BASIC commands
PROGRAMMING MANUAL
148
Revi
si
on 3.0
3.2.275 VFF_GAIN
/i
3.2.276 VP_SPEED
/i
3.2.277 VR
/i
Type
Axis parameter
Syntax
VFF_GAIN
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 0.
Adding speed feed forward gain to a system decreases the Following Error
during a move by increasing the output proportionally with the speed.
Note: In order to avoid any instability the servo gains should be changed only
when the
SERVO
is off.
Arguments
N/A
Example
No example.
See also
D_GAIN
,
I_GAIN
,
OV_GAIN
,
P_GAIN
.
Type
Axis parameter (read-only)
Syntax
VP_SPEED
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.
Arguments
N/A
Example
' Wait until at command speed
MOVE(100)
WAIT UNTIL SPEED = VP_SPEED
See also
AXIS
,
MSPEED
,
UNITS
.
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 TJ1-MC__ has in total 1024 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.
Notes:
•
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 pro-
gram writes to the global variable at a time.
•
The TABLE and VR data in RAM will be lost when the power is switched
off.
Arguments
•
address
The address of the VR variable. Range: [0,1023].
Example
In the following example, the value 1.2555 is placed into VR variable 15. The
local variable
val
is used to name the global variable locally:
val = 15
VR(val) = 1.2555
I52E-EN-03.book Seite 148 Freitag, 29. Juni 2007 11:55 11