Rockwell Automation 1779-KP3R DATA HIGHWAY II - Manual (Page 9)

Overview
Chapter 1
1-3
The Data Highway II network offers:
a transmission rate of one megabit per second
high immunity to noise
easy connection to control devices
This network is meant for time–critical operations where the status or
position of one device (e.g., PLC Programmable Controller, personal
computer, etc.) may affect another device, or an entire production line.
All communication on Data Highway II travels from one device to
another through the trunkline (figure 1.3). The trunkline varies in length
depending on the number of nodes and their location. Data Highway II
cabling is compatible with IEEE Specification 802.4 for single channel
phase–continuous FSK (frequency shift keying) systems.
You connect Allen–Bradley PLC Programmable Controllers to the Data
Highway II trunkline via an Allen–Bradley communications interface.
Data Highway II droplines connect the communication interfaces to the
trunkline. The mechanical connection between the dropline and the
trunkline is a local tap (figure 1.3).
Figure 1.3
The KP3 Communications Interface on Data Highway II
1779-KP3
Communication Interface PLC-3 Programmable
Controller
Data Highway II Trunkline
Allen-Bradley
Dropline
local tap
10993-I
For information on planning and installing Data Highway II refer to the
Allen–Bradley Data Highway/Data Highway Plus/Data Highway II/Data
Highway 485 Cable Planning and Installation Manual, publication
1770–6.2.2.
Data Highway II Cabling