Table of Contents
Advertisement
7.5.10
0x604C vl_dimension_factor
This object is used to configure the numerator and denominator of the vl_dimension_factor. The
vl_dimension_factor is used to scale the user units so that they can be used in a way that relates to
the specific application.
Calculating the vl_dimension_factor:
Every user-specific velocity consists of a specific unit referred to as a specific unit of time (e.g. 1/s,
bottles/min, m/s,...). The purpose of the vl_dimension_factor is to convert this specific unit to the
revolutions/minute unit. A value of 0 must not be used.
Velocity [user-defined unit] / Dimension factor [rpm/user-defined unit] = Velocity [rpm]
Table 7-51 0x604C vl_dimension_factor
0x604C
vl_dimension_factor
Sub-index 0
Access: RO
Default:
2
Description:
The number of sub-indices in this object.
Sub-index 1
Access: RW
Default:
1
Description:
vl_dimension_factor numerator (a value of 0 is not valid).
Sub-index 2
Access: RW
Default:
1
Description:
vl_dimension_factor denominator (a value of 0 is not valid).
The vl_target_velocity object is re-read every new profile cycle. It is scaled to appropriate units
using the vl_dimension_factor and vl_setpoint_factor objects and then written to the drive preset
reference 1 parameter (Pr 01.021).
The object vl_velocity_min_max is handled every profile cycle. The vl_target_velocity is limited
according to the values set in the object vl_velocity_min_max, which is read every profile cycle. The
object vl_velocity_min_max_amount is mapped to vl_velocity_min_max.
The value of the vl_velocity_demand object is calculated in the background. The option reads the
value of parameter Pr 02.001 (post ramp reference), scaled from RPM to user units using
vl_dimension_factor and vl_setpoint_factor, and writes the value to the vl_velocity_demand object.
On a closed-loop drive, the speed feedback is calculated internally every profile cycle, scaled to the
same units as vl_target_velocity and written to the vl_velocity_actual_value object. On an open-
loop drive, the estimated motor speed is read from Pr 05.004 (motor RPM) in the background,
scaled to the units of vl_target_velocity and written to the vl_velocity_actual_value object.
The vl_velocity_acceleration and vl_velocity_deceleration objects are handled in the background.
They are read, scaled to drive acceleration units (depending on the drive operating mode), and
written to the drive acceleration rate and deceleration rate presets. In addition, if the drive
acceleration rate preset is changed, the vl_velocity_acceleration object is updated, and if the drive
deceleration rate preset is changed (Pr 02.021), the vl_velocity_deceleration object is updated.
SI-EtherCAT User Guide
Issue Number: 2
Range: N/A
Range: -32768 to +32767 Size: Signed 16
Range: -32768 to +32767 Size: Signed 16
Size: Unsigned 8
Type: USINT
Type: INT
Type: INT
Unit: N/A
Unit: N/A
Unit: N/A
63
Advertisement
Table of Contents
