Efficient Networks Siemens Sinamics S120 - Manual (Page 187)

Basic functions
6.6 Direction reversal without changing the setpoint
Drive Functions
Function Manual, (FH1), 07/2007 Edition, 6SL3097-2AB00-0BP4
187
Restrictions
The following restrictions must be taken into account when a dv/dt filter is used:
● The output frequency is limited to a maximum of 150 Hz.
● Maximum permissible motor cable lengths:
– Shielded cables: max. 300 m
– Unshielded cables: max. 450 m
● Other restrictions: see the Equipment Manual.
Commissioning
The dv/dt filter must be activated when commissioning the system (p0230 = 2).
6.6 Direction reversal without changing the setpoint
Features
● Not change to the speed setpoint and actual value, the torque setpoint and actual value
and the relative position change.
● Only possible when the pulses are inhibited
CAUTION
If direction reversal is configured in the data set configurations (e.g. p1821[0] = 0 and
p1821[1] = 1), then when the function module basic positioner or position control is
activated, the absolute adjustment is reset each time the system boots or when the
direction changes (p2507), as the position reference is lost when the direction reverses.
Description
The direction of rotation of the motor can be reversed using the direction reversal via p1821
without having to change the motor rotating field by interchanging two phases at the motor
and having to invert the encoder signals using p0410.
The direction reversal via p1821 can be detected as a result of the motor direction of
rotation. The speed setpoint and actual value, torque setpoint and actual value and also the
relative position change remain unchanged.
The direction change can be identified as a result of the phase voltage (r0089). When the
direction reverses, then the absolute position reference is also lost.
In the vector control mode, in addition, the output direction of rotation of the drive converter
can be reversed using p1820. This means that the rotating field can be changed without
having to interchange the power connections. If an encoder is being used, the direction of
rotation must, when required, be adapted using p0410.