High-Performance Encoders for Motion Systems
Integrates the high accuracy and robustness of inductive technology with the wide alignment tolerances of magnetic systems.
Represented in the UK by Torquety, FLUX designs and manufactures high-performance frameless hollow-shaft encoders, engineered specifically for mechatronic developers, robotic designers, control engineers, and aerospace system integrators. By operating with a unique 360° holistic scanning geometry, FLUX systems inherently eliminate eccentricity errors, simplifying closed-loop motion control in the most demanding physical environments.
Engineered to Solve Encoder Constraints
FLUX overcomes the traditional trade-off between installation complexity, physical ruggedness, and accuracy.
Patented GMI® Technology
Giant Magneto Impedance (GMI®) technology utilizes the electromagnetic skin effect in specialized materials. The sensor determines the relative position of the scale with zero hysteresis and high resolution (up to 25 bits), providing real-time data under IP67 protection.
Advanced Inductive Scanning
Patent-pending absolute inductive technology provides high-precision position feedback in the smallest physical footprint. Complete immunity to stray magnetic fields and electromagnetic interference allows direct motor integration without shielding.
360° Holistic Scanning
Instead of single-point or segment reading, FLUX encoders scan the full 360° circumference. This holistic scanning averages out static alignment run-out and operational axis shifts, neutralizing eccentricity errors.
The Physics of Eccentricity Error Correction
In conventional single-point encoders, rotor eccentricity (misalignment between geometric and rotational centers, denoted as \(e\)) introduces significant angular errors. The static or dynamic eccentricity error in arcseconds is defined by:
FLUX’s 360° holistic scanning continuously averages signals from the entire circumference, reducing eccentricity-induced angular errors to virtually zero.
Angular Error under Misalignment (Single-Point vs. FLUX 360° Scanners)
| Encoder Size / Diameter (D) | Error with Eccentricity \(e = 10\ \mu\text{m}\) | Error with Eccentricity \(e = 20\ \mu\text{m}\) |
|---|---|---|
| GMI (96 mm) | FLUX: < ±1″ (Single-Point: ±43″) | FLUX: < ±2″ (Single-Point: ±86″) |
| GMI (160 mm) | FLUX: < ±1″ (Single-Point: ±26″) | FLUX: < ±1″ (Single-Point: ±52″) |
| GMI (180 mm) | FLUX: < ±1″ (Single-Point: ±23″) | FLUX: < ±1″ (Single-Point: ±46″) |
| GMI (250 mm) | FLUX: < ±1″ (Single-Point: ±16″) | FLUX: < ±1″ (Single-Point: ±32″) |
Frameless Absolute Encoders Portfolio
GMI-ANG Series • High Accuracy Angle Encoders
High-precision rotary axes, CNC machine tool tables, and calibration systems require absolute positioning feedback with sub-arcsecond repeatability. Under dynamic operating conditions, standard encoders face structural strain and misalignment, causing thermal drift and measurement errors.
Traditional optical encoders offer high accuracy but are highly susceptible to dust, condensation, and mechanical shock, and require complex mounting setups with precise alignments. FLUX GMI-ANG series addresses this vulnerability by utilizing patented GMI® technology to deliver optical-grade accuracy combined with the physical ruggedness of an inductive sensor and generous mounting tolerances.
Featuring a bearingless, frameless design with a generous hollow shaft, the GMI-ANG encoders are built into a heavy-duty stainless steel housing. The integration is simplified with sliding fits, and an onboard alignment LED provides real-time feedback on installation quality.
Technical Specifications:
| Model | Outer Diameter | Stator ID / Rotor ID | Max Resolution | Standard Accuracy | High Accuracy (Opt C) |
|---|---|---|---|---|---|
| GMI-ANG-096 | 96 mm | 50 mm / 35 mm | 23-bit | ±14″ | ±8″ |
| GMI-ANG-160 | 160 mm | 110 mm / 110 mm | 24-bit | ±7″ | ±5.5″ |
| GMI-ANG-180 | 180 mm | 130 mm / 110 mm | 24-bit | ±7″ | ±5.5″ |
| GMI-ANG-250 | 250 mm | 200 mm / 180 mm | 25-bit | ±4″ | ±3″ |
* Standard operating specifications: 2,000 rpm max speed, nominal air-gap 0.30 mm (±0.25 mm tolerance), 4.35 to 36 Vdc supply with reverse polarity protection, IP67 protection, vibration 20G, shock 200G.
