More Functionality for Special Machine HMIs

When the manufacturer of special bearings Rollax reached its limits with its existing proprietary HMI for its production machines, it set out to find a solution that could both provide a high degree of functionality and offer plenty of flexibility for the implementation of project-specific requirements. The choice was VisiWin from INOSOFT.

Whether it be the chassis, steering column, gearbox or adjustment systems for car seats, the requirements placed on ball bearings in the automotive industry are wide-ranging and demanding. Every vehicle manufacturer has individual requirements for all its applications. As a supplier of ball bearings, Bad Salzuflen-based Rollax specializes in the production of customer-specific products which meet the highest standards of quality in the industry.

The company started 50 years ago in a garage set-up and has since developed into an internationally successful medium-sized company with production sites in Germany, China and Mexico. To be able to offer its customers custom-tailored solutions in high volumes, Rollax operates a highly automated production system. The machines for all three production plants are developed and made by an in-house team in Bad Salzuflen.

“We are proud of the fact that today, for example, we are able to manufacture a high-quality suspension strut bearing, which plays a decisive role in the driving characteristics of a vehicle, in just a few seconds,” says Uwe Stieghorst, Head of the Control Systems department at Rollax. “And we owe that to our in-house mechanical engineering department.”

Machine Complexity Requires New Approaches

When it comes to machine control, the ball bearing specialist relied in the past on proprietary technology from a well-known manufacturer. Here, however, it came up against limitations in terms of HMI. This is because the HMIs (Human Machine Interface) of the machines, which have spatial dimensions of up to 10 m × 10 m, are required to not only record a high volume of process and log data, but also be capable of managing parameters and integrating image processing functions. “At some point we realized that we could no longer reliably map the functionality we needed in the HMI with our previous system,” explains the programmer. Thereupon, he, together with his team, started looking for an alternative.

In the course of this search, Rollax came across the VisiWin process visualization from INOSOFT. VisiWin essentially provides a fully-featured HMI/SCADA system. At the same time, the software provides a solid basis for functions developed in-house, because VisiWin is directly integrated in developer tools such as Visual Studio and Blend, and users can program in C#, VB and XAML with the technology of .NET and WPF.

Stieghorst quickly gained positive experience with the possibilities offered by programming in Visual Studio and C# for creating and extending his operator interfaces, and created a central library with all the basic functionalities required. He was able to integrate the operator interfaces generated using VisiWin directly and easily with the existing control systems.

Over time, Stieghorst's team then decided to switch to a manufacturer that also uses a Visual Studio-based programming environment for the control systems. “For us it’s a major advantage that we now have just a single engineering tool for everything,” says the software expert. “We use Visual Studio for all PLC projects, the drive controls and the HMIs.”

All-Round Flexibility

Fully-automated Rollax machine with HMI panel

The transition to new PLC technology was straightforward for the ball bearing manufacturer. This is because, thanks to VisiWin, it was basically only necessary to adjust the communication channels with the corresponding variables. For the machine operator there was no perceptible difference in terms of look-and-feel on the operator interface after the change.

“The changeover to VisiWin really made clear to us the amount of freedom gained when it comes to the PLC,” says Stieghorst. “Be it control or drive systems from the Siemens world, Codesys, B&R, Beckhoff or others, VisiWin offers corresponding drivers and makes us independent of the manufacturers of automation software. That’s a great benefit.” This was a decisive point for him to decide to redesign all graphical user interfaces.

VisiWin process visualization provided Rollax with optimum support in this respect. In terms of architecture, users can choose from a variety of modular graphical user interfaces that make it easy to implement everything from single-computer systems to combinations of large monitors and compact operator panels or multi-monitor solutions and mobile devices. Rollax relies 99 percent on an architecture in which a single PLC controls the entire machine. Larger machines are designed so that the operator panel can be moved around the entire machine. The worker is therefore in a position to operate the HMI from anywhere. In addition, the operator has access to an industrial WiFi tablet that can be disconnected from a docking station and used, for example, by the maintenance technician for remote access during maintenance work — during this time, the main operating station is locked.

Since the ball bearing specialist relies on Windows domains in the Active Directory for the administration of user rights in the company, the VisiWin-integrated connection of the user administration is used here. At Rollax each employee is provided with a hardware key. This key contains a unique identification number to which a corresponding user is assigned in the domain. When the employee inserts their key in the reader on the PC, the system automatically logs them on to the Windows server and receives the list of the group or roles to which they are assigned. VisiWin matches these with the internally assigned authorization groups and activates them accordingly. This enables machine operation to be directly and conveniently integrated into the general authorization system.

Which means that the users and their roles are administered in the Windows domains, while VisiWin administers (or assigns) the authorizations for machine operation. This eliminates the usual administration of users at the machine, with more favorable central user administration for machine and office workstations instead.

Engineering Time Halved Thanks to Individual Special Machine HMIs

After the successful launch of the first operational machine with a VisiWin graphical user interface based on the Visual Studio engineering framework, all new machines were equipped exclusively with it for the future. Of the approximately 90 ball bearing machines in use worldwide, around half are now equipped with VisiWin-based HMIs.

“VisiWin has brought us a whole host of advantages,” summarizes Stieghorst. “Thanks to the ability to create the basic functionality of our machines in basic packages that can be easily integrated into a new machine and relatively quickly supplemented with project-specific elements, we are able to implement new graphical user interfaces for machine operation very quickly. Compared to before, our engineering time for HMIs has been reduced to 50 percent.”

He also considers the fact that his team can now integrate any functionality that can be mapped in Visual Studio into the HMI accordingly to be a big advantage as well. This means, for example, that even image processing data can be integrated directly in the HMI via C# classes — and this can be achieved without circuitous routes and an additional PC for the camera technology.

For the future, Stieghorst is planning to make more use of WPF and HTML5 for greater independence in terms of display units. One focus is also the issue of IoT and database binding. His team is currently setting up an SQL database that will be linked to the HMI and PLC. With VisiWin he is also ideally positioned for these issues as well.

More information about Rollax Kugellagerfabrik can be found here