Principles Of The Fl-Net System; Differences Between A General-Purpose Ethernet And Fl-Net - Sharp JW-20FL5 User Manual

[7] Principles of the FL-net system

The goal of an FL-net is real-time communication between controllers, such as programmable control-
lers, robot controllers, and numeric control devices, in production systems.
The FL-net constructs a token passing mechanism using an instantaneous information transfer based
on Ethernet UDP/IP protocols to execute cyclic and message communications.

[8] Differences between a general-purpose Ethernet and FL-net

FL-net is a network developed specifically for the FA (Factory Automation) field. Therefore, not all
general purpose Ethernet equipment can be used on the FL-net. Some items may not have suitable
noise immunity in an electrically noisy environment.
FL-net is must respond immediately, to maintain real-time communication for control, and therefore
only controllers and control equipment compatible with the FL-net can be connected.
FL-net employs a cyclic communication method, using the instantaneous information transfer func-
tion of UDP/IP communication on 10BASE5/10BASE-T systems. Therefore, it has the following limi-
tations.
1. The devices currently available are only compatible with a 10Mbps Ethernet LAN.
2. Cannot have other general-purpose Ethernet devices connected to the network.
3. Does not support the TCP/IP communication function.
4. The use of a switching hub is not supported.
5. When a router is used, some router functions cannot be used.
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Chapter 15: Appendix
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