I am new to this, so excuse me if I sound ignorant ... How can DSR signal be asserted/deasserted on serial port programmatically using Win32 API's? I know that EscapeCommFunction() can be used to assert/deassert DTR... Does asserting DTR implicitly deassert DSR? Is this how DSR state is toggled? Thanks, Ruchika
"I am new to this, so excuse me if I sound ignorant ..." Ignorance can easily be cured by learning! Unfortunately, there is an awful lot of misinformation about RS232 on the web; eg, see http://www.8052.com/forum/read.phtml?id=46426 If you are serious about understanding RS-232, then you must obtain a copy of the official standard - and read it! See http://www.8052.com/forum/read.phtml?id=24916 Then you will be able to sort the wheat from the chaff!