Industrial Automation Components

• Field Instruments

• Control Hardware

• Control Software

Typical Setup

Field Instrument

Field Instruments are connected to input and output module of control hardware.

Wide range of I/O modules are available including: Digital (logical) I/O module and Analog (Contineous) I/O module.

Some examples of input/output field device are listed below:

• Digital input field device : Switches, Pushbuttons, Relays, Pump Valve on/off status, Alarms.

• Digital output field device : Solenoid valve, Lamps, Actuators, Dampers, Pump valve start/stop.

• Analog input field device : Pressure transmitter, Flow transmitter, Level transmitter, RTD, Thermocouple.

• Analog output field device : Control valve, Speed, Vibration,Variable speed drives, Chart recorder. 

Sensor,Transmitter and Transducer

Sensors, transmitters and transducers monitor process variables, such as temperature, pressure, level and  flow.

The sensor measures the controlled variable in the process and sends a non standardized signal to the transmitter.

The sensor is the primary sensing element and exists in close proximity to process.

The transmitters contains a transducer which converts a non-standardized signal of the sensor into a standardized form that it amplifies.The most common standardized form are either 4-20 milliamps or 3-15 psi.

Transducers converts one instrument signal value to another, usually a pneumatic signal to an electronic signal (Pressure to current, abbreviated "P to I") or an electronic signal to pneumatic signal (I to P).

There are many different types of sensors and transducers available in the marketplace.

Common sensors and transducers are:

• Temperature transducer: RTD, thermocouple, thermistor,thermostat

• Pressure transducer: Strain gauge, Pressure switch, load cells

• Flow transducer : Orifice, Venturi tube, dall tube,pitot tube, rotameter

• Level transducer : Radar, electromechanical, ultrasonic,capacitance, hydrostatic pressure

Manufacturers of Sensors and Transducers

• Acromag, Inc - Wixom, Michigan

• Endress+Hauser, Inc - Greenwood, Indiana

• Rotork PLC - Bath, Somerset

• Ambetronics engineers pvt ltd - Mumbai, Maharashtra

• AMSAT EDC - Pune, Maharashtra

• Emerson Process Management - Austin, Texas

• Foxboro M&I Division - Foxboro, Massachusetts

• Fuji electric corp of America - Saddle brook, New Jersey

• Honeywell Process Solutions - Phoenix,  Arizona

• Omega Engineering Inc - Stamford, Connecticut 

Control Hardware

Control Hardware are the ruggedized microprocessor based controllers which provides plant automation by monitoring sensor and controlling actuators.

Automation control hardware are:

• PLC - Programmable Logic Controller

• PAC - Programmable Automation Controller

• DCS - Distributed control system

• PC Based control system

PLC

The most significant development in the industrial control field in previous half century

PLC stands for Programmable Logic Controller. It is solid state control system that has a user programmable memory for storage of instructions to implement specific functions such as:

• I/O control

• Logic

• Timing

• Counting

• Report generation

• Communication

• Arithmetic

• Data file manipulation.

A controller consists of a central processor, power supply, input/output interface, and memory. A controller is designed as an industrial control system.

A Programmable Logic controller (PLC)is a single microprocessor based device

PAC

A programmable Automation Controller (PAC) is a 2 or more processor based device like a personal computer (PC) is and is basically a PC merged with a PLC using multitasking capabilities to automate control of one or more pieces of equipment.

Although the PAC includes the PLC capabilities, its hardware architecture and software are designed to be more user friendly to the IT/Computer programmer.Difference include multitasking; multiple processor modules per rack, multiple programming languages like structured text, distributed control system(DCS), tag based addressing, motion control, standard PC networking like Ethernet, to name a few.

DCS

A Distributed control system(DCS) is a control system for a process or plant, wherein control elements are distributed throughout the system instead of having a centrally located device controlling all machine, each section of a machine has its own computer that controls the operation.

For instance, there may be one machine with a section that control dry element of a cake frosting and another section controlling the liquid elements, but each section is individually managed by a DCS.

PC Based control
PC based controlled are programmed on a windows computer and used to communicate with and monitor an entire material handling system or specific material handling equipment.

Famous Brands

• Siemens

• Rockwell Automation

• Schneider electric

• ABB

• Emerson

• GE Intelligent platform

• Honeywell

• Yokogawa

• Beckoff

• OMEGA

Control software

Control software is a system operating with coded signal over communication channels so as to provide control of remote equipment.

Automation control softwares are:

• SCADA - Supervisory Control And Data Acquisition

• HMI - Human Machine Interface

SCADA

SCADA is an acronym for Supervisory Control And Data Acquisition.  SCADA system let you control and monitor various remote functions and processes by using communication links between master and remote locations

Features

• Dynamic process graphics

• Real time and Historical trending

• Alarms

• Recipe management

• Security

• Device connectivity

• Script for logic development

• Database connectivity

HMI

HMI stands for Human Machine Interface. HMI is a hardware operator interface device installed on control panels. It lets the operator monitor real time data and perform real time control functions by connecting the operator interface to the controller through communication port.

Famous Brands

• Wonderware - Intouch

• Siemens - Simantic WinCC

• Rockwell Automation - RS View

• Schneider electric - Citect

• GE intelligent platform - Cimplicity & IFix