In the age of data, connectivity is of prime importance and the industrial world has set foot into Industrial Internet of Things. Data can be easily acquired if it is done using standard and open interfaces. This forms the crux of a successful Industrial IoT and Industry 4.0 implementation.
Non-standardized interfaces: Hindrance in connectivity
Achieving horizontal and vertical connectivity is necessary for a successful Industrial IoT and Industry 4.0 implementation. Horizontal or vertical connectivity in a factory or plant can only be achieved if all the vendors conform to common standards for communication. It implies that all the vendors should use a common language of communication. But the current market scenario today is very different and there are many proprietary communication technologies being used and promoted which prove as a hindrance to complete plant connectivity. This leads to the high cost for development and maintenance of multiple, congruent solutions. Eventually, the plant and factory operator and builder needs to coordinate with multiple vendors resulting in excessive hardware costs and implementation delays.
Today, industries focus on having such vendor independence along with the machine-to-machine and machine-to-cloud seamless connectivity. They want to leverage the benefits of the internet in manufacturing setups and this is only possible with using open interfaces.
Open connectivity from the field to cloud.
Based on the needs of the user there could be different variants of Ethernet which are open source at the same time based on standard Ethernet and complying with the IEEE 802.3 which can be deployed in the factories and plants. The process layer, MES, and ERP need Ethernet-based communication which is not real time but offers a high level of security. The network which is active at this layer should have appropriate connectivity options to the cloud without having the need for hardware modifications. Similarly, the network in the field connecting the sensors, actuators, motions components and other field devices needs to be real-time and deterministic. As the need is for an end to end connectivity, the network to has to be based on standard Ethernet. Safety is a crucial aspect of Industry 4.0 and to have a safe horizontal and vertical communication all vendors needs to comply with safety which is able to exchange information on these different Ethernet-based buses.
Is Opensource a myth?
There are many myths and misconceptions about open source. Vendors provide software’s and charge machine builders for licenses or provide object codes for their software or ask the machine builder to purchase a custom-made hardware like ASICs and justify they are still open source. What open source truly means is there are no charges; no copyrights and users have access to the complete source code. This is when the platform is truly recognized as open source.
Open source software and applications are definitely free of cost but are also governed by different licenses. Some licenses allow the modification of the code but ask the user to provide the modified or derived work back to the community for usage by others, while some licenses allow the user to modify or have derived works and the users do not need to provide their work back, in fact they can even copyright their modified work under their name and distribute it. The most common licenses are the GPL, BSD and MIT licenses. GPL is the most widely used free type of license and has a strong copy-left requirement. In any scenario of distributing the derived works, the source code of the work has to be made available under the same license. Linux is a major example of the GPL license. The MIT license is again a free permissive license which allows the users to do anything with the code with proper attribution. OPC UA is an example of an MIT license. BSD alike the MIT license also is a free permissive license which allows users to do anything with the code with proper attribution. Ethernet POWERLINK and openSAFETY are examples of a BSD license. Thus, users can make use of these established global open source automation technologies in their systems in order to meet their customer demands.
OPC UA: Process to cloud or MES / ERP
Using available open source solutions is the answer to the current market situation and breaking the shackles of proprietary solutions. This is also a crux of the Industry 4.0 approach. OPC Unified Architecture (OPC UA) which is handled by the OPC Foundation is a completely open source, vendor, and platform independent solution based on standard Ethernet. Its simplicity is enhanced by the use of PLCopen function blocks for programming.
This provides a non-real-time communication from the various machines to the upper layers as well as facilitates a machine to machine communication without hassles using the existing systems and controllers. OPC UA also offers connectivity not only till ERP / MES but also up to the cloud as many cloud providers already have OPC UA drivers readily available for usage. OPC UA has robust security mechanism already in place to meet the IIoT needs and Industry 4.0 needs of the plants and factories.
Applications of Ethernet POWERLINK: Field to process
Ethernet POWERLINK is another open-source protocol based on standard Ethernet which satisfies the real-time communication needs of the plants and factories down to 100µs. It offers multi-master, media and ring redundancy at the controller level and field level which has a changeover time of less than 2 POWERLINK cycles. Thus, these controllers having higher availability are able to gather data from the sensors, actuators and many other peripheral devices in real time and transfer this data via OPC UA to the upper layers. OPC UA can be still taken down to the sensors by combining the OPC UA with the determinism offered by POWERLINK. POWERLINK uses an isochronous phase for deterministic data communication. Apart from this phase, a dedicated bandwidth is reserved for non-real-time data exchange which at no point degrades or affects the real-time data exchange. OPC UA and POWERLINK both being based on standard Ethernet it is possible to transfer the OPC UA client-server right down to the sensors.
openSAFETY: Fieldbus independent SIL3 certified safety
In any plant and factory, safety is of supreme importance. Again, the multiple proprietary, Fieldbus dependent safety standards prove to be a major obstacle in connecting the complete shop floor. openSAFETY is a completely open source Fieldbus independent, SIL 3, TÜV certified safety protocol which is used in the industry for over a decade for transferring safe data in the field. Being Fieldbus independent this safety protocol works on a black channel principle over any Fieldbus. Plant and factory builders and operators can thus benefit from the safe connectivity from the field to the cloud as openSAFETY works on POWERLINK, OPC UA, Modbus, Ethernet, CANopen and any network of your choice.
Edge computing – is it necessary?
A factory is generally equipped with several machines with hundreds of controllers, thousands of sensors and actuators. Even if in some cases it is possible to send data from the individual controller to the upper layers such as MES / ERP / cloud, it is difficult for them to gather data individually. One can look at an organizational structure for comparison – directors have only a handful of people, who directly report to them, they, in turn, might have hundreds reporting to them. The directors do not have to report of everyone in the organization. This is possible, yet not feasible. This is similar to any factory, where it is possible to get data from individual stations and sensors, but not feasible. It is of utmost importance to have a central point, which collects data from the individual machine and passes it to the upper layers. Edge computing is an ideal solution for factories in order to collate data, provide trends and convert it into valuable and interpretable information before sending it for analytics.
Challenges in gathering data
However, data gathering also comes with its own challenges, especially when we talk about collecting data from legacy systems and brownfield installation. In greenfield installations, it is relatively easier as the controllers have latest technologies and users define their needs before the factories are set up. On the other hand, in brownfield installations, controllers could have either legacy fieldbuses or no connectivity options. These serve as the greatest challenge for gathering data from the field. Remote connectivity, predictive maintenance, energy monitoring, OEE and adaptive manufacturing are some of the demands and technology trends witnessed with Industrial IoT and Industry 4.0.
Industrial IoT and Industry 4.0 are continuously evolving over the past decade. Today, everyone is talking about connectivity, data analytics, and cloud platforms to be Industrial IoT ready. However, data from the field is the most vital aspect of one thinks about analytics. It is very important to gather process data from various machines and controllers, in order to make it available to upper layers of analytics. Edge computing enables factories to gather data and acts as the final physical hardware point in the factory premise before it moves into the IT space from the OT space.
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To know more, attend Ninad Deshpande’s talk on “LEVERAGING DIGITIZATION IN BROWNFIELD MACHINES & FACTORIES FOR COST-EFFECTIVE MANUFACTURING” at EFY Conferences 2018