C H A P T E R 3 - S E R I A L I N T E R F A C E
6
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
two DTE devices together, a null modem cable is required to swap the pins and convert the signals
accordingly.
F i g u r e 5 : D T E t o D C E I n t e r f a c e
F i g u r e 6 : D C E t o D C E I n t e r f a c e
J 1
J 2
S I G N A L
F i g u r e 7 : D B 9 F t o D B 9 F S t r a i g h t T h r o u g h C a b l e
1
1
DCD
2
2
RXD
3
3
TXD
4
4
DTR
5
5
GND
6
6
DSR
7
7
RTS
8
8
CTS
9
9
RI
Shell
Shell
GND
MDR292A Modem (DCE)
RS232 Device (DTE)
CTS
RTS
TXD
RXD
GND
DCD
DTR
DSR
RI
CTS
RTS
TXD
RXD
GND
DCD
DTR
DSR
RI
MDR292A Modem (DCE)
RS232 Device (DTE)
CTS
RTS
TXD
RXD
GND
DCD
DTR
DSR
RI
CTS
RTS
TXD
RXD
GND
DCD
DTR
DSR
RI
NC
NC
NC
NC
J1
6
1
9
5
1.70
72.00
1
1.70
5
9
6
J2
