Omron SYSMAC CS/CJ Series User Manual

166
Using Tasks Section 4-2
4-2-4 Designing Tasks
We recommend the following guidelines for designing tasks.
1,2,3... 1. Use the following standards to study separating tasks.
a) Summarize specific conditions for execution and non-execution.
b) Summarize the presence or absence of external I/O.
c) Summarize functions.
Keep data exchanged between tasks for sequence control, analog
control, man-machine interfacing, error processing and other pro-
cesses to an absolute minimum in order to maintain a high degree
of autonomy.
d) Summarize execution in order of priority.
Separate processing into cyclic and interrupt tasks.
2. Be sure to break down and design programs in a manner that will ensure
autonomy and keep the amount of data exchanged between tasks (pro-
grams) to an absolute minimum.
3. Generally, use an overall control task to control the READY/Standby status
of the other tasks.
4. Allocate the lowest numbers to tasks with the highest priority.
Example: Allocate a lower number to the control task than to processing
tasks.
5. Allocate lower numbers to high-priority interrupt tasks.
6. A task in READY status will be executed in subsequent cycles as long as
the task itself or another task does not shift it to Standby status. Be sure to
insert a TKOF(821) (TASK OFF) instruction for other tasks if processing is
to be branched between tasks.
7. Use the Initial Task Execution Flag (A20015) or the Task Start Flag
(A20014) in the execution condition to execution instructions to initialize
tasks. The Initial Task Execution Flag will be ON during the first execution
of each task. The Task Start Flag each time a task enters READY status.
Input
proces-
sing
Overall
control
(may in-
clude error
processing
in some
cases)
Breakdown by function
Error processing
Sequence control
Analog control
Man-machine interfacing
Interrupt
Output
processing
Breakdown by execution and non-execution conditions
Order priority
External I/O
External outputs
Minimize data
exchange

Omron SYSMAC CS/CJ Series Specifications

General

Series	CS/CJ Series
Category	Controller
Programming Languages	Ladder Diagram, Structured Text, Function Block Diagram, Sequential Function Chart
I/O Capacity	Varies by model (e.g., up to 5120 I/O points)
Communication Ports	RS-232C, RS-422/485
Mounting	DIN rail
Power Supply	AC or DC (varies by model)
CPU Type	Various CPUs available within the CS/CJ series (e.g., CS1H, CS1G, CS1D, CJ1M, CJ2M, CJ2H)
Ethernet Support	Yes (varies by model)
Operating Temperature	0°C to 55°C (32°F to 131°F)

Summary

PRECAUTIONS

1 Intended Audience

Specifies the intended audience for this manual, requiring electrical system knowledge.

2 General Precautions

General guidelines for operating OMRON products according to specifications and consulting representatives.

3 Safety Precautions

Critical safety warnings regarding PLC usage, I/O memory, and handling units.

4 Operating Environment Precautions

Precautions for operating the PLC system in various environmental conditions.

5 Application Precautions

Precautions to observe when using the PLC system, including software and data transfer.

6 Conformance to EC Directives

Information on compliance with EMC and Low Voltage directives for CS/CJ PLCs.

SECTION 1: CPU Unit Operation

1-1 Initial Setup (CS1 CPU Units Only)

Procedures for initial setup and battery installation for CS1 CPU Units.

1-2 Using the Internal Clock (CS1 CPU Units Only)

How to set and use the internal clock for CS1 CPU Units.

1-3 Internal Structure of the CPU Unit

Overview of CPU Unit internal structure, memory, and diagrams.

1-4 Operating Modes

Description of PROGRAM, MONITOR, and RUN modes of the CPU Unit.

1-5 Programs and Tasks

Explains how programs are grouped into tasks for execution.

1-6 Description of Tasks

Details various types of tasks like cyclic and interrupt tasks.

SECTION 2: Programming

2-1 Basic Concepts

Fundamental concepts for writing CS/CJ-series PLC programs.

2-2 Precautions

Important precautions when programming, focusing on flags and sections.

2-3 Checking Programs

Procedures for checking programs for errors using CX-Programmer or console.

SECTION 3: Instruction Functions

3-1 Sequence Input Instructions

Instructions for handling input signals and execution conditions.

3-2 Sequence Output Instructions

Instructions for outputting results of logical processing to bits.

3-3 Sequence Control Instructions

Instructions for controlling program flow, such as END, JMP, and IL.

3-4 Timer and Counter Instructions

Details on various timer and counter instructions.

3-5 Comparison Instructions

Instructions for comparing values and creating execution conditions.

3-6 Data Movement Instructions

Instructions for transferring data between memory areas.

