Overcoming interoperability issues in smart factories

16 February 2018

A whitepaper written by Edward Lin, product manager at Moxa, discusses challenges faced by systems integrators today with OT-to-OT, OT-to-IT, and OT-to-IIoT interoperability. It also looks at the solutions available to ensure non-stop connectivity throughout converged networks. Control Engineering Europe reports.

The utopian IIoT (Industrial Internet of Things) world heralds the promise of cost-efficient, nonstop operations. It is the task of the systems integrator (SI) to deal with realities of making this possible – figuring out how the different platforms in a network can communicate with each other. The big challenge is dealing with the three divergent domains of network architecture – Operation Technology (OT), Information Technology (IT), and the IIoT. Each domain comes with its own set of protocols that effectively creates non-interoperable silos, making it impossible for useful data to reach those who need it on an enterprise level to make important decisions. Matters are further complicated by the fact that both the OT and IT departments are generally unfamiliar with the protocols used in each other’s domains.

The good news is that solutions are now available to bridge these interoperability issues through a variety of protocol conversions.

OT-to-OT interoperability 
OT-to-OT communications in factories are not as simple as they used to be. The IIoT has brought sensors and machines to the Internet on a massive scale. According to a new report from IHS Markit, the number of connected IoT devices is expected to rise by 15% in 2017 to reach 20 billion. This surge is impacting factory floors in such a big way. M2M communications have evolved into communications between divergent operational subsystems to fulfil data collection and analytics. The snag, however, is that the heterogeneous systems that fall under OT, such as manufacturing executive systems (MES), SCADA systems and PLCs, as well as the machines and sensors on the plant floor, all run their own protocols; so the issue of non-operability rears its head again and a multitude of protocol conversions are required. 

The growing complexity of operations processes brings more heterogeneous systems into the equation. Installation and setup requires more time to plan the architecture and perform device commissioning. For SIs it is all about saving time and costs by reducing commissioning and configuration times. However, it is not uncommon for them to spend many hours on communication and troubleshooting programming when using communication modules or small PLCs. A solution to simplify protocol conversions would result in more time being spent on core tasks, such as programming. 

Industrial protocol gateways can accomplish mass configuration of devices and protocol conversions between different devices to keep operations running smoothly. For example, bridging a large number of Modbus RTU power meters to a Modbus TCP network is usually time-consuming due to the configuration of the slave ID routing table. A convenient solution includes an auto device routing function that automatically detects the commands from a SCADA system and sets up the slave ID routing table. With only one click, this configuration can be achieved. Furthermore, a ready-to-use protocol gateway, which supports the multiple industrial protocols commonly used in OT – such as PROFINET, PROFIBUS, EtherNet/IP, and Modbus – simplifies protocol conversions, resulting in cost- and time-savings. 

OT-to-IT interoperability 
Close cooperation between IT and OT professionals is fundamental to leverage any smart application’s IIoT platform. Although OT and IT’s approaches to problem-solving differ, they both work towards the same goal – optimised production and, to be successful, both domains need access to industrial data. There is now a trend, in the era of Industry 4.0, towards an increasing recognition among OT staff of the importance and convenience of IT technology, as it helps them achieve their goals. 

IT departments face an increasing demand to collect production data from shop floors to optimise production. However, IT staff are not familiar with the process of collecting data via industrial protocols. Concurrently, OT staff members face a similar predicament in that once they have transferred OT data to the IT layer, IT departments often request interfaces they are not familiar with. It should be noted that it is not in any organisation’s best interests to keep the OT and IT domains apart and eliminating the knowledge gap between them and aligning them more closely should be the goal of operation managers.   

A multi-protocol integrated device will make the lives of SIs much easier here. For example, a smart I/O that supports various protocols – such as Modbus/TCP and EtherNet/IP for IA engineers, and SNMP and RESTful API for IT engineers – allow communications with different interfaces. Such a solution makes it possible for both IT and industrial automation (IA) engineers to conveniently retrieve data from the same I/O device. 

Worlds apart
Demonstrating just how far apart the OT and IT worlds are is the fact that OT network devices are always treated as transparent, making it difficult to monitor them – even in the case of emergencies. This adds to the frustration of network operators as troubleshooting becomes almost pointless when they are experiencing downtime. This situation is not acceptable, as situational awareness is vital for network operators, in order to ensure continuous production and prevent abnormal situations. Ensuring continuous visibility of all network devices and the status of a network in a control room is a top priority. However, to capture abnormal events on the shop floor and then interpret the information about these perceived events in real time is challenging due to the complexity of the protocols and networks. 

For production lines that employ OT protocols, Ethernet switches that support PROFINET, Modbus TCP, and EtherNet/IP protocols enable engineers to simultaneously view data and the network status at a central site on a SCADA system or locally on an HMI. If an industrial protocol fails, the switch reports it, and the PLC sends an alarm so that the situation can get fixed immediately. 

Leveraging IT’s expertise and sensibilities can speed up troubleshooting, reduce system downtime, and increase situational awareness. 

OT-to-IIoT interoperability 
In the boardroom, executives expect data mining and analytics to pay dividends in reduced operation costs, optimised production, and predictive maintenance to minimise downtime. This data needs to be collected from field sites, and it has become the job of OT engineers to transfer this data from the devices in the field to the cloud, where it is stored for analytics purposes. This new addition to their job description can takes OT engineers out of their comfort zone. Many would rather focus on programming that adds value to their specific field instead of communications tasks. 

OT engineers’ lack of IT knowledge is definitely their Achilles’ heel. As it is, sending data from an edge device to the cloud can be time-consuming, and OT engineers’ unfamiliarity with IT technology only compounds the process. In the race to IIoT connectivity, the biggest challenge for them is to cut down on the time to set up and program the networking connections between edge devices in the field and the cloud. 

To spare engineers a great deal of programming effort and reduce time and costs, an embedded computing platform that supports versatile interfaces, coupled with a software suite that integrates a ready-to-use Modbus engine and cloud connections such as AWS, enables fast integration between devices in the field and the applications required for the IIoT. Furthermore, for those who want to adopt OPC UA in order to unify automation interfaces, a software suite solution is available that provides both an OPC UA server as well as cloud connection capabilities. The beauty of this solution is that it requires no extra costs to implement additional architecture for cloud connectivity. 

More information about the portfolio of solutions available from Moxa to make interoperability smoother in factory automation is available: Click here

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