Programming instructions

5
LESSON 2 – FX Series Hardware Review
This lesson discusses the hardware structure of the FX-Series logic controller. This
includes a review of the different CPU module types, input/output modules and
interfacing variations.
Lesson Objectives: At the conclusion of this lesson, you will be able to…
9 Explain the general sections of a PLC.
9 Describe the different models of the FX family.
9 Describe the characteristics of the I/O modules available.
9 List some of the factors to be considered in specifying hardware.
Materials: FX-Series PLC Training Manual
FX Family Brochure
2.1 What is a dedicated PLC?
A dedicated PLC is a microprocessor controlled computer that is designed
specifically to perform real-time industrial machine control.
There are 3 general sections to all PLC’s, INPUT, CONTROLLER, and
OUTPUT.
 INPUT - The input section consists of integrated inputs, or extension
…………inputs that machine input devices will be wired to, like limit
switches, …………or transistor sensors. When the input voltage
reaches its specified …………level the input becomes active. Once
active, the input can be read …………by controller.
 CONTROLLER - The controller is the main unit. Several CPU
modules are …………available depending on the demands of your
application.
 OUTPUTS
- The third section is the outputs. Based on the condition of
the
inputs, the controller will judge which outputs should turn on, to
activate machine devices like lights, buzzers, relays,
solenoids, or motors.
The 3 sections are controlled by custom sequencing software called ladder
programming, which takes the place of hardwired circuits. The relationship
between inputs and outputs is controlled by the logic in your ladder program.
Because hard-wired circuits are now replaced by software logic, machine
modifications and improvements, are much easier to complete.