User Manual Owner's manual
Table Of Contents
- 1772-6.5.8, Mini-PLC-2/02, -2/16, -2/17 Processor, User Manual
- Important User Information
- Summary of Changes
- Table of Contents
- 1 - Using This Manual
- 2 - Fundamentals of a Programmable Controller
- 3 - Hardware Features
- 4 - Installing Your Programmable Controller
- 5 - Starting Your Processor
- 6 - Maintaining and Troubleshooting Your Processor
- 7 - Memory Organization
- 8 - Scan Theory
- 9 - Relay-Like Instructions
- 10 - Program Control Instructions
- 11 - Timers and Counters
- 12 - Data Manipulation and Compare Instructions
- 13 - Three-Digit Math Instructions
- 14 - EAF Math Instructions
- 15 - EAF Log, Trig, and FIFO Instructions
- 16 - EAF Process Control Instructions
- 17 - Jump Instructions and Subroutines
- 18 - Block Transfer
- 19 - Data Transfer Instructions
- 20 - Bit Shift Registers
- 21 - Sequencers
- 22 - Selectable Timer Interrupts
- 23 - Report Generation
- 24 - Program Editing
- 25 - Programming Techniques
- 26 - Program Troubleshooting
- A - Specifications
- B - Processor Comparison Chart
- C - Number Systems
- D - Glossary
- E - Quick Reference
- Index
- Back Cover

Chapter
8
8-1
Scan Theory
In this chapter you will read about:
scan function
scan time
The processor controls the status of output devices or instructions in
accordance with program logic. Every instruction in your program
requires execution time. These times vary greatly depending upon the
instruction, the amount of data to be operated on, and whether the
instruction is true or false.
As a review from chapter 2, there are two types of scans (Figure 8.1):
I/O scan
Program scan
Chapter Objectives
Scan Function