Lab III: Programming Logic Circuit (PLC) OMRON CP1L

Objective

Learn the Sysmac CP1L programmer

Make a ladder diagram programming for a given question

Equipment

A computer with CX-Programmer software

OMRON Sysmac CP1L (PLC)

Introduction

A microprocessor is a single IC that contains multiple circuits that perform arithmetic, logic, communication, and control functions.

A microcomputer is a single-board computer that contains a microprocessor, interface, and memory chips.

A microcontroller is a single IC containing specialized circuits and functions required to design Mechatronic systems. A microcontroller is a microcomputer on a single chip.

Microcontrollers are used in many applications. For example: home appliances, entertainment equipment, telecommunication equipment, automobiles, airplanes, toys, tools, exercise equipment, and office equipment.

Programmable Logic Controllers (PLC) also referred to as programmable controllers are in the computer

family. A PLC monitors inputs, makes decision based on its program, and controls outputs to automate a

process or machine.

In this experiment we will use OMRON CP1L PLC

Theory

PLCs consist of input modules or points, a central processing unit (CPU), and output modules or points.

An input accepts a variety of digital or analog signals from various field devices (sensors) and converts

them into a logic signal that can be used by the CPU. The CPU makes decision and executes control

instructions based on program instructions in memory. Output modules convert control instructions

from the CPU into a digital or analog signal that can be used to control various field devices (actuators).

A programming device is used to input the desired instructions. These instructions determine what the

PLC will do for a specific input. An operator interface device allows process information to be displayed

and new control parameters to be entered.

Basic Programming

i) A program consists of one or more instructions that accomplish a task. Programming a PLC is

simply constructing a set of instructions.

ii) Ladder logic diagram

The left vertical line of a ladder logic diagram represents the power or energized

conductor. The output element or instruction represents the neutral or return path of

the circuit. Ladder logic diagrams are read from left-to-right, top-to-bottom. Rungs are

sometimes referred to as networks. A network may have several control elements, but

only one output coil.

iii) I/O Allocation on CP1L with 14-point I/O

On 14-point I/O units, 8 inputs, from 0.00 to 0.07 (bits 00 to 07 on 0CH), are allocated to the input terminal block. Also, 6 output relays, from 100.00 to 100.05 (bits 00 to 05 on 100CH), are allocated to the output terminal block. Unused upper bits on the input channel (bits 08 to 15) cannot be used as a work area. Unused upper bits on the output channel (bits 06 to 15), however, can be used.

iv) Contacts

Two of the most common programming functions are the normally open (NO) contact and

the normally closed (NC) contact.

v) Coils

Cols represent relays that are energized when power flows to them. When a coil is

energized, it causes a corresponding output to turn on by changing the state of the status

bit controlling that output to 1.

vi) Boxes

Boxes represent various instructions or functions that are executed when power flows to

the box. Typical box functions are timers, counters and math operations.

Instruction

1) Learn and explore the basic programming through the additional notes and example of CX

Programming.

2) Write out a programming for a given question using CX Programmer. Include the detail of your

programming (flow chart, designation of input and output, etc..) .

Set A

In the following example a tank will be filled with two chemicals, mixed, and then drained. When the

Start button is pressed at input I0.0, the program starts pump 1 controlled by output Q0.0. pump 1 runs

for 5 seconds, filling the tank with the first chemical, then shuts off. The program then starts pump 2,

controlled by output Q0.1. Pump 2 runs for 3 seconds filling the tank with the second chemical. After 3

seconds pump2 shut off. The program starts the mixer motor, connected to output Q0.2 and mixes the

two chemicals for 6 seconds. The program then opens the drain valve controlled by output Q0.3, and

starts pump 3 controlled by output Q0.4.Pump 3 shut off after 8 seconds and the process stops. A

manual stop switch is also provided at input IO.1.

SET B

A counter might be used to keep track of the number of vehicles in parking lot. As vehicles enter the lot

through an entrance gate, the counter counts up. As vehicles exit the lot through an exit gate, the

counter counts down. When the lot is full a sign at the entrance gate turns on indicating the lot is full.

Consider the movement of up and down of the gate barrier in your programming.