Chapter
1
Publication 17706.5.20 - June 1997
ControlNet System Overview
This chapter briefly describes the network architecture. For detailed
information, refer to the ControlNet Cable System Planning and
Installation Manual (1786-6.2.1).
Overview of ControlNet
ControlNet combines the capabilities of Data Highway Plus and
Remote I/O in a single local area network (LAN). It provides
time-critical communication capabilities for realtime control, and
messaging services for peer-to-peer communication.
Several devices can be connected to the ControlNet cable system
including personal computers, programmable logic controllers,
modems, variable speed drivers, operator interfaces, and other
devices with direct ControlNet cable system connections. To connect
directly, devices must be able to handle ControlNet communication
protocol. The PLC-5/40C15 is such a device. Some equipment,
however, requires an intermediate device to act as an interface
between it and the network. The KFC15/KFCD15 module acts as
this interface. Refer to Chapter 2 for more information on the
KFC15/KFCD15 module.
Physical Characteristics
The physical base for ControlNet is coaxial cable with redundant
media connections as an option. The allowable length of a cable
segment in the network depends on the number of nodes in the
segment. A single subnet can accommodate several segments by
using repeaters.