07-08-2012, 03:06 PM
Programmable Logic Control and SCADA
SCADA(1).ppt (Size: 1.63 MB / Downloads: 68)
What is Automation
Automation is basically the delegation of human control function to technical equipment for
Ladder Diagram
The Ladder Diagram (LD) programming language originated from the graphical representation used to design an electrical control system
Finally CPUs were added to take over the function of the logic circuits
Control decisions accomplished through programming
Ladder diagram ( LD) was developed to make program creation and maintenance easier
Computer based graphical representation of wiring diagrams that was easy to understand
Reduced training and support cost
What is Rung?
A rung of ladder diagram code can contain both input and output instructions
Input instructions perform a comparison or test and set the rung state based on the outcome
Normally left justified on the rung
Output instructions examine the rung state and execute some operation or function
In some cases output instructions can set the rung state
Normally right justified on the rung
Configuration of PLC : Allen Bradley
The PLC is programmed interface between the field I/p element like limit switches, sensors, push button and the final control elements like actuator, solenoid/control valves, drives, hooters etc
Supervisory Control and Data Acquisition
SCADA refers to a system that collects data from various sensors at a factory, plant or in other remote locations and then sends this data to a central computer which then manages and controls the data.
SCADA focuses on gathering and circulating the right amount of system information to the right person or computer within the right amount of time.
Application of SCADA system
Water Management Systems.
Electric Power.
Traffic Signals.
Mass Transit Systems.
Environmental Control Systems.
Manufacturing Systems.
Transmission, Generation, Distribution system.
Mining plants,
water and electrical utility installations to oil gas plants.