Feature Configuration
ANCA Motion
DS619-0-00-0019 - Rev 0
121
10
10.1.20
Modulo Operation
Description
The ‘modulo’ operation is a feature that can be applied only to position feedback. Internally the drive represents
variables relating to “joint” motion as distinct from “motor” motion. Motor motions are used in tightly coupled, very
fast current control loops that need not concern the end user for most applications, whereas joint motions are
reported in scaled values of a more relevant type and magnitude related to movements in position and velocity on
the particular machine or automation application.
Modulo operations are almost always applied to rotational axes where one revolution, or a sector of one
revolution, results in the ‘joint’ returning to a reference starting position (e.g. one complete revolution of a shaft or
gear). The axis position as it is represented internal to the drive can be wrapped upon a specific proportion of a
revolution (usually a full revolution). For example, a 500° motion from an initial reference starting point will be
shown as 140° if the modul
e operation is configured to “wrap” or “modulo” the motion every 360°.
To enable module operation, set bit 7 of the position scaling parameter IDN (S-0-76/76) to 1. The Modulo
parameter (S-0-
103/103) must then be set to the value at which “wrapping” occurs. The Modulo operation is
applied to the joint position, which means it applies to motions that are measured by the external encoder
feedback that are closer to the end effector, tool tip, or driven end of the machine, rather than the motor or
driving end. If the gear ratio is not 1:1 then the motor will have done more than (or less than) a full revolution
before the joint motion completely covers one full modulo of motion
IDN
Label
S-0-76/76
SoE Position Scaling
– Type
S-0-103/103
Modulo Value
10.1.21
Motion Constraints and Limits
Description
In practice most machines, and thereby machine axes, cannot move through an unlimited range of motion.
People or machine parts can impede the motion. There may also be fundamental limitations governing rates and
accelerations to do with the machining process itself. The AMD2000 provides a number of useful configuration
parameters for restraining its controlled axis’ movements.
These can be applied to both the
command
and
feedback
quantities for position, velocity, acceleration, and
force/torque.
Constraints
are applied to
commands
(i.e. control demands) so that the axis can never exceed
certain settings. If a particular demand exceeds a constraint value, it is merely held at the constraint
value, but otherwise no errors or warnings are issued. Constraints come in two flavours, and are both
applied if enabled;
Global, and
Safety related.
Limits
are applied to
feedback
variables and used for monitoring axis behaviour. They result in Class
1 Diagnostic (C1D) errors if exceeded.
