Siemens SIMATIC MV500, Руководство по эксплуатации, Страница: 45 / 294

Image processing
3.2 Code verification
SIMATIC MV500
Operating Instructions, 03/2021, C79000-G8976-C494-05
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Marking quality
To recognize and ensure the readability and quality of a marking, a verifier is required instead
of a pure optical reader. A pure optical reader (without verifier) outputs only the "read/not
read" result. This means the optical reader does not provide any trend data to the marking
device.
Figure 3-2 Course of marking quality when using a reader without a verifier
The verifier, in contrast, assigns a quality grade from 4 to 0 to the readable marking. These
levels provide information to the marking device to detect when preventive maintenance is
required. Based on this knowledge, maintenance can be planned at a suitable time before the
device actually becomes defective.
Figure 3-3 Sequence involved in marking quality when using a verifier
Make sure that the measuring procedure and marking quality are suitable for the marking
method used. Depending on the particular requirements there are several test standards that
define the quality of a marking using a combination of different quality features. Data matrix
codes on labels can be tested, for example, with test systems according to ISO/IEC 16022.
With direct part marking (DPM), the data matrix code is applied directly to the surface of the
object. Here, other marking errors occur that make it necessary to use verification specially
designed for this purpose. A test system according to ISO/IEC 29158 is usually used.
The verifiers of the SIMATIC MV500 series support these and other verification standards for a
wide range of applications and marking processes.