Operational Technology (OT) vs Information Technology (IT)

OT and IT: What’s the Difference?

Information Technology (IT)

Information Technology (IT) is a familiar concept to most modern office workplaces encompassing the products and networks providing data-centric computing, supporting various business functions such as finance, personnel, management and administration. This has grown to being fundamental to corporations large and small, and continues to rapidly develop in scale and capability.

Operational Technology (OT)

By contrast, Operational Technology (OT) is understood by utilities, transport, manufacturing and other industrial sectors, as encompassing an array of systems engineering, event monitoring and process control to facilitate operations. Historically, the technologies and products used to implement the required infrastructure have been bespoke and separate from other corporate systems.

The growth of standardisation

With the explosion of computing devices, the internet and communications generally, the underlying IT hardware and software have become ubiquitous and standardised. The majority of businesses now deploy products and networks which are interchangeable with most other global corporations, bringing overall costs down, increasing ease-of-use and enabling global inter-operations.

In recent years, there has been a trend to capitalise on these developments by seeking to replace old OT bespoke systems with widely available and deployed IT products.   

The problem with convergence

Despite the advantages brought by a move to using IT technologies to fulfil Operational infrastructure needs, there are some draw-backs. 

Although no-one wants systems to fail, and high performance is often a key requirement, in traditional OT systems, there is an emphasis on availability, reliability and ‘mission-critical’ operations, dictating deterministic technologies which standard IT products are not designed to provide. The packet-oriented ‘best-efforts’ nature of TCP/IP networking solutions is not sufficient to provide the performance required. Some operational systems have specific timing requirements, utilising PDH and SDH TDM-based technologies to deliver signalling and tele-protection information. 

For years, ‘security’ against ‘remote attacks’ was not an issue, because most OT systems were regionally based and not connected to the wider world. And even those with remote monitoring and control tended to use bespoke equipment which was not widely understood or utilised by non-specialists. With a move to going ‘on-line’, and utilising ‘standard’ IT equipment to fulfil OT requirements, this is no longer necessarily the case. Which brings the possibility of outages due to system or denial of service attacks. ‘Cyber-security’ in recent years has needed to become part of the considerations for OT infrastructure, learning from the experiences of threats to IT systems and ‘denial-of-service’ attacks. 

And whilst modern IT communications bring gigabit data bandwidths, OT data needs have remained modest, often to fulfil the unchanged monitoring requirements for an enormous existing deployed network of slow-speed kilobit data devices, such as pumps, valves and actuators. 

In short, the needs and desires of businesses for computing devices, networking systems and global communications to provide ever-increasing bandwidth and application support continues to diverge from the requirements of industrial operations, requiring availability, compatibility and mission-critical performance.  

Future trends

Whilst vendors of networks, computing and communications continue to develop advanced technologies to meet the growing needs of IT for businesses, the desired ‘convergence’ to replace OT systems continues to be a work-in-progress.

OT systems tend to be built with longevity as a priority over cost of ownership, due to the challenges of replacement once in continuous operation. Whereas IT products are often ‘written down’ and replaced over a much shorter timescale, with a view to taking advantage of continuous developments to provide higher performance and productivity.

Consequently, technologies that are considered ‘legacy’ by IT professionals continue to be maintained and even further deployed as trusted and proven OT systems to fulfil operational needs. 

Your operational systems requirements

@YellowsBestLtd would like to know your infrastructure goals, deployment experiences and maintenance challenges and how we may assist you to fulfil your OT and IT requirements, for both new and existing operational systems. We look forward to understanding your needs for technical support, solutions sourcing, repair services and equipment spares.

Optical Teleprotection Signalling (TPSO) Equipment (C37.94)

Electrical power systems protection

Teleprotection for power systems protection has been deployed by utility companies for many years. It’s purpose is to monitor the condition of the Electricity Grid, isolate faults, disconnecting faulty parts from the rest of the network and thereby prevent damage to critical parts of the power infrastructure.

Teleprotection is a physical interface between the telecommunications equipment and the electrical grid protection relays. When a fault occurs, the protection system switches on circuit breakers or reclosers to avoid a fault rippling through the network. Also, in the event of an outage, teleprotection helps restart power to a part of the grid.

Early teleprotection systems used voice-frequency signalling technologies. These were replaced by digital electrical Tele-Protection Signalling (TPS) equipment using 4 or 8 command channels encoded into a 64kbit/s standard digital data channel, in accordance with the ITU-T G.703 recommendations. This brought dependability and interoperability of systems, meaning that dedicated channels were no longer required as any standard digital transmission network could be used, separate from the power system.

This was later enhanced by the development of Tele-Protection Systems with Optical (TPSO) interfaces, which allowed the direct fibre connection between the teleprotection device and the primary multiplexer. 

The IEEE C37.94 standard for TPSO interfaces

The IEEE C37.94 standard defines an optical fibre interface for use between teleprotection systems and digital multiplexer equipment, operating at a data rate of nx64kbit/s. 

This allows the interconnection of different vendors teleprotection equipment with different vendors multiplexer equipment, without any restriction on the content of the nx64kbps data, using up to 2km of 50μm or 62.5μm multimode (or up to 20 km of 9μm single-mode) optical fibre.

Critical Systems deployment 

Teleprotection systems are typically installed in high-voltage transmission grids where distances are usually greater than in distribution grids and play a critical role in preventing instability in the grid and damage to expensive substation equipment.

Teleprotection systems monitor conditions on transmission lines and coordinate tripping of the transmission lines to quickly isolate faults. 

A teleprotection system usually has two components: a protection relay, which executes the actual switching; and the teleprotection equipment itself, which is the interface to the mission-critical communications network. 

Typical Teleprotection Systems Network

To ensure that the power systems are properly protected, real-time exchange of status information messages and commands between teleprotection equipment must be reliably transferred with tightly-controlled latency over a deterministic mission-critical communications network, traditionally composed of TDM multiplexers and optical PDH or SDH equipment. 

Nokia ‘Dynanet’ TPSO 24204

An example of a vendor’s multiplexer is the Nokia ‘Dynanet’ equipment family. This utilises the TPSO 24204 interface unit for connecting the teleprotection devices directly to the primary multiplexer. This provides four IEEE C37.94 standard interfaces, with nx64kbit/s optical data channels (where n is 1 to 12).

TPSO – 24204

Because of the direct connection, there is no need for a separate converter to change the optical connection to electrical. This eliminates electrical interference and data corruption caused by disturbances from the high voltage power line.

Your operational systems requirements

Let us know how we can assist you to keep your new and legacy systems operational with technical support, repair services and equipment spares. We look forward to hearing from you.