GMI-ROT Series • Precision Rotary Encoders
Modern collaborative robot (cobot) joints, compact satellite communication (satcom) gimbals, and surgical robotic systems demand extremely flat feedback devices. These systems require high resolution and repeatability to maintain smooth velocity control and precise trajectories in highly space-constrained environments.
Standard optical and magnetic encoders are often too thick, require dedicated bearings, or suffer from signal latency and hysteresis during direction changes. The FLUX GMI-ROT series provides a compact, frameless rotary solution that operates without hysteresis, providing real-time absolute position updates at high resolution up to 23 bits.
Built with an axial installation profile of just 8 mm, the GMI-ROT series offers rotor mounting variations (internal, external, or radial clamping) in either lightweight anodized aluminum or high-strength steel housings. The non-contact design permits wide axial air-gap tolerances from 0.20 to 0.80 mm.
Technical Specifications:
| Model | Outer Diameter | Stator ID / Rotor ID | Max Resolution | Standard Accuracy | High Accuracy (Opt C) |
|---|---|---|---|---|---|
| GMI-ROT-055 | 55 mm | 26.20 mm / 17 mm (A11) or 25 mm (B11) | 21-bit | ±50″ | ±36″ |
| GMI-ROT-069 | 69 mm | 40.20 mm / 29 mm (A11) or 39 mm (B11) | 22-bit | ±36″ | ±29″ |
| GMI-ROT-080 | 80 mm | 51.20 mm / 40 mm (A11) or 50 mm (B11) | 23-bit | ±25″ | ±14″ |
| GMI-ROT-096 | 96 mm | 67.20 mm / 56 mm (A11) or 66 mm (B11) | 23-bit | ±18″ | ±10″ |
| GMI-ROT-120 (OEM) | 120 mm | Custom OEM | 22-bit | Custom OEM | Custom OEM |
| GMI-ROT-150 | 150 mm | 121.20 mm / 110 mm (A11) or 120 mm (B11) | 23-bit | ±12″ | ±8″ |
* Standard operating specifications: 6,000 rpm max speed, nominal air-gap 0.30 mm (0.10-0.80 mm range), 4.35 to 36 Vdc supply, IP67 protection, available in Anodized Aluminum (AL) or Stainless Steel (ST).
IND-ROT Series • Inductive Flat Rotary Encoders
Compact mechatronic actuators, exoskeletons, and mechatronic grippers operate under severe space and weight restrictions. Feedback sensors integrated into these systems must add minimal weight while remaining completely immune to stray magnetic fields from nearby motor coils.
Traditional magnetic encoders are disrupted by magnetic stray fields from high-power density motors, while optical encoders are too bulky and fragile for wearable or high-vibration applications. The FLUX IND-ROT series solves this constraint by utilizing a patent-pending inductive absolute scanning principle that is completely immune to electromagnetic interference.
Consisting of an ultra-lightweight open PCB stator and a stainless steel or aluminum rotor, the IND-ROT series features a thickness below 6 mm and a total weight of just 9 g to 30 g. The bearingless, non-contact design ensures a maintenance-free lifetime with generous mounting tolerances.
Technical Specifications:
| Model | Outer Diameter | Stator ID / Rotor ID (A21) | Max Resolution | Standard Accuracy | Max Achievable Accuracy |
|---|---|---|---|---|---|
| IND-ROT-034 (MINI) | 34 mm | 9 mm / 8 mm | 18-bit | ±0.050° (±180″) | ±0.030° (±108″) |
| IND-ROT-036 (MINI) | 36 mm | 11 mm / 8 mm | 19-bit | ±0.040° (±144″) | ±0.025° (±90″) |
| IND-ROT-045 (MINI) | 45 mm | 17 mm / 8 mm | 19-bit | ±0.040° (±144″) | ±0.025° (±90″) |
| IND-ROT-055 (Std) | 55 mm | 26 mm / 17 mm | 21-bit | ±0.025° (±90″) | — |
| IND-ROT-069 (Std) | 69 mm | 40 mm / 29 mm | 21-bit | ±0.020° (±75″) | — |
| IND-ROT-080 (Std) | 80 mm | 51 mm / 40 mm | 21-bit | ±0.018° (±65″) | — |
| IND-ROT-096 (Std) | 96 mm | 67 mm / 56 mm | 22-bit | ±0.012° (±45″) | — |
* Standard operating specifications: IP00 open PCB design (acrylic conformal coating optional), nominal air-gap 0.50 mm (0.20-0.80 mm range), 4.35 to 36 Vdc supply for MINI and 5 V for Standard, 6,000 rpm max speed, operating temp -20° to +85°C (extended to +105°C optional).
