Headquarters: SIKO GmbH Weihermattenweg 2 79256 Buchenbach Germany Phone+49 7661 394-0

Overview of Encoders for Industrial Drive Technology

Electrical drive units in industrial automation processes require precise and reliable control. Intelligent encoders are indispensable, especially for direct drives, where motors and driven machines are directly connected and a gearbox is not required.

SIKO's open and non-contact encoders transmit the position and speed of the motor to subsequent electronics. These in turn regulates at what speed, in what direction and with what precision the motor is to move. The measuring system must be precisely adapted to the requirements of the application to make the electrical drive work as efficiently, safely and resource-saving as possible.

The magnetic encoders from SIKO meet the high requirements of industrial drive technology for precision, insensitivity to external influences, shock and vibration resistance. Customer-specific solutions, for example in the form of caseless encoders (PCB solution), are predestined for the smallest possible and compact designs. SIKO's measuring technology functions as an open and non-contact rotary encoder.

Incremental or absolute position feedback
When selecting a motor feedback system, it should also be considered whether an incremental or an absolute solution is required. Absolute position feedback is more convenient than the incremental option, as the sensor always knows exactly at which position it is due to the unique absolute coding – even in a non-energized state. Less expensive encoders with incremental coding always require referencing to bring the sensor back to a reference point. Consequently, absolute encoders are indispensable in applications, especially those that are critical to safety.


Real-time feedback with magnetic encoders on linear and rotary direct drives

The magnetic encoders serve for highly accurate position and speed detection for a wide range of linear and rotary applications:

Linear motors and linear drives

Linear motors are used where a very good force/mass ratio, optimum synchronization and constant speed as well as the highest path accuracy are required.
The encoders of MagLine-Serie from SIKO provide incremental and absolute position feedback for various linear motor designs.

Small, compact designs permit simple integration and efficient commissioning. SIKO’s magnetic measurement systems have an outstanding positioning accuracy and control quality in dynamic processes. The advantages with motor feedback for linear motors at a glance:

  • Completely contactless and wear-free

  • Robust when exposed to shocks and vibration

  • Simple installation and commissioning

  • Incremental and absolute measuring technology

Linear measurement with PCB solutions for small installation spaces – the SIKO linCoder technology
With With linCoder technology, SIKO provides the possibility for customized, individual PCB solutions for linear applications. It enables integration into small installation spaces and implementation of compact drive solutions. The linCoder products provide incremental or absolute measurement data to measure position and speed.

linCoder incremental
Encoder for outputting digital increments or analog sine/cos signals based on SIKO magnetic tapes. Alternatively, the motor magnets can be read directly via SIKO pole sensors.

linCoder absolute
Encoder for direct, absolute position feedback. The measured values are immediately available after de-energized states or after switching on. This is particularly useful in safety-critical applications. Measurement lengths of up to 16 m are currently available.

Gantry axes: Position values for two linear drives in one portal

Gantry axes (portal axes) are special variants of linear drives. These are two separate linear motors that run in parallel on two rails and that are controlled together in the control unit. Gantry axes are stable, accurate and are used for handling, assembly or pick & place applications, for example. Very precise interaction of the two rails is important for the portal axes, which is only possible with a coordinated measurement technique for detecting position and speed. The two feed motors must be synchronized, each with their own measuring system. In addition, the positions of the X and Z axes must be recorded. The advantages of the SIKO encoders for this application are:

  • High positioning accuracy and resolution

  • Long service life (contactless and bearing-free)

  • High operational reliability

  • Insensitivity to soiling and moisture

  • Simple installation

Torque motor: Position feedback for rotary movements

In the case of rotary direct drives, torque drives in particular are becoming increasingly important due to their widespread use. Rotary direct drives function in a similar way to linear drives. However, the coil is rotated in the magnetic circuit on the rotary motors. Torque motors usually have a continuous hollow shaft so that cables or compressed air lines can be passed through them. Torque motors are ideal for applications where high torque combined with ideal synchronous operation is required. Thanks to the high torque, rapid accelerations are possible that give the system a high level of dynamics. The demands on sensor technology are correspondingly high. The SIKO advantages at a glance:

  • Small, integrable (open) sensor designs

  • Integrable scale (Magnet ring) for different sizes

  • Interfaces with real-time signal output

  • High accuracy for exact position feedback and optimum control quality

  • Incremental and absolute measuring technology

Robotics: Compact sensors tailored to customer requirements

Torque motors are used in robot applications such as pick-and-place modules. The robot arms are usually encapsulated and contain small to medium torque motors. Consequently, the challenge for the measuring task in robotics is the precise detection of rotary and swivel movements with simultaneously limited installation space. These requirements require the integration of the encoders and benefit from the individual solutions of SIKO's linCoder and flexCoder technology.

