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Command, function and parameter description
Section 6-3
Example:
>> PRINT COS(0)
1.0000
6-3-46
CREEP
Type:
Axis Parameter
Description:
The CREEP axis parameter contains the creep speed on the axis. The creep
speed is used for the slow part of an origin search sequence. CREEP is
allowed to have any positive value (including zero).
The creep speed is entered in units/s using the unit conversion factor UNITS.
For example, if the unit conversion factor is set to the number of encoder
edges/inch, the speed is set in inches/s.
See also:
AXIS, DATUM, UNITS
Example:
BASE(2)
CREEP = 10
SPEED = 500
DATUM(4)
CREEP AXIS(1) = 10
SPEED AXIS(1) = 500
DATUM(4) AXIS(1)
6-3-47
D_GAIN
Type:
Axis Parameter
Description:
The D_GAIN axis parameter contains the derivative gain for the axis. The
derivative output contribution is calculated by multiplying the change in follow-
ing error with D_GAIN. The default value is zero.
Adding derivative gain to a system is likely to produce a smoother response
and allow the use of a higher proportional gain than could otherwise be used.
High values may cause oscillation.
See section 1-4-1 Servo System Principles for more details.
See also:
AXIS, I_GAIN, OV_GAIN, P_GAIN, VFF_GAIN
Precautions:
In order to avoid any instability the servo gains should be changed only when
the SERVO is OFF.
6-3-48
DATUM
Type:
Motion Control Command
Syntax:
DATUM(
sequence
)
Description:
The DATUM command performs one of 6 origin search sequences to position
an axis to an absolute position and also can be used to reset the following
errors. The origin search mechanism of the Servo Driver is used for axis 0.
Axis 1 uses the mechanism in the MC Unit.
DATUM uses both the creep speed and the demand speed for the origin
searches. For axis 0 the Servo Driver function is used. The creep speed in the
sequences is set using the CREEP axis parameter and the demand speed is
set using the SPEED axis parameter. The datum switch input number, which
is used for sequences 3 to 7, is selected by the DATUM_IN parameter.
DATUM works on the default basis axis (set with BASE) unless AXIS is used
to specify a temporary base axis.