5motor control (mctrl) – Lenze 8400 User Manual
Page 264
5
Motor control (MCTRL)
5.11
Encoder/feedback system
264
Lenze · 8400 protec HighLine · Reference manual · DMS 3.0 EN · 03/2013 · TD05
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Low speeds with edge counting
The minimum speed that can be measured and the quantisation error of speed measurement in the
edge-counting procedure (
= 3) depend on the scanning time that can be set in
and the encoder resolution.
Depending on accuracy and the requirements with regard to the dynamic performance, the
respective scanning time must be selected and set in
:
Encoder
resolution
(Number of
increments)
Scanning time [ms]
1
2
5
10
20
50
100
200
500
1000
Min. measurable speed in [rpm]
8
1875
938
375
188
93.8
37.5
18.8
9.4
3.8
1.9
16
938
469
188
94
46.9
18.8
9.4
4.7
1.9
0.9
32
469
234
94
46.9
23.4
9.4
4.7
2.3
0.9
0.5
64
234
117
46.9
23.4
11.7
4.7
2.3
1.2
0.5
0.2
128
117
58.6
23.4
11.7
5.9
2.3
1.2
0.6
0.2
0.12
256
58.6
29.3
11.7
5.9
2.9
1.2
0.6
0.3
0.12
0.06
512
29.3
14.6
5.9
2.9
1.5
0.6
0.3
0.15
0.06
0.03
1024
14.6
7.3
2.9
1.5
0.7
0.3
0.15
0.07
0.03
0.01