serial port - Is it really necessary the handshakng on an RS232 connection? -


i'm building electronic device has prepared rs232 connections, , i'd know if it's necessary make room more 3 pins (tx, rx, gnd) on each port.

if don't use rest of signals (those made handshaking): going find problems communicating device?

generally, yes, that's problem. kind of problem can avoid if can give specific instructions client on how configure port on end. never not problem, if that's not done data transfer won't occur , finding out why can awkward. guaranteed support call.

a lot of standard programs pay attention dtr signal, dsr on end. data terminal ready indicates device powered , whatever client receives not produced electrical noise. without dsr they'll ignore send. simple implement, tie power supply.

pretty common flow control through rts/cts signals. if enabled in client program, won't send until turn on request send signal. again simple implement if don't need flow control, tie logically high dtr client program's configuration doesn't matter.

dcd , ring modem signals, pretty unlikely matter generic device. tie them logically low.

very simple implement, avoids lots of mishaps , support calls, do wire them.

and do consider whether can live without flow control. problem on client end, modern machines can keep kind of data rates common on serial ports. not case on end, usual limitation amount of ram can reserve receive buffer , speed of embedded processor. modern machine can firehose data pretty easily. if uart fifo or receive interrupt handler or data processing code cannot keep inevitable data loss hard deal with. not issue if use rts/cts or xon/xoff handshaking or if use master/slave protocol or comfortable low enough baudrate.


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