Siemens SINAMICS S120 Function Manual page 334

Basic functions
7.10 Direction reversal without changing the setpoint
NOTICE
Uncontrollable acceleration of the drive with an external speed actual value
When using an external speed actual value for the speed controller via p1440, positive
feedback can occur in the speed control loop. As a consequence, the drive accelerates up
to its speed limit and can be damaged.
• When using external speed actual values for the speed controller, additionally change
Note
Position reference is lost at direction reversal
If direction reversal is configured in the data set configurations (e.g. p1821[0] = 0 and
p1821[1] = 1), when the function module "Basic positioner" or "Position control" is activated,
the absolute adjustment is reset after each data set changeover (p2507), as the position
reference is lost when the direction of rotation is switched over.
Overview of the important parameters (see SINAMICS S120/S150 List Manual)
• r0069[0...8]
• r0089[0...2]
• p1820[0...n]
• p1821[0...n]
• p1959[0...n]
• p2507[0...n]
334
its polarity when reversing the direction of rotation (p1821 = 1).
CO: Phase current actual value
Phase voltage, actual value
Reverse output phase sequence
Direction of rotation
Rotating measurement configuration
Position control absolute encoder adjustment status
Function Manual, 11/2017, 6SL3097-4AB00-0BP5
Drive functions