Key points
Here, editor Phil Black, asks Matthew Hawkridge, Chief Technology Officer at Ovarro, a selection of questions about Remote Telemetry Units and why they allow engineers to better understand industrial processes.
What are the benefits of RTUs?
There are benefits for engineers overseeing remote sites that are vulnerable to theft and vandalism, too. Deploying a suite of RTUs for the monitoring of equipment ensures a cost-effective and safe way to protect physical assets at these locations. The opportunity list is virtually endless.
Where are RTUs used in industrial processes?
RTU’s are widely used for process automation and control as part of a supervisory control and data acquisition (SCADA) system. Effectively, they are mini-computers that collect data locally, act upon it immediately, and report securely to the central control room, whilst maintaining a local historical store as an additional backup.
Although RTUs were traditionally used to monitor and control remote field devices, they are now routinely specified for industrial processes as engineering, operations and planning teams gain a better understanding of their benefits.
In these applications, the RTU connects to a plant control room or SCADA, providing a low latency response to changing process conditions as well as performing data filtering. They ensure that only key, critical information is passed securely via the narrow communications links, minimising data throughput but maximising useful information received.
How can RTU’s help in process control applications?
When it comes to process control, RTU’s operate in a very similar way to PLCs. Both are controllers that can have multiple different types of I/O, different communications modules, and programming of processes. This allows them to act without operator intervention.
With the RTU acting as the site co-ordinator and maintaining a full history of events, engineers have a better understanding of the site conditions both in a live environment and historically.
What are the advantages of an RTU over a PLC?
The single biggest advantage of an RTU compared to a PLC is that the environmental robustness of the former makes it the stand-out choice for demanding industrial and manufacturing applications.
That means RTU’s can be used in localities with extreme climatic temperatures and/or remote locations that are off the power grid. For instance, Kingfisher RTU’s have been selected as high availability process controllers with extensive communications capabilities for sites with temperatures ranging from -40C to +85C.
Their resilient and secure nature, combined with independent communications links, redundant power supplies and redundant process controllers make them an extremely robust.
Again, RTUs can perform autonomous control in real time and then report to SCADA that it has everything under control. Engineers at the SCADA interface can ‘supervise’ the operations by setting new KPIs (Set Points) or updating instructions (open/close this, start/stop that, for example) for RTUs to then act upon and manage locally.
What are the key features of an RTU?
The key features needed in an RTU are security and resilience to the site environment, an ability to operate with minimal drain on local power resources and the processing power to perform local control algorithms autonomously. It is also beneficial to have extensive diagnostics capability and a low MTTR (Mean Time To Repair) to reduce the time required for engineer to spend on site, improving both efficiency and personnel safety.
A challenge in remote areas is power supply, which is the reason why the RTU should incorporate intelligent management of power consumption as well as battery or solar power sources.
Can RTU’s facilitate IIoT?
There has been a significant improvement in RTU processing power and memory recently, which means they run and store data in the most challenging of applications. This increased processing power is helping facilitate IIoT.
A significant area of opportunity is the ability of RTU’s to create smart assets, even those that are part way through their lifecycle. For example, deploying RTU’s with latest processing power on an old asset can turn it into ‘smart’ asset, making the most of their ageing equipment and reduce lifecycle costs.
