TWK-ELEKTRONIK GmbH: Sensorik für Winkel, Wege und mehr.

Press Releases

Fast PROFINET rotary encoder with new encoder profile

Following the publication of the new version 4.2 of the PROFIdrive/encoder profile, TWK has revised its PROFINET rotary encoder.
In addition to the class 3 and class 4 encoder application classes familiar from version 4.1, the new version 4.2 of the encoder profile now also includes the older class 1 and class 2 classes from version 1.0. To do this, the simpler telegrams defined in the old version have been taken over into the new profile version. As a result, the devices according to the new profile are compatible for use with old PROFIBUS or PROFINET devices, which means that only one version of the profile has to be supported. TWK has taken this opportunity to launch a new version of its PROFINET TRT rotary encoder model onto the market. This now supports application classes 1-4 and achieves cycle times of less than 250 µs thanks to a new, faster sensor system. This means that it is highly suitable for time-critical and clock-synchronised applications. The position signal's resolution is now 16 bits. The simultaneously output speed signal has the same updating rate as the position value, and can be output in steps/s, steps/100 ms, steps/10 ms or revolutions/min formats. The optional incremental output with up to 65,535 pulses is also new. Its shortened, robust aluminium or stainless steel housing can be designed for protection classes up to IP69K, and is available with a cable as well as a plug outlet.

TWK merges sensors: sensor fusion

TWK has developed a new generation of inclinometers. They measure more precisely and faster than before, and are insensitive to interfering acceleration and lateral inclination excursion. These sensors are highly suitable for applications with dynamic requirements in which precise inclination angles nevertheless have to be registered and transferred to a control system.
This improved performance is enabled by extending the original acceleration sensor with a yaw rate sensor, also known as a gyroscope, and skilfully combining the measurement signals to form a corrected output signal that precisely indicates the measured angle. Both sensor types are based on MEMS technology. The measured variables of the original acceleration sensor and the gyroscope are merged and processed by adding a Kalman filter. This filter technology enables the measurement value that is to be output to be calculated, corrected and predicted for a short time. This is necessary because the acceleration sensor is unable to supply a measured inclination value when subject to dynamic interfering acceleration; instead, the yaw rate sensor calculates and predicts a measurement value with the aid of the Kalman filter. Unlike the acceleration sensor, the yaw rate sensor does not react to linear interfering acceleration but only to changes in the inclination angle. All possible, realistic application simulations and measurements at TWK show that the sensor fusion system operates precisely and safely. This sensor system not only guarantees safe, hazard-avoiding operation in mobile machines, even when using motors and hydraulic pumps or during other operations that generate strong vibrations. The sensors have an operating temperature range of -40° to +85°C, and measure inclination angles of up to ±100° with a resolution of 0.01° and an accuracy of ±0.2°. Measurement can be carried out on one or two axes. With its protection class of IP67, the stable aluminium housing also withstands harsh environmental conditions with ease. Protection classes up to IP69K are possible.

Rotary encoder TBN58/E1 with 14 bits and E1 approval from the German Federal Motor Transport Authority

TWK-ELEKTRONIK has had its new TBN58 rotary encoder generation with E1 approval certified by the German Federal Motor Transport Authority (KBA). The single-turn rotary encoder is characterised by the following features: 14 bits in the single-turn range, completely autonomous design, i.e. 2 sensors supply position data and speed values according to CANopen class 2, CIA DSP406 version 4.0.1. Sensors 1 and 2 are each connected to the CAN bus with a 5-pin M12 connector. 14 bits/revolution equate to 16,384 steps/revolution or a resolution of 0.022°. The speed value is calculated using sliding averaging. The 14-bit position value is used as the basis for calculation, and the speed value is determined depending on the gate time, which may lie between 1 ms and 1000 ms. The gate time can be parameterised by the customer and therefore adapted depending on the application. The vehicle speed signal has digits/gate time as its physical unit. The rotary encoder's ø 58 design enables its use in a high number of applications such as e.g. various shaft diameters of ø 6, 10 or 12 mm, with and without flat area, with clamped and synchroniser flange, connector and cable versions as electrical connections, housing made of seawater-resistant aluminium (ALMGSi1) or stainless steel (1.4305 or 1.4401) and moisture protection measures. This means that the rotary encoder can be completely cast, enabling the housing to comply with protection class IP69K. Of course, customer wishes such as mechanical adaptations, for instance, can also be implemented. In combination with the development of the TBN58/E1, the multiturn version TRN 58 was also extended on the basis of the 14-bit technology in the single-turn part. We are therefore talking about a rotary encoder with 14 steps/revolution + 12-bit revolutions = 26 bits as a total number of steps. Profile 4.0.2 according to CANopen class 2, CIA DSP406 is integrated in this. CANopen Safety SIL2 is implemented in this rotary encoder. This means that it is designed according to IEC61508 with SIL2 and according to performance level ' d ' as per DIN EN ISO 13849. In addition to the position value, the speed value is also classified as a safe value. Extensive measures have been implemented to achieve the reliability values, including time behaviour monitoring, voltage level monitoring and CRC validation, amongst others.

