C H A P T E R 3 - S E R I A L I N T E R F A C E
5
1 - 8 7 7 - 8 7 7 - 2 2 6 9
w w w . b l a c k b o x . c o m
R S 2 3 2 - M D R 2 9 2 A
RS232 is a single-ended data transmission protocol. The RS232 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.
I N T E R F A C I N G T O O T H E R R S 2 3 2 E Q U I P M E N T
The MDR292A is a DCE (Data Communications Equipement) device. Typically devices like PC’s are
considered DTE (Data Terminal Equipment) devices while periphial devices are classified as DCE. A DCE
device can be interfaced to a DTE device using a straight through serial cable. When interfacing two DCE or
T A B L E 3 : M D R 2 9 X D B 9 M A L E C O N N E C T O R P I N O U T
D B 9 P I N
S I G N A L N A M E
D E S C R I P T I O N
1
DCD
Data Carrier Detect
2
RXD
Received Data
3
TXD
Transmitted Data
4
DSR
Data Set Ready
5
GND
Ground
6
DTR
Data Terminal Ready
7
CTS
Clear To Send
8
RTS
Request To Send
9
RI
Ring Indicator
5
1
6
9
