The FG4S‑250G‑90G‑NG incremental encoder is a legacy industrial device widely used in heavy-duty applications, including steel mills, rolling machinery, and automated conveyor systems. As this model has reached end-of-life, acquiring the original encoder has become increasingly difficult. To address this, we provide a 1:1 custom replacement solution, precisely replicating all mechanical dimensions, electrical specifications, and pulse outputs to ensure seamless integration without requiring any system modifications.
Our replacement encoders are designed for harsh industrial environments, offering high reliability, vibration resistance, and long-term accuracy. They provide dependable incremental feedback for controlling drives, motors, and conveyors, maintaining operational consistency even under high load, dust, or vibration conditions.
By leveraging advanced manufacturing processes, the custom replacement can be produced and delivered within 15 working days, reducing downtime and supporting continuous production. This solution has been successfully adopted in multiple industrial sectors, helping operators maintain equipment performance while mitigating the risks associated with discontinued models.


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 |

