The success of industrial production companies depends largely on the quality of the manufactured products. This is achieved and ensured by testing the products as thoroughly as possible at the end of the manufacturing process. At Asco, a subsidiary of Emerson and manufacturer of solenoid valves, actuators and devices for compressed air treatment and control, every single product has always been subjected to a 100% test with end-of-line testers (EoL) by trained specialists in quality assurance. The products only leave the factory after passing the test.

Modernize the old, preserve the tried and tested

In the past, EoL testers were set up on the basis of conventional desktop PCs. Depending on the product to be tested, the test systems were equipped with different PCI measurement cards tailored to the measurement task. On the software side, the solution was based on LabWindows and connected SQL databases. Over the years, a flexible test system was developed that could test the entire product range. In order to meet the increased requirements for flexibility and performance, to significantly increase the transparency of the test results and also to achieve future use of the measurement data in Industry 4.0 or IoT applications, Asco now relies on an embedded solution consisting of a real-time-capable industrial PC and the Ethernet-based Ethercat fieldbus system.

A test device from Asco, in the background of which the real-time solution from Spectra and Sybera takes care of data evaluation and transfer.

© Spectra

For Asco, real time was important when recording measured values in certain test situations. If, for example, the switching time is measured on a valve, various measured variables such as voltage, current and pressure must be recorded in a specific time - increasingly often in ranges of less than 10 ms. There are also test sequences where signal changes in the millisecond range are necessary.
In the real-time networking sector, Ethercat is one of the leading fieldbuses, especially when it comes to fast cycle times well below the millisecond range. The popularity of Ethercat is also due to the fact that I/O terminals are available from a large number of suppliers for every conceivable measurement task. Spectra also offers EA modules for Ethercat as part of its distributed IO port portfolio.

With Asco's decision to retain the essential components of the mature and user-friendly LabWindows application program and to adapt only the substructure, i.e. the PC hardware and the fieldbus, while retaining the real-time capability, an open software solution was required to enable this integration in a simple manner. This is essentially the functionality of the Sybera software, which offers a real-time extension for Windows operating systems on the one hand and an easy-to-use interface to the application program in the form of Windows programming libraries on the other.

Once the fieldbus and the essential software components have been selected, the question of a suitable hardware platform arises.

Hardware and software must work together

The answer to this question is by no means trivial and a naive approach of the type "we'll just take any PC and that's it..." often leads to major problems. This is because Windows installations, BIOS settings, interface specifications and similar parameters are by no means the same on all PCs. Either a user has to test and set all this himself with great effort or he falls back on a provider who can already guarantee this compatibility.

The real-time solution can be implemented with the Powerbox 100-RTE computer system. A panel version is currently in the test phase.

© Spectra

The SpectraSybera partnership offers the user exactly that: a tested complete hardware-software system for real-time automation under Windows, on which the user only has to install his own application. This eliminates all the initial installation tasks that are necessary to give the 'bare' hardware real-time capabilities. The customer does not receive two separate products, separated into hardware and software, but a single solution. This is very important for technicians and engineers from the fields of mechanical engineering, automotive, measurement and testing technology, assembly and packaging, because they want and need to concentrate on their core competencies and not carry out complex real-time tests themselves. Asco has opted for this approach. Fanless mini PCs from Spectra are now being used as the new hardware platform. In combination with the Sybera real-time software, the Powerbox 100 series is given the suffix RTE - for the integrated real-time engine.

Decisive factors for the selection of this product were the extensive interfaces - in addition to Ethernet and serial ports also on-board DIO - and the compact design, which made installation in the existing test box possible. Compactness without sacrificing high performance is a feature of modern industrial PC systems that brings them ever closer to the machines and devices. In addition, the PowerBox 100-RTE offers many other industrial features as standard, such as a 9 V (DC) to 48 V (DC) wide-range voltage input, DIN rail, VESA or side panel mounting and an operating temperature range between -20 and +60 °C.

Real-time only with software

Two different software approaches are possible for real-time on the computer system. As a complete solution, X-Go Logic Control offers all the functions of a soft PLC, including programming of the control logic using adaptive PLC language and simple creation of operating and display elements. The software can therefore be used for both IO devices and drive controllers and is particularly suitable for service, commissioning, diagnostics and system control. As an alternative to the standard X-Go Logic application, developers of their own programs have access to extensive libraries for Ethercat masters, Profinet masters and other real-time protocols for integration into their own applications.

Principle sketch of the real-time software structure: Both the X-GO Logic application program and the fieldbus master programming libraries are based on the X-Realtime real-time extension for Windows.

© Spectra

Both X-Go Logic and the fieldbus master libraries are based on the asynchronous XRealtime technology. The X-Realtime engine works without additional hardware under Windows, enables real-time multitasking down to well below 1 ms with minimal jitter behavior and can be used in a variety of ways for application and driver projects. Developers can work within their familiar development environment. The programming of real-time tasks, the control of hardware components and the programming of Windows routines are carried out as a single application within the same development environment, for example Visual Studio. Data exchange between the real-time system and the Windows application can be carried out via shared, synchronized memory areas.

The partnership solution with the completely pre-installed, ready-to-use IPC offers the user a number of advantages. Tested functionality that makes in-house testing and installation work superfluous. A modular structure that makes the system easy to expand. And - also very important for newcomers or switchers like Asco - a range of training courses as well as qualified and intensive technical support from partner companies Spectra and Sybera.

New developments

The first systems are currently being tested at Asco and have already demonstrated their performance. In the next steps, the visualizations will be converted to browser display and the integration of the test data into the company network will be driven forward.

And the solution providers - Spectra and Sybera - are not standing still either. The joint plan includes the real-time certification of further hardware platforms such as the Powertwin panel PC with modular display processor concept or a powerful Intel7-based IPC for the highest performance requirements. In addition, the real-time properties, which are largely determined by software parameters, are subject to constant optimization. With the latest development of the 'Realtime Silent Mode' on the Powerbox, Sybera has succeeded in reducing jitter to below 5 µsec for the first time. This opens up new application possibilities in the field of robotics and drive technology.

Author:
Uwe Hollarek is Product Manager Automation at Spectra.