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Early development of PLC’s

Early development of PLC’s

Product News Monday, October 15, 2012: PDF Electric & Supply

Earlier, PLCs were intended to substitute relay logic systems. Therefore, these PLCs were programmed resembling a schematic diagram of relay logic. The purpose behind this notation was to minimize training demands for the existing technicians and to support automation.. Modern PLCs like the GE Fanuc PLC can programmed and employed n a variety of ways. They use traditional programming languages like as BASIC and C. For the PLCs based on state transition diagrams, a high-level programming language, State Logic is employed.

If you take a look at the very early PLCs, there were no programming terminals associated with them. The logic was represented as a series of logic expressions in some edition of Boolean format. But with the progress of programming terminals, it made more sense to use ladder logic, as it was a well-known format used for electromechanical control panels. Although you many come across some new formats like Function Block and State Logic, but it is the ladder logic that is still more popular. One good reason could be that PLCs resolve the logic in an expected and repeat sequence. Moreover, the ladder logic allows the programmer to easily resolve any issues with the timing of the logic sequence more than other formats.

The very early PLCs also used non-volatile magnetic core memory and the programs were amassed on cassette tape cartridges. Due to shortage of memory capacity, there were minimal facilities for printing and documentation. The modern PLCs, like the GE Fanuc PLC are programmed employing application software on personal computers. Debugging and troubleshooting the PLC software is carried out by the software itself. The current status during operation or via simulation is highlighted in the logic. The software is capable of uploading and downloading the PLC program for restoration and backup purposes. Explore GE Fanuc for the most advanced PLC’s.