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The speed controller is a PI controller with an internal resolution of 12 bits per rpm. In order to
eliminate wind-up effects, the integrator function is stopped upon reaching subsidiary limitations.
In speed-controlled mode only the current controller and the speed controller are active. In the case of
setting via analogue set point inputs it is optionally possible to define a “safe zero”. If the analogue set
point is within this range, the set point is then set to zero (“dead zone”). This can suppress
interferences or offset drifts. The function of a dead zone can optionally be activated and deactivated
and the width can be set.
The set points of the speed as well as the actual position are generally determined from the encoder
system inside the motor, which is also used for commutation. For the actual value feedback to the
speed control any encoder interface may be selected (for example reference encoder or
corresponding system at external incremental encoder input). The actual speed value for the speed
controller is then fed back for example via the external incremental encoder input.
The set point for the speed can also be set internally or can be derived from the data of an external
encoder system (speed synchronisation via [X10] for speed controller).
5.2.6 Torque-limited speed control
The ARS 2100 SE series servo drives support torque-limited speed-controlled operation with the
following features:
Fast updating of the limit value, for example in 200 µs cycle
Addition of two sources of limitation (for example for servo control values)
5.2.7 Synchronization to the external clock signal
The servo drives use sinusoidal constrained current operation. The cycle time is always bound to the
PWM frequency. In order to synchronise the current control to the external clock signal (for example
CANopen) the device has a corresponding PLL. Accordingly the cycle time varies within certain limits,
to allow synchronisation to the external clock signal. For synchronisation to an external clock signal
the user must enter the rated value of the synchronous cycle time.
5.2.8 Load torque compensation for vertical axes
For vertical axis applications, the holding torque at standstill can be determined and stored. It is then
added to the torque control loop and improves the start-up behaviour of the axes after releasing the
holding brake.
Product Manual „Servo drives ARS 2100 SE“
Version 5.0
