (variable) to have the data back (too
> long
> !). I need to be faster (at least 10 ms), with Labview it takes 6-7
> ms.
>
> Any suggestion, help ? Probably some setting on obj1 is wrnog, we
> looked at every attribute of obj1 but we don't know where we can
> put
> our hands...
> Any suggestion and/or check to do, and/or auto-config and/or tool
> to
> reduce the time ?
> Thanks a lot !!
> Emanuele Secco
> <http://www3.deis.unibo.it/Staff/Fel...ueleLindoSecco/>



have you asked GPI? maybe they have seen this question from another
customer.
Emanuele

2007-03-30, 7:11 pm

I did, no reply.
Thanks, emanuele

Emanuele wrote:
>
>
> Hi !
> First, thanks for your attention, second thanks for your eventual
> support.
>
> I got a problem: I am reading an USB encoders (Gurley Precision
> Instr) with Matlab - the USB works as a COM port, I am able to read
> the encoder with:
>
> load GPI_encoder; obj1 = GPI_encoder;
> fopen(obj1);
> % data = query(obj1, 'A', '%c', '%s')
> tic,
> fprintf(obj1, '%c', 'A');
> data = fscanf(obj1, '%s'),
> toc
>
> I can send to you more details on the port, etc.
> PROBLEM: it takes 15-50 ms (variable) to have the data back (too
> long
> !). I need to be faster (at least 10 ms), with Labview it takes 6-7
> ms.
>
> Any suggestion, help ? Probably some setting on obj1 is wrnog, we
> looked at every attribute of obj1 but we don't know where we can
> put
> our hands...
> Any suggestion and/or check to do, and/or auto-config and/or tool
> to
> reduce the time ?
> Thanks a lot !!
> Emanuele Secco
> <http://www3.deis.unibo.it/Staff/Fel...ueleLindoSecco/>

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