CPB EtherCAT Technical Manual

Velocity

Description

This mode operates the motor at a preset target speed, similar to a frequency inverter. Unlike the profile velocity mode, this mode does not permit the selection of jerk-limited ramps.

Controlword

The following bits in object 6040h (controlword) have a special function:

  • Bit 8 (Halt): If this bit is set to "1", the motor stops. On a transition from "1" to "0", the motor accelerates with the acceleration ramp to the target speed. On a transition from "0" to "1", the motor brakes according to the deceleration ramp and comes to a standstill.

Statusword

The following bits in object 6041h (statusword) have a special function:

  • Bit 11: Limit exceeded: The target speed is above or below the set limit values.

Object entries

The following objects are necessary for controlling this mode:

  • 604Ch (Dimension Factor):

    The unit for speed values is defined here for the following objects.

    Subindex 1 contains the denominator (multiplier) and subindex 2 contains the numerator (divisor) with which the internal speed values are converted to revolutions per minute. If, for example, subindex 1 is set to the value "60" and subindex 2 is set to the value "1", the speed is specified in revolutions per second (60 revolutions per 1 minute).

  • 6042h: Target Velocity.

    The target speed is set here in user-defined units.
  • 6048h: Velocity Acceleration

    This object defines the acceleration. Subindex 1 contains the change in speed, subindex 2 the corresponding time in seconds. Both together are used to calculate the acceleration:

  • 6049h (Velocity Deceleration):

    This object defines the deceleration (deceleration ramp). The subindices here are arranged as described in object 6048h; the change in speed is to be specified with positive sign.

  • 6046h (Velocity Min Max Amount):

    The limitations of the target speeds are specified in this object.

    The minimum speed is set in 6046h:1h. If the target speed (6042h) falls below the minimum speed, the value is limited to the minimum speed 6046h:1h.

    The maximum speed is set in 6046h:2h. If the target speed (6042h) exceeds the maximum speed, the value is limited to the maximum speed 6046h:2h.

  • 604Ah (Velocity Quick Stop):

    This object can be used to set the quick-stop ramp. Subindices 1 and 2 are identical to those described for object 6048h.

The following objects can be used to check the function:
  • 6043h (Vl Velocity Demand)

  • 6044h (Vl Velocity Actual Value)

Speeds in Velocity Mode



Objects for Velocity Mode

The ramp generator follows the target speed, remaining within the set speed and acceleration limits. As long as a limit is active, bit 11 in object 6041h is set (internal limit active).

▶   next

Contents