Automation systems typically sit on top of the pyramid when it comes to process controls and measurement instrumentation. These systems incorporate discrete and analog inputs and generate outputs to control a wide range of processes, with little or no human involvement. Often several independent process control systems exist within a single facility. Even when provided by a single supplier, as an example, the control modules for receiving/transfer, grinding, batching, blending/mixing, loadout and the control systems of other processes within a feed manufacturing facility are monitored independently, sometimes each having their own touchscreen display within a common control room. But the accountants, managerial, and administration personnel do not usually have access to these systems or the data they gather. This is where the emerging use of a remote supervisory control (RSC) app comes into play.
RSC apps are browser-based software application packages that allow users on a corporate network to access data from process control systems. These RSC apps provide the ability to remotely manage many aspects of the process control system(s). This can include ingredients, formulas, bin assignments, schedules, and other data tables. They also allow for viewing and generating/printing historical data reports, such as for batching and other processes.
Many process control systems today are PLC-based and are constrained by limited PLC memory. They hold a limited amount of data (ingredients, formulas, etc.). RSC apps store data in a standard database, such as Microsoft SQL Server/Express. Nearly an unlimited amount of data can be stored and maintained. The RSC app monitors key process data and alarm conditions within the process control systems. It can provide logging and historical analysis of this data. In short, PLCs and process control systems are good at controlling equipment. Computers and databases are good at managing, manipulating, and storing data. The RSC app provides the means to bridge these two worlds to provide a seamlessly integrated solution.
A typical RSC app uses web browser-based technology to provide supervisory control. This makes it easy to access data from any computer that is on the same network as the computer hosting the RSC app. The RSC app does not require internet access. All network traffic and data reside internally on the plant network. The RSC app does require a server to host the application, which can be reached by any corporate PC user who has need for the data. This means the appropriate accounting, management, and other admin personnel can be given independent access to the process control system data, and they can independently analyze and generate reports as they require. The hosting server/computer must also be able to reach the PLC/process control systems network. This usually means that the hosting server/computer will require two network cards: one for accessing the corporate network and one for accessing the isolated process control network.
In addition, RSC apps can be accessed via smartphones or other devices, provided they can join the corporate network. If a corporate VPN is in place, and applicable corporate policies, the RSC app can be used remotely from the plant network, like at home, etc. This takes place once a VPN connection to the plant network has been established.
Security, Analysis and Reports
The typical RSC system app includes security setup for users and can contain many different reports that can be run to extract and display information by each user, whatever is important to that specific individual or job function.
A remote supervisory control app is important to getting the most for your business from your process control systems. Your controls/automation supplier should be able to offer it and explain its capabilities. The RSC software application is increasingly becoming an important part of overall plant control systems, allowing a virtually unlimited number of personnel to remotely view and manipulate data gathered by your process control systems. This can be from their remote office or location. PLCs and process control systems are good at controlling equipment, whereas PCs and database apps are good at managing data. The RSC system app provides the means to bridge these two worlds for a seamlessly integrated solution.
Joe Lewis is responsible for marketing functions at Sterling Systems & Controls Inc. and has more than 40 years of experience in the process measurement and control industry.
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