PROGRAMMABLE LOGIC CONTROLLER DNT 353/3 BY: Salsabila Ahmad

CHAPTER 1 ELECTRICAL CONTROLLER EQUIPMENT BY: Salsabila Ahmad

ELECTRICAL CIRCUIT BASIC 4 ELECTRICAL BASICS POWER SUPPLY INPUT DEVICE Input Controller Equipment CONDUCTOR OUTPUT DEVICE Output Controller Equipment

A device which supplies energy needed to create an electrical current POWER SUPPLY Definition: A device which supplies energy needed to create an electrical current

EXAMPLES OF POWER SUPPLY Battery DC Power Supply AC Power Supply

INPUT DEVICE DEFINITION 2 TYPES OF INPUT DEVICE Mechanical input device Solid state proximity device ELECTRICAL SWITCHING Basic Principle of Electrical Switching Types of Contacts How do These Contacts Work?

DEFINITION: A device which allows/ controls the flow of current in a circuit These devices are known as “ELECTRICAL CONTROLLER EQUIPMENTS” Provides Electrical Switching

MECHANICAL INPUT DEVICES Definition: An input device with a mechanical contact

EXAMPLE OF MECHANICAL INPUT DEVICES Contact Relay Push button Limit Switch Selector Switch Toggle Switch Temperature Switch Pressure Switch Solenoid Switch Induction Motor Controller

CONTACT RELAY Relay Coil output device But Relay Contact input device

RELAY 2 TYPES OF RELAY: EMR SSR

CHARACTERISTICS OF EMR & SSR RELAY SYMBOLS

ELECTROMAGNETIC RELAY (EMR) Definition: An EMR is an electromagnetic device composed of a frame/core, electromagnet coil and contacts (move and fixed) Based on simple electromagnetic principle

SOLID STATE RELAY (SSR) HOW IT OPERATES? Operates similarly to EMR, but with no mechanical contact. Employ semiconductor switching elements thryristors triacs diodes transistors.

Employ optical semiconductors called photo couplers to isolate input and output signals. Photo couplers change electrical to optical signals and relay the signal through space.

CHARACTERISTICS OF EMR AND SSR slow speed wears out easily noisy cheap high speed, high frequency for switching operations no failure due to wear out, since no mechanical contacts little noise expensive

RELAY SYMBOLS Commonly used in electrical machine diagram Normally open (NO) Normally close (NC) Coil

BASIC PRINCIPLE OF ELECTRICAL SWITCHING A situation of breaking and open an electrical circuit Or to direct current from one conductor to another. The PLC is the solution to today’s electrical switching requirements where it is able to solve complex switching requirements.

2 TYPES OF CONTACT NO NC

HOW DO THESE CONTACTS WORK? Once coil is energized, the contact will change state NO  NC NC  NO

PUSH BUTTON Definition Concepts of Operation Application of Push Button Schematic Symbols

DEFINITION pushbutton-type operator Have one set or more contact/spring Mostly have a set of normally open (NO) and normally closed (NC) contact

CONCEPTS OF OPERATION Pushing the operator causes the contacts to change state Spring causes switch operator to automatically return to it’s natural state when it is released. NO  NC  NO NC  NO  NC natural state change state automatic return a switch with this return spring action, is called a momentary switch.

APPLICATIONS Frequently used in industrial applications to control functions such as starting and stopping the machine’s operation With a safety nature. Why?

SCHEMATIC SYMBOLS FOR PUSH BUTTON Normally Open Contact Normally Closed Contact

LIMIT SWITCH

SELECTOR SWITCH Definition Application Schematic Symbols

DEFINITION Similarly to pushbutton, but instead of pushing, you rotate a knob may be designed to stay in a selected position or may have a momentary action selector switch that stays in a certain position is called a maintained switch.

APPLICATION for switching mode of operation Widely used in industrial applications for switching mode of operation For example from automatic to manual modes to turn the main power on and off to select between AC or DC output. Some requires key (authorized person) to turn on for safety reason.

SCHEMATIC SYMBOLS FOR SELECTOR SWITCH Normally open contact Normally close contact Selector switch with two contacts

TOGGLE SWITCH Toggle switch is a maintained switch What is a maintained switch?

TEMPERATURE SWITCH

PRESSURE SWITCH

SOLENOID SWITCH Use concept of magnetic flux for armature/plunger to move Produces linear mechanical motion

INDUCTION MOTOR CONTROLLER Commonly used micro-controllers

PROXIMITY SENSORS

SOLID STATE PROXIMITY DEVICES Definition: An electronic input device which needs power to be able to operate Proximity Sensors Category

PROXIMITY SENSORS CATEGORY Proximity sensors inductive capacitive dielectric type conductive type ultrasonic optical diffuse reflective type retro reflective type thru beam fiber optic sensor color mark sensor encoder sensor

INDUCTIVE PROXIMITY SENSOR Sense only metallic objects e.g. steel, iron, aluminum, tin, copper etc Has limited sensing range range affected by the type of metal sense

An oscillator and a detection coil generate a magnetic field that produces Eddy currents in a nearby metallic object (the detectable object). These Eddy currents generate a magnetic field that influences the field produced by the sensor’s detection coil.

