Yaskawa SmartTrac DeviceNet Card - Manual (Page 9)

SMART TRAC DeviceNet Card
Technical Manual 3554-0070 DeviceNet Basics
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DeviceNet Basics
Introduction
Originally developed by Bosch for the automotive industry, DeviceNet is a low-
cost communications protocol to connect industrial devices (i.e., limit switches,
sensors, bar code readers, variable frequency drives, panel displays and operator
interfaces) to a network. DeviceNet provides an open network standard with
high noise immunity, suitable to industrial environments. The protocol includes
device-level diagnostics. It allows the addition of other devices on a network
without cycling power to the network.
Network
Configuration Tool
Other Devices
Controller
Pushbutton
Cluster
Barcode
Scanner
DeviceNet
+24 Volt
power supply
Motor
Starter
Input/Output
Devices
Smart Trac
AC1
Figure 1. Typical DeviceNet Network configuration
The Open Systems Interconnect (OSI), established in 1984 by the ISO
(International Standards Organization), divides network functions into seven
layers: Physical, Data Link, Network, Transport, Session, Presentation and
Application Protocol. DeviceNet provides the Application Protocol (highest
level 7), Data Link Layer (layer 2), Physical Layer (layer 1) and Transmission
Media (a sublevel of level 1, sometimes referred to as an eighth layer 0).
DeviceNet incorporates the CAN protocol to provide the Data Link Layer.