3-7 Data Shift Instructions

Instructions for shifting bits or words within data.

3-8 Increment/Decrement Instructions

Instructions for incrementing or decrementing numerical data.

3-9 Symbol Math Instructions

Instructions for performing arithmetic operations on signed binary and BCD data.

3-10 Conversion Instructions

Instructions for converting data between BCD, binary, and ASCII formats.

3-11 Logic Instructions

Instructions for performing logical operations (AND, OR, XOR) on bits and words.

3-12 Special Math Instructions

Instructions for specialized mathematical operations like square roots.

3-13 Floating-point Math Instructions

Instructions for performing mathematical operations on floating-point numbers.

3-14 Double-precision Floating-point Instructions (CS1-H, CJ1-H, or CJ1M Only)

Instructions for handling double-precision floating-point data.

3-15 Table Data Processing Instructions

Instructions for manipulating data in tables and stacks.

3-16 Data Control Instructions

Instructions for controlling data flow and scaling.

3-17 Subroutine Instructions

Instructions for calling and managing subroutines and macros.

3-18 Interrupt Control Instructions

Instructions for setting up and managing interrupt tasks.

3-19 High-speed Counter and Pulse Output Instructions (CJ1M-CPU22/23 Only)

Instructions for high-speed counter and pulse output.

3-20 Step Instructions

Instructions for step-by-step program execution.

3-21 Basic I/O Unit Instructions

Instructions for interacting with basic I/O units.

3-22 Serial Communications Instructions

Instructions for serial communications.

3-23 Network Instructions

Instructions for network communication.

3-24 File Memory Instructions

Instructions for manipulating file memory.

3-25 Display Instructions

Instructions for displaying messages.

3-26 Clock Instructions

Instructions for calendar and time operations.

3-27 Debugging Instructions

Instructions and functions for debugging programs.

3-28 Failure Diagnosis Instructions

Instructions for diagnosing and reporting failures.

3-29 Other Instructions

Miscellaneous instructions not covered elsewhere.

3-30 Block Programming Instructions

Instructions for creating and managing block programs.

3-31 Text String Processing Instructions

Instructions for processing text strings.

3-32 Task Control Instructions

Instructions for controlling task execution status.

SECTION 4: Tasks

4-1 Task Features

Overview of tasks, their advantages, and structure.

4-2 Using Tasks

How to use TASK ON/OFF instructions and manage task status.

4-3 Interrupt Tasks

Details on types, priority, flags, and precautions for interrupt tasks.

4-4 Programming Device Operations for Tasks

How to manage tasks using CX-Programmer and Programming Console.

SECTION 5: File Memory Functions

5-1 File Memory

Information on types of file memory, data, files, and procedures.

5-2 Manipulating Files

Procedures for reading, writing, and managing files using various methods.

5-3 Using File Memory

Procedures for initializing Memory Cards and EM File Memory.

SECTION 6: Advanced Functions

6-1 Cycle Time/High-speed Processing

Functions related to cycle time optimization and high-speed operations.

6-2 Index Registers

Explanation of index registers and their usage for indirect addressing.

6-3 Serial Communications

Details on serial communication protocols like Host Link and No-protocol.

6-4 Changing the Timer/Counter PV Refresh Mode

How to select and configure BCD or binary modes for timer/counter PVs.

6-5 Using a Scheduled Interrupt as a High-precision Timer (CJ1M Only)

Using scheduled interrupts as high-precision timers.

6-6 Startup Settings and Maintenance

Functions related to system startup, maintenance, and protection.

6-7 Diagnostic Functions

Overview of diagnostic tools like error logs and failure diagnosis.

6-8 CPU Processing Modes

Details on normal and parallel processing modes.

6-9 Peripheral Servicing Priority Mode

Settings for prioritizing peripheral servicing.

6-10 Battery-free Operation

Procedures for operating without a battery using flash memory or Memory Cards.

6-11 Other Functions

Includes I/O response time settings and I/O area allocation.

SECTION 7: Program Transfer, Trial Operation, and Debugging

7-1 Program Transfer

Procedures for transferring programs to the CPU Unit.

7-2 Trial Operation and Debugging

Functions for testing and debugging programs, including forced set/reset and tracing.

Appendix A: PLC Comparison Charts

Functional Comparison

Compares features like capacity, I/O points, and processing speed across PLC series.

PLC Comparison Charts

Detailed comparison of PLC features across different series.

Appendix B: Changes from Previous Host Link Systems

RS-232C Ports

Differences in wiring and other aspects for CS/CJ-series products.

RS-422A/485 Ports

Differences in wiring and other aspects for RS-422A/485 ports.