Desenvolvimento de uma estação de rede MAP para a automação industrial.

Abstract

This work describes the design and implementation of a communications front-end processor (PFC) f o r MAP type networks. In the f i r s t part of t h i s work i s a presentation of the development of the hardware in the form of a board for the PP (Processador Preferencial) general purpose super-microcomputer developed by Telebras. This board contains a 16 b i t microprocessor, a network controller IC, and up to 512 kbytes of memory. The second part of t h i s work describes the developed multi-tasking nucleus, called the Executive, which is designed s p e c i f i c a l l y for t h i s hardware and optimized for real-time operation and the support of the implantation of the protocols which follow the RM OSI/ISO standard. The Executive offers task management services, intertask communication services, timing services and dynamic memory allocation services. The third part of this work describes the implementation of the layers LLC (Logic Link Control) and MAC (Media Access Control) f o r the i n s t a l l a t i o n of protocols following a mini-MAP architecture. These two layers are implemented i n the form of a single task which executes under the Executive.