• Due to 128 functional and performance tests high complexity of the solution
• Need for a functional, flexible and simple solution due to large proportion of exports.
• Test rig had to be to be designed for both current and future models.

Hofmann Prüftechnik GmbH in Elze near Hanover has been building test benches for passenger vehicles and commercial vehicles since 1947. The special purpose machine manufacturer was recently awarded the contract to construct a test bench for combine harvesters, on which 128 test routines are to be performed. The personnel responsible for safety technology opted for a flexible safety solution based on the Sirius 3SK1 safety relays from Siemens. This cost-effective safety solution forms the foundation for subsequent modifications of the safety technology without any complications.
Hofmann Prüftechnik opted for a conventional safety engineering set-up with compact SIRIUS 3SK1 safety relays. A safety system consisting of a basic unit plus expansions for detecting all protective doors, the pressure-sensitive edge and emergency stop buttons was used in the test system and a second safety system with the same setup was used in the light array. SIRIUS 3SK1 cannot only be easily adapted via DIP-switches to each respective requirement, but may also be upgraded with up to five expansion units for digital inputs and outputs in its advanced version. For the verification of the safety concept, Siemens' Safety Evaluation Tool is used.