6 feedforward control of the motor before release, Feedforward control of the motor before release, 8basic drive functions (mck) – Lenze 8400 User Manual
Page 551
Lenze · 8400 protec HighLine · Reference manual · DMS 3.0 EN · 03/2013 · TD05
551
8
Basic drive functions (MCK)
8.12
Holding brake control
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8.12.6
Feedforward control of the motor before release
The motor is precontrolled by selecting the lower speed threshold for applying the brake (control
modes without feedback). When the upper speed threshold for brake release is reached, the motor
is precontrolled with the for the release time set in
with the lower threshold value before
the brake switches to the release mode.
Here, the direction of the feedforward control depends on two conditions:
1. On the settings selected under
• Bit 2 = feedforward control inverted (for vertical drives/hoists)
• Bit 3 = direction of the axis
2. On the sign of the setpoint.
Truth table for the direction of the feedforward control
Setpoint
Direction
Feedforward control
Scheme
Direction
Feedforward
control value
Start value
n ≥ 0
vertical/hoist
: Bit 3 = 0)
not inverted
: Bit 2 = 0)
inverted
: Bit 2 = 1)
n < 0
not inverted
: Bit 2 = 0)
inverted
: Bit 2 = 1)
n ≥ 0
horizontal/winding drive
: Bit 3 = 1)
Inversion via bit 2 with
horizontal direction not
effective
n < 0
0
P
Q
0
P
Q
0
P
Q
0
P
Q
0
Q
0
Q