First inclinometer with PROFIsafe interface

TWK is the first sensor manufacturer to offer an inclinometer for SIL2/PLd applications with PROFIsafe via a PROFINET interface. In addition to the NBN/S3 inclinometer with CANopen Safety interface, TWK also supplies the NBT/S3 model with PROFIsafe via a PROFINET interface. Thanks to a redundant sensor system and additional internal monitoring measures, the NBT/S3 achieves a classification in SIL2 or performance level D. Its certified PROFIsafe via PROFINET interface and its two PROFINET connections enable effortless integration into standard PROFINET networks. The integrated 2-port switch enables line, tree and ring topologies. LEDs for supply voltage, link and status facilitate commissioning and fault finding. The inclinometer has a measuring range of up to -90°…+90°, and can be supplied with one or even two measurement axes. Its resolution is 0.01°. Disturbing vibrations and impacts can be suppressed with optional vibration filters. Its robust aluminium or stainless steel housing can be designed for protection classes up to IP69K, making the NBT/S3 suitable for all applications from mobile working machines up to and including plant engineering.
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Save Sensors For Man And Machine

At this year's SPS / IPC / Drives the company TWK ELEKTRONIK shows new products related to Safety Integrity Level 'SIL 2'.The new model TRK/S3 is an absolute multi turn encoder based on Hall Effect technique with an interface according to 'Failsafe over EtherCAT' (FSoE). The measuring range of 4096 rotations (12 bit) has a resolution of 8192 steps (13 bit). The encoder was SIL2 certified by German TÜV. The dual-bearing shaft allows an axial and radial load of 250 N. The massive aluminum housing of the transducer provides protection up to IP69K. This makes it particularly suitable for machinery and heavy engineering applications. Furthermore TWK provides a vibration sensor based on MEMS technology. The model NVA/S3 measures in three axes. Six factory-adjustable frequency ranges are from 0.1 to 60 Hz. They allow for dedicated filtering of vibrations. The measuring range is +/- 2g. The resolution is 4096 digits per g. The secure interface is CANopen Safety. With two analog outputs of 4 to 20 mA and two safety relays switching outputs the sensor reaches the SIL2 requirements. The robust aluminum housing with two M12 plug connectors has a protection class of IP67. Preferred areas of application are, for example, wind turbines.

Rotary encoder with slewing ring functionality

When used on slewing rings or spindles, normal rotary encoders encounter their limits. Firstly, 'curved' transmission ratios often occur and secondly, the rotary encoder should always supply a value between 0 and 360° irrespective of how often the slewing ring is rotated in one direction. No jump should therefore occur on passage through the rotary encoder's internal zero point. TWK-ELEKTRONIK can now equip your robust TRT or NOCN model series PROFINET and CANopen rotary encoders with slewing ring functionality as required. This enables the number of slewing ring and rotary encoder teeth to be set directly in the rotary encoder, allowing all conceivable transmission ratios to be implemented and the rotary encoder to be adapted precisely to the relevant slewing ring by the customer. The rotary encoder then supplies the position of the slewing ring in degrees (resolution adjustable) and its speed in degrees/time unit (time unit adjustable) as output values. From Q2 2015, the slewing ring functionality will also be available for the SIL2-certified PROFIsafe and CANopen Safety rotary encoders. Show product overview

