Dotcodes - Siemens SIMATIC MV540 H Operating Instructions Manual

Range of application
● The codes can have any alignment in the image.
● The code can be printed both dark on a light background and light on a dark background.
● Codes with a bar width ≥ 3 pixels and in which the height of a single row of symbols is ≥ 9
pixels can be read.
● The width of the black and white bars must be uniform over the entire code field.
● The viewing angle of the sensor to the surface can be between 70° and 90°.
● The code should not make contact with any other objects in the image, you can do this,
for example by keeping the quiet zone free with twice the column width.
● Within the code, the ratio of contrast (in other words, the difference between black and
white) to noise should be at least three. The ratio must be about the same throughout the
code field.
● The image background must have a homogeneous brightness, for example no texture
such as stripes.
● The error correction codes (in other words, the lower part of the barcode) must not be
covered.
● At the minimum bar width, each symbol column requires 51 pixels. Along with the four
start and stop patterns, the width of the code with n code columns is at least:
Width = 51 x (n + 4) pixels.
Due to the limited image resolution, codes can be read as follows:
– SIMATIC MV500 S up to 40 code lines and up to 6 code columns.
– SIMATIC MV500 H up to 60 code lines and up to 12 code columns.
3.1.2.5

DotCodes

The recognition process of the optical reader allows reliable and fast reading of printed dot
codes of good quality.
Range of application
● The range of image sizes is from 4 to 40 pixels per cell. The range is static.
● The cells are isolated.
● The distortions are minimal, for example due to installation of the optical reader at an
angle.
● There are no or only a few foreign objects in the area of the code.
● There are no interference patterns (grooves, granularity) in the area of the code.
● Fluctuations in contrast are slight.
SIMATIC MV500
Operating Instructions, 06/2018, C79000-G8976-C494-01
Image processing
3.1 Code reading (1D/2D codes)
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