
7.FEEDRATE CONTROL/ACCELERATION AND DECELERATION CONTROL B-63943EN-1/02
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7.1.7.2 Feedrate override
Overview
A programmed feedrate can be reduced or increased by a percentage
(%) selected by the override dial. This feature is used to check a
program.
For example, when a feedrate of 100 mm/min is specified in the
program, setting the override dial to 50% moves the tool at 50
mm/min.
Tool
Check the machining by altering
the feedrate from the value
specified in the program.
Feedrate 100 mm/min
(Specified by programmed)
Feedrate 50 mm/min after
feedrate override
Workpiece
Fig. 7.1.7 (b) Feedrate override
Signal
Feedrate Override signal *FV0 to *FV7<Gn012>
[Classification] Input signal
[Function] These signals override the cutting feedrate. Eight binary code signals
correspond to override values as follows:
Override value=
∑
×
7
0=i
%|2| Vi
i
Vi=0 when *FVi is "1" and
Vi=1 when *FVi is "0"
These signals have the following weight.
*FV0 : 1% *FV1 : 2%
*FV2 : 4% *FV3 : 8%
*FV4 : 16% *FV5 : 32%
*FV6 : 64% *FV7 : 128 %
When all signals are "0", they are regarded as overriding 0% in the
same way as when all signals are "1" .
Thus, the override is selectable in steps over a range of 0 to 254%.
[Operation] Actual feedrate is obtained by multiplying the specified speed by the
override value selected by this signal.
The override is regarded as 100%, regardless of this signal, in the
following cases:
- Override cancel signal OVC<G0006#4> is "1".
- During cutting in tap cycle of canned cycle;
- Tapping mode (63); or
- Thread cutting is in progress.