required to allow users to perform task programming, the

88 Pages·2013·0.71 MB·English

by  Lim, Choo-chiang

AN ABSTRACT OF THE THESIS OF
Choo-Chiang, Lim for the degree of Master of Science in Electrical
and Computer Engineering presented on December 8, 1989.
Title : A Programmable System Scheduler For Control Oriented
Local Area Networks (COLAN)
Redacted for privacy
Abstract approved:
James H. Herzog
The Control-Oriented Local Area Network (COLAN) is a
distributed control system for a series of networked
microcontrollers, which has been under development at Oregon
State University since 1986. A reliable master controller, func-
tioning both as a task scheduler and as a network controller, is
required to allow users to perform task programming, the
transmission and reception of commands and data packets, and
network status monitoring.
The Task Master Controller (TMC) has been designed and
developed to provide these capabilities. The TMC provides an
integrated environment to aid in the editing of task programs, the
execution of task programs, the interpretation of program
statements, the manipulation of files, the maintenance of a
communication protocol between the host computer and remote
microcontrollers, the maintenance of a device and task library, and
the display of network status. The TMC provides two different
modes of operation, a user mode and a command mode, to allow
both the novice user and the experienced system developer to use
the system.
The TMC language also includes such basic programming
language elements as conditional statements, repetitive statements,
and block statements. It also includes such built-in functions as
time delay, print message, reception of data, and save response.
These elements provide the skilled system developer with a
powerful tool to program tasks in any desired sequence. It
provides the novice user with a friendly user interface to schedule
tasks by selecting from a menu of high level commands included in
the system library.
A Programmable System Scheduler
For Control Oriented Local Area Networks (COLAN)
by
Choo-Chiang, Lim
A THESIS
Submitted to
Oregon State University
in partial fulfillment of
the requirements for the
degree of
Master of Science
Completed December 8, 1989
Commencement June, 1990
APPROVED :
Redacted for privacy
Associate Pessor of ES/&kt&al and Computer Engineering in
charge of major
rm
Redacted for privacy
Head of Departmett of Electrical and Computer Engineering
Redacted for privacy
I
Dean of Graduate(!fhool
Date thesis is presented December 8. 1989
ACKNOWLEDGEMENT
I would like to express my sincere gratitude to my advisor, Prof.
James Herzog, for his guidance, encouragement and support
throughout this study and for the many hours he spent reading my
work and commenting on it while it was being done. I also like to
thanks Prof. Joel Davis, Prof. Roy Rathja and Prof. Bella Bose for
acting as my committee members and for giving me useful advice.
I warmly thank all of my friends and colleagues whose assistance,
encouragements have been invaluable.
Finally I thank my parents and family members for their financial
support and encouragement throughout my education.
TABLE OF CONTENTS
Page
Chapter
1. INTRODUCTION 1
1.1 Motivation 1
1.2 Background 1
1.3 Multiple Microprocessor Systems 2
4
1.4 Local Area Networks
1.5 TASMASTER Systems 5
1.6 Cotrol-Oriented Local Area Networks 7
1.7 Task Scheduling Problem for COLAN 8
1.8 Objective of the Thesis 9
1.9 Outline of the Thesis 11
15
2. DATA COMMUNICATION INTERFACE
15
2.1 Overview
2.2 Host Computer 15
2.3 Microcontroller System 16
2.4 EIA RS-485 Bus Standard 17
2.5 RS-232C/RS485 Converter 18
22
3. DESIGN AND IMPLEMENTATION OF TMC SOFTWARE
22
3.1 Overview
23
3.2 Main Program
23
3.3 Communication Protocol
26
3.4 Interpreter
3.5 Task Processor 2 7
30
3.6 Screen Editor
31
3.7 System Library
32
3.8 File Handling
33
3.9 Network Monitoring
33
3.10 User Interface
34
3.11 Miscellaneous
TABLE OF CONTENTS (continued)
Chapter Page
4. USER MANUAL FOR TMC SOFTWARE 40
4.1 Overview 4 0
4.2 Installation 4 0
4.3 Getting Started 41
4.4 Using the Menu System 41
4.4.1 Main Menu 42
4.4.2 Quick-Ref Line 43
4.4.3 Editor Window 44
4.4.3.1 User Mode Task Editing 44
4.4.3.2 Command Mode Task Editing 46
4.5 Menu Commands 46
4.5.1 File Menu 46
4.5.2 Edit Command 48
4.5.3 Execute Menu 48
4.5.4 Setup Menu 5 0
4.5.5 Library Menu 51
4.5.6 Netlnfo Command 52
4.6 Basic Task Program Statements 52
4.6.1 Command Package Statements 52
4.6.1.1 Device Address 53
4.6.1.2 Prefix 53
4.6.1.3 Task Number 54
4.6.1.4 Suffix 55
4.6.1.5 Data Field 5 6
4.6.1.6 Echo Requests 56
4.6.2 Data Packet Statements 5 7
4.6.3 Conditional Statements 57
4.6.4 Repetitive Statements 5 8
4.6.5 Block Statements 58
4.6.6 Built-In Function Statements 5 9
TABLE OF CONTENTS (continued)
Chapter page_
67
5. SUMMARY AND RECOMMENDATIONS
5.1 Summary 6 7
5.2 Recommandations for Future Reseach 68
71
BIBLIOGRAPHY
73
APPENDIX A TMC APPLICATION EXAMPLES
A.1 Application Overview 7 3
A.2 Example 1: A Museum Project 7 4
A.3 Example 2: A Greenhouses Temperature
Control Project 76
LIST OF FIGURES
Figure Page
1-1 Tightly Coupled Multiprocessor System 12
1-2 Loosely Coupled Multiprocessor System 12
1-3 System Configuration For TASKMASTER 13
1-4 Network Configuration For COLAN 13
1-5 Robot Arm Using COLAN Configuration 14
2-1 Half-duplex RS-485 Multidrop Network 20
2-2 RS-232C/RS-485 Converter 21
3-1 Flowchart for Establish Asynchronous Communication- 36
3-2 Circular Queue Operations 37
3-3 Syntax Graph For A TMC Statement 38
3-4 Data Structure For TMC Library 39
4-1 The Main Menu 62
4-2 User Mode Task Editing 62
4-3 Command Mode Task Editing 63
4-4 The File Menu 63
4-5 The Execute Menu 64
4-6 The Setup Menu 64
4-7 Device Library 65
4-8 Task Library 65
4-9 Network Status Window 66
A PROGRAMMABLE SYSTEM SCHEDULER
FOR CONTROL ORIENTED LOCAL AREA NETWORKS (COLAN)
CHAPTER 1
INTRODUCTION
1.1 Motivation
The purpose of this research was to develop and implement a
reliable software for the host computer in COLAN (Control Oriented
Local Area Network) to allow users to synchronize and control all
the system activities and monitor the network status.
1.2 Background
The development of VLSI technology during the past decade
has pushed the evolution of the microprocessor to its practical
limits. Methods used to increase microprocessor performance
include increased word (data-bit) length, increased clock speed,
and the use of more sophisticated architectures. However, none of
these factors will continue to increase at the rate experienced
during the past decade. The current 16-bit and 32-bit