IND-MAX Series • Rugged Inductive Encoders
Unmanned aerial vehicles (UAVs), tactical defense gimbals, naval radar mounts, and heavy heavy-duty machinery operate in extreme environments subject to heavy rain, dirt, and severe vibration. Positioning feedback systems in these applications must guarantee absolute reliability and high precision despite temperature fluctuations and mechanical shock.
Conventional absolute encoders are prone to physical wear or sealing degradation under exposure to mud, saltwater, and high-G forces, leading to sensor failures. The FLUX IND-MAX series overcomes these challenges by using an inductive absolute technology encapsulated in a rugged IP67-rated housing, providing high-precision feedback under severe conditions.
The IND-MAX series is housed in anodized aluminum with optional electroless nickel plating, delivering high rigidity in a hollow-shaft, frameless design. It supports high operating temperatures from -45°C to +105°C and can withstand vibrations up to 20G and mechanical shocks of 200G.
Technical Specifications:
| Model | Outer Diameter | Stator ID / Rotor ID | Max Resolution | Accuracy Grades |
|---|---|---|---|---|
| IND-MAX-075 | 75 mm | 25.80 mm / 25 mm | 23-bit | Grade B / C / D (down to ±36″) |
| IND-MAX-100 | 100 mm | 50.80 mm / 50 mm | 22-bit | Grade B / C / D / E (down to ±18″) |
| IND-MAX-125 | 125 mm | 75 mm / 75 mm | 21-bit | Grade B / C / D / E (down to ±18″) |
| IND-MAX-160 | 160 mm | 110 mm / 110 mm | 23-bit | Grade B / C / D / E (down to ±18″) |
| IND-MAX-180 | 180 mm | 130 mm / 110 mm | 23-bit | Grade B / C / D / E (down to ±18″) |
| IND-MAX-200 | 200 mm | 150 mm / 150 mm | 23-bit | Grade C / D / E / F (down to ±14″) |
| IND-MAX-250 | 250 mm | 200 mm / 180 mm | 23-bit | Grade C / D / E / F / G (down to ±7″) |
| IND-MAX-300 | 300 mm | 250 mm / 250 mm | 23-bit | Grade C / D / E / F / G (down to ±7″) |
| IND-MAX-375 | 375 mm | 325 mm / 325 mm | 23-bit | Grade C / D / E / F / G (down to ±7″) |
* Standard operating specifications: IP67 sealing (upgradeable to IP68), air-gap nominal 0.50 mm (reduced to 0.35 mm for Grade G with high-accuracy Option C), 6,000 rpm max speed, EMI compliance EN IEC 61000-6-2/4.
IND-MAX Marine Grade • Subsea Position Encoders
Offshore oil and gas platforms, underwater ROVs/AUVs, azimuth thrusters, and deck winches operate under constant exposure to high salinity, corrosive galvanic action, and immense pressure. Position feedback sensors in these applications must resist chemical degradation while maintaining absolute accuracy during long-term immersion.
Standard industrial encoders quickly corrode in saltwater or leak under hydraulic pressure, requiring frequent and costly replacements. The FLUX IND-MAX-100 Marine Grade resolves this issue by combining the electromagnetic immunity of 360° inductive scanning with a fully sealed, marine-grade stainless steel enclosure.
Sealed to IP68/IP69K for permanent submersion and high-pressure washdowns, this Marine Grade version features extreme temperature tolerances and an optional rating for pressure resistance up to 200 bar. The housing design eliminates cathodic corrosion risks and is immune to high electrical noise from massive naval generators.
