[h-e-w] programming a timer

[Richard M. Heiberger]

I have a Compaq cp-2w home network between my pc and the DSL line.
The cp-2w times out an idle telnet buffer after 10 minutes.  I would
like emacs to automatically send a carriage return (or something) after
9 minutes of inactivity in that buffer.  I usually have several telnet
buffers open so this has to be done independently in each.  Has anyone
worked this out or have suggestions on where to start?

thanks
Rich