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Command, function and parameter description
Section 6-3
Note This parameter is read-only.
Example:
>> PRINT VERSION
1.6100
6-3-197 VFF_GAIN
Type:
Axis Parameter
Description:
The VFF_GAIN parameter contains the speed feed forward gain. The speed
feed forward output contribution is calculated by multiplying the change in
demand position with the VFF_GAIN parameter value. The default value is
zero.
Adding speed feed forward gain to a system decreases the following error
during a move by increasing the output proportionally with the speed.
See section 1-4-1 Servo System Principles for more details.
Precautions:
In order to avoid any instability the servo gains should be changed only when
the SERVO is OFF.
See also:
AXIS, D_GAIN, I_GAIN, OV_GAIN, P_GAIN
6-3-198 VP_SPEED
Type:
Axis Parameter
Description:
The VP_SPEED parameter contains the speed profile speed in user units/s.
The speed profile speed is an internal speed which is accelerated and decel-
erated as the movement is profiled.
Note This parameter is read-only.
See also:
AXIS, MSPEED, UNITS
Example:
’Wait until at command speed
MOVE(100)
WAIT UNTIL SPEED = VP_SPEED
6-3-199 VR
Type:
System Command
Syntax:
VR(
address
)
Description:
The VR command reads or writes the value of a global (VR) variable. These
VR variables hold real numbers and can be easily used as an element or as
an array of elements. The MC Unit has in total 251 VR variables.
The VR variables can be used for several purposes in BASIC programming.
The VR variables are globally shared between tasks and can be used for
communications between tasks.
Precautions:
1.
The Table and VR data can be accessed from all different running tasks.
To avoid problems of two program tasks writing unexpectedly to one global
variable, write the programs in such a way that only one program writes to
the global variable at a time.
2.
The Table and VR data in RAM will be lost when the power is switched
OFF. If valid data needs to be recovered during start-up, write the data into
Flash memory using the FLASHVR command.
Arguments:
address
The address of the VR variable. Range: [0,250].
See also:
CLEAR_BIT, READ_BIT, SET_BIT, TABLE
Examples:
Example 1