“Implementación de un traductor de protocolo Modbus para una unidad terminal remota de un sistema SCADA”

Abstract

The systems of control and data acquisition are known by their initials as SCADA systems. They are used to supervise and control the operation of diverse physical processes. Basically, the SCADA system is composed by a series of devices called remote terminal units, which serve as interfase with the controlled physical processes, and a central computer that takes charge of sending messages with the different control and supervision instructions that the remote terminal units should carry out. To establish the communication between the central computer and the remote terminal units of a SCADA system, different protocols can be used. A standardized protocol used by several makers, is the call Modbus protocol. The Instituto Costarricense de Electricidad possesses a SCADA system for the supervision of the distribution nets in which they offers the electric power service to they clients. This system is modernizing, through the redesign of all of its parts. Inside the design of the remote terminal unit. For that, it is wanted to endow it of a standardized communication protocol, for what has been appealed the Modbus. This report documents the realization of a translating device that allows the communication between the central computer and the remote terminal unit of a SCADA system, using the Modbus protocol.