Download Real-Time Systems Exam Questions for Computer Applications Students and more Exams Computer Science in PDF only on Docsity! Cork Institute of Technology Bachelor of Science (Honours) in Computer Applications - Award (KSDEV_8_Y4) Summer 2008 Real-Time Systems (Time: 3 Hours) Instructions Answer any THREE questions. Note: Question 1 = 34 marks All other questions = 33 marks Real-time Systems Reference Booklet Available. Examiners: Dr. J. Creagh Dr. M. O Cinneide Mr. M. Donnelly Q1. As part of the security system of a large building, the entrance gates are managed by the system. When the owner arrives, a sensor detects the vehicle. The owner may use a remote control to cause the gates to open. The gates are opened. A sensor is required to detect that the gates are fully open. The vehicle now passes. A separate sensor detects that the vehicle has entered into the premises. If the light sensor detects poor light, then the lights are turned on when a vehicle is detected and the lights remain on for 10 minutes after the vehicle has passed. (a) Write a HRT – HOOD design for the security system. (12 marks) (b) Write an ADA program for sensor that detects that the vehicle has entered into the premises. The program must deal with closing the gates and turning off the lights after 10 minutes. The vehicle detector sensor indicates a reading of 0 or 1 and must be monitored every 250ms. For actuators 1 = ON, 0 = OFF or 1 = OPEN, 0 = CLOSED. Note: A register called ‘CSR’ controls the hardware. Refer to the reference booklet. A second register ‘READING’ is provided for reading a value from a sensor. A third register ‘WRITING’ is provided for writing a value to an actuator. (14 marks) (c) Write the ADA code for the protected object LightStatus. Choose appropriate methods and parameters. Comments are required. This object keeps a record of the light value. (8 marks) 2 Q2. (a) “OS-9 provides a complete development environment for the development of embedded systems. This includes HAWK and OS-9 on the target”. Discuss. Firstly, list a set of points that you wish to make. Then, expand on each point in your list. Clear examples required. (14 marks) (b) Consider a simple embedded system for managing the automatic opening and closing of windows in a greenhouse complex. (i) Draw a diagram of the system. (2 marks) (ii) From a programming viewpoint, explain why OS-9 is suitable for implementing such a system. Firstly, list your points (4 points required). Then, explain/justify each point you make. (11 marks) (c) What are the main advantages of using signals with OS-9 real-time programs? Give examples. (6 marks)
