| Author | Tarongoy, Francis Noel J. |
| Call Number | AIT Thesis no.IE-94-08 |
| Subject(s) | Programmable controllers
|
| Note | A thesis submitted in partial fulfillment of the requirements
for the degree of Master of Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. IE-94-08 |
| Abstract | In order to cope up with the increasing efficiency and flexibility requirements imposed on the
industrial control systems, programmable logic controllers (PLCs) have been widely and extensively
used in industries. These programmable devices are programmed frequently for the controlled
components/equipments to perform various tasks. However, the development of PLC control program
takes much time and requires good knowledge and understanding of PLC operation and functioning.
Furthermore, the verification and testing of the PLC program is usually done on-line which increases
the equipment down-time and even presents danger both to the personnel and machines involved due to
some logic errors in the program.
This thesis work is aimed at developing a PLC simulator specifically for training and program
verification purposes in the personal computer (PC). The two most commonly used PLC programming
methods, the ladder diagram and the mnemonic code, are simulated. The development of the PLC
simulation system uses object-orientation in all its stages of development. The analysis starts with the
identification of various components involved in the simulation based from the PLC requirements
specification; then, the interaction among these components is established along with their essential
attributes and functions. As the analysis merges to design, more attributes and functions are added to
each object for actual computer implementation. Inheritance hierarchy is further established which
serves as the basis for coding the classes in the Borland C++ programming environment. Strategies for
checking the connection of the constructed ladder diagram and the syntax of the components used as
well as run-time simulation strategies for both programming methods are also developed and
implemented.
The PLC simulation software developed has been successfully tested and found helpful in
understanding the underlying concepts and principles of operation of PLCs. The software enables the
users to develop their PLC control programs either in ladder diagram or in mnemonic codes, checks the
connection and syntax of the constructed PLC program, and displays its operation on the graphical
interface screen. Thus, the software can be used as an excellent tool for acquiring theoretical and
practical knowledge about PLC programming and operation even in PC. |
| Year | 1994 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. IE-94-08 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Industrial Systems Engineering (DISE) |
| Academic Program/FoS | Industrial Engineering (IE) |
| Chairperson(s) | Batanov, Dentcho N. |
| Examination Committee(s) | Qi, Yulu ;Bohez, Erik L.J.
|
| Scholarship Donor(s) | ADB - Japan; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1994 |