Why STW?

assembly lineSTW is the premier manufacturer of mobile controllers and measurement technology. Here’s why:


Mobile working machines are valuable assets that must work reliably non-stop in the field, typically a long way from repair facilities or troubleshooting resources.  Electronic controllers and peripherals (displays, joysticks, sensors, etc.) must be exceedingly robust and reliable or they can have a negative operational and monetary impact far exceeding their cost.  Quality control and reliability are the hallmarks of German engineering and manufacturing.  With an average mean-time-between-failure (MTBF) of over 50 years, STW controllers and peripherals provide the solid foundation of a control system that you can depend on in all of the challenging environments that your machines face.

STW performs full quality testing of every single device that it manufactures, consisting of automated optical inspection, a full in-circuit test and complete functional testing done at normal temperatures and then again in temperature chambers at extreme cold (-40º) and extreme hot (+85 ºC).

cold testing Technology

New controllers are developed on a regular basis to take advantage of the latest technologies.  Our newest 32 bit processor based controllers, the ESX-3XL and ESX-3XM, use the one of the fastest, most powerful automotive processors – the Infineon Tricore.

STW controllers are continually upgraded using the best available components.  As individual controller components become obsolete, new ones are sourced and the design modified to keep any changes transparent to the end user.


STW has a unique controller architecture that allows you to expand your I/O and memory to your exact requirements.  Within the controller enclosure, expansion boards (called ‘baby board’) may be added to customize a controller.  This flexible architecture provides an immense range of options for the control design, improves cost efficiency, minimizes extra wiring and connections, and keeps all of the electronics in a single, protected enclosure.

STW controllers are freely programmable.  You have full access to all hardware and can use a variety of software packages to do the programming – from ANSI standard C to IEC 1131-3 compliant graphical programs such as CoDeSys or Matlab/Simulink.  That means you are not locked into a specific set of programs or functions and have total flexibility to build the system according to your needs.  STW also provides an extensive function library and employs an excellent and highly efficient embedded real-time operating system for its controllers with pre-emptive multi-tasking and multiple priority and interrupt levels.

STW has had a long history of tailoring its electronics according to customer needs.  Whatever your design constraints or specifications, STW can adapt its flexible architecture to your needs and quickly design and manufacture a custom board.  This optimizes the solution for your environment and reduces cost for larger production runs.

concrete pumpsSafety

The ESX, and soon the ESX-3XL/3XM controllers, are designed to meet the rigoruous requirements for Safety Integrity Level (SIL) 2 based on the IEC61508  standard.  The International Electrotechnical Commission’s (IEC) standard IEC 61508 defines SIL using requirements grouped into two broad categories: hardware safety integrity and systematic safety integrity. A device or system must meet the requirements for both categories to achieve a given SIL rating.

Each controller contains an independent watchdog and main relay to power the various outputs.  In the event of a system failure, the watchdog will open the main relay and cut the power to the outputs.  This main relay is controlled from both the independent watchdog and the main program.  Both must be satisfied for the controller to operate.


In addition to controllers, STW provides a comprehensive line of pressure sensors, mobile rated displays, joysticks, pedals, angle sensors, and telemetry devices.

STW can provide you with a complete control solution, including wiring designs, wiring recommendations, and wiring harnesses.


STW is the premier provider of mobile-rated controllers and sensors in Europe, with a fast-growing presence in the U.S.  Its technology has been time-tested in the most rigorous and demanding environments for over 20 years.