Rockwell Automation 1770 DH,DHII,DH485 CABLE - Manual (Page 120)

Constructing RS-232-C and
Longline Cables
Appendix A
A-8
Figure A.9
Connecting a module to data communication equipment (DCE) with
handshaking.
2
3
4
5
6
7
8
9
20
1
2
3
4
5
6
7
8
22
1 AA
BA
BB
CA
CB
CD
AB
CF
CE
RS-232-C
Connector of
1773-KA, or
1775-KA,
Module
RS-232-C
Connector or DCE
(E.g., a modem)
RS-232-C
Pin Assignments:
AA Protective Ground
AB Signal Ground
BA Transmitted Data
BB Received Data
CA Request to Send
CB Clear to Send
CC Data Set Ready
CD Data Terminal Ready
CE Ring Indicator
CF Received Line Signal Detector
25-pin Male
Connector
25-pin Male
Connector
12539
25
20
11 CC
Important: For the 1775-KA module, you do not have to ground pin 25 as long
as switch 3 on the module is turned on (closed).
Figure A.10
Connecting a 1770ĆKF2 to an IBM AT without handshaking.
2
7
3
4
5
6
8
20
2
5
3
1
4
6
7
8
25-pin Female
1770-KF2
9-socket
IBM-AT
18771
RXD
GND
TXD
DCD
DTR
DSR
RTS
CTS
RTS
CTS
DSR
DCD
DTR