Siemens SIMATIC MV500, Руководство по эксплуатации

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Application
5.1 Program
SIMATIC MV500
Operating Manual, 05/2019, C79000-G8976-C495-02
33
Parameter Possible values Default Description
Edge-triggered
start/stop
• On
•
Off
Off Only valid when the initial trigger is enabled and the trigger
source is DI/DO or PROFINET. The attempt to read is end-
ed either by a successful read or by a negative edge after
the timeout. If reading is aborted by a negative edge, the
"N_OK" result is output.
Timeout 0.0 … 600.0 s 5.0 s Valid only when initial trigger is enabled. The read attempt is
ended either by a successful read or at the latest after a
timeout. If reading is aborted due to a timeout, the "N_OK"
result is output. Setting 0.0 s only makes sense when "Edge
triggered start/stop" is enabled and reading needs to be
stopped immediately with a negative edge.
Recognize double
reads
0 … 50 1 The result buffer is used to avoid multiple output of results.
•
0: Each read code is output (again) with each read.
• 1: If the content of the code that is currently in the image
matches the last code read, the code is not output
again. If the content of the code has changed, the next
output is made.
•
n: As 1, but the last n different code contents are stored
and compared before output.
Buffer deleted if
absent
•
On
• Off
Off Valid only when initial trigger is disabled. The buffer is de-
leted as soon as there is no readable code in the image. If
the code moved out of the image in the meantime, it is pos-
sible to read the same code multiple times using the "Auto
trigger" function.
Note
When an image acquisition interval that is too short is se-
lected, unintended double readings may occur.
Scan
With this setting, you can use the reader to scan a code on an object, for example, on a
rotating shaft. In contrast to the "Auto-trigger" option, a number of images can be buffered
and processed later. This may result in long processing times. Example: very poor marking.
One code is read per trigger signal. The code must be fully visible in one of the acquired
images. If a code cannot be decoded in any of the acquired images, an "N_OK" read is
output.