Re: difference between rs232 and rs485
Dear all,
the general difference is the extended length of communication wire in RS-485 and apart from that RS-485 can perform multi node operations which RS-232 can't.
example 2 wired and four wired connection for RS-485. you can check it out
---------- Post added at 17:10 ---------- Previous post was at 17:05 ----------
There are few points which v can discuss on these are
1) Ya first main important point is RS232 is point to point communication n RS485 is multidrope communication which means ...
on RS232 u can not connect more than two device...
RS485 u can connect upto I think max 128 device theorically..(its depends on noise level as well as on distance and burd rate also)
Practicall as max 32...
2)Voltage level of RS232 is
-3 to -25 for 1
+3 to +25V for 0
while RS485 is based on differential voltage (0-5v) diff is 240mV for 1 and -240mV for 0.
3)distance limitation is 100meter for RS232 and 1Km for RS485,
4)noise immunity is high for RS485 as it is balance protocol and differencial protocol..
5)Software point of view u need to set transmit enable line in RS485 rest of the software is same...
6)pin for 232 is (Rx Tx and GND) while in case of RS485 it is (A(+) and B(-)) no need to transmit GND..signal
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Answers.com - What is the difference between RS-232 and RS-485