Interfaces of HEIDENHAIN Encoders

As defined transitions between encoders and subsequent electronics, interfaces ensure the reliable exchange of information.

HEIDENHAIN offers encoders with interfaces for many common subsequent electronics. The interface possible in each respective case depends, among other things, on the measuring method used by the encoder.

Incremental signals

Sinusoidal signals1 VPPHEIDENHAIN encoders with 1 VPP interface provide voltage signals that can be highly interpolated.
11μAPPHEIDENHAIN encoders with 11 μAPP interface provide current signals. They are intended for connection to ND position display units or EXE pulse-shaping electronics from HEIDENHAIN.
Square-wave signalsTTLHEIDENHAIN encoders with TTL interface incorporate electronics that digitize sinusoidal scanning signals with or without interpolation.
HEIDENHAIN encoders with HTL interface incorporate electronics that digitize sinusoidal scanning signals with or without interpolation.

Position values

EnDatThe EnDat interface is a digital, bidirectional interface for encoders. It is capable both of transmitting position values as well as transmitting or updating information stored in the encoder, or saving new information. Thanks to the serial transmission method, only four signal lines are required.
Company-specific serial interfaces

PROFIBUS is a nonproprietary, open fieldbus in accordance with the international EN 50 170 standard. The connecting of sensors through fieldbus systems minimizes the cost of cabling and reduces the number of lines between encoder and subsequent electronics.


PROFINET IO is the open Industrial Ethernet Standard for industrial communication. It builds on the field-proven function model of PROFIBUS-DP, but uses fast Ethernet technology as physical transmission medium and is therefore tailored for fast transmission of I/O data. It offers the possibility of transmission for required data, parameters and IT functions at the same time.

SSIThe absolute position value beginning with the Most Significant Bit (MSB first) is transferred on the DATA lines in synchronism with a CLOCK signal transmitted by the control. The SSI standard data word length for singleturn absolute encoders is 13 bits, and for multiturn absolute encoders 25 bits. In addition to the absolute position values, incremental signals can be transmitted.