Fl-Net Features; Figure 1-2 Fl-Net Protocol Basis Structure - Hitachi FL.NET User Manual

1.2 FL-net Features

FL-net has the following features:
• An open system can be implemented.
• A multivendor environment can be established.
• Programmable controllers (PLCs), computer numerical control (CNC) devices, and various
other factory automation controllers and personal computers of many different brands can be
interconnected to exercise control and monitoring functions.
Application layer
FA link protocol layer
Transport layer
Network layer
Data link layer
Physical layer
<A widely accepted standard is complied with.>
FL-net is based on Ethernet, which is a standard for OA (office automation) equipment.
Further, standard UDP/IP is used to achieve a high degree of communication efficiency.
• Low price
Since common communication devices can be used as components, the price is decreased.
• Use of widespread network equipment
Transceivers, hubs, cables, personal computer LAN cards, and various other widely accepted
Ethernet devices can be used.
• Future speed increase
In the future, you can expect that the speed of transfer will increase from 100 Mbps to 1 Gbps.
• Introduction of fiber-optic communication
Optical repeaters and other widespread devices for Ethernet can be used to replace relevant
portions with fiber-optic lines. The introduction of such fiber-optic lines will permit
transmission over a distance of 500 m or longer, provide increased noise immunity, and
protect against a lightning surge in outdoor wiring.

Figure 1-2 FL-net Protocol Basis Structure

Controller interface
Service function
Cyclic
transmission
Message transmission
Token function
UDP
IP
Ethernet
(IEEE 802.3-compliant)
1-3
1 OVERVIEW
FL-net
protocol