Re: Serial (rs232 etc.) to IP

On Thu, 27 Oct 2005 16:55:49 GMT, "Sonic" <spam@xxxxxxxx> wrote:

>There is no need to 'use' another protocol like Telnet if all you wish to do
>is transfer a serial stream of characters from one place to another over IP.
>That is what TCP/IP does.

TCP/IP is useful when you just want to transfer error-free data but
without any realtime constraints.

However, in many realtime systems, the TCP/IP is directly harmful due
to the unpredictable propagation delay, which sometimes delivers data
(say 10 ms) too late, in which case it is useless and the resends just
loads the network by sending this outdated data.

Many realtime systems work much better with direct serial or raw
Ethernet or UDP systems. If the data frame does not arrive within the
expected time, it is simply discarded and the sample is marked as
invalid at the receiver end and processed accordingly.

Paul

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