CHAPTER I
INTRODUCTION
This chapter explains the traditional Programmable Logical Controller PLC status monitoring system compared with the proposal system.
1.1 Introduction
Programmable Logical Controller PLC is one of the famous automation process controller used all over the world. It is mainly apply in control of machinery on factory
assembly line, quality control line or light fixtures for more economy operational cost. Programmable Logical Controller PLC is famous because of its flexibility and user
friendly ladder diagram programming language.
Programmable Logical Controller PLC was invented during the rise of automotive manufacturing trend in America. During the period without the invention of Programmable
Logical Controller PLC in America, whenever the production model change, the control panel must had been re-wired in order to change the sequence of automation process. After
the introduction of Programmable Logical Controller PLC, the re-wiring process is not necessary anymore; this is because the Programmable Logical Controller PLC had been
adopted into automotive industry when software revisions replace the modification of hardware.
By the way, Programmable Logical Controller PLC is not as perfect as we think, it is good at flexibility for automation process control and other applications, but, the
monitoring of it is limited to those people who know how to use and program the Programmable Logical Controller only. In order to monitor how much data or the counter‟s
value, the user will need to enter the Programmable Logical Controller PLC ladder diagram to view the data they need. In addition, every different kind of Programmable
Logical Controller got their own custom ladder diagram programming language, although the flow to program is almost the same, the end user still unable to learn every kind of
language for it except for those expertises.
From the above paragraph, it is clear that if want to know the status or data of automation process, will need to hire someone who able to access and read Programmable
Logical Controller PLC ladder diagram just to obtain the data we want from Programmable Logical Controller PLC, and this phenomena is really waste of human
resources. Thus, the implementation of PC base simulator is require to show the data of Programmable Logical Controller PLC on the screen of PC without need any access into
the Programmable Logical Controller PLC.
Every kind of Programmable Logical Controller PLC only can be communicate with PC software such as Microsoft Visual Studio, Microsoft Visual Basic, MATLAB, and
etc. through their own unique protocol. Some examples of Programming Logical Controller PLC are Omron, Keyence, Panasonic, Mitsubishi, Allen Bradley,
Telemechanique, Hitachi, and etc.. But, in this project, I only was going to do the PC simulator for the OMRON Programmable Logical Controller PLC CQM1H-CPU21.
1.2 Problem Statement
