Hollow-shaft Encoders

The InTrack-EN25 absolute encoders feature SSI or BiSS interfaces. They use an inductive resonant target sensor technology to achieve a resolution of 19 bits for single revolutions and up to 16 bits for the multiturn counter. The hollow shaft encoder is designed for 25 mm shafts and has an outer diameter of 108 mm. The zero setting input and the counting direction input are available via M12, 8-pin or radial cable connections.
Absolute encoder with 25mm through-hole
A high level of precision. The accuracy specification is higher than most optical encoders.
Provides reliable position feedback in the presence of strong magnetic fields and under the risk of internal condensation. Ceramic balls in hybrid bearings act as galvanic separators and thermal decouplers. They reliably eliminate corrosion and wear of the bearings caused by shaft currents. Temperature range from -40°C to +90°C, tight and resistant in daily use with IP54 protection.

Technical data


Voltage supply

4.75…30 VDC

Reverse polarity protection

Yes, including any wiring faults

Short-circuit proof


Consumption w/o load

≤90 mA (5 VDC)

Power consumption

typ. 0.5 W


SSI 32 bit (multiturn)
SSI 24, 25, or 26 bit (singleturn)
UART 921,600/8-N-1


Multiturn (with Power off brake)

Steps per revolution

19 bit (2.5″)

Number of revolutions

11 bit (SSI)
16 bit (BISS)

Absolute accuracy

±0.005 ° (20″)

Repeat accuracy

±0.0014 ° (5″)

Sensing method

Inductive, resonant target

Input signals

SSI/BISS clock
Zero setting input
Counting direction

Output stage


Output signals


Clock frequency

2 MHz (SSI)
10 MHz (BISS)

SSI configuration

Parity bit
Error bit
Output code: Gray or Binary

SSI Multipath transmission


Internal cycle time

20 µs

Fixed latency

40 µs, synced to SSI/BISS requests

Group delay

50 µs

Cyclical scanning

up to 20kHz

Interference immunity

EN 61000-6-2



Ø 100 mm

Installation height

39 mm

Shaft type

40 mm hollow shaft
35 mm hollow shaft
30 mm hollow shaft
25 mm hollow shaft
25.4 mm hollow shaft

Insertion depth min

25 mm 

Working temperature

-40 °C … +90 °C

Bearings type

Ceramic Hybrid Bearings

Protection level

IP 54


Radial cable
M12, 8-pin

Max. rotational speed

6,000 rpm mechanical
12,000 rpm electrical limit


Housing: aluminium
Shaft: brass


Torque support:
Mounting holes ø107 mm

Shaft mounting

Clamping ring

Weight approx.

400 g