Function overview
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5.2.4
Torque-controlled mode
In torque control mode a certain setpoint torque is set, which the servo positioning controller generates in the motor. In this
case only the current controller is activated, since the torque is proportional to the motor current.
5.2.5
Speed-controlled mode
This mode of operation is used, if the motor speed is to be kept constant regardless of the acting load. The motor speed
exactly follows the speed set by the setpoint management.
The cycle time of the speed control loop for the item servo positioning controller C 1-Series is twice the PWM period duration,
thus typically 208,4 µs. However, it can also be set as an integer multiple of the current controller cycle time.
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 control mode only the current controller and the speed controller are active. In the case of setting via analog setpoint
inputs it is optionally possible to define a “safe zero”. If the analog setpoint is within this range, the setpoint is then set to zero
(“dead zone”). This can suppress interferences or offset drifts. The function of a dead zone can be activated and deactivated
and the width can be set.
The setpoints 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 setpoint 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 item servo positioning controller C 1-Series 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 controllers work with 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, EtherCAT) 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.
