5 Enabling the servo drive and selecting the set values
5.2
Operating modes
The operating mode can be changed in the "Commands" window. This window is
permanently displayed. To change the operating mode, select the corresponding button.
However, this should not be done when the servo drive is enabled.
The various operating modes are described in detail in the next chapters.
Figure 24: "Commands" window
5.2.1
Torque-controlled mode (torque control)
In torque-controlled mode, a target torque that the motor is to provide can be specified. If
there is no counter-torque, the motor will accelerate up to its idling speed.
In this operating mode, only the current controller is active. In addition, a speed limitation
can be activated in this operating mode.
The target torque can be specified in A or Nm. This can be selected under
Options/Display
units
. The associated actual value and set value menus will then automatically adopt the
selected unit.
If you want to use the unit Nm for the torque, you have to specify the torque constant, i.e.
the conversion factor between the current and torque. The torque constant must be
entered under
Parameters/Device parameters/Motor data
. In general, it can be calculated
using the information stated on the type plate of the motor: To do so, divide the rated
torque by the rated current.
Torque constant
A torque constant of 0 Nm/A is not permissible if "Torques in Nm" has been selected.
This operating mode is used if the servo drive is controlled by a superordinate control
system, e.g. via an analogue input or via a fieldbus, so that positioning processes are
calculated by the control system, and if a superordinate, external speed and position
control circuit and an external positioning control system are present.
Product manual BL 4000-C
Page 65 of 298