1.3.8. Calibration and compensations

Due to the fact that the range-finder chip does not know its surrounding environment and the phase-shifts caused by the electronic imple-

mentation and also due to manufacturing tolerances, a calibration of the sensor is necessary.

Whereas a simple light barrier doesn't need the same accuracy as a range-finder, the compensation and the required calibration is depen -

dent on the application.

Influencing variables for various attributes are:

■ Distance: Offset, Slope scaling, Linearity, Reflectivity, Quality, Ambient-light, Integration time, Temperature.

■ Reflectivity of the object: Quality, Ambient-light.

■ Ambient-light: Offset, Slope scaling, Linearity, Integration time, Temperature.

■ Temperature: Offset, Slope scaling, Linearity.

These compensations are necessary for the microprocessor to correct the raw distance data in the final measurement.

1.3.9. Extended operating range

The epc600 is a range-finder designed as a system-on-chip for minimum part count circuits. Therefore, a LED driver is integrated on-chip.

In cases where the illumination, achieved with the built-in driver, is not sufficient to detect near and far objects in the expected operational

range or in the necessary response time, the epc600 chip can be used with a more powerful external LED driver (refer to chapter 2.5. Ex-

ternal LED driver).

1.3.10. Multi range-finder application

Light barriers are not always operating in a single sensor application. In some applications, more than one sensor is deployed to partially

or entirely cover the same observation field. The epc600 range-finder uses signal-processing based on the sinusoidal modulation theory of

the time-of-flight principle.The LEDs are modulated with 10MHz square-wave and a duty cycle of 1:1. There is no coding in the modulation

signal to make each device unique. To date, in multi range-finder applications, cross-talk between the signals of closely placed individual

sensors can occur.

The single shot principle of the epc600 chip allows an easy synchronization of multiple sensors by a fixed time synchronization between

range-finder devices (sequencing of sensors).

© 2014 ESPROS Photonics Corporation

Characteristics subject to change without notice

16 / 30

Datasheet epc600 - V1.3

www.espros.ch