CL4424 User’s Manual
2.1RS-232
RS-232 is a single ended data transmission protocol. The RS-232 signals are represented by voltage levels with respect to a system common (power / logic ground). The "idle" state (MARK) has the signal level negative with respect to common, and the "active" state (SPACE) has the signal level positive with respect to common. RS-232 has numerous handshaking lines (primarily used with modems), and also specifies a communications protocol.
Figure 5- RS-232 Male/Female Connector Pin out
RS-232 DB9 Female Connector | RS-232 DB9 Male Connector |
Pin Description
1DCD
2RxD
3TxD
4DTR
5GND
6DSR
7RTS
8CTS
9RI
2TxD
3RxD
4DSR
5GND
6DTR
7CTS
8RTS
NC RI
| | | | Figure 6- DCE to DTE Interface |
OEM Host/PC | | | | CL4424 Modem |
| | | |
CTS | | | | | | CTS |
RTS | | | | | RTS |
| |
RXD | | | | | TXD |
TXD | | | | | RXD |
GND | | | | | | GND |
| | | |
DCD | | | | | DCD |
| | |
DSR | | | | | DSR |
| | | | | |
DTR | | | | | DTR |
| | | | | | |
| | | | | | |
| DTE | DCE |
| Straight Through Cable |
| |