PROFIsafe rotary encoder for secure 32-bit value processing

So far, the evaluation of PROFIsafe rotary encoders in F control systems has been anything but comfortable due to the control systems' limitation to values with a maximum of 16 bits. In the case of measuring ranges with more than 65,536 steps, the position value had to be subdivided into 2 words and these then evaluated separately. The new PROFINET-based PROFIsafe rotary encoder TRT/S3 from TWK-ELEKTRONIK now also makes use of the Step7 Safety Advance (TIA portal) option of processing double words in the safety programme. When ordered with code type 'D', the encoder now transmits the secure position value as a 32-bit value, which can then be used as one value in the F programme. Besides the secure position value, the SIL2-certified TRT/S3 also supplies a secure speed value. Position and speed recording can be adapted to the application via PROFINET. The rotary encoders are optionally available in aluminium or stainless steel with protection types up to IP69K. Electrical connection is carried out using a connector or cable outlet.
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Compact Vibration Sensor

TWK-ELEKTRONIK has developed the NVA / NVN vibration sensor as its latest product for the wind power industry. This very compact acceleration sensor is tailored specifically to the operating conditions in a wind turbine. Certain low-frequency bands which are important for vibration monitoring are digitally filtered out. Acceleration which is measured as a result of vibrations in the relevant band is output as a measurement signal – in analogue or CANopen form. Uninteresting interference frequencies are suppressed. One or more limit value relays, which switch on exceeding specific acceleration values in order to trigger an alarm or cause the control system to shut the system down, are also installed. The corresponding values for the vibration frequencies which are to be monitored and the relevant limit values can be programmed in the factory to avoid laborious parameterisation by the customer. The customer may also optionally programme them itself. This enables imbalance caused e.g. due to rotor blade icing to be detected at an early stage without leading to damage to the system. The sensor is of a twin-axis design, so that measurement can be undertaken in each X-Y plane direction. Various housing orientations are possible depending on the installation situation. As an established supplier within this sector, TWK is rounding off its product range for the wind industry with the vibration sensor.

Inclinometer with SIL2 certificate

A range of NBN 65 type inclinometers from TWK-ELEKTRONIK are now available with TÜV certification. This primarily involves the models with 1 or 2 measurement axes, which are in great demand in the mobile crane engineering sector and are required to undergo SIL 2 acceptance. The two-axis model with the measuring angles x = ± 20° and y = ± 20° is used to align the vehicle substructure horizontally at the operating location and to monitor this alignment, whereas the single-axis model with the measuring angle x = ± 90° is used to measure the extension of the crane's jib. Designed in redundant form, the system internally compares both measured values (plausibility check) and transfers the measured value to the control system. If the deviation exceeds a specific value with tight tolerances or any other system error is present in the inclinometer, an error message is generated. Secure data transfer to the control system is carried out via the CANopen safety interface. The robust sensors with stable aluminium housing comply with protection type IP 67 (optionally IP 69 K) and have an operating temperature range of -40°C to + 85°C.

50th anniversary of TWK-ELEKTRONIK

2012 TWK ELEKTRONIK was celebrating its 50th anniversary. The family-owned company founded in 1962 by Theo W. Kessler in Düsseldorf initially traded in high-quality electronics components, primarily from France, for recording angles and travel. TWK was the sole distributor in Germany. In the 70s, the company established its own development and manufacturing activities in this field. Today, TWK has around 100 employees and has established a solid reputation on the rotary encoder, inclination and longitudinal measuring systems market. As a reliable supplier, the company, which is now managed by Johannes W. Steinebach, is always focussed on customer satisfaction. As every customer application reveals special features, TWK has set itself the task of adapting components to the customer's wishes, enabling the company to always offer the optimal solution. TWK is well-known for this flexibility and has been established for a number of years. An important role is played by the research & development department. This ensures that TWK-ELEKTRONIK will continue to be represented on the market with innovative new products and remain a reliable partner to its customers in the future.

SIL2 certification for TWK Profisafe rotary encoder

In November 2008, the optoelectronic rotary encoder CRD/S with PROFIsafe protocol became the world's first to achieve SIL2 certification. A TWK electromagnetic rotary encoder was SIL2-certified back in 2007. Show product overview

New building for production and development at TWK

The growth displayed by TWK in recent years is continuing. Following an entirely positive result for 2008, the building inaugurated on 18 September 2009 in Wedel near Hamburg will extend TWK's production and development potential. A usable area of over 2000 m² and state-of-the-art equipment will enable new, flexible production processes and the development of further innovative solutions.

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