Lika XAC77 FB, Руководство пользователя

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XAC77 Profibus-DP
®
6.8 "Dead Zone"
The so-called "Dead Zone" occurs when:
Number of revolutions is not a power of 2.
Device operates in "Dead Zone" for the remaining positions needful to complete
the difference between “Total hardware resolution” and
Total resolution when
the result of the difference is lower than Total resolution .
Example
“XAC77
16/16384
PX-xx”:
•
“Hardware counts per revolution” = 65.536 (2 16 )
•
“Hardware number of revolutions” = 16.384 (2 14 )
•
“Total hardware resolution” = 1.073.741.824 (2 30 )
Set parameters values:
• Total resolution = 400.000.000
• Counts per revolution = 50.000
• Number of revolutions = 8.000
It follows that, for 384 revolutions (16.384 - 2 * 8.000 = 384), the encoder will
work within the "Dead Zone" limits.
It can be explained graphically:
NOTE
•
In “Dead Zone”, the transmitted position is coherent with setting resolution:
it is calculated so that the last position transmitted before zero position is
Total resolution -1.
•
Make attention using the values sent by the encoder while working in “Dead
Zone”. When the encoder changes from normal status to “Dead Zone” status
(and vice versa) a jump of position occurs.
MAN XAC77 PX I_E 1.0.odt 53 Profibus® interface
048 . 2
8000
16384
” revolution of “number
” revolution of number “hardware
= =
transmitted
position
hardware total
resolution
total resolution
red
zone
position
” revolution per “counts
” resolution “total
=