7 Operation
7.1 Operating Modes
The ISD 510/DSD 510 servo drives implement several modes of operation. The behavior of the servo drive depends on the activated
mode of operation. It is possible to switch between the modes while the servo drive is enabled. The supported modes of operation
are according to CANopen
®
CiA DS 402 and there are also ISD-specific modes of operation. All supported modes of operation are
available for EtherCAT
®
, Ethernet POWERLINK
®
, and PROFINET
®
. The various modes of operation are described in detail in the
VLT®
Servo Drive System ISD 510, DSD 510, MSD 510 (VLT® Flexmotion
™
) Programming Guide
.
Inertia meas-
urement
mode
This mode measures the inertia of an axis. It is used to measure the inertia of the servo drive and the external
load, and to optimize the control loop settings. The friction effects are eliminated automatically.
Profile veloc-
ity mode
In profile velocity mode, the servo drive is operated under velocity control and executes a movement with con-
stant speed. Additional parameters, such as acceleration and deceleration, can be parameterized.
Profile posi-
tion mode
In profile position mode, the servo drive is operated under position control and executes absolute and relative
movements. Additional parameters, such as velocity, acceleration, and deceleration, can be parameterized.
Profile tor-
que mode
In profile torque mode, the servo drive is operated under torque control and executes a movement with constant
torque. Linear ramps are used. Additional parameters, such as torque ramp and maximum velocity, can be para-
meterized.
Homing
mode
In homing mode, the application reference position of the servo drive can be set. Several homing methods, such
as homing on actual position, homing on block, limit switch, or home switch, are available.
CAM mode
In CAM mode, the servo drive executes a synchronized movement based on a master axis. The synchronization
takes place by means of a CAM profile that contains slave positions corresponding to master positions. CAMs can
be designed graphically with the DDS Toolbox software, or can be parameterized via the PLC. The guide value can
be provided by an external encoder, virtual axis, or the position of another axis.
Gear mode
In gear mode, the servo drive executes a synchronized movement based on a master axis by using a gear ratio
between the master and the slave position. The guide value can be provided by an external encoder, virtual axis,
or the position of another axis.
Cyclic syn-
chronous
position
mode
In cyclic synchronous position mode, the trajectory generator of the position is located in the control device, not
in the servo drive.
Cyclic syn-
chronous ve-
locity mode
In cyclic synchronous velocity mode, the trajectory generator of the velocity is located in the control device, not
in the servo drive.
AC1
In application class 1 (AC1) mode a main setpoint (for example speed setpoint) is used to control the servo drive
in PROFINET
®
IO. Speed control is handled entirely within the servo drive.
AC4
Application class 4 (AC4) defines an interface between the speed setpoint interface and actual position value in-
terface, where speed control is executed on the servo drive and position control on the controller. The motion
control for multiple axes is performed centrally, for example by numerical control (NC). The position control loop
is closed by the fieldbus. Clock synchronization is required to synchronize the clocks for the position control in
the controller and for the speed control in the drives (PROFINET
®
with IRT).
7.1.1 Motion Functions
Function
Description
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.
Touch probe
This functionality stores the position actual value at a rising or falling edge of the configured digital input.
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Danfoss A/S © 2020.08
Operation
VLT® Servo Drive System ISD 510/DSD 510
Operating Guide
