Estudio comparativo de la red de control RS-485 con la red de control ethernet para un sistema de envasado de líquidos en el laboratorio de automatización de la FIE-ESPOCH.

Abstract

The objective of the present graduation work was to compare the RS-485 control network with the Ethernet control for a liquid packaging system in the automation laboratory of the FIEESPOCH. A Modbus o Splitter distribution block was used for the 485-communication process, allowing communication in a single fieldbus between modules, cables for 485 communication, two Programmable Logic Controllers (PLC) and for Ethernet communication it was used a switch, unshielded twisted pair cable (UTP) and RJ45 connectors. The liquid packaging system consists of five stations, but with the SCRUM methodology, two were selected to carry out 485 communications and Ethernet for later data collection. The stations represented correspond to Dosed (Master) and Mixed (Slave). The operation sequence starts when the Dosing station sends a message to the station of mixing to run the program and activate the valves of the liquids, mix them and if the tank of the master station is empty send the liquid through the activation of the water pump of the slave. The stations have maximum and minimum level sensors to control the emptying and filling of containers. Additionally, a human- machine interface (HMI) was installed and programmed, which is always monitoring each step of the process. In conclusion, the RS-485 control network allowed a faster communication between the stations versus the Ethernet control network due to the way the Programmable Logic Controllers (PLCs) carry the data under the model of the International Standardization Organization (ISO). It is recommended to develop more projects by adding more slave devices to the network of communication in such a way that its structure and applications can be explored in depth.