A personal computer has driven the open architecture revolution. A personal computer capable of replacing a PLC, given the proper input and output components. As a result there are many companies that develop products to make the control using personal computer architecture. Most of these devices use two basic variations:
1. a standard personal computer with a normal operating system, like Windows NT, runs a virtual PLC.
- Computers connected to a normal PLC rack.
- I / O cards used in computers to control the input / output functions.
- Computer network for a variety of sensors.
2. A personal computer miniature is inserted into the PLC rack running a virtual OT.
In all cases the systems running standard operating systems, with some connection to rugged input and output cards. PLC functions performed by a virtual PLC that interprets the ladder logic and simulates a PLC. It can be faster, and more capable than a stand-alone PLC, but also prone to regular computer reliability problem.
For example, if an employee installs and runs on a computer game controller, the controller may act erratically, or stop working altogether. The solutions of this problem are being developed, and stability issues should be resolved in the near future.