Rockwell Automation 1770 DH,DHII,DH485 CABLE - Manual (Page 82)

Planning a DH II Cable System
Chapter 5
5-6
Each node on a DH II network requires a tap. Each tap contains the following
components:
a tap box with two trunkline jacks and a dropline jack
a cap for covering the dropline jack when there is no dropline attached
a 2-foot (61.0 cm) dropline cable that connects an interface module to the
dropline jack on the tap
two cable plugs that connect the trunkline cables to the trunkline jacks on
the tap
You can purchase additional cable plugs (part no. 225886-6) from:
AMP, Inc.
Harrisburg, PA 17105
For information on installing droplines and taps refer to Chapter 6.
Terminators
A terminator (cat. no. 1779-XT) must be installed at both unused trunkline
jacks on a tap to maintain proper electrical impedance on the trunkline
(Figure 5.4).
Figure 5.4
A terminator.
12640
There will be two unused trunkline jacks, one at each end of the trunkline.
Terminators are supplied in pairs.