Technical Specifications:
| Model | Outer Diameter | Stator ID / Rotor ID | Max Resolution | Accuracy Grades | Sealing Class |
|---|---|---|---|---|---|
| IND-MAX-100-Marine | 100 mm | 50.80 mm / 50 mm | 22-bit | Grade B / C / D / E (down to ±18″) | IP68 / IP69K (Subsea) |
* Standard operating specifications: 200 bar high pressure option, storage temperature -55°C to +100°C, full marine-grade anodized aluminum construction, 360° scanning.
Communication Interfaces & Pinouts
FLUX encoders support a wide range of standard protocols for direct integration with control systems.
Absolute Serial Protocols
BiSS-C (Bidirectional Synchronous Serial): Designed for real-time high-speed data transmission. Includes status flags (Error, Warning) and 6-bit CRC checking. Clock rates up to 5 MHz are supported with line delay compensation for cable runs over 3 meters.
- BIS00: 32-bit position, right-aligned. (Recommended for linear systems).
- BIS10: 24-bit position, left-aligned. (Recommended for rotary systems up to 24-bit).
- BIS20: 32-bit position, left-aligned. (Recommended for rotary systems 25-bit and higher).
SSI (Synchronous Serial Interface): Unidirectional protocol using RS-422 differential signals. Supported options include SSI00 (Error, Warning, and Even Parity), SSI01 (Raw position data transmission), SSI02 (SPI master compatible in Mode 2), SSI03 (Virtual Multi-Turn configuration with 46-bit transmission), SSI04 (24-bit transmission containing 22 right-aligned position data bits and 1 active-low Error status bit (nE)), and SSI11 (Position data transmission with no status bits in the data frame).
Asynchronous & Incremental Protocols
UART (UATxx Series): Asynchronous serial data is transmitted continuously over differential RS-485/RS-422 lines without a clock signal. Available baud rates are: UAT00: Operating at 230.4 kbps (230,400 bps) with a 2.5 kHz frame cycle. UAT01: Operating at 921.6 kbps (921,600 bps) with a 10.0 kHz frame cycle. UAT10: Supported on select models (GMI-ANG and IND-MAX) for custom asynchronous communications.
Incremental A/B/Z (INCxx Series): Dual square waves phase-shifted by 90° electrical with a differential Z index channel (RS-422 / TTL).
- INC00: 5.0 MHz maximum frequency before quadrature evaluation (20M counts/sec). Supports speeds up to 4,577 rpm at 18-bit resolution, or 6,000 rpm at 14-bit resolution.
- INC01: 2.5 MHz maximum frequency before quadrature.
Connector Pinout Tables
IND-ROT MINI Series (11-Pin, 1.25mm Pitch)
| Pin | SSI / BiSS-C | Incremental | Description |
|---|---|---|---|
| 1 | VDD | VDD | Supply Voltage (4.35-36 Vdc) |
| 2 | GND | GND | Power Ground |
| 3 | NC | B+ | Incremental B (+) |
| 4 | NC | B- | Incremental B (-) |
| 5 | NC | A+ | Incremental A (+) |
| 6 | NC | A- | Incremental A (-) |
| 7 | SCLK+ | NC | Sync Clock (+) |
| 8 | SCLK- | NC | Sync Clock (-) |
| 9 | SDATA+ / TX+ | Z+ | Data (+) / Serial TX (+) / Index (+) |
| 10 | SDATA- / TX- | Z- | Data (-) / Serial TX (-) / Index (-) |
| 11 | SHIELD | SHIELD | Cable Ground Shield |
IND-ROT Standard Series (10-Pin, 0.80mm Pitch)
| Pin | SSI / BiSS-C | Incremental | UART |
|---|---|---|---|
| 1 | VDD | VDD | VDD |
| 2 | GND | GND | GND |
| 3 | NC | B+ | NC |
| 4 | NC | B- | NC |
| 5 | NC | A+ | NC |
| 6 | NC | A- | NC |
| 7 | SCLK+ | NC | NC |
| 8 | SCLK- | NC | NC |
| 9 | SDATA+ | Z+ | TX+ |
| 10 | SDATA- | Z- | TX- |