7. CONNECTION TO FA NETWORKS
FL–net is the open FA network standardized by the FA open promotion
conference (JOP) in Manufacturing Science and Technology Center,
which is an outside organization of the Ministry of International Trade and
Industry. As shown below, many personal computers and FA controllers
of different manufacturers such as programmable controllers (PLC) and
CNCs are interconnected, controlled, and monitored.
High–order LAN Ethernet (TCP/IP, UDP)
FL–net (Ethernet base control network)
Fig. 7.5.1 Example of FA control network
FL–net has various features required for FA.
1) Large–scale network
Up to 254 units (nodes) can be connected.
2) Two types of communication functions suitable for applications
FL–net supports a common memory function that allows each node to
share the same data at all times through cyclic communication, and a
message communication function that exchanges only necessary
information only when required.
3) Large–capacity common memory
The common memory is as large as 8K bits + 8K words.
4) High–speed response
Response as fast as 50 ms/32 nodes (with 2K bits + 2K words) can be
5) High reliability based on masterless method
No master is present, so that nodes can be connected to and
disconnected from the network without affecting the communication
of other nodes. So, each node allows free power–on/off operation and