2-Channel Rail Speed Sensor GEL 2471 - MiniCoder GEL 2471

Speed Sensor Gel 2471 - Lenord & Bauer Rail Speed Sensors and Rotary Pulse Encoders Rail Speed Sensor Gel 2471

General information

The MiniCoder family from Lenord + Bauer offers spacesaving solutions for the contactless measurement of rotational movements with direction sensing. The MiniCoders operate from 0 Hz on for the detection of very slow movements without pulse loss and up to 20 kHz for the direct integration into high-speed motors and machines. The high interference immunity ensures reliable function even under adverse operating conditions. The MiniCoder GEL 2471 works according to the induction principle and scans targets made of electrically conducting materials. The sensor can be factory-programm to scan either toothed wheels made of steel or for example, a weightsaving aluminium toothed ring mounted on an existing motor fan wheel.

Main Features

  • module range from m = 2.0 to m = 3.0
  • measuring frequency from 0 to 20 kHz
  • simple flange-mounting without adjustment
  • robust stainless steel casing
  • straight or side cable outlet
  • customized cable fittings
  • very high protection class IP 68
  • wide temperature range -40 C to +120 C
  • high electromagnetic compatibility

Fields of application

  • rail vehicles
  • - traction control
    - wheel slip prevention
    - engine speed
  • machine automation
  • - measurement of speeds and positions in machines and motors

Output signals

  • signal forms:
  • - single-track square-wave signals
    - two 90-shifted square-wave signals for direction sensing
    - one square-wave signal and one direction signal
All signals are also available in their inverted form.

Technical data

Electrical Data
Supply voltage UB = 10 ... 20 V DC, reverse polarity protected
Current consumption without load IB≤ 40 mA
Output signals square-wave, push-pull driver Imax = 20 mA
Signal pattern
Input and output frequency 0 ... 20 kHz
Duty 0.5 +/- 0.25
Rise time (2 m cable) ≥ 10 V/s
Max. cable length 100 m
Electromagnetic Capability *
Case 1: screen connected to housing
Case 2: screen not connected to housing
rail vehicles: EN 50121-3-2
industry applications: EN 50081-1; EN 61000-6-2
rail vehicles: test in according with EN 50121-3-2 1)
Isolation strength 500 V
Connection fully potted cable outlet with stress relief, 6 x 1 mm2
screen connected at encoder (recommended), optionally insulated
cable specification: please request separately
Mechanical data
Module m = 2.0; 3.0
(other modules between 2.0 and 3.0 available on request)
Admissible air gap depending on module, frequency and temperature range up to max. 1.5 mm
Working and operating temperature range -40C ... +120C
Storage temperature range -40C ... +120C
Protection class IP 68
Vibration resistance (EN 60068 part 2-6) 200 m/s2
Shock resistance (EN 60068 part 2-27) 2000 m/s2
Width of measuring toothed-wheel ≥ 10 mm taking into account all tolerances
Form of measuring toothed-wheel involute teeth, slotted teeth, others on request
Material of measuring toothed-wheel steel or alternatively aluminium other electrically conducting materials on request
Weight with 2 m cable without fittings approx. 500 g
Housing Stainless Steel

(1) When the shield is not connected at the encoder end, the test level in acc. with EN 61000-4-4 may be lowered depending on installation conditions.

* Test according to EN 61000-4-3: In some cases strong electromagnetic fields can inherently affect the sensors HF-oscillator when the sensor is mounted in the open. Sensors installed in a casing are generally sufficiently screened from such fields.


Speed Sensor Gel 2471 Straight Cable outlet - Lenord & Bauer Rail Speed Sensors and Rotary Pulse Encoders

Signal level

Speed Sensor Gel 2471 Side cable outlet - Lenord & Bauer Rail Speed Sensors and Rotary Pulse Encoders

Installation drawing, EMC and ESD instructions

Speed Sensor Gel 2471 Installation Drawing - Lenord & Bauer Rail Speed Sensors and Rotary Pulse Encoders

EMC Instructions

To improve the electromagnetic environment please observe the following installation advice:
  • Connect the screen at the end of the cable using a large contact surface, if possible.
  • Keep all unscreened cables as short as possible.
  • Keep grounding connections as short as possible using large cross-sections (low-induction grounding strip, ribbon cable)
  • If the event of differences in potential between machine ground and ground of electronic circuit, appropriate measures must be taken to prevent equalizing currents from flowing via the cable shield (e.g. by providing for large-section equipotential bonding conductors or by using cables with separate double shielding where the shields are connected only at one end).
  • Lay signal and control cables away from power lines.
  • The power supply must correspond to installation class 0 or 1 in according with B.3 of EN 61000-4-5 of 1995.

ESD instructions

(Components sensitive to electrostatic discharge) As with any other electronic device, the MiniCoder must be connected with the necessary precautions against the risk of electrostatic discharge. Connector pins and connecting wires must not be touched without suitable discharge protection devices. Observe the instructions of EN 100 015-1.

Supply voltage concept

Speed Sensor Gel 2471 standard, screen connected at the encoder housing
Speed Sensor Gel 2471 (option, screen not connected at the encoder housing)

Examples of customized cable connections

Speed Sensor Gel 2471 standard, screen connected at the encoder housing
Speed Sensor Gel 248 Dimensions - Lenord & Bauer Rail Speed Sensors and Rotary Pulse Encoders

Cable Wire Assignment

(GEL 2471 without fittings, screened) Speed Sensor Gel 2471 Cable Wire Assignment - Lenord & Bauer Rail Speed Sensors and Rotary Pulse Encoders

Speed Sensor Gel 2471 Typecode

Speed Sensor Gel 2471 typecode - Lenord & Bauer Rail Speed Sensors and Rotary Pulse Encoders

Ordering information: If customized cable, conduit and connectors are required, please supply detailed specifications.

Lenord & Bauer: Rail Speed Sensors & Rotary Pulse Encoder

Other products relating to GEL 2471 are: GEL 247, GEL 248, GEL 2472, GEL 2474, GEL 2477, GEL 2478