Lenze EMF2141IB - Manual (Page 33)

Parameter setting
6-11
L
BA2141 EN 1.0
6.4 VSD control VSD
6.4.1 Network variable (VSD)
6.4.1.1 Speed setpoint
network input SNVT_switch nviDrvSpeedStpt;
The input network variable offers the following:
•
Motor start/stop option
•
Speed selection in percent
(resolution = 0.5% ref. to value selected under
nciMaxSpeed )
Input range
Status Value Command Explanation
0 (FALSE) NA Stop
1 (TRUE) 0 0%
1 (TRUE) 1 to 200 0.5% to 100.0%
1 (TRUE) 201 to 255 100.0%
jFF
hex
NA AUTO (invalid) Standard value.
This value will be set after a reset or if the time set under
nciRcvHrtBt
expires with an update of the variables.
AUTO has the same function as stop, but is also used to check whether
the “Receive Heartbeat Time” has expired.
Function
The speed setpoint for the controller is calculated as follows:
n
soll
=
nviDrvSpeedStpt.value × nviDrvSpeedScale
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 controllers use a 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 servos use a 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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