
B–61404E/08
5. FEED FUNCTIONSPROGRAMMING
57
When a one–digit number from 1 to 9 is specified after F, the feedrate set
for that number in a parameter (Nos. 788 to 796) is used. When F0 is
specified, the rapid traverse rate is applied.
The feedrate corresponding to the number currently selected can be
increased or decreased by turning on the switch for changing F1–digit
feedrate on the machine operator’s panel, then by rotating the manual
pulse generator.
The increment/decrement, ∆F, in feedrate per scale of the manual pulse
generator is as follows:
F +
Fmax
100X
∆
Fmax : feedrate upper limit for F1–F4 set by parameter 583, or
feedrate upper limit for F5–F9 set by parameter 584
X : any value of 1–127 set by parameter 216
The feedrate set or altered is kept even while the power is off. The current
feed rate is displayed on the CRT screen.
A common upper limit can be set on the cutting feedrate along each axis
with parameter No. 527. If an actual cutting feedrate (with an override
applied) exceeds a specified upper limit, it is clamped to the upper limit.
NOTE
An upper limit is set in mm/min or inch/min. CNC calculation
may involve a feedrate error of "2% with respect to a
specified value. However, this is not true for
acceleration/deceleration. To be more specific, this error is
calculated with respect to a measurement on the time the
tool takes to move 500 mm or more during the steady state:
D One–digit F code feed
D Cutting feedrate clamp