SOURCE: SIEMENS INDUSTRY
Modern HMIs provide solutions
To address these concerns, manufacturers need an edge device on the plant floor to make efficient use of bandwidth in communications outside the plant, and to ensure secure data transactions. By processing data on the plant floor closer to its source, this type of component improves data integrity compared to processing in the cloud. Though essential, the reliable movement of data from plant floor to cloud is only part of the need. Engineering, operations, and maintenance staff alike must be able to effectively visualize, analyze, and interact with machines to keep the plant running in an efficient manner, and unified HMIs at a network’s edge facilitate these functions. Unified HMIs provide different capabilities than standard edge controllers with built-in apps for managing edge devices and data, and they bring advanced IT capabilities to the machine level in a cost-effective manner. When implemented, they serve as a central repository for data across the plant floor, enabling direct visualization and analysis of machine health and performance through a single interface. Compared to direct cloud connection of individual sensors, unified edge HMIs are less complicated to implement and more feature-rich out of the box, adding capabilities to plant-floor data processing.
Configuration and usage
Acting as a bridge between OT and IT, unified HMIs are automation infrastructure agnostic, and their applications can scale as plant floor layouts evolve. This is largely in part to a wide variety of applications available for managing and interacting with machines. While developers have a host of tools available for custom app creation on unified HMIs, they are also equipped with a wide selection of 11. 2020
built-in, scalable edge apps. In light of the headache-inducing challenge of managing application dependencies and compatibility across devices, unified HMIs use docker and container structure to alleviate this issue, freeing developers to focus on app logic and functionality. This makes unified HMI apps heavily configurable, as opposed to programmable, because the underlying infrastructure is already vetted. Containerization wraps up all dependencies for an app into a single package, allowing it to be deployed to any device, without the need for a checklist of external resource requirements on the target. It is similar to virtualization of a personal computer (PC)— where an operating system (OS) and its entire file system are stored in a directory, and can be run without extensive external dependencies—though containers require lower overhead than virtual machines (VMs). A docker engine running on a device’s OS enables the storage and execution of multiple containers. As a container is to a VM, so an HMI’s docker is to a host PC’s hypervisor. In addition to using pre-built apps, machine builders can develop their own apps utilizing a unified HMI’s docker engine. The docker incorporates security intrinsically, another advantage enabling focus on app development and less time spent on building and maintaining infrastructure. For machine builders and end users short on time, there is likely already ‘an app for that’. Native and third-party apps are available for purchase to run on unified HMIs, accomplishing tasks such as: • Performing advanced production algorithms and calculations • Connecting to data from multiple sources over multiple protocols • Visualizing data
i n d u str i a l e th e r n e t b o o k
Applications
Machine builders can simulate proposed production changes prior to implementation.
• Automating workflows • Managing inventory • Analyzing machine and drive health, and calling out predictive maintenance • Analyzing performance and creating insights • Creating notification pipelines and sending alerts • Simulating production with digital twin Furthermore, unified HMIs are repositories for data collection, analysis, storage, and forwarding. With the right apps, users can connect to automation controllers, drives, OPC UA devices, and other edge devices. Using the MQTT protocol, these devices can efficiently publish data to the cloud, consuming minimal network resources. Due to their multilingual properties, unified HMIs perform well as interfaces for establishing key performance indicators (KPIs) and measuring actual production output from multiple machines. Unified HMIs also eliminate the need for PCs in many applications because they can execute many of the IT functions performed by PCs within their industriallyhardened HMI housing.
Device and app management
Adding another IT characteristic increasingly making its presence known in OT, unified HMIs include enterprise management. Machine builders and manufacturers can centrally manage devices and apps from on or off premise through a web-based interface independent of the HMI automation project file. This can be done from any device capable of hosting a web browser, such as a laptop, smartphone, or tablet. This model provides the flexibility to store apps and licenses on servers, remotely deploy or update apps without modifying machinelevel functionality, apply security patches, and manage content of all unified HMIs across the enterprise. Communication among devices is encrypted, and HMIs can be configured for automatic system backup to prevent data loss. Apps run in the background fulltime with their hooks in the docker—independently of the OS running the classical HMI automation project also present on a unified HMI—so a change in app configuration does not impact HMI runtime execution. This provides the flexibility to update apps on a regular basis without concern of modifying the automation program file.
Results
For an industrial heater manufacturer, struggling to keep up with growing demands from its stakeholders, implementing Siemens WinCC Unified HMI software and panels enabled it to deliver greater functionality and performance to its users. This empowered the manufacturer to develop its own apps for machine and performance
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