Computers as Components, 2nd Edition

430 CHAPTER 8 Networks

Position

sensor

Coarse

indicators

Fine

indicators

FIGURE 8.26

Sensing elevator position.

Coarse-sensor* Master-control-panel*

Car-control-panel*

Car

Floor

Controller

1

1

1

1

1

1

F(2S 1 1)

1

1

1

1

N

F

F

1

N

Motor*

Floor-control-panel*

Fine-sensor*

FIGURE 8.27

Basic class diagram for the elevator system.

the cost and bulk of the elevator system. But because the elevators are controlled

by the computers,the proper operation of the embedded hardware and software is

very important.

8.7.2 Specification

The basic class diagram for the elevator system is shown in Figure 8.27.This diagram

concentrates on the relationships among the classes and the number of objects