Omron CJ1W-FLN22, Operation Manual, Page: 225 / 277

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Appendix C
Network System Definitions
Communications Protocol Standard
The communications protocol indicates the rules for exchanging information through the communications lines
between two systems. The communications protocol used by FL-net conforms to the following standards.
Communications Protocol Layer Configuration
The communications protocol is modeled in a layers, and is expressed and standardized using a layer configu-
ration, in which communications processing is divided into several layers.
FL-net consists of six protocol layers,
as shown in the following diagram.
FL-net Physical Layer
When a baud rate of 10 Mbps is used, five transmission methods can be used in the Ethernet’s physical layer,
including 10Base-5, 10Base-2, 10Base-T, 10Base-F, and 10Broad-36 (although not commonly used). There is
also 100 Mbps Ethernet. Of these transmission methods, FL-net uses 10Base-5 (recommended), 10Base-2,
and 10Base-T.
FL-net
communications
protocol
Standards
FL-net FA link protocol specification
(MSTC FA Open Systems Promotion Forum
FA Control Network Technical Committee)
UDP RFC768
IP, ICMP, etc. RFC791, 792, 919, 922, 950
ARP etc. RFC826,894
Ethernet IEEE802.3
UDP
IP
Application layer
FA link protocol layer
Cyclic transmission
Controller interface
Message service
Message transmission
FL-net protocol
Token functionality
Transport layer
Network layer
Data link layer
Physical layer
Ethernet
(IEEE802.3 standard)