PROGRAMMING5. FEED FUNCTIONS
B–63684EN/01
60
When the feedrate difference between blocks along each axis is larger than
the value specified in parameter No. 1781, the relationship between the
feedrate and time is as shown below. Although accumulated pulses
equivalent to the hatched area remain at time t, the next block is executed
because the feedrate of the automatic acceleration/deceleration circuit is
smaller than the feedrate specified in parameter No. 1741.
t
Feedrate V
Block A
Block B
Parameter–set feedrate
Time t
When acceleration/deceleration before interpolation is effective, the
relationship between the feedrate and time is as described below.
When the feedrate difference between blocks A and B along each axis is
larger than the value specified in parameter No. 1780, the feedrate is
decelerated to the corner feedrate calculated from the feedrate difference
along each axis.
Let the feedrate be F. Compare the feedrate difference along each axis
(Vc[X], Vc[Y], ...) with the value specified in parameter No. 1780, Vmax.
When the difference exceeds Vmax, calculate R as shown below.
R=
Vmax
Vc
Find the maximum value for R among the calculated values for the axes.
Let it be Rmax. Then, the corner feedrate can be obtained as follows:
Fc=F*
Rmax
1
N1
N2
N1 G01 G91 X80. Y20. F3000 ;
N2 X20. Y80. ;
(Example)
When this movement is specified, the feedrate along each axis is as shown
in the next figure.
Rmax=
Vmax
Vc[X(Y)]
F*
Rmax
1
From the figure, it can be seen that the feedrate differences along the X–
and Y–axes (Vc[X] and Vc[Y]) exceed Vmax. Calculate Rmax to get Fc.
When the feedrate is decelerated to Fc at the corner, the feedrate difference
along each axis do not exceed Vmax.
D Feedrate and time
D Acceleration /
deceleration before
interpolation