Siemens - Schneider - Panasonic - Allen-Bradley - LG - Delta - Mitsubishi
1- Siemens :
Jul 18, 2010
Most common manufacturer of plc
Number Systems
Any number system has a radix or base. We can use any system for counting. Every system has its own symbols. The radix of a number system determines the total number of system symbols.
Number systems are:
• Decimal number system
• Binary number system
• Octal number system
• Hexadecimal number system
PLC APPLICATIONS
PLCs perform all control tasks, from simple machines control applications to sophisticated manufacturing and process control Applications.
PLC almost in every part of industry:
1- Steel mills (rolling mills).
rolling mills
Programming devices
We can enter program into PLC by one of two basic types of programming devices
• Personal computers (PC).
• Mini programmers.
1- Personal computer
Due to the general-purpose architecture of personal computers, most PLC manufacturers and provide the necessary PC software to implement ladder program entry, editing, and real-time monitoring of the PLC’s program. The figure blow show PC software for PLC
Classifications of plc
We can classify plc into two categories
1- Classification by I/O modules.
2- Classification by application ranges.
1- Classification by I/O modules.
2- Classification by application ranges.
Classification by I/O modules:
1- DISCRETE I/O SYSTEMS.
The discrete (I/O) system provides the physical connection between the CPU and field devices that transmit and receive digital signals.
1- DISCRETE I/O SYSTEMS.
The discrete (I/O) system provides the physical connection between the CPU and field devices that transmit and receive digital signals.
2- ANALOG I/O SYSTEMS.
Analog input modules, are used in applications where the field equipment’s signal is continuous such as Pressure and Temperature.
Analog input modules, are used in applications where the field equipment’s signal is continuous such as Pressure and Temperature.
Analog output module are used in applications which need to continuous voltage or current levels for control. An example of this type of field device is a electric motor drives.
Classification by application ranges
Jul 17, 2010
Jul 11, 2010
What Is SCADA?
- SCADA is formed from the first letters of "Supervisory Control And Data Acquisition"
- SCADA is the technology that enables a user to:
• Collect data on Process & Equipment (data acquisition (DAQ)).
• Monitor & Supervise Process at one or more geographically scattered
distant facilities (Remote Terminal Units (RTUs)) - • Send limited control instructions to those facilities from central location
(Master Terminal Unit (MTU)).
Remote Terminal Unit (RTUs)
RTU is a standalone data acquisition and control unit, generally microprocessor based, which monitors and controls equipment at some remote location from the central station. Its task is to control and collect data from process equipment at field and transfer this data to a central station (MTU) Control Room. It generally also has the facility for having its configuration and control programs dynamically downloaded from some central station.PLCs is an example for RTU.
Master Terminal Unit (MTU)
Master Terminal Unit (MTU) is Operator interface and operator intervention tools are usually located in a central location (MTU). This interface is normally called “operator workstation”.
The CONTROL ROOM composed of:
PC or PLC with monitors, Keyboards, Mouse , printers, switches, pushbuttons data storage media.
Jul 10, 2010
Advantages of PLCs
Reference : Siemens Basics of Plc
a PLC can do complex tasks, replacing wiring between devices and relays by PLC
program.Modifying the application and correcting errors are easier . program in
a PLC easy to create and change .
START With Programmable Logic Controller (PLC)
Introduction to PLC and Types of Control System
Programmable Logic Controllers ( PLCs ), are in the computer family. They are used in industrial applications. A PLC oversee inputs, run its control program then makes decisions , and controls outputs to make a process or machine run automatically. I will discuss basic information on the of PLCs functions and configurations
Jul 9, 2010
HISTORY OF AUTOMATIC CONTROL
Reference : Applied Optimal Control and Estimation, Prentice-Hall, 1992
Feedback (Automatic) control
is an engineering discipline. As such, its progress is closely tied to the practical problems that needed to be solved during any phase of human history. The key developments in the history of mankind that affected the progress of feedback control were:
1-The Water Clocks of the Greeks and Arabs.
2-The Industrial Revolution.
3-Age of Computer and programmable devices