Here, Jean Burton, Technical Sales Support Manager at Ovarro, the new name for Servelec Technologies, looks at how RTU’s play a key role if managing big data, helping improve situational awareness, security, productivity, safety and operations.
What role do RTU’s play in process control applications?
The principle benefit of being able to remotely monitor an asset using an RTU is that it allows operators to regularly verify from a laptop or smart device that is operating withing agreed parameters.
RTU’s capture big data so that operators can monitor all critical applications in a process, ranging from hours of run time, oil temperature, through to faults and load levels.
Subscribe to PII and receive:
Our long-established bi-monthly digital magazine *Process Industry Informer*, featuring exclusive articles, news and updates across the Process Industries, plus commentary from our three industry experts:
Sean Moran
Gavin Smith
Dave Green
PLUS:
- Process Industry Update — our weekly e-newsletter
- PII Podcast
- Special messages from our advertising partners
They monitor the external environment, too; for example, local temperature. This can be particularly useful in harsh environments as it allows engineers to take pre-emptive actions to prevent overheating or freezing.
The alternative is to send an engineer for routine inspection which in a remote location or expansive industrial site can be hazardous and time consuming.
In some cases, it will require a second visit because they will only be able to identify faults when on site and then must source a replacement part back at base. Knowing this information beforehand can save valuable time by carrying out maintenance in a single visit.
How do RTU’s operate?
RTU’s, such as our TBox, act as both the site controller and the site communications gateway. They collect data directly, or provide a secure VPN, to PLCs used to monitor the asset. The collected data is then made available to the operators who can issue commands back to the RTU to control the asset.
In parallel, the RTU relays key information to the asset owner or maintenance partner. With its ability to report alarms and historical data via email, SMS and FTP, it means nominated personnel are always being updated on its status.
Can RTU’s help on the journey to IIoT?
Operating an aged or geographically remote asset can make it a challenge to access IIoT. The physical constraints of not being on the ‘net’ is the first hurdle, whilst the age of some gensets means that operators believe that they must undertake considerable investment to replace ‘old’ assets with new, ‘smart’ versions.
The best way of thinking about RTU’s is that they are ‘mini-computers in the field’, so adding one to an older genset can turn it into a ‘smart’ asset. In terms of benefits, RTU’s help optimise industrial assets in both near and remote applications by providing greater monitoring and control. As such, they are a powerful, cost effective method of getting on the IIoT journey.
Once fitted, an RTU allows organisations to monitor and control processes wherever they are in the world. RTU’s facilitate communication to local sensors and/or to an interface at a central monitoring location. At the same time, they provide remote access to control and monitor through standard HTML pages.
How can RTU’s support maintenance partners?
Where maintenance of assets is factored out, knowing the status of the device before the end customer ensures better outcomes for all project partners. Where the asset could potentially develop a fault that prevents it from operating, the RTU allows maintenance teams to take preventative action.
Another useful feature is being able to control the asset from a smart device to ensure that it is fully functional. Again, without an RTU, it would require a visit to the site by an engineer.
It is already possible to fit GPS modules to the RTU to provide a positioning of the system, which can be useful in terms of movement of smaller assets.
Can RTU’s help companies meet environmental commitments?
With a growing focus on the environment, ‘big data’ captured using RTUs allow accurate monitoring of emissions. In Asia, our TBox RTU technology monitors diesel generator systems 24/7, providing emissions data to a central reporting location.
The centralised data can be accessed by the wider community through an Air Quality Index app on smart devices as a means of keeping their energy providers in check. In addition, for the benefit of the owner, the RTU’s monitor the generator health, by tracking exhaust temperatures, heater exchange throughput and oil quality as part of proactive maintenance measures. Monitoring fuel use also benefits efficiency management and deters fuel theft.
What should I look for before specifying an RTU?
As a starter, RTU’s should be certified to IEC 60068 for running in environments with shocks and vibrations. Our TBox has local I/Os suitable for smaller assets, whilst being able to collect direct signals fast is a benefit when it comes to safety systems. The TBox LT2 supports multiple field protocols (ModBus, Ethernet IP, ISO-TCP) to communicate to a local interface. A dedicated add-on for specific protocol can be developed if required.
How reliable are RTU’s?
Of all the pathways that your data must traverse, the connection to site is the one most likely to fail, and servers sitting in data centres are on the wrong side of that link. It is the RTU that sits at the true edge of your control system gathering information, providing local, low latency control, and protecting your financial interests, irrespective of communications connectivity.
RTU’s therefore need to be resilient to environmental extremes, withstanding anything from -40C to +70C climatic temperatures. Having multiple, independent communications links, redundant power supplies and redundant process controllers provides another buffer to site conditions and future technological developments. Their resilient nature and layers of redundancy ensure that RTU’s are a reliable part of an effective management information system.
What about future technological developments?
In recent years, site owners have been undergoing Digital Transformation, increasing the number of wired and wireless sensors to improve operational efficiency.
TBox RTUs connect directly to wired sensors via I/O loops, and to the wireless sensor gateways via local communications links, providing access to all the new data points from the new data sources. This greatly increases the amount of information available to the operators for analysis and efficiency planning.
RTU’s can also respond immediately to any identified problems before the information leaves the asset. The new sensors are a highly valuable source of information, but it is the RTU that completes the loop of “See, Decide, Act”.
With the RTU acting as the site co-ordinator and maintaining a full history of events, the operators have a better understanding of asset condition at all times, both in the present and historically, allowing them to respond more efficiently to changing situations and improve timeline management for long term activities.
Are RTU’s cyber secure?
The short answer is yes. Historically, industrial networks were isolated from IT networks however, now they are deeply interconnected and as such need to be robust against cyberattacks.
As a result, RTUs should incorporate a range of security measures such as Firewall SSL (Authentication & encryption), HTTPS, FTPS & SFTP, SMTPS and open VPN. Auditing is carried out regularly according to IEC 62443 4 2 and ISO 27019.
Conclusion
We can see that deploying RTU’s on industrial assets is an important element of capturing, interpreting and using big data from an industrial process. They give you full control of the asset, wherever it is located geographically, including remote, harsh environments. Once in place, the RTU gathers operational data and transmits it to a dashboard on a smart device or stores it in the cloud for trending and future analysis.
