Datalogic AMT58 Series, Manual

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AMT58x-PB Profibus®
41
6.8 "Red zone"
The so-called "red zone" occurs when:
Number of revolutions =
Total resolution
Counts per revolution
is NOT a power of 2.
When this problem arises, the device must operate within the “red
zone” for a certain number of positions. The size of the “red zone” is
variable. To calculate it we must subtract the
Total resolution value
from the Hardware total resolution of the device as many times as
until the difference is less than the the set
Total resolution value.
When the encoder crosses the limit of the last Total resolution section
thus entering the “red zone”, a counting error occurs, i.e. a jump in
the position count. The problem can be represented graphically in the
Figure below.
Example
25-bit resolution multiturn encoder

Hardware counts per revolution = 8192 (2
13
)

Hardware number of revolutions = 4096 (2
12
)

Hardware total resolution = 33554432 (2
25
)
Set parameters values:

Counts per revolution = 5000

Total resolution = 10000000

Number of revolutions = 2000
Hardware number of revolutions
=
4096
= 2.048
Set number of revolutions 2000