What is RS 232 and RS 485

Explain RS 232 and RS 485

RS232 and RS485 is the communication method which is related to the electronic circuit.

RS232 uses a transmitter and receiver circuit at both ends… while RS845 uses a transceiver at both ends. This is why RS232 determined to use 3 cables, and the RS485 should use 2 or 4 cables.

RS-232 is point-to-point only, maximum 2 devices talking to one another. There are software and hardware means of handshaking, to determine who talks when. Hardware handshaking was widely employed for telephone modem communication.

RS-232 is a short distance electrical standard; it maxes out at about 15-20m. RS-232 requires a signal ground connection between both devices.

RS-485 can be point-to-point but was designed for multidrop, multiple devices on one daisy chained (1 to 2 to 3 to 4 . . . 32) network. RS-485 does not tolerate wiring spurs or stubs well. RS-485 requires a signal ground but uses differential transceivers for much better noise rejection than RS-232.

RS-485 uses a tri-state condition when the bus is in idle mode, no device talking. There are no hardware handshaking signals for RS-485. The network bus distance for RS-485 is determined by the baud rate, the higher the baud rate, the shorter distance that is useable. At 90Kb baud and slower, RS-485 will work out to 1500m; at 10Mb thebdistance is only 5m.