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From: chris@yarra.oz.au (Chris Jankowski)
Newsgroups: comp.dcom.modems
Subject: break condition, framing errors
Message-ID: <5464@yarra.oz.au>
Date: 20 Nov 89 10:35:25 GMT
Organization: Pyramid Technology Corp Pty Ltd, Melbourne
Lines: 28

Can somebody explain what is break condition and where is it
defined ie. in what standard?

Just to start things off I will give you my intuitive understanding:

When you press BREAK key on your terminal a voltage on one of the
RS232C control lines is dropped (which line (?) and for how long (?)).
A modem if present should detect this condition and pass it to
the remote modem (by stopping to issue carrier (?) for how long (?)).
The remote modem then should pass this condition by dropping
voltage on one of its RS232C lines - again which (?) and for how long(?).
This in turn may trigger some action in the receiving computer.

This however contradicts what my termio(7-att) manual page says:
....the break condition (a character framing error with data all zeros)...

What is character framing error then?

Thanks for your help.

      -m-------   Chris Jankowski - Senior Systems Engineer chris@yarra.oz{.au}
    ---mmm-----   Pyramid Technology Corporation Pty. Ltd.  fax  +61 3 820 0536
  -----mmmmm---   11th Floor, 14 Queens Road                tel. +61 3 820 0711
-------mmmmmmm-   Melbourne, Victoria, 3004       AUSTRALIA       (03) 820 0711

``If you're crossing the nation in a covered wagon, it's better to have four
  strong oxen than 100 chickens.  Chickens are OK but we can't make them work 
  together yet.'' - Ross Bott, Pyramid U.S., on multiprocessors at AUUGM '89.