Encoders for robotics must be very small and can often be installed without housing. SIKO provides customer-specific solutions depending on the space available in the application. The advantages at a glance:

  • Very small encoder designs for integration into torque motors

  • Customized solutions, e.g., with open PCB

  • High accuracies

  • Exact position feedback for optimum control quality in robotics

  • Absolute and incremental solution

  • Adaptation of the scales to the existing installation space

Rotary measuring systems with PCB solutions for small installation spaces – the SIKO flexCoder technology
With flexCoder technology, SIKO provides customized, individual PCB solutions for rotary applications, especially for direct integration of an encoder into the motor. It enables integration into small installation spaces and implementation of compact drive solutions. The open flexCoder encoders provide incremental or absolute measurement data. Rotational speed, position and velocity are detected. The encoders enable precise installation in the motor design.

flexCoder incremental
The encoders of the flexCoder product range provide digital increments or analog sin/cos signals. Commutation signals for motor control are also provided.

flexCoder absolute
The encoders of the flexCoder product range, such as MSAC200, provide direct, absolute position feedback, even after de-energized states. Customized adaptation to the radius of the motor shaft makes it possible for the flexCoder measuring systems to be fitted accurately into the motor design. flexCoder systems are available as singleturn and multiturn solutions as well as with resolutions up to 20 bits.

Magnetic encoders under extreme conditions

Motors sometimes work under very adverse conditions, which not only places high demands on the motor itself, but also on the measurement technology. Even in the case of dust generation (stone processing), moisture (glass cutting), in oil baths or in the case of mechanical effects such as shock and vibration, the measuring technology must function reliably. The magnetic encoders reliably detect revolutions and angles, incrementally or absolutely. The open encoders are predestined for these extreme tasks; the advantages, for example, when used in an oil bath:

  • Long service life (contactless and bearing-free)

  • High operational reliability

  • Protection category IP69K

  • Flexible, customized solutions

Magnetic encoders from SIKO: MagLine
Magnetic measuring systems have proven themselves in numerous applications and industries in which robustness, freedom from wear, durability and high accuracy are important in sensor technology. Examples are linear and rotary guidance and drive technology. They are also suitable for production machines in the fields of wood, metal, stone, glass or plastic as well as storage, conveying and elevator technology. The SIKO MagLine measurement technology operates according to the principle of contactless scanning of magnetic fields and converts their measured values into digital or analog signals. Depending on the requirements, four product families provide coordinated solutions composed of magnetic sensor, scale (magnetic tape or magnetic ring) and downstream electronics. The general advantages of magnetic encoders:

  • Completely wear-free

  • Are insensitive to external influences such as dust, moisture, oil, grease, etc.

  • Extremely robust when exposed to shocks and vibration

  • Provide high system accuracy and repeatability

  • Provide incremental or absolute encodings

  • Simple handling and installation (magnetic tapes as rolls for cutting to length)

  • Durable and economical

More safety – magnetic sensor with SIL2 certificate and DRIVE-CLiQ interface
Compliance with required safety functions is becoming increasingly important in mechanical engineering. Therefore, it is advantageous if individual components of the machine are already safety-certified and no longer need to be taken into account in the safety assessment of the entire system. The MagLine sensor MSA111C is the first absolute measuring magnet sensor in an open design – in which the scale and electronics are mechanically completely decoupled – that is certified according to SIL2. It was developed based on the Siemens DRIVE-CLiQ interface, whose SIL capability makes it possible to implement safety functions. Certain applications require a safe position or a reliably reduced motor speed to protect the operator. It must therefore be ensured that the encoder always reliably transmits the signal; the user has certified certainty with the absolute measuring encoder MSA111C.

Functional safety – safety encoders for reliable position detection
SIKO encoders help implement intelligent safety concepts and support the implementation of safety functions.

Safe, redundant encoders and systems help you to set up your complete system in accordance with standards. Selected encoders meet the requirements for use in applications up to performance level d (PLd). Special encoders with SIL2 certification permit use in safety applications.

Observance of the mechanical requirements for magnetic rings as positive locking for safe assembly are part of the system solution for safety applications


In addition to the conventional incremental output signals (digital counting pulses or analog sine-cosine signals), SIKO supports a variety of absolute interfaces that are present in a motor controller. For example, these include SSI, BISS INTERFACE, CANopen, IO-Link and DRIVE-CLIQ.



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