L18C Photoelectric Linear Encoder

by Precizika Metrology

The sealed linear encoder L18C 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 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 (lubricants and chips), the encoder has sealing lips.  Filtered air can be supplied into the housing of the encoder for extra protection.

The photoelectric unit of the ready head generates sinusoidal micro-current or TTL square-wave (standard RS422) output signals.

MECHANICAL DATA

Measuring lengths (ML), mm 70; 120; 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; 3140; 3240) (other intermediate lengths on request)

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

-for ML 70 to 2040

-for ML 2040 to 3240

±10; ±5 µm

±10 µm

Grating period 20 µm; 40 µm (optional)

Reference marks (RI):
-standard S1

-standard S2

-optional

middle of ML±2 mm

40±2 mm from left end of ML

40±2 mm from right end of ML

one Rl at any location, or two or more Rl's separated by distance of n x 50 mm

Max. traversing speed: 

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

-when interpolation factor is 25

-when interpolation factor is 50

1 m/s

 

0.5 m/s

0.4 m/s

Required moving force with sealing lips < 3 N

Protection (IEC 529)

-without compressed air

-with compressed air (optional)

IP53

IP64

 

Weight 0.4 kb + 1.0 kg/m
Operating temperature 0...+50°C
Storage temperature -20...+70°C            
Permissible vibration (40 to 2000 Hz) ≤30 m/s²     
Permissible shock (11 ms) ≤100 m/s²

ELECTRICAL DATA 

VERSION L18C-A ∼ 11 µApp L18C-AV ∼ 1 Vpp L18C-F TTL
Power supply +5 V ± 5% / < 90 mA
Light source LED LED LED
Incremental Signals

Two sinusoidal l¹ and l² Amplitude at 1 k Ohm load:

- l¹ = 7-16 µA

- l² = 7-16 µA

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

Amplitude at 120 Ohm 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

- high (logic "1") ≥ 2.4 V

Reference signal Quasi-triangular l° = 2-8 µA

Quasi-triangular +R and its complementary -R.  Signals magnitude at 120 Ohms load

-R = 0.2-0.8 V

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

- low (logic "0") <0.5V

- high (logic "1") >2.4V

Maximum operating frequency 50 kHz 50 kHz

50xk kHz, when interpolation factor is 1, 2, 5, 10

1000 kHz when interpolation factor 25, 50

Direction of signals l² lags l¹ at reading head displacement from left to right B+ lags A+at reading head displacement from left to right U2 lags U1 at reading head displacement from left to right
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 0.5mm².