Check out our 2024 Corporate Sustainability Report!

Crane Hot Line

Smart Draw-Wire Encoders Measure Position, Speed, and Inclination

May 10, 2022 - Mobile elevating work platforms, mobile cranes, truck-mounted concrete pumps, and other mobile equipment need smart sensors that can reliably detect their complex movements.

Siko’s Pure Mobile family of draw-wire encoders can detect several measured variables at the same time, thus reducing the installation effort and cost.

Various sensors are necessary to detect all the geometric positions of a boom or mast on mobile machines or forklift trucks.

Alongside draw-wire sensors to detect the linear position, rotary encoders or inclinometers are also used to detect rotational movements. Although all of those sensors are essential to ensure the machine’s safe operation and stability, using a large number of sensors also means increasing complexity due to more cabling and installation work.

The integrated sensor variants of the Pure Mobile family from Siko save space, installation effort, and cost.

The central components of the Pure Mobile series are SG31 and SG61 wire-actuated encoders, with a maximum measuring length of 9.84’ to 19.7’.

Integrating the latest generation of inclinometers, they can detect position, speed, and inclination. The two wire-actuated encoders are complemented by the large SG121 and SG150 variants, which offer a maximum measuring length of 39.4’ and 49.2’, respectively.

The integrated single-axis inclinometer is available as an option. It measures inclinations in the range of ±180° with a resolution of up to 0.001° and a precision of ±0.2°. That means the sensor can detect even minor displacements.

Its integrated temperature compensation keeps the values stable over the entire measurement and temperature range. The sensor data is transmitted to the controller via CANopen, CANopen Safety or SAE J1939 interface independently of the position value.

Thanks to the modular sensor design, the inclinometer can be integrated into every Siko draw-wire encoder without changing the sensor’s design, size or connection type. Increasing the range of functions helps reduce machine-related installation space, installation effort and product costs.

The SG31 and SG61 draw-wire encoders are also available in a redundant and a non-redundant variant for position and inclination detection. This means they can also be used for safety-critical applications up to performance level d.

All Pure Mobile sensors have been developed according to the requirements of mobile machines and feature an extremely robust design. That includes E1 certification from the German Federal Motor Transport Authority as well as high EMC, shock and vibration resistance. Protected by their compact housings, the sensors consistently deliver reliable and precise values even when exposed to harsh environmental conditions.

Profile of draw-wire encoders:

  • robust design

  • easy mounting

  • measuring lengths from 3000 mm to 15000 mm

  • flexible wire outlet thanks to Wire-Flex technology

  • also available in safety version in combination with the WV58MR rotary encoder

  • great flexibility thanks to freely selectable rotary encoders with a standard flange of 58 mm

  • various wire types


Crane Hot Line is part of the Catalyst Communications Network publication family.