FL-net (OPCN-2) Open Controller Level Network

FL-net (OPCN-2) is the result of a standardization initiative of JEMA (Japan Electrical Manufacturers Asscociation) and several other important Japanese standardization authorities. FL-net is the Controller level network which is complemented by the device-level network OPCN-1. FL-net is based on Industrial Ethernet, designed to provide intercommunication between controllers such as PLC, CNC or robot controller.from different manufacturers based on the public standard. Its basic specification responds to the requirements of the Japan Automobile Manufacturers Association (JAMA) for building a highly reliable production system. FL-net devices are certified for interoperability and conformance to the FL-net standards by an independent Japanese certification committee

FL-net topology

The FL-net is based on standard Ethernet technology. The largest difference between FL-net and standard Ethernet lies in its capability to guarantee the transmission times for data transfers, in other words, its capability for real-time data transmission. FL-net uses the FA link protocol which provides good Real-Time capabilities on top of UDP/IP. An FL-net (OPCN-2) unit is implemented in an FA controller such as a programmable controller (PLC), a numerical control unit (CNC), etc. and transmits and receives data cyclically among controllers only by assigning a station number (a node number) and common memory (also called link register) for linking in the same manner as the "CPU link unit" of a normal PLC.

The employment of the common memory system, in which the equipment on the FL-net shares their output, realizes a high speed synchronization between the equipment on a transfer line. Moreover, individual equipment can be added to or deleted from the network freely, making the system highly flexible in its configuration as well as realizing high system reliability. The network guarantees a good response to a large data message, making the most of the high speed feature of the Ethernet.

FL-net is used in a variety of systems including machining lines in the automotive industry. For the CNC's, and for robots controllers FL-net can be used ito build FA systems with great ease by combining them with a variety of peripheral equipment.

Network Type:   Ethernet-UDPIP based Control level network
Topology:    Very flexible with star, tree or line structures.
All topologies that can be implemented with standard Ethernet
Installation:    Standard 10 or 100 Mbit/s Ethernet technology based on copper cables or fibre optics standards can be used.
Speed :    10 Mbit/s
max. Stations :    Max 252 nodes
Data:    Max 1024 byte per Telegram frame
Total I/O data on the network: Max 17 kbyte
Network Features :    Token-Bus network.
Organization:   Open PLC Network Organization and JEMA