Lenze EMF2141IB - Manual (Page 35)

Parameter setting
6-13
L
BA2141 EN 1.0
6.4.1.3 Scaling of the speed setpoint
network input SNVT_lev_percent nviDrvSpeedScale;
The setpoint can be scaled through this input network variable ( nviDrvSpeedStPt ).
Negative values result in the opposite direction of rotation.
Actual speed setpoint = nviDrvSpeedStpt × nviDrvSpeedScale
Example:
•
nviDrvSpeedStpt.value = 50%
•
nviDrvSpeedScale = –150%
The actual speed setpoint is –75% of the rated value.
Input range
The possible bandwidth for the input variables is between –163.840% and 163.830% . Resolution
0.005% .
The value +163.835% (7FFF
hex
) is assumed to be wrong.
Standard value
The standard value is determined by the “Configuration Property” nciDrvSpeedScale .
This value will be set after a reset or if the time set under nciRcvHrtBt passes without an update
of the variable.
Function
The value of nviDrvSpeedStPt.value is multiplied with the value of nviDrvSpeedScale and
divided by 100.
The result is used as setpoint preselection in per cent. The setpoint selection is mapped to the AIF
input data word 1 of the process data channel. Since 82XX and 93XX controllers expect different
values here, the setpoints are converted in two different ways.
82XX controller expect the setpoint in [Hz] and a factor of 50 (24000 = 480Hz). The value for AIF data
word 1 is calculated as follows:
AIFIn.W1 =
nviDrvSpeedStPt.value
100[% ] × 2 [ NVfactor]
×
nviDrvSpeedScale
100[% ] × 200 [ NVfactor]
×
nciNmlFreq
10 [ NVfactor]
× 50 [ AIFfactor]
93XX controllers expect the setpoint in [% ] and a factor of 163.83 (16383 = 100% ). The value for AIF
input data word 1 results from the following:
AIFIn.W1 =
nviDrvSpeedStPt.value
100[% ] × 2 [ NVfactor]
×
nviDrvSpeedScale
100[% ] × 200 [ NVfactor]
× 16383 [ AIFfactor]
If the result of the calculation is a negative value, the direction of rotation will be reversed. This is done
by setting bit 2 in the AIF control word.
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