Drives and Controls Magazine
Rexroth uses EtherCat for ‘the most open automation platform’
Published:  06 December, 2019

Bosch Rexroth used the recent SPS automation exhibition in Germany to unveil a major new automation platform which, it claims, will be “the most open on the market” and will cut engineering effort by 30–50%, reducing time-to-market “significantly” for new machines.

The ctrlX platform, which has taken three years to develop, spans everything from PLCs, motion controllers, industrial PCs, software, I/O and HMIs, to multi-axis servodrives, inverters and safety systems. It uses EtherCat as its main communications technology, rather than the Sercos system that Rexroth developed and has been the backbone of its motion systems for many years. But the company will continue to use Sercos in its drives and as an option for slave controls. 

“We have renewed the portfolio from the ground up,” says Rexroth’s director of market and product management for PLC and IoT systems, Hans Michael Krause. A driving principle, he adds, has been to remove any limitations in power or performance for customers.

Rexroth says that ctrlX breaks down the traditional boundaries between machine control systems, IT and the Internet of Things. The scalable platform –­ which is based on a real-time Linux operating system, open standards, apps and Web-based engineering – can be used to create centralised or decentralised automation topologies.

Rexroth says that the new platform is its response to the merging of mechanical engineering and software activities. Software functions can be combined in many ways using ready-made customised and customisable apps. These apps can be created in languages such as C++, Python, or graphical languages such as Blockly.

This, the company says, will give machine-builders new freedoms. They can decide whether to program in IEC 61131, PLCopen, G-Code or in conventional high-level or Internet languages. They will no longer be dependent on the availability of PLC specialists and proprietary systems.

Configuration and commissioning of the automation components is Web-based, eliminating the need to install software. Within minutes of switching a system on, the software can be programmed. A digital twin virtual automation environment is available, enabling programming without needing hardware. System functions can be extended at any time via user’s process functions, apps, or open-source software.

The new platform supports more than 30 connection options and communication standards for maximum networking flexibility and low-cost end-to-end connections from the field level up to the cloud.

The platform is based on a new generation of multi-core processors which, Rexroth says, are powerful enough for most automation tasks. They can be integrated into embedded PCs and industrial PCs, or into drives. The hardware and software modules will cover automation tasks from simple control applications and IoT systems, to high-performance motion controls.

The user-centred platform is said to end current restrictions in terms of openness and flexibility. The key components include:

•  Drives including flexible, modular multi-axis systems that are up to half the size of the previous generation. They include single- and dual-axis drives, and regenerative supplies with peak ratings of up to 260kW. Single-cable motor connections save space and reduce the need for cables and accessories. 40 axes can fit in a 1m-wide rack.

•  PLCs, which can be drive-based, embedded, running on an IPC, on a server or in the cloud. A free choice of programming languages helps to reduce engineering time.

•  Motion controls with an “open and secure” software architecture using apps to integrate specific functions, which can be synchronised “in microseconds” and offer “nanometre precision”

Building blocks: Bosch Rexroth’s new cntrlX platform offers users high levels of flexibility when choosing and combining hardware, software, programming languages and apps.

•  Open, modular controls with distributed intelligence that can be embedded, or based in PCs or drives. They use ARM multi-core processors and offer flexible extendability with compact, fine-increment I/O functions

•  Web-based HMIs with integrated Web servers which show important information on high-performance displays. The scalable hardware ranges from small panels to 21” multitouch displays. Third-party HMI tools can be integrated.

•  I/Os to connect control systems with the machine automation and communication levels. They provide up to 20 I/O points in 12mm installation widths and support IO-Link for integrating intelligent sensors

•  Integrated IoT support which helps to obtain information more quickly and to use it to improve OEE. The need for IPC and VPN router hardware is reduced significantly, and IoT can be used to view all of the controllers on a site.

•  Industrial PCs with scalable performance, sizes and options from entry-level to high-end. The PCs use Windows 10 IoT or Linux operating systems and incorporate secure-by-design chips and high-performance graphics cards for demanding visualisation and simulation applications.

•  Safety components with reaction times of 4ms, ­said to be the fastest on the market. Applications are created easily using graphical programming of the safety logic and dialogue-based support for acceptance tests.

•  A hardware-independent, Web-based graphical configurator which allows users to choose and configure automation systems quickly and easily, using the optimum combination of components. Topologies can be created without in-depth knowledge. System-wide consistency of configurations is ensured through automatic verification of product relationships.

System commissioning is also Web-based, using software components such as PLCs, firmware and motion controls acting like “containers”. Users can create their own containers, which are Linux-based. Dynamic simulation allows machines to be tested “virtually” using digital twin techniques.

Rexroth has designed the ctrlX platform to support future communications standards such as TSN (Time-Sensitive Networking) and 5G. At SPS, it was demonstrating the use of 5G in partnership with the communications specialist, Qualcomm. Rexroth has applied for licences to use 5G in its own plants.

In another demonstration on the stand, a machine was being controlled by components from the new platform with the claim that it needed only half as many components as comparable systems from Siemens or Beckhoff. The machine included a tablet-holder with a built-in emergency-stop button that, Rexroth rays, will allow tablets to be used instead of a dedicated safety HMIs at a much lower cost.

Another aspect of the new platform is its use of digital service assistants that can run on smartphones. For example, if a drive develops a fault it can show a QR code on its display which can be scanned using a phone, which will then show a diagnosis of the problem.

Bosch Rexroth is reassuring existing users that it will continue to support Sercos. "The multi-Ethernet interface with Sercos and other popular Ethernet-based protocols will remain," says Krause. "Users can continue to operate drives with these standards on their control system."

The ctrlX platform is due to start reaching the market in April 2020. Bosch Rexroth is guaranteeing long-term support for the platform and has committed itself to making it available until 2045, at least.

On its stand at the SPS show, Rexroth demonstrated a machine being controlled using elements from its ctrlX platform, claiming that it needed far fewer components than rival systems