FGH 8 Optical Rotary Encoders – Hollow-shaft 80mm



Optical rotary encoders with hollow shaft up to 80 mm

  • Hollow shafts up to Ø 80 mm
  • B14 flange as basis to attach 3 more devices
  • Up to 4096 pulses HTL / TTL
  • Options: Second signal output, FOC transmitter, overspeed switch, further signal options, isolation sleeve

Incremental encoders Overspeed switches

Optical rotary encoders for main drives

The incremental encoders FGH 8 for continuous hollow shafts up to Ø 80 mm are mostly mounted on the unused shaft end by means of an isolated adapter flange or directly onto the shaft. Thanks to the flat design they are ideally suitable for attaching further sensors such as speed switches, absolute encoders or combinations of these. Furthermore, there is also the option of a redundant configuration with two equal scanning systems and evaluation electronics. That increases safety or facilitates the provision of separate signals to the motor controls and a higher-level controller.

Technical Data


Supply voltage 12-30 VDC (Option 5 VDC)
Signal amplitude HTL or TTL
Pulse rate 600, 720, 750, 1000, 1024, 1200, 2048, 2560, 2800, 4096
Output signals 0° track
Maximum frequency Hollow shaft: up to 3000 rpm (up to 1200 rpm with IP66) / max. 100 kHz
Electrical connection
  • Terminal box (copper cable or FOC connection)
  • Plug-in connector (circular connector / industry quality connector)
  • Preinstalled connection cable
Construction type / Ø shafts Hollow shaft / up to Ø 80 mm with feather key
Device temperature range -25 °C to +85 °C
Degree of protection Up to IP66
Weight Approx. 13 kg
Device options
  • Redundant version (KK) with second terminal box
  • S: Electronic overspeed switch with two mutually independent, programmable switching points
  • FOC: Encoder signals transmitted via a fiber optic cable 50/125 µm
  • 90: Second pulse track as basic track, however, electrically phase shifted by 90°
  • N/N2: Mechanically fixed reference pulse (N), one square-wave pulse per revolution, with inverted signal
  • G: Additional inverted output signals for basic track, 90° track, reference pulse including LED indication
  • 2F: Twice as many basic track pulses by combining the 0° and 90° tracks
  • B: Rapid direction of rotation sensing at each edge of 0° and 90° tracks
  • B2: Rapid direction of rotation sensing at each edge of 0° and 90° tracks; additional standstill detection
  • V: Electronic doubling of the basic track and 90° track pulses through multiple evaluation
  • L2: 150 mA power output for basic track, 90° track and their associated inverted signals
  • J: Optically adjusted pulse disk for reduced rotational frequency modulation
Mechanical options
  • B14 flange for attachments
  • Torque bracket (on request)
Special features and certificates



FGH 5/6/8/14 (de/en)


FG … (en)
Inquiry forms


FGH 8 (en)
Operating and assembly instructions


FGH / 5 / 6 / 8 / 14 (de/en)
EC declaration of incorporation