Huebner Giessen system solutions are not only setting standards across the globe for crane controlling solutions with the compact and modular U-ONE® system, but also with single devices like EGS 4..® (programmable electronic overspeed switch) and FG 4 (incremental encoder with fibre optic signal transmission by direct cable connection or by means of fibre optic components transmitter and decoder).
SIL 2 conformity
As the only ‘on the market’ available components, Huebner Giessen provides U-ONE® and EGS 41® with functional safety certification according IEC 61508 SIL 2 (software) and EN ISO 13849-1 PL d (software and hardware).
Current safety regulations for cranes require a safety analysis of the electrical control system. A determined failure of the control system must lead to a safe controlled overspeed signal. Therefore, the safety related measure must comply with SIL level 2.
Otherwise the complete safety circuit must be improved by adding additional components and monitoring functions. As of now the basic device U-ONE® fulfils these safety functions. With its 12 different electronic, functional modules (incremental output, BUS coupled absolute positions equipped with all BUS interfaces, synchronisation module, overspeed monitoring, electronics position switch for positioning and so forth) this solution offers a certified, reliable measuring systems for cranes.
Key components
Modular system U-ONE®, electronic overspeed switch EGS 4..®, incremental encoders with direct fiber optic output and separate transmitter/decoder units for fiber cable transmissions are key components for crane applications around the world.
Modular system U-ONE®
The system is based on a universal basic unit connected to electronic function modules in the switchboard via fiber optic cables that are immune to EMI. The electronic function modules are linked by an internal bus structure, and can be freely connected in series as required (series plug-in modules).
The main advantages of the system U-ONE® are:
• Space saving compact design
• EMI immune fiber optics signal transmission
• High safety by switchboard mounted electronic modules
• Easy central programming through common interface
• Extreme reduction of cabling costs by using only one dual fiber
cable
• Reduction of commissioning time by the modular structure
• Easy extendibility by connecting the electronic modules in
series as required
• Highly flexible and saving spares by the modular system
Electronic overspeed switch EGS 4..®
This programmable overspeed switch provides decisive advantages over mechanical overspeed switches, such as adjustability for very low speeds, high shock and vibration resistance, and better switching dynamics and accuracy. Electronic overspeed switches also achieve considerably higher reliability, thanks to their self monitoring for functional faults and the possibility of verification.
As standard it is fitted with two electronic switch contacts that can be set independently of one another over the entire speed range from 0,63 – 4,800 rpm. This avoids having to install stepup gearboxes to use overspeed switches with very slow drives. As an option, it can be delivered with four programmable switching speeds. An additional pulse output is available as an option.
A separate switched output serves as a system check and monitors the supply voltage, functional faults and the output contacts. The Windows-based software that is provided with the overspeed switch facilitates comfortable programming of both overspeed and underspeed limits, as well as a switching delay time to blank out very
short overspeeds that can occur, for instance, during a load change.
EMI prooof signal transmission through fiber optic components Electromagnitic interferences on sinal transmission cables can e. g. be caused by close power cables, high starting currents of DC motors or strong magnetic fields of breaks. Huebner Giessen is providing fiber optic transmission components for incremental
encoders with the following advantages:
• EMI immune fiber optics signal transmission
• Suitable for long distances up to 1,000 m
• Reduction of cabling costs by only one fiber optic cable for all
encoder channels
• Decoder is equipped with two output blocks (TTL and/or
HTL) saving a pulse splitter
