Differences Between General-Purpose Ethernet And Fl-Net - Hitachi S10mini User Manual

8 APPENDIXES

8.2.8 Differences between general-purpose Ethernet and FL-net

Since the FL-net is a network for FA (factory automation) fields, it cannot use all the
general-purpose Ethernet devices. Some devices are inapplicable to the FL-net due to
their noise immunity or environment resistance.
The FL-net is required to offer a specified degree of real-time communication response
capability for control purposes. Therefore, it can be connected to FL-net-compliant
controllers and other control devices only.
The FL-net employs a cyclic communication method that exercises the broadcast features
of 10BASE5/10BASE-T based UDP/IP communication. Therefore, the following
limitations are imposed due to the current standard.
• Currently supported devices are limited to 10 Mbps Ethernet LAN devices.
• Connections to the other general-purpose Ethernet networks cannot be established.
• The TCP/IP communication features are not supported.
• The use of a switching hub produces no beneficial effect.
• The inability to function may result if a router or the like is used.
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