L50 Photoelectric Modular Linear Encoder

by Precizika Metrology

Modular photoelectric sealed linear encoder L50 has measuring length from 3240 mm up to 30040 mm.

The encoder is used to convert linear displacements of key machine components into electrical signals containing information about the value and direction of the displacement.

The encoder determines position by detecting light reflected off a metal band.  Metal band with 40 µm pitch scale is fixed in rigid aluminum housing with protection lips. 

The encoder consists of several separate rigid modules with length up to 2.0 m, which are joined together, and reading head. 

Two versions of output signals are available: 

  •  - L50-AV - Sinusoidal signals, with amplitude approx. 1 Vpp, require external
  •   subdividing electronics.  Resolution 0.1 µm is possible with respective external electronics.  
  •  - L50-F - Square-wave signals, with integrated subdividing electronics for interpolation x1, x2, x5, x10.


Measuring Lengths from 3240 up to 30040 (length of each module with steps 200 mm)
Accuracy grades to any metre within the ML (at 20°C) ±10 µm/m
Grating period 40 µm

Reference marks (Rl)

- C

- P

- E

at coded distance 80 mm

at constant step 50 mm

selectable through magnet


Max. traversing speed 1 m/min
Required moving force < 6 N

Protection (IEC 529):

-without compressed air

-with compressed air




Weight  1.8 kg + 3.3 kg/m
Operating temperature 0...+50°C
Storage temperature -20...+70°C
Permissible vibration (10...2000 Hz) ≤ 100 m/s²
Permissible shock (11 ms) ≤ 300 m/s²
Coefficient of thermal expansion

10.6 x 10‾6 °C


Power supply +5 V ±5% / 100 mA (120 Ohms) +5 V ±5% / 150 mA (120 Ohms)
Light source LED LED
Resolution Up to 0.1 µm depending on external subdividing electronics 10; 5; 1; 0.5 µm (after 4-fold dividing on sunsequent electronics)
Incremental signals

Differential sine +AV-A and +B/-B

Amplitude at 120 Ohms load:

- l¹ = 0.6...1.2 V

- l² = 0.6...1.2 V

Differential square-wave U1/¯U1 and U2/¯U2.  Signal levels at 20 mA load current:

-low (logic "0") ≤0.5V

-high (logic "1") ≥2.4 V

Reference signal

Quasi-triangular R Magnitude at 120 Ohms load:

-R = 0.25-0.8V (usable part)

U2 lags U1 at reading head displacement from left to right
Direction of signals B lags A at reading head displacement from left to right  
Electrical protection inversion of power supply polarity and short circuit on output port  
Cable length (standard) 4 m  4 m 
Maximum cable length (total with extension cable) 150 m  50 m