L35T Photoelectric Linear Encoder

by Precizika Metrology

The precision sealed linear encoders L35T is used to convert linear displacements of key machine components into electrical signals containing information about the value and direction of the displacements.

The encoder consists of a glass scale installed into a rigid hollow housing and a ball-bearing-guided reading head.  To be able to work in harsh environments (cooling liqud, lubricants and chips), the encoder has two rows of sealing lips.  Filtered compressed air can be supplied into the housing of the encoder for extra protection from dust. 

Characteristic feature of encoder is a rigid housing that provides better resistance to vibration and higher protection grade due to two pairs of sealing lips.

Mounting of encoder on the object is made through two end housings wih built-in devices to enhance the thermal stability.

Reference marks can be selected by magnet, which moves in horizontal groove on the front side of encoder (optional).

 Three versions of output signals are available:

  • L35T-A - sinusoidal signals, with amplitude approx. 11 µApp.
  • L35T-AV - sinusoidal signals, with amplitude approx. 1 Vpp.
  • L35T-F - square wave signals, type TTL or HTL (standard RS422) with integrated subdividing electronics for interpolation x1, x2, x5, x10, x25, x50.

 MECHANICAL DATA

Measuring Lengths (ML), mm 170; 220; 270; 320; 370; 420; 470; 520; 620; 720; 820; 920; 1020; 1140; 1240; 1340; 1440; 1540; 1640; 1740; 1840; 1940; 2040; 2140; 2240; 2340; 2440; 2540; 2640; 2740; 2840; 2940; 3040; 3141; 3240

Accuracy grades to any metre within the ML (at 20°C)

-for ML from 170 up to 2040 mm

-or ML from 2040 up to 3240 mm

 

 

 

±5; ±3; 2 µm (optional)

 

±10 µm

Grating period

 

20 µm; 40 µm

Reference marks (RI):

-standard for ML ≤ 1020 mm

-standard for ML > 1140 mm

-optional

-distance-coded

-selection by magnets

 

35mm from both ends of ML

 

45mm from both ends of ML

 

onr Rl at any locations, two or more Rl's separated by distance of ( n x 50 mm)

see drawing

standard - one magnets (Rl) in ML middle

Max. traversing speed:

-when interpolation factor is 1, 2, 5, 10

-when interpolation factor is 25

-when interpolation factor is 50

 

1 m/s (shortly 2 m/s)

 

 

0.5 m/s

 

0.4 m/s

Required moving force with sealing lips < 5 N

Protection (IEC 529)

-without compressed air

-with compressed air (optional)

 

 

IP54

 

IP64

 

Weight 0.4 kg + 2.8 kg/m
Operating temperature 0...+50°C
Storage temperature -20...+70°C            
Permissible vibration (40 to 2000 Hz) ≤ 150 m/s² 
Permissible shock (11 ms) ≤ 300 m/s²

ELECTRICAL DATA

VERSION L35T-A ∼ 11 µApp L35T-AV ∼ 1 Vpp L35T-F TTL; HTL
Power supply +5 V ± 5% / < 90 mA +5 V ± 5% < 90 mA +5 V ± 5% / < 120 mA; +12V±5% / < 130 mA
Light source  LED LED LED
Resolution Depends on external subdividing electonics Depends on external subdividing electronics 5; 2.5; 1; 0.5; 0.2; 0.1 µm (after 4-fold dividing in subsequent electronics)
Incremental signals

Two sinusoidal l1 and l2

Amplitude at 1 k Ohms load:  

-l1 = 7-16 µA

-l2 = 7-16 µA

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

Amplitude at 120 Ohms load:

-A = 0.6-1.2 V

-B = 0.6-1.2 V

Differential square-wave U1/¯U1 and U2/¯U2. 

Signal levels at 20 mA load current:

-low (logic "0") ≤0,5 V at Up=+5V

-high (logic "1") ≥2,4 V at Up=+5V

-low (logic  "0")≤1,5 V at Up=+12V (HTL)

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

Reference signal

One quasi-triangular l0. Signal magnitude at 1 kOhms load:

-l0 = 2-8 µA (usable component)

One quasi-triangular +R and its complementary -R per revolution.  Signals magnitude at 120 Ohms load.

-R = 0.2-0.8 V (usable component)

One differential square-wave U0/U0 per revolution.  Signal levels at 20 mA load current:

-low (logic "0") ≤0.5 V at Up=+5V

-high (logic "1") ≥2,4 V at Up=+5V

-low (logic "0") ≤ 1,5 V at Up=+12V (HTL)

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

Maximum operating frequency 

50 kHz (v=1 m/s)

100 kHz (v=2 m/s shortly)

where k- interpolation factor

50 kHz (v=1 m/s)

100 kHz (v=2 m/s shortly)

(50 x k) kHz for k = 1, 2, 5, 10

1000 kHz for k = 25, 50

Direction of signals l² lags l¹ B+ lags A+ U² lags U¹ (displacement from left to right and head position down respective glass scale)
Standard cable length 3 m, without connector 3 m, without connector 3 m, without connector
Maximum cable length 5 m 25 m  25 m 

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