Absolute Encoder

POSITAL has introduced a low-cost and flexible alternative for safety-critical motion control systems. This increases POSITAL’s range of certified SIL safety encoders. The new ‘diverse-redundant absolute encoders’ are an attractive choice for many installations where safety is paramount. When combined with functional safety PLCs, these devices are suitable for applications that need to comply with Performance Level/ PL d, Cat. 3, according to ISO 13849. ‘Redundancy’ means that these devices contain two independent sensor systems. Measurements from these two systems are processed by a functional safety PLC. If the two measured values are equivalent (within defined tolerances), safe operation continues.

Moreover, if any differences occur, the controlling PLC triggers an alarm. This gives an option of moving the system to a pre-determined safe condition. POSITAL makes use of a combination of magnetic and optical sensor technology – the key words are diverse redundancy. Applications for the new safety-ready encoders range from heavy construction equipment and mobile machines, through crane technology and elevators, to complex stage technology for theatrical or film productions.

Instead of installing the redundant systems in separate housings, POSITAL has chosen an all-in-one solution. The new devices are designed as space and cost-saving encoders. The magnetic and optical sensor elements are integrated in a compact housing (58 mm in diameter) that is easy to install. Similarly, to other products in the modular POSITAL portfolio, the encoders are available with a range of mechanical options.

Additionally, communications occur through the well-established CANopen interface. The new safety-ready encoders are suitable for harsh environments and a wide temperature range. Magnetic encoder technology is robust, while the optical components have been protected against condensation. Both sensor elements, optical and magnetic, are absolute encoders that measure the position value in single and in multi-turn mode – absolutely battery and maintenance-free.