User guide

Xenus Plus User Guide Operational Theory
Copley Controls 31
2.7.1: CAN Communication Details (XPL/XP2)
CAN Network and CANopen Profiles for Motion
In position mode, the XPL/XP2 can take instruction over a two-wire Controller Area Network
(CAN). CAN specifies the data link and physical connection layers of a fast, reliable network.
CANopen is a set of profiles (specifications) built on a subset of the CAN application layer protocol.
These profiles specify how various types of devices, including motion control devices, can use the
CAN network in a highly efficient manner. Xenus Plus supports the relevant CANopen profiles,
allowing it to operate in the following modes of operation: profile torque, profile velocity, profile
position, interpolated position, and homing.
Supported CANopen Modes
In profile torque mode, the drive is programmed with a torque command. When the drive is
enabled, or the torque command is changed, the motor torque ramps to the new value at a
programmable rate. When the drive is halted, the torque ramps down at the same rate.
In profile velocity mode, the drive is programmed with a velocity, a direction, and acceleration and
deceleration rates. When the drive is enabled, the motor accelerates to the set velocity and
continues at that speed. When the drive is halted, the velocity decelerates to zero.
In profile position mode, the drive is programmed with a velocity, a relative distance or absolute
position, and acceleration and deceleration rates. On command, a complete motion profile is
executed, traveling the programmed distance or ending at the programmed position. The drive
supports both trapezoidal and s-curve profiles.
In PVT (Position-Velocity-Time) mode, the controller sends the drive a sequence of points, each of
which is a segment of a larger, more complex move, rather than a single index or profile. The drive
then uses cubic polynomial interpolation to “connect the dots” so that the motor reaches each point
at the specified velocity at the programmed time.
Homing mode is used to move the axis from an unknown position to a known reference or zero
point with respect to the mechanical system. The homing mode is configurable to work with a
variety of combinations of encoder index, home switch, and limit switches.