The FG4S‑500G‑90G‑NG incremental encoder is a legacy model widely used in heavy industrial applications such as steel rolling mills, metallurgical plants, and automated machinery. With the original product discontinued, acquiring this encoder has become increasingly difficult. To address this, we provide a 1:1 custom replacement solution that replicates the original encoder’s mechanical dimensions, shaft design, electrical interfaces, and pulse output, ensuring seamless integration into existing systems.
Designed for high-demand industrial environments, this replacement ensures stable incremental feedback, precise signal output, and reliable operation under vibration, dust, and temperature fluctuations. By offering a direct replacement, operators can maintain production continuity without costly modifications or downtime. Optional customizations are available for non-standard pulse rates and voltage levels to meet specific operational requirements.
Our solution is particularly suitable for the metallurgical and heavy machinery sectors, where reliability, precision, and durability are critical. With a rapid production cycle of approximately 15 working days, our replacement encoders provide a timely and practical solution for discontinued FG4S‑500G‑90G‑NG units.


Technical Datasheet
Pulse rates
| Category | Value |
|---|---|
| Standard pulse rates | 500, 600, 1000, 1024, 1200, 2000, 2048, 2400, 2500 |
| Special pulse rates | 4000, 4096, 4800, 5000, 8192, 10000, 12000, 16000, 16384, 20000, 25000(further pulse rates according to customers specification) |
Connection data
| Parameter | Details |
|---|---|
| Supply voltage | 12 V … 30 V DCFor UL and CSA Class 2 supplied |
| No load-current | approx. 50 mA at 24 V |
| Outputs | Current limited, short-circuit proof push-pull line driver with integrated impedance adaptation for 30 to 140 Ω lines. |
| Pulse height (HTL) | approx. as supply voltage, output saturation voltage < 0.4 V at Iₗ 30 mA |
| Output current | max. 150 mA at 24 V (observe derating) |
| Internal resistance | 75 Ω bei 24 V |
| Slew rate | 200 V / μs with Cₗ 100 pF |
| Duty cycle | 1:1 ± 3 % for standard pulse rates1:1 ± 5 % for special pulse rates up to 25000 pulses |
| Square wave displacement 0°, 90° | 90° ± 3 % for standard pulse rates90° ± 5 % for special pulse rates up to 25000 pulses |
| Max. frequency | 200 kHz, Higher max. frequency on request |
Special output voltage 5V (TTL)
| Parameter | Details |
|---|---|
| Pulse height | 5V, RS422-compatible (TIA/EIA - Standard) |
| Supply voltage | 12 … 30 V DC (optional: 5 V DC)For UL and CSA Class 2 supplied |

