Functional Description - Siemens SIMATIC MV440 Operating Instructions Manual

3.8

Functional description

Image acquisition
The readers capture the code to be read using digital image acquisition.
Following image acquisition, the image is analyzed by a powerful digital signal processor.
Multistage complex algorithms are used in the analysis:
● To find the codes contained in the image.
● To decode the code.
● To verify the code.
● To find and read the plain text in the image.
The results of the evaluation are transferred to an automation system connected via the
communications interfaces.
When working with the reader, the user is supported because the parameter settings for the
image acquisition and decoding software are made by the device. Once the reader has been
mounted, aligned and focused, reading is performed regardless of the orientation for one or
more codes in the image.
User interface
The user interface is based on Web server technology. This means that only a computer with
an Internet browser connected via Ethernet is necessary. The reader is then called using its
IP address. The display of the user interface appears in the display window of the Internet
browser. Display via Ethernet allows convenient setting and control of all parameters of the
reader. Operator control of the code reader is supported by context-sensitive online help.
If the automatic settings do not produce an ideal result due to special conditions, you can
readjust individual parameters of the reader using the user interface. You can store 15
different settings on the reader.
All the settings for communication with other devices must be performed in the user
interface.
Reading code
The actual reading is triggered by different events.
● In the simplest situation, the code reader generates the trigger event itself. The this end,
the readers have an autotrigger function.
● Depending on the application, it may be advisable to provide the trigger event via the I/O
cable. In this case, the code reader obtains the signal, for example from a light barrier.
The trigger signal immediately triggers image acquisition followed by evaluation. The
result of the evaluation is then transferred to the higher-level control system via the
selected communications connection. Once the evaluation result has been transferred,
reading can be started again.
SIMATIC MV420 / SIMATIC MV440
Operating Instructions, 04/2013, A5E02371045-06
Description
3.8 Functional description
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