Danfoss VLT Series Programming Manual page 81

Servo Drive Operation
the servo drive, which performs velocity control and
torque control.
Target velocity (0x60FF) Velocity
control
Torque actual value (0x6077)
Velocity actual value (0x606C)
Position actual value (0x6064)
Illustration 2.118 Cyclic Synchronous Velocity Mode Overview
Illustration 2.119 shows the inputs and outputs of the servo
drive control function. The input value (from the control
function point of view) is the target velocity.
Target velocity (0x60FF)
Multiplier
Drive mirror mode (0x2016,02)
Max motor speed (0x6080)
Multiplier
Drive mirror mode (0x2016,02)
Quick-stop deceleration (0x6085)
Quick-stop option code (0x605A)
Interpolation time period (0x60C2)
Minimum
Max torque (0x6072)
comparator
Illustration 2.119 Cyclic Synchronous Velocity Control Function
The servo drive supports limitation of motor speed and a
quick stop function for emergency reasons. The torque is
limited as well. The interpolation time period defines the
time period between 2 updates of the target velocity
and/or additive velocity and is used for intercycle interpo-
lation. The position actual value is used as mandatory
output to the control device. The PLC calculates the actual
velocity from the changes to the actual position changes.
All values are given in user-defined units.
2.5 Motion Functions
Function Description
Digital CAM This functionality controls whether the digital
switch output is enabled or disabled, depending on the
axis position. It performs a function comparable
to switches on a motor shaft. Forward and
backward movements of the axis position are
allowed. On and off compensation and hysteresis
can be parameterized.
ISD touch This functionality stores the position actual value
probe at a rising or falling edge of the configured digital
input.
MG36D102
Programming Guide
Torque
M
control
s
Target
Position actual
velocity
value (0x6064)
Following error
actual value
(0x60F4)
Drive
control
Velocity actual
function
value (0x606C)
Torque actual
Torque
limit value (0x6077)
Danfoss A/S © 01/2017 All rights reserved.
Function Description
Guide value The guide value is used in all synchronous modes
of operation (CAM mode and Gear mode). It is
used as the master position within the
synchronous modes.
Table 2.57 Motion Functions
2.5.1 Digital CAM Switch
This functionality controls whether the digital output is
enabled or disabled, depending on the axis position. It
performs a function comparable to switches on a motor
shaft. Forward and backward movements of the axis
position are allowed. On and off compensation and
hysteresis can be parameterized.
The digital CAM switches are stored and handed over to
the servo drive using the contents of an XML file. The
content is stored automatically in the servo drive. There is
only 1 configuration for the digital CAM switches and a
maximum of 100 switches are supported.
The calculation of the digital CAM switches is based on the
Position actual value (see chapter 7.7.5 Parameter 50-03:
Position Actual Value (0x6064)) in all modes of operation
except CAM mode. In CAM mode, the calculation is based
on the Logical CAM position (see chapter 7.14.12 Parameter:
Logical CAM Position (0x2020)). The cyclic usage of switches
is based on the range of the Position actual value and/or
the Logical CAM position.
Information about the state of the digital CAM switching
functionality is given in object 0x2005 (see
chapter 7.22.13 Parameter 50-07: Overlaying Motion Status
(0x2005)).
A compensation time with which the switching on (see
chapter 7.17.1 Parameter: On Compensation (0x3840)) or the
switching off (see chapter 7.17.2 Parameter: Off Compen-
sation (0x3841)) can be advanced or delayed in time.
A hysteresis can be defined by using object 0x3842 (see
chapter 7.17.3 Parameter: Hysteresis (0x3842)) to avoid
jittering around the switching point.
To use the digital CAM switch, transfer the file content to
object 0x3844 (see chapter 7.17.5 Parameter: Digital CAM
Switches Data (0x3844)). Afterwards, parse the profile using
object 0x3843 (see chapter 7.17.4 Parameters: Digital CAM
Switch Parsing Control (0x3843)). When the status signals
that the data is valid, the functionality can be enabled by
using the Controlword (see chapter 7.2.1 Parameter 16-00
Controlword (0x6040)).
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