Connecting Communication Cables 4 - Allen-Bradley 1779-KFMR User Manual

Chapter 4
Installing the 1779 KFM Interface
Connecting Communication
Cables
4 10
After you have set the host-board switches to select the type of operation
you want, you can begin connecting the communication cables necessary
for your application. You must connect the cable from the interface to the
host device before power up to prevent a fault condition.
Your Data Highway II cable redundant interface module
(Cat. Nos. 1779-KFLR, -KFMR, -KP2R, -KP3R) has a connector on the
front panel labeled DHII AUX ACCESS. This connector is for future use.
Do not connect any cable to this connector.
CAUTION: Your redundant module is shipped with a
conductive cap to help protect the DHII AUX ACCESS
connector from electrostatic discharge. This cap must remain
on the connector at all times to help prevent electrostatic
discharge damage to your redundant module.
To Host Device
You must connect a cable (4,000 feet maximum) from the RS-449
CHANNEL connector on the interface to the RS-449 connector on the
host device (Figure 4.7).
Figure 4.8 shows a wiring diagram for constructing a cable for connection
to the host device. Use a 24-AWG copper-conductor twisted-pair
telephone cable with a shunt capacitance of 52.5 pF/m
(16 pF/ft.). We show a twisted pair like this:
At the 1779-KFM end of the cable, use a 37-pin male D-shell connector
with a right-angle hood.