CAPACITIVE PROXIMITY SENSOR sense all material with mass. operation for both dielectric and conductive type are the same

CAPACITIVE PROXIMITY SENSOR The dielectric type works best for high density material Low density material (e.g. paper, foam etc) do not cause a detectable change in dielectric. The conductive type works best on electrically conductive material e.g. metal or water-based material)

ULTRASONIC SENSOR Use ultrasonic technology How does it works?

CONCEPTS OF ULTRASONIC SENSOR Use an ultrasonic “ping” sent from sensor to target Sensing area is a funnel shape area Therefore, target must be located directly in front of sensor When echo is returned, sensor detects target by measuring time delay between transmitted ping and returned echo sensor calculate distance between sensor and target

CONCEPTS OF ULTRASONIC SENSOR (cont’) Do not work well on cloth, foam rubber since good absorber of sound waves Works best on high density material where sound waves reflects best

DIFFUSE REFLECTIVE Emitter and receiver located in same housing

DIFFUSE REFLECTIVE Emitter and receiver Light emitted is received when the object is present Works well on glossy target but not transparent

RETRO-REFLECTIVE Emitter and receiver located in same housing.

RETRO-REFLECTIVE Light emitted is received when the object is absent. Emitter and receiver reflector Light emitted is received when the object is absent. Does not work well with glossy target. Why? Because glossy target acts like a reflector

EXERCISE: If you have a shinny object as a target, which type of sensor do you choose; retro or diffuse?

THRU-BEAM Emitter and receiver is located in different housing

THRU-BEAM emitter receiver Sense the object’s present when it passes through between emitter and receiver where it stops the light from hitting receiver

FIBER OPTIC Available in both thru beam and reflective

FIBER OPTIC Use plastic and glass fibers to carry lights Thru-beam object Reflector Use plastic and glass fibers to carry lights

COLOR MARK A special type of diffuse reflective optical sensor that can differentiate between colors some can detect contrast between colors. Typically used to check labels and sort packages by color mark.

ENCODER Used for position feedback and some for velocity feedback Two main types Incremental absolute

CONDUCTOR

CONDUCTOR Definition: A medium that connects all the components and allows current to flow. Examples: copper wire bread board What else???

OUTPUT DEVICE Definition Example

DEFINITION A component that will produce a desired output. E.g. Sound Light Movement etc It is also referred to as a load.

EXAMPLE Coil Buzzer/Alarm Lamp Motor Solenoid Timer Counter

COIL Can represents various forms of output including Motor Light Pump Counter Timer Relay

BUZZER LAMP

MOTOR Types of Motor In PLC, motor can only be controlled for power (ON/OFF) direction (CCW/CW) preset speed

TYPES OF MOTOR DC motor type wound field permanent magnet electronics commutation dc motors AC motor type induction motors synchronous motor

SOLENOID VALVE

TIMER Function: Used to delay actions Common symbols Timer Characteristics How they are differentiate? How they are programmed?

DEFINITION Used to provide time delay.

COMMON SYMBOLS OF TIMER TMR TIMER0 T0 K40 INPUT most common symbol for displaying timer function is in block diagram uses a box shape to display the timer function Sometimes, timer is displayed in coil format symbol

CHARACTERISTICS OF TIMER Timers typically have one or two input Timer with one input has functions as a timer enable input. When input ‘high’, the timer begins timing A timer with 2 inputs has additional functions which is used to reset the timer accumulated time to zero when the second input is ‘high’ Every timer has a time base Typically; 1 sec, 0.1 sec and 0.01sec.

HOW TIMERS ARE IDENTIFIED? Each timer will have number to identify it There are two parameters for timer timer number Used to identify timer e.g. Timer 0, Timer 2. Preset value Is the delay time set for the timer

TIMER’S PROGRAM There are still many similarities in the way the timers are programmed even when PLC are different brand Let say the time base of a timer is 0.1 second Therefore, if a programmer entered 50 for the number of delay increments What is the timer’s delay? the timer would have a 5-second delay. 50 x 0.1 sec = 5 sec

COUNTER What is it? What is its characteristics?

DEFINITION used to capture and store number of occurrence Common applications of counters include keeping track of the number of items moving past a given point determining the number of times a given action occurs

CHARACTERISTICS set to some preset number value when this value of input pulses has been received, it will operate its contacts Let say the counter is set for 10 pulses, then when 10 pulse impulses have been received, the counter contacts will close When there is a input transition for X0 from OFF to ON, counter starts counting When the RESET is ON, the counter resets to 0