The BREAK signal dates back to the origin of RS232 _before_ computers
even existed!!! The function of the break signal was to cause the
bell on teletype machines to ring notifying the recipient that a new
message had arrived. As an aside, if you've ever wondered why RS-232
uses +12v and -12v for signalling when those voltages make little
sense with modern transistors it's because RS-232 predates computers.
Okay, enough history. The BREAK signal is generated by holding the
transmit line low for more than 250 milliseconds. RS-232 transmit and
receive signals are normally at +12v when idle, the start bit is
created by pulling the line low for a single bit time. A BREAK is
created by holding it low for longer than a full frame of data.
No other control lines are affected when a BREAK is being generated.
Cheers,
Bruce.
>The function SerControl in the Serial manager can be used to turn on and
>off the BREAK signal. Does this affect the CTS or RTS lines? You can also
>detect the BREAK signal. Once again one does this do at a hardware level?
>Any input would be greatly appreciated.
>
>Thank you
>
>Oliver
>
>
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Bruce Thompson | "Pinkie! Are you pondering what I'm pondering?"
Software Engineer | "I think so Brain, but if they called them Sad
Partner Engineering | Meals kids wouldn't buy them!"
Palm, Inc.
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