Introduction
The management of remote assets, whether in oil fields, water treatment facilities or sprawling manufacturing campuses, requires the integration of complex and ongoing communication, control and data management tasks. While organizations have used a variety of techniques to achieve this goal over the years, many methodologies employed prove costly and/or complex.
Today's new industrial cellular offerings help minimize risk, reduce cost, and simplify the overall network infrastructure required to manage remote assets, allowing more organizations to reliably extend control to the edge of their operations to take advantage of the Industrial Internet of Things (IIoT).
Understanding how cellular technology can deliver IIoT benefits requires a review of traditional remote management approaches, including both architecture examples and the communications networks in use. When planning IIoT implementations, it is important to remember that the goal for remote monitoring and control functionality should include deploying a solution that will keep tasks operating regardless of communication status to improve production and reduce points of failure.
Communications Network Options
As organizations embrace IIoT and expand industrial networks to the edge, cellular technology is replacing traditional landline cables and satellite communications for the following reasons:
- Legacy twisted copper telephone lines offer very limited bandwidth and poor reliability to support many of today's applications and are increasingly expensive to operate.
- Satellite communications are costly, provide poor link latency and often suffer connection downtime during inclement weather.
Cellular communications offer a reliable, low-cost, high-bandwidth solution. With rugged design and built-in redundancy, industrial cellular solutions are ideal for critical remote applications. When a communications network is deployed to provide control capabilities for remote systems or processes, there are multiple local solutions and technologies that can be used. Each approach prioritizes certain characteristics, possibly at the expense of alternate capabilities.
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Three examples follow:
1. Centralized SCADA Control – the Cost is in the Connection
SCADA networks prioritize the centralization of control. They are commonly setup with a polling-response method, whereby remote sites are polled for operational data by a centralized computer, and control parameters are transmitted back to the remote site from the centralized computer.
While this method provides centralized management for the coordination of processes between remote locations, it is costly and challenging to maintain a 100% always-available network to ensure efficient operations. If the network is temporarily unavailable, remote processes will not have supervisory control so issues could quickly arise.
2. Edge PLC Control – the Cost is in the Complexity
To mitigate the threat of loss of control due to network communication problems, a common solution is to deploy programmable logic controllers (PLCs) at the remote site that connect to a centralized SCADA network. PLCs provide accurate control of local processes without having to rely on data transmitted from a centralized computer so even if communications are lost, local systems and processes will continue to function.
However, PLCs are complex and time-consuming to configure and require implementation with additional devices to handle other important network functionality like routing, I/O concentration, security, and local switching. This results in additional programming, more points of failure, and ultimately higher deployment costs.
Additionally, while PLCs will ensure ongoing operation of devices, they too require communication connections for long-term management and centralization of data. Using legacy telephone or satellite systems for these communication channels carries the same costs as SCADA systems.
3. Industrial Cellular RTUs – Reduces Cost and Complexity
Another local control technology, remote terminal units (RTUs) allow for remote site process coordination without expensive network infrastructures. This last method uses a software-based "event engine" that is embedded into industrial cellular RTUs. An event engine is the next step in process control, building in capabilities that complement cellular communication to provide a secure, easy-to-configure solution that evaluates operational data and executes commands based on system requirements.
A simple example of how an event engine works could be in the case of a pressure sensor. If a pressure sensor connected to an industrial cellular RTU exceeds a certain assigned value, the system automatically opens a valve to bring the pressure back to the acceptable levels that are noted in the event engine. In addition to this local control execution of control locally, the cellular RTU also proactively sends an SMS notification to the operator to alert when an event triggers.
Today's industrial cellular RTUs, like those from Red Lion Controls, seamlessly consolidate all of the required functions of remote site communication, monitoring and control into a single device to reduce equipment costs and ease implementation. One of the biggest differences between integrated event engine solutions and traditional PLCs is that the operational data an event engine can evaluate extends beyond just the process being monitored. It can also include other variables such as cellular communications, local network, Modbus registers, and device-level information. Being able to leverage a single device/log-in/dashboard simplifies the deployment and operation of remote site processes.
IIoT-ready products include HMIs, RTUs, panel meters, displays, industrial Ethernet switches and cellular M2M communications.
Conclusion
The IIoT will mean that organizations will be able to connect many different devices, including older field-deployed equipment, and get them to seamlessly "talk" with each other in a way that they could not before. By gathering data from both new and legacy devices, organizations can use that data to reduce costs, improve process performance and increased reliability.
By reducing the number of devices at remote sites, operators not only simplify deployment, but also minimize complex programming requirements alongside the cost and hassles associated with potential points of failure. In addition, industrial cellular RTUs easily integrate with existing SCADA networks to act as back-up controllers to provide redundancy as well as send alarm notifications.
While maintaining control at the network's edge isn't a new concept, implementation to aid IIoT helps drive real value across critical remote applications and processes. Customers with remote sites can now easily implement control at the edge to immediately realize benefits that range from simplified deployment and configuration to more reliable and efficient operations.
About the Author
Colin Geis is Director of Product Management – IIoT at Red Lion Controls. Red Lion Controls is a US manufacturer of industrial automation and networking solutions that help organizations connect, monitor and control assets worldwide. For more info, visit http://www.redlion.net.
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