Lenze 8400 - 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 ( C00496 = 3) depend on the scanning time that can be set in C00425/1
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 C00425/1 :
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