Installation guide

Mint™ v4 Advanced Programming Guide
120 MN1270 02.2002
See also:
BOOST, CONFIG, FREQ, PULSE, PWMONTIME, STEPDIRECTION
SPLINE/SPL
Purpose:
Perform a SPLINE move.
Controllers Supported:
NextMove PCI NextMove PC NextMove BX MintDrive ServoNode 51
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Format:
SPLINE[axis] = <expression> {,<expression> ...}
v = SPLINE[axis]
Dot Parameters:
Axis - Axis No.
Attributes:
Controller Read Write Command Multi-Axis Scaled Default Range
NextMove
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0 ≤ x ≤ 7
Description:
A spline move provides a means of specifying motion where arbitrary position and velocity information
needs to be specified in terms of time.
A spline move is created by breaking the motion into a number of segments. Each segment defines the
how far the axis will travel in a given time duration and optionally the velocity of the axis at the end of
that segment. Once these segments have been defined, NextMove will interpolate between them and
‘fill in’ the missing information, producing a smooth path as it goes. The user controls the size and
accuracy of these segments. The more critical the axis motion, the more segments that can be defined.
The segment information for a spline move is defined in an array. An array of positions has to be
defined together with optional arrays of velocities and segment durations. The arrays to use are
specified with the
SPLINETABLE keyword. Axis positions can be interpreted in one of three ways:
1. The values represent relative movements. Each value is the relative distance that the axis must
move over that segment.
2. The values represent absolute positions within a spline cycle. During a continuous spline, each
repetition of the segments is known as a cycle. Each time the cycle starts, the current axis position
is considered as zero and the position values are taken as absolute to that point.
3. The values represent true absolute positions. The value are absolute with reference to actual axis
position. The zero position is from when the axis was last reset or homed.
Example:
dim exampleArray (11) = 10, 2, 4.5, 6, 5.7, 2, 0.1, -3.4, -9.3, -6.1, 0
SPLINETABLE(0, exampleArray, null, null)
SPLINE.0 = _spABSOLUTE
The above defines an array of positions and uses the SPLINETABLE keyword to specify the name of the
array to use. The value passed to the
SPLINE keyword indicates how the data is to be interpreted. In
the example, the data is to be taken as absolute positions.