Datasheet

13
Figure 15. Typical eld bus communication physical model.
Digital Field Bus Communication Networks
To date, despite its many drawbacks, the 4 - 20 mA ana-
log current loop has been the most widely accepted
standard for implementing process control systems. In
today’s manufacturing environment, however, automat-
ed systems are expected to help manage the process,
not merely monitor it. With the advent of digital eld bus
communication networks such as CC-Link, DeviceNet,
PROFIBUS, and Smart Distributed Systems (SDS), gone
are the days of constrained information. Controllers can
CONTROLLER
TRANSCEIVER
OPTICAL
ISOLATION
BUS
INTERFACE
TRANSCEIVER
OPTICAL
ISOLATION
BUS
INTERFACE
TRANSCEIVER
OPTICAL
ISOLATION
BUS
INTERFACE
TRANSCEIVER
OPTICAL
ISOLATION
BUS
INTERFACE
TRANSCEIVER
OPTICAL
ISOLATION
BUS
INTERFACE
FIELD BUS
XXXXXX
YYY
SENSOR
DEVICE
CONFIGURATION
MOTOR
STARTER
MOTOR
CONTROLLER
HCPL-0710 fig 16
now receive multiple readings from eld devices (sen-
sors, actuators, etc.) in addition to diagnostic informa-
tion.
The physical model for each of these digital eld bus
communication networks is very similar as shown in
Figure 15. Each includes one or more buses, an interface
unit, optical isolation, transceiver, and sensing and/or ac-
tuating devices.