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Re: problem with usbtmc-communication

Subject Re: problem with usbtmc-communication
From wrw@mac.com
Date 2012-12-11 21:21 -0500
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Newsgroups comp.lang.python
Message-ID <mailman.764.1355278877.29569.python-list@python.org> (permalink)

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On Dec 11, 2012, at 3:48 PM, Jean Dubois <jeandubois314@gmail.com> wrote:

[byte]

>> 
>> OK - I see where the examples came from, and I notice -
>> 
>>         int my_inst;
>>         my_inst=open(“/dev/usbtmc1”,O_RDWR);
>>         write(my_inst,”*RST\n”,5);
>>         close(my_inst);
>> 
>> and similarly in another place -
>> 
>>         retval=write(myfile,"*IDN?\n",6);
>> 
>> Note that both write commands contain a byte count of the number of characters to be written (\n counts as one character).
>> Again, the read commands contain byte counts.  I'm very suspicious that a write command with no byte count writes nothing, but does move a buffer pointer.
>> 
>> -Bill
> 
> Does Python support/implement simular commands? Can I use
> usbkeith.write("*IDN?\n",6) and  something simular for the reading
> commands?
> 
> thanks,
> jean
> -- 
> http://mail.python.org/mailman/listinfo/python-list

Yes of course.  BUT, that isn't really a python question, it depends on how the device driver implements the function call.

-Bill

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Thread

[newbie] problem with usbtmc-communication Jean Dubois <jeandubois314@gmail.com> - 2012-12-04 04:14 -0800
  Re: [newbie] problem with usbtmc-communication wrw@mac.com - 2012-12-04 09:33 -0500
    Re: problem with usbtmc-communication Jean Dubois <jeandubois314@gmail.com> - 2012-12-04 08:12 -0800
      Re: problem with usbtmc-communication wrw@mac.com - 2012-12-05 10:26 -0500
        Re: problem with usbtmc-communication Jean Dubois <jeandubois314@gmail.com> - 2012-12-05 12:38 -0800
          Re: problem with usbtmc-communication wrw@mac.com - 2012-12-05 17:21 -0500
            Re: problem with usbtmc-communication Jean Dubois <jeandubois314@gmail.com> - 2012-12-06 05:50 -0800
              Re: problem with usbtmc-communication wrw@mac.com - 2012-12-06 09:50 -0500
                Re: problem with usbtmc-communication Jean Dubois <jeandubois314@gmail.com> - 2012-12-06 11:41 -0800
                Re: problem with usbtmc-communication Dave Angel <d@davea.name> - 2012-12-06 15:10 -0500
                Re: problem with usbtmc-communication wrw@mac.com - 2012-12-06 15:15 -0500
                Re: problem with usbtmc-communication Jean Dubois <jeandubois314@gmail.com> - 2012-12-07 05:46 -0800
                Re: problem with usbtmc-communication Jean Dubois <jeandubois314@gmail.com> - 2012-12-10 05:31 -0800
                Re: problem with usbtmc-communication wrw@mac.com - 2012-12-10 10:34 -0500
                Re: problem with usbtmc-communication Jean Dubois <jeandubois314@gmail.com> - 2012-12-10 22:58 -0800
                Re: problem with usbtmc-communication wrw@mac.com - 2012-12-11 09:34 -0500
                Re: problem with usbtmc-communication Jean Dubois <jeandubois314@gmail.com> - 2012-12-11 12:48 -0800
                Re: problem with usbtmc-communication wrw@mac.com - 2012-12-11 21:21 -0500
                Re: problem with usbtmc-communication Jerry Hill <malaclypse2@gmail.com> - 2012-12-11 19:49 -0500
                Re: problem with usbtmc-communication Jean Dubois <jeandubois314@gmail.com> - 2012-12-12 08:16 -0800
          Re: problem with usbtmc-communication Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2012-12-05 18:08 -0500
  Re: [newbie] problem with usbtmc-communication Terry Reedy <tjreedy@udel.edu> - 2012-12-04 14:55 -0500
    Re: problem with usbtmc-communication Jean Dubois <jeandubois314@gmail.com> - 2012-12-06 06:05 -0800
    Re: problem with usbtmc-communication Jean Dubois <jeandubois314@gmail.com> - 2012-12-06 07:44 -0800
      Re: problem with usbtmc-communication Terry Reedy <tjreedy@udel.edu> - 2012-12-06 15:28 -0500
        Re: problem with usbtmc-communication Jean Dubois <jeandubois314@gmail.com> - 2012-12-07 05:51 -0800

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