On the 19th of September 2013 the first approval for the unique memory protection mechanism for the electronic control unit ESX-3XL was received. With that, the application software can access both standard and safety functions in parallel.

Following on from that success, the SIL2/PLd approval was received for the STW implemented CANopen Safety (ECoS) Protocol. With that, Safety data can be transferred at system level between safety components, for example sensors, actuators or across decentralised control networks. The high performance and high availability characteristics of the STW solution were confirmed at the CANopen safety Plug-fest of CAN in Automation (CiA) back in October 2013.

In February 2014 STW received the SIL2/PLd certificate for the ESX-3XM electronic control unit. With that, both 32 bit safety controllers, the ESX-3XL and ESX-3XM offer a certified independence between safety and standard functionality. This means that both safety and standard I/Os can be controlled on one control unit, and the safety functionality is protected from the interference. With this approach, there are literally millions of feasible control unit variants available through the inclusion of approved expansion boards. Additional I/O, RS232/RS485, CAN, Ethernet and USB functionality can be all added without compromising the safety functionality or certification.

Currently there are 14 expansion boards (EBs), which can be used for independent standard functions. The first Safety Expansion Board (according to DIN IEC 61508 and EN ISO 13849) is in development. This can be used in the ESX-3XL and ESX-3XM basis for SIL 2/PL d functions. The Safety EB offers, with a redundant mainboard channel, the following additional safe I/O functionality:

• 16 safe digital High-Side outputs,

• 16 safe digital or voltage inputs, and,

• 2 safe analogue current inputs.

When combined with the basis I/O channels of the ESX-3XL that adds up to 84 safe I/O channels within one control unit.

On the 14th of March 2014 the first certificate for CODESYS Safety SIL 2 Runtime System for the ESX-3XL was issued. STW was thereby the first mobile controller manufacturer to offer a certified Runtime System for application developers. For the first time, developers could develop a safety related IEC-61131 application on a mobile controller.

"Being able to offer holistic, long term system solutions for the control of mobile machines, and having the unique safety concept confirmed and approved by the TÜV Süd is very satisfying, and I’m very pleased to have achieved these milestones" Mr. Wolfgang Wiedemann, Managing Director of Sensor-Technik Wiedemann GmbH.