The characteristics of RS232C are as follows:

- This standard has been defined for communication that is asynchronous. The timing between data bits are specified whereas the timing between two characters is not fixed.

- This standard guarantees 50 ft coverage and 25 signal lines are defined by it.

- For each direction only a single wire is defined.

The characteristics of the RS422A standard are as follows:

- The data rate of this standard is 10Mbits/sec.

- In this standard every signal is considered to be a pair of wires and the voltage difference between them is sensed by the receiver.