MATRIX 450™ QUICK REFERENCE GUIDE
23
REFERENCE READING DIAGRAMS
The following reading diagrams are to be considered as references and are given for
typical performance at 25°C using high quality grade A symbols: Code 128 (1D code) and
Data Matrix ECC 200 (2D code) from the Test Charts provided with the reader.
Testing should be performed with the actual Matrix 450™ + LT-03x assembly using
application codes in order to evaluate whether maximizing application performance
requires adjustments to the HW/SW configuration with respect to the Reference
Conditions given under each diagram.
The ratio of the Vertical FOV width with respect to the Horizontal FOV width in the
diagrams is about equal to 0.84; specifically 2050/2448. (i.e. FOV
V.
FOV
H
x 0.84).
The focus distance and reading distance ranges are measured from the Lens Cover
window surface.
When using a 25 mm focal length lens (LNS-1225), it is possible to use Super Narrow
Angle Lighting Systems (LT-030 or LT-031) as well as the Narrow Angle Lighting System
LT-032. It is suggested to use the LT-032 in applications with very low contrast codes
and in all cases where the higher lighting power of the LT-030 isn't necessary. LT-030
and LT-031 Lighting Systems are especially effective in high speed code movement
applications.
When defining a HW/SW configuration for the Matrix 450™ + LT-03x assembly for
conditions different from those of the reference diagrams, it is suggested to keep in mind
the following rules:
Changes in the diaphragm aperture influence the depth of field (reading distance
range) and the luminosity of the image. Increasing the the diaphragm aperture by
one stop (i.e. from F/8 to F/5.6 or from F/11 to F/8) doubles the luminosity of the
image, but can cause significant reduction in the reading distance range.
Changes
in
Exposure Time
act directly proportional to the luminosity of the image
and inversely proportional to the maximum code reading movement speed.
Consequently, reducing the
Exposure Time
by half, reduces the luminosity of the
image by half but doubles the theoretical code reading movement speed.
Changes in
Gain
act directly proportional to the luminosity of the image.
Increasing the
Gain
value however, can reduce the quality of the acquired image.
The LT-030 lighting power (at the center of the field of view) is about equal to
twice that of the LT-031 and 3.5 times that of the LT-032.
For example, for the purpose of only changing the luminosity of the image, the
following three adjustments are equivalent:
increase the the diaphragm aperture by one stop;
double the
Exposure Time
;
double the
Gain
.
