Building automation has long been a fixed planning component in every new building, in residential buildings as well as factories and all other commercially used functional buildings such as office buildings or shopping centers. The tasks of building automation range from the efficient use of energy in air conditioning, heating, ventilation or lighting technology to security solutions using automated locking technology or visualization via surveillance cameras.
The implementation of such automated building control systems began in functional buildings, with so-called Direct Digital Controls (DDCs) and PLC modules primarily being used at the automation level. These record the information from the sensors at field level, process the data according to their control algorithms in the stored control program and send the results back to the actuators at field level as control commands.

The Raspberry Pi 3 B+-based Smart Manager 4.0 top-hat rail PC for the control cabinet makes it possible to implement even complex tasks in control technology and building automation with open source-based hardware and software.

© STV

This has also led to a variety of proprietary automation solutions within different trades, especially as the transmission systems used at field level often use different media and protocols. If you want to create interoperability between the various building automation technologies, you need a platform that not only provides comprehensive hardware interfaces at field level, but also offers the option of integrating the various systems on the software side, for example to implement needs-based, software-based PLC applications. Current trends - such as digitalization, IIoT and smart metering - make it necessary to connect even individual systems via a dedicated edge computer. It makes it possible to seamlessly connect IP technology with central dashboards as well as management and maintenance clouds. This also enables the integration of suitable edge logic on site. This must be increasingly freely programmable in order to meet the growing demand for smartphone-based control of every building function, for example, or to execute inference logic that is required for predictive maintenance purposes, as it is not possible or desirable to push every measured value into the cloud.

More freedom in building automation

OEMs and system integrators are therefore looking for a solution for building automation that can be integrated into the control cabinet in a flexible and cost-optimized way. One such solution could be platforms based on the new, performance-optimized Raspberry Pi 3 B+. They are equipped with an open-source Linux distribution and can be adapted to specific requirements. This means that there are virtually no restrictions when installing additional software such as development environments or automation applications that are to be used on such edge control centers for building automation and control technology.
But what are the specific advantages of an approach with Raspberry Pi?

From educational object to industrial platform

The interface equipment and the separate expansion bus allow the Smart Manager 4.0 to be used in the control cabinet as an IoT/edge server - both for building automation and industrial control solutions. Even meters in the classic M-Bus field bus can be managed via MQTT using a level converter docked onto the mini PC.

© STV

In 2012, the Raspberry Pi was introduced to the market in its original, first version for educational purposes as a particularly inexpensive yet complete open source development platform. Anyone with an interest in IT hardware - and hardware programming and development in particular - could get started with the low-cost single-board computer almost immediately.
And so it was not long before the devices were increasingly used as a practicable
development platform in the embedded industry, as the Raspberry was a fully-fledged Linux mini-computer that could be used as a development and test platform at the same time.

To date, around 30 million Raspberry Pi devices have been sold, which is also reflected in an impressively large online support community. In the meantime, the Raspberry Pi is well on its way to becoming a new standard industry platform. Oracle, for example, uses a cluster of 1060 Raspberry Pis for the world's largest Pi supercomputer. And NASA's Jet Propulsion Laboratory has published a blueprint that uses a Raspberry Pi as the basis for a replica of the Mars rover. Now the minicomputer is setting out to conquer industrial applications. STV Electronic is one of the first manufacturers to have an industrial-grade version of the minicomputer in its portfolio with the Smart Manager 4.0.

Industrial-grade Raspberry

Version 3 of the Raspberry Pi comes with a BCM2837 SoC from Broadcom, which is made up of a 1.2 GHz quad-core ARM processor with a generously dimensioned visual processing unit (400 MHz). The four Arm Cortex-A53 cores are responsible for the high computing power, enabling the platform to take on even very complex tasks in the IoT/edge area of building automation. The Armv8-A architecture impresses with up to 60% more performance than its Cortex-A7 predecessor. It also offers improved power management for minimal heat generation, meaning that the Smart Manager 4.0 can operate without active ventilation even at extreme temperatures of -40 to +55 °C inside and outside the control cabinet.

In addition to the 1 GB LPDDR2 SDRAM RAM, the STV Smart Manager 4.0 can be ordered with either 8, 16 or 32 GB on-board eMMC flash, providing sufficient storage space for every application. Alternatively, the Smart Manager 4.0 is available as a variant with an SD slot.
The open source-based Raspberry PCs are fully suitable for industrial use. This is because the Smart Manager 4.0 uses SODIMM processor modules specially designed for use in the industrial sector, for which the Raspberry Foundation alone guarantees long-term availability until at least 2026.
In addition to the corresponding planning security, the modular design also offers flexibility and scalability, as the industrial PC can also be expanded on the hardware side with higher-performance CPU modules. STV has therefore set the long-term availability for its industrial PC at ten years, which is another important requirement for electronic components in industrial use.