Programmable logic controller optical fibre sensor interface module

Most automated industrial processes use Distributed Control Systems\n(DCSs) or Programmable Logic Controllers (PLCs) for automated control.\nPLCs tend to be more common as they have much of the functionality of\nDCSs, although they are generally cheaper to install and maintain. PLCs\nin conjunction with a human machine interface form the basis of\nSupervisory Control And Data Acquisition (SCADA) systems, combined with\ncommunication infrastructure and Remote Terminal Units (RTUs). RTU's\nbasically convert different sensor measurands in to digital data that is\nsent back to the PLC or supervisory system. Optical fibre sensors are\nbecoming more common in industrial processes because of their many\nadvantageous properties. Being small, lightweight, highly sensitive, and\nimmune to electromagnetic interference, means they are an ideal solution\nfor a variety of diverse sensing applications. Here, we have developed a\nPLC Optical Fibre Sensor Interface Module (OFSIM), in which an optical\nfibre is connected directly to the OFSIM located next to the PLC. The\nembedded fibre Bragg grating sensors, are highly sensitive and can\ndetect a number of different measurands such as temperature, pressure\nand strain without the need for a power supply.