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