On Wednesday, May 13, 1998 12:29, WirtAtmar wrote:
> John Zoltak writes:
>
> > Monitoring for a voltage change on data-out would not work if someone
> >  moves the console.
>
> The console messages aren't a necessary condition of the Keep Alive circuit,
> merely icing on the cake. A small job sending a message to Port 20's session
> every 90 seconds would be all that's necessary, regardless of whether or not
> it was the console at the moment.
>
> I would suggest the message be "Esc A CR LF". This message would cause the
> cursor on the terminal to simply recycle in place.
>
> What would kill the circuit would be if someone should sign on to another
> session on the Port 20/console terminal. The Keep Alive job would have to be
> restarted with the new session number entered. Alternatively, with 10 minutes
> more programming, the program could be made to seek out and find the session
> number of the Port 20 device automatically. The only killer would then be that
> someone would simply sign the terminal off by doing a ":BYE". But I would
> suspect you'd find that out in about two minutes :-).
>
> Wirt Atmar
>
>

The job sending the messages could check to see if a session for port 20 existed and if not
do a STARTSESS.
--
Sam Knight                                     Email: [log in to unmask]
Senior Programmer/Analyst                      Phone: (904) 745-7509
Jacksonville University                          Fax: (904) 745-7149
Jacksonville, FL 32211