Delta Tau GEO BRICK LV User Manual
Turbo PMAC User Manual
Setting Up a Coordinate System
255
SETTING UP A COORDINATE SYSTEM
Once you have set up your motors, gotten them well tuned, and are doing controlled jogging and homing
search moves, you will want to assemble one or more coordinate systems from the motors so that you can
run motion programs.
search moves, you will want to assemble one or more coordinate systems from the motors so that you can
run motion programs.
Turbo PMAC has several methods of coordinating multiple motions, whether they are all under Turbo
PMAC’s direct control or not. Depending on the user’s situation and needs, one of the coordination
strategies below can be implemented.
PMAC’s direct control or not. Depending on the user’s situation and needs, one of the coordination
strategies below can be implemented.
What is a Coordinate System?
A coordinate system in Turbo PMAC is a grouping of one or more motors for the purpose of
synchronizing movements. A coordinate system (even with only one motor) can run a motion program; a
motor by itself cannot. Turbo PMAC can have up to 16 coordinate systems, addressed as &1 to &16, in a
flexible fashion (e.g. 16 coordinate systems of 1 or 2 motors each, 1 coordinate system of 9 motors, 4
coordinate systems of 8 motors each, etc.).
synchronizing movements. A coordinate system (even with only one motor) can run a motion program; a
motor by itself cannot. Turbo PMAC can have up to 16 coordinate systems, addressed as &1 to &16, in a
flexible fashion (e.g. 16 coordinate systems of 1 or 2 motors each, 1 coordinate system of 9 motors, 4
coordinate systems of 8 motors each, etc.).
In general, if you want certain motors to move in a coordinated fashion, put them in the same coordinate
system. If you want them to move independently of each other, put them in separate coordinate systems.
Different coordinate systems can run separate programs at different times (including overlapping times), or
even run the same program at different (or overlapping) times.
system. If you want them to move independently of each other, put them in separate coordinate systems.
Different coordinate systems can run separate programs at different times (including overlapping times), or
even run the same program at different (or overlapping) times.
A coordinate system must first be established by assigning motors to axes in that coordinate system. For
simple relationships between motors (actuators) and axes (tool coordinates), this is done with on-line
commands called “axis-definition statements” (see below). For more complex relationships, it is done by
writing special kinematic subroutines that describe the relationship (covered in a following section).
simple relationships between motors (actuators) and axes (tool coordinates), this is done with on-line
commands called “axis-definition statements” (see below). For more complex relationships, it is done by
writing special kinematic subroutines that describe the relationship (covered in a following section).
A coordinate system must have at least one motor assigned to an axis within that system, or it cannot run a
motion program, even non-motion parts of it. When a program is written for a coordinate system, if
simultaneous motions are desired of multiple motors, their move commands are simply put on the same
line, and the moves will be coordinated.
motion program, even non-motion parts of it. When a program is written for a coordinate system, if
simultaneous motions are desired of multiple motors, their move commands are simply put on the same
line, and the moves will be coordinated.
What is an Axis?
An axis is an element of a coordinate system. It can be thought of as one of the coordinates of the tool, or
of the mechanics relative to the tool. An axis is often similar to a motor, but not the same thing. An axis is
referred to by letter. There can be up to nine independent axes in a coordinate system, selected from X, Y,
Z, A, B, C, U, V, and W (it is possible to assign multiple motors to an axis). Normally, an axis is defined
by assigning it to a motor with a scaling factor and an offset (X, Y, and Z may be defined as linear
combinations of three motors, as may U, V, and W). The variables associated with an axis defined in this
manner are scaled floating-point values.
of the mechanics relative to the tool. An axis is often similar to a motor, but not the same thing. An axis is
referred to by letter. There can be up to nine independent axes in a coordinate system, selected from X, Y,
Z, A, B, C, U, V, and W (it is possible to assign multiple motors to an axis). Normally, an axis is defined
by assigning it to a motor with a scaling factor and an offset (X, Y, and Z may be defined as linear
combinations of three motors, as may U, V, and W). The variables associated with an axis defined in this
manner are scaled floating-point values.
Single-Motor Axes
In the vast majority of cases, there will be a one-to-one correspondence between motors and axes. That is,
a single motor is assigned to a single axis in a coordinate system. Even when this is the case, however, the
matching motor and axis are not completely synonymous. The axis is scaled into engineering units, and
deals only with commanded positions. Except for the PMATCH function, calculations go only from axis
commanded positions to motor commanded positions, not the other way around.
a single motor is assigned to a single axis in a coordinate system. Even when this is the case, however, the
matching motor and axis are not completely synonymous. The axis is scaled into engineering units, and
deals only with commanded positions. Except for the PMATCH function, calculations go only from axis
commanded positions to motor commanded positions, not the other way around.