Chapter 15: Appendix

15-3 Definition of network systems

[1] Communication protocol standards

The term "Communication protocol" refers to the rules for exchanging information between systems on a particular communication circuit. The communication protocols used by FL-net conform to the following standards.

FL-net communication protocols

FL-net supported

Compatible specifications

communication protocol

 

 

FA link protocol specification sheets

FL-net

(MSTC FA open promotion committee, issued by the

 

FA control network promotion committee)

 

 

UDP

RFC768

 

 

IP, ICMP etc.

RFC791, 792, 919, 922, 950

 

 

APR etc.

RFC826, 894

 

 

Ethernet

IEEE802.3

 

 

[2] Hierarchical structure of the communication protocols

The communication protocols are configured as a layered structure. Communication processes are expressed and standardized by classification and they are arranged in various levels. The FL-net consists of the following six protocol layers.

Application layer

 

 

 

 

 

 

Controller interface

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Cyclic transfer

Service function

 

 

 

 

 

 

 

 

 

 

 

 

 

 

FA link protocol layer

 

 

 

 

 

 

Message transfer

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Token function

 

 

FL-net

 

 

 

 

 

 

 

 

 

 

 

protocol

Transport layer

 

 

 

 

 

 

 

UDP

 

 

Network layer

 

 

 

 

 

 

 

IP

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Data link layer

 

 

 

 

 

 

Ethernet

 

 

 

 

 

 

 

 

 

 

(Compatible with IEEE802.3)

 

 

 

Physical layer

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Hierarchical structure of the FA link protocol

15

15-12