Diseño e implementación de un sistema de comunicación hardware/software para el PLC mmi-cpc02a y una pantalla TFT en la empresa ACSIMB Cia. Ltda.

Abstract

The objective was to design and implement a System of Communication Hardware /Software for the Programmable Logical Processor (PLC) MMI-CPC02A and screen with thin film transistors (TFT) intended to the control for water pumping systems with a constant pressure with a range of two alternating pumps. The process was developed through two micro controllers of architecture ARM of 32 bits, placed in both devices, one acting as master and the other as slave, the communication interface was developed for the data exchanging between both controllers. These microchips were linked in an asynchronous serial way (UART), with a speed of 2.5 Mbs, looking for obtaining a data transmission and reception in a permanent and steady way. Necessary algorithms and judgements for the new device controlling of the hydraulic systems were developed, the aim of the net variations. A Proportional – Integral - Derivate controller (PID) was implemented; it was capable to control this kind of systems without knowing the function of transference to witch the process is governed. Errors that carry the information processing were reduced through the implementation of the clinical redundancy code (CRC); with an error margin of 1%, giving as result a reliable communication system. It is concluded that as the data transfer speed increases the error will increase proportionally. It is recommended to know the structure of the implemented microcontrollers and the existing protocols for the information transference.