Questions on PLC's

I need help on the following questions:-

1. In which era was PLC's developed?
2. What is the differance between a Hard wired system and a soft wired systems?
3. What are PLC's used for?
4. List advatages of PLC's.

Look here: http://www.plcs.net/contents.shtml

Just hang around Lancie1 will be along in a moment to answer all your questions

While you are waiting why dont you try and think of some answers !

1) I believe that Dick Morley, also known as the "father" of the PLC who was involved with the production of the first programmable logic controller (PLC) for GM the Modicon, at Bedford and Associates in 1968.

3) They are mainly used for automation of industrial processes, such as control of machinery on factory assembly lines.

I hope i helped out this African student

joeboy said:

4. List advatages of PLC's.

Click to expand...

PLCs are well-adapted to a certain range of automation tasks. These are typically industrial processes in manufacturing where the cost of developing and maintaining the automation system is high relative to the total cost of the automation, and where changes to the system would be expected during its operational life. PLCs contain input and output devices compatible with industrial pilot devices and controls; little electrical design is required, and the design problem centers on expressing the desired sequence of operations in ladder logic (or function chart) notation. PLC applications are typically highly customized systems so the cost of a packaged PLC is low compared to the cost of a specific custom-built controller design.

From Wikipedia