OMRON C200HS-CPU01-E SYSMAC PROGRAMMABLE CONTROLLER

OMRON C200HS-CPU01-E SYSMAC PROGRAMMABLE CONTROLLER

PC Terminology

Section 1-4

Although also provided in the Glossary at the back of this manual, the following

terms are crucial to understanding PC operation and are thus explained here.

PC

Inputs and Outputs

Controlled System and

Control System

Because the C200H is a Rack PC, there is no one product that is a C200H PC.

That is why we talk about the configuration of the PC, because a PC is a configu

ration of smaller Units.

To have a functional PC, you would need to have a CPU Rack with at least one

Unit mounted to it that provides I/O points. When we refer to the PC, however, we

are generally talking about the CPU and all of the Units directly controlled by it

through the program. This does not include the I/O devices connected to PC in

puts and outputs.

If you are not familiar with the terms used above to describe a PC, refer to Sec

tion 2 Hardware Considerations for explanations.

A device connected to the PC that sends a signal to the PC is called an input

device; the signal it sends is called an input signal. A signal enters the PC

through terminals or through pins on a connector on a Unit. The place where a

signal enters the PC is called an input point. This input point is allocated a loca

tion in memory that reflects its status, i.e., either ON or OFF. This memory loca

tion is called an input bit. The CPU, in its normal processing cycle, monitors the

status of all input points and turns ON or OFF corresponding input bits accord

ingly.

There are also output bits in memory that are allocated to output points on

Units through which output signals are sent to output devices, i.e., an output

bit is turned ON to send a signal to an output device through an output point. The

CPU periodically turns output points ON or OFF according to the status of the

output bits.

These terms are used when describing different aspects of PC operation. When

programming, one is concerned with what information is held in memory, and so

I/O bits are referred to. When talking about the Units that connect the PC to the

controlled system and the places on these Units where signals enter and leave

the PC, I/O points are referred to. When wiring these I/O points, the physical

counterparts of the I/O points, either terminals or connector pins, are referred to.

When talking about the signals that enter or leave the PC, one refers to input

signals and output signals, or sometimes just inputs and outputs. It all depends

on what aspect of PC operation is being talked about.

The Control System includes the PC and all I/O devices it uses to control an ex

ternal system. A sensor that provides information to achieve control is an input

device that is clearly part of the Control System. The controlled system is the

external system that is being controlled by the PC program through these I/O

devices. I/O devices can sometimes be considered part of the controlled sys

tem, e.g., a motor used to drive a conveyor belt.

1-4 OMRON Product Terminology

OMRON products are divided into several functional groups that have generic

names. Appendix A Standard Models list products according to these groups.

The term Unit is used to refer to all of the OMRON PC products. Although a Unit

is any one of the building blocks that goes together to form a C200H PC, its

meaning is generally, but not always, limited in context to refer to the Units that

are mounted to a Rack. Most, but not all, of these products have names that end

with the word Unit.

The largest group of OMRON products is the I/O Units. These include all of the

Rack-mounting Units that provide non-dedicated input or output points for gen

eral use. I/O Units come with a variety of point connections and specifications

High-density I/O Units are designed to provide high-density I/O capability and

include Group 2 High-density I/O Units and Special I/O High-density I/O Units.

Special I/O Units are dedicated Units that are designed to meet specific needs.

These include some of the High-density I/O Units, Position Control Units, High

speed Counter Units, and Analog I/O Units.

Link Units are used to create Link Systems that link more than one PC or link a

single PC to remote I/O points. Link Units include Remote I/O Units, PC Link

Units, Host Link Units, SYSMAC NET Link Units, and SYSMAC LINK Units.

SYSMAC NET Link and SYSMAC LINK Units can be used with the CPU11 only.

Other product groups include Programming Devices, Peripheral Devices,

and DIN Rail Products