Rockwell Automation 1770-KF2 Data Highway or Highway Plus Interface Module User Manual - Manual (Page 36)

Installation
Chapter 3
3-12
must be connected to the GND of the modem or computer. Note that this
type of connection does not provide electrical isolation between the
module and the connected device.
If a connection is made between the KF2 and an RS-422-A compatible
device, you can mount the device and the module up to 4,000 cable-feet
apart.
Direct Connection to a Computer
To connect the module directly to a computer, you can construct your own
cable according to the wiring diagram in Figure 3.6.A. This cable plugs
into the COMPUTER ASYNCHRONOUS connector on the module and
the RS-232-C or RS-422-A compatible connector on the computer
(Figure 3.6.A). 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 or the
RS-422-A limit of 4,000 feet.
Figure 3.6
Connection to a Computer
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 or
RS-422-A Compatible
Port Connector
of Computer
RDA
RDB
TDA
TDB
Asynchronous
Port Connector
of 1770-KF2 Module
(RS-422-A)
RS-422-A
25-Pin Female
Connector
1
14
25
16
18
4
5
6
8
20
Cable (Not
C. Wiring Diagram for RS-422-A
Exceeding 4,000 Ft.)
Note:
The connector and the pinouts for
the RS-422-A compatible computer
port will depend on the computer
manufacturer’s standard assignment.
Other pins may have to be jumpered
on the computer connector to ensure
proper operation.
Compatible Port
Connector of
Computer
1
7
3
4
2
5
20
8
Asynchronous
Port Connector
of 1770-KF2 Module
(RS-232-C)
25-Pin Female
1
7
2
4
3
5
6
8
20 6
Cable (Not
Connector
25-Pin Male
Exceeding 50 Feet)
Signal Ground
RXD
TXD
DTR
DCD
DSR
RTS
CTS
Chassis Ground
B. Wiring Diagram for RS-232-C
11309
RS-232-C
Compatible Port
Connector of
Computer
Connector