Factory networks are the backbone that provide the infrastructure to collect data from various sensors, actuators, and controllers, and aggregate the data for presentation, monitoring, and influencing by human operators, or other automated computing platforms.
However, historically, long before digital technologies for Supervisory Control for Data Acquisition (SCADA) or Human Machine Interfaces (HMIs) were developed, instruments which displayed the measured value of the process variables were installed in control panels and were connected directly to sensors in the field. Control rooms were also equipped with other capabilities such as alarms and the means to shut down the plant if unacceptable events took place in the monitored processes. Many workers were required both on the floor and in the control room to ensure that the industrial processes were running as they were expected to.
With development of microelectronics and digital technology, programmable controllers (PLCs), distributed and supervisory control, and data acquisition systems (SCADA/HMI), a new generation of control and monitoring systems were made available that were able to consolidate more functionality into smaller better integrated units that enabled greater productivity at the production plants. This generation of controllers and HMIs still operated on a “standalone” basis and their ability to communicate with a central server or with each other was either limited or non-existent.
The next leap forward came when industrial buses were introduced. Multiple devices – sensors, actuators, I/Os, controllers, etc. – could connect to the same bus and exchange information about underlying physical processes and react to instructions sent from a central control system or other parts of the plant. The specifications of some of these buses became open standards so that different manufacturers of instruments and controllers could generate and consume data on the same bus.
Enabling various parts and components in the factory to exchange information with each other and to interact with the business software of an enterprise has many advantages. Creating the capability to exchange, aggregate, categorize, correlate, and analyze information offers many opportunities to reaping benefits. These benefits include decreasing costs, improving products quality, increasing productivity, and improving overall business efficiency. Many tools, software elements, components, and standards come into play to make such seamless exchange of information between parts supplied by many different vendors possible. Implementation of these systems is at the core focus of IIoT and industry 4.0.