socket.sendto / UDP problem

[MRAB]

On 21/10/2010 15:57, Todd Walter wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
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>
> On Thu, 21 Oct 2010 00:07:58 +0100
> MRAB<python at mrabarnett.plus.com>  wrote:
>
>>>
>> [snip]
>>
>> The docs for 'sendto' say:
>>
>>       """The socket should not be connected to a remote socket, since
>> the destination socket is specified by address."""
>>
>> Could your problem be caused by you binding the socket to a source
>> port, so it's going out both to the bound port _and_ the one given the
>> binding?
>>
>> Have you tried using two sockets, one outgoing and the other incoming?
>>
>> BTW, your code for handling the response doesn't cope with it coming
>> in a bit at a time. It loops discard any previous data from the
>> previous iteration.
>>
>> Also, it's more Pythonic to say:
>>
>>       while '\r' not in response:
>>           ...
> I haven't bound the socket to a remote port, as I read it; it's bound to
> a source port (192.168.10.2:2260, the local machine) and just transmits
> to an address with a port glommed on (192.168.10.1:2002, the PLC).
[snip]
What I meant was that you're using 'pcSocket' for both directions and
using .bind on it.

Try creating two sockets, 'pcInSocket' and 'pcOutSocket', and bind only
pcOutSocket.