Appendix 1 Definition of Terms
A-2
Appendix 1.2 Serial Communication Terms
Describes serial communication term
(1) Communication type
(a) Simplex
This is the communication type that data is transferred in a constant direction. Information can not
be transferred in the reverse direction.
(b) Half-Duplex
Data is transferred in two ways with one cable if time interval provided, though it can’t be transferred
simultaneously.
(c) Full-Duplex
Data is simultaneously transferred and received in two ways with two cables.
(2) Transmission type
(a) Serial transmission
This type transmits bit by bit via 1 cable. The speed of transmission is slow, but the cost of
installation is low and the software is simplified.
01001101
01234567
송신 수신
7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0
RS-232C, RS-422 and RS-485 are the examples
RX
TX