L23 Phototelectric Modular Linear Encoder

by Precizika Metrology

Modular sealed phototelectric linear encoder L23 has measuring length up to 20 meters and more on special order. 

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

The encoder operates in reflected from metal band light beam.  Metal band with made on its surface grating scale is fixed in rigid aluminum housing with double protection lips.

The encoder consists of several separate modules with length up to 3,0 m, which are jointed together, and reading head. 

The standard encoder has three square-wave TTL out-put signals:  2 main signals, shifted by 90 degrees and one reference signal.



Measuring lengths (ML), mm 250, 300, 350, 400, 450, 500......20000 (more on option)
Accuracy grades to any metre within the ML (at 20°C) ±10; ±5; ±3 µm
Grating period (T) 400; 40; 20 µm

Max. traversing speed:

-when T=400 µm and resolution 100, 50 10 µm

-when T=40 µm and:

-resolution 10, 5 µm

-resolution 1 µm

-when T=20 µm and:

-resolution 5 µm

-resolution 0,5 µm

120 m/min  



80 m/min

25 m/min  

60 m/min      

12 m/min              

Reference marks (RI):

- N

- M

- P (optional)

without reference mark

every 50 mm

RI number and place

Required moving force < 4 N

Protection (IEC 529)

-without compressed air

-with compressed air



Weight 0.4 kg + 2.8 kg/m
Operating temperature 0....+50°C
Storage temperature -20...+70°C     
Permissible vibration (10...2000 Hz) ≤ 100 m/s² 
Permissible shock (11 ms) ≤ 150 m/s²   
Coefficient of thermal expansion 10.6x10‾6 °C




Supply voltage (U)

+5V±5%/ 65 mA;

+12V±5%/ 65 mA

Light Source LED
Resolution 100, 50; 10; 5; 1; 0.5 µm (after 4-fold in subsequent electronics)
Incremental signals Differential square-wave U1/U1 and U2/U2
Reference signal Differential square-wave U0/U0
Signal levels at load current 20 mA:

-low (logic "0") 

-high (logic "1") >2.4 V at Up=+5V

-low (logic "0") 

-high (logic "1") >(Up-2) V at Up=+12V (HTL)

Direction of signals U2 lags U1 (displacement from left to right and head position down)
Standard cable length 4 m armoured, without connector    
Maximum cable length 25 m    

Note:  If cable extension is used the power supply conductor section should not be smaller than 0.5 mm².