Measure it to control it

10 June 2020

Matthew Hawkridge, Chief Technology Officer at Ovarro, previously Servelec Technologies, looks at how advances in Remote Telemetry Units (RTU) allow engineers to better understand critical, complex pieces of equipment

The adage that if you can't measure it, you can't control it, stands as true today as it always has. However, measuring physical parameters such as speed, distance, temperature, pressure and flow has become challenging as assets grow in complexity or are located in remote, hard to reach places. Set against this are the many thousands of assets in a modern industrial setting; a single failure of any one component has the potential to result in production downtime, financial loss or environmental incident.

As a result, engineers have begun looking for better ways of carrying out these processes remotely. In this new industrial landscape, data is king and it is the RTU (Remote Telemetry Unit) that is able to best convert this data into usable management information.

Remote telemetry units (RTU) are now used widely in the industrial sector for process automation and control as part of a supervisory control and data acquisition (SCADA) system. Effectively, RTU’s are mini-computers that collect data locally, act upon it immediately, and report to the central control room, whilst maintaining a local historical store as an additional backup. For example, our TBox RTU’s are often referred to as a ‘SCADA in a box’ because of this ability.

The RTU is the device that sits between the control room and the field instruments, providing a low latency response to changing site 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.

RTU’s have an ability to act autonomously to monitor and control critical assets

Technology in the form of RTUs are a practical way of achieving this and it is the reason why they are a critical part of an efficient industrial process. As well as converting vast amounts of digital data into effective management information, RTU’s have an ability to act autonomously to monitor and control critical assets. This digitisation of industrial processes using RTUs is happening at pace; RTU’s were traditionally used on remote assets, although we are seeing them deployed more widely on a range of industrial sites. Engineers don’t currently have visibility of asset condition – until it fails – meaning that they are forced to adopt a reactive rather than proactive approach.

Collecting and leveraging data via an RTU system can deliver improved operational efficiency and better maintenance outcomes. Specific areas of concern can be identified, and appropriate measures taken to ensure that run-to failure is avoided. RTU’s work by allowing engineers to understand critical complex pieces of equipment – especially those off-grid in remote locations.

Key features needed in 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 technicians to spend on site, improving both efficiency and personnel safety.

Data extracted from assets can be stored in the cloud, analysed using customized embedded algorithms and data analytics to identify anomalies – detecting problems before they occur – allowing operators to reduce waste and refine maintenance strategies.

RTUs continue to evolve and become more powerful. It’s worth bearing in mind that one thing that works in their favour is their rapid return on investment – for example, quantifying the cost of avoiding an outage is straightforward. Other financial benefits include monitoring tank levels at a remote location, which has the potential to make significant savings as larger and less frequent refill deliveries can be made. Distribution automation is another benefit because it allows assets to be controlled autonomously whilst avoiding having to place personnel in hazardous industrial environments.

All this means that telemetry projects have a rapid return on investment, making them self-funding in the short term. This means that the careful choice of an RTU as part of a well-planned approach can bring enormous advantages to process and manufacturing industries.