Rockwell Automation 1770-KF2 Data Highway or Highway Plus Interface Module User Manual - Manual (Page 37)

Installation
Chapter 3
3-13
This type of connection includes the DTR signal to allow each end to
detect the loss of the other end’s ability to communicate. If your
computer does not provide the DTR signal, jump Pins 6 and 8 at the KF2
module to Pin 20.
Connection to a Modem
To connect the module to a modem, you can construct your own cable
according to the wiring diagram in Figure 3.7. This cable plugs into the
COMPUTER ASYNCHRONOUS connector on the module and the
RS-232-C compatible connector on the modem (Figure 3.7). Connect the
cable shield at one end only. Be sure that the cable length does not exceed
the RS-232-C limit of 50 feet.
Figure 3.7
Connection to a Modem
25-Pin Female Connector 25-Pin Male Connector
Cable
Asynchronous
PORT Connector
of 1770-KF2
Module (RS-232-C)
A. Connection Diagram
RS-232-C
Compatible Port
Connector of
Modem
1
7
2
6
3
4
5
Asynchronous
Port Connector
of 1770-KF2 Module
(RS-232-C)
25-Pin Female
Cable (Not
Connector
25-Pin Male
Exceeding 50 Feet)
Signal Ground
TXD
RXD
RTS
CTS
DSR
Chassis Ground
B. Wiring Diagram
RS-232-C
Compatible Port
Connector of
Modem
8
20
1
7
2
6
3
4
5
8
20
DCD
DTR
14831 Connector