# Fanuc Series 15i/150i-MA (Programming) Operators Manual

5.FEED FUNCTIONS PROGRAMMING B-63324EN/03
- 174 -
[Method of feedrate specification on a virtual circle for a rotation axis]
With the method of feedrate specification on a virtual circle for a
rotation axis, feedrate control is exercised so that the time T
calculated by the expression below is used to travel a specified
distance.
()()
Time:,
min)/min,/( feedrate Specified:
Distance:,
(deg) axiseach on distance Travel:,
),( axiseach on distance Travel:,,
180/**180/**
22
222
TT
inchmmF
LL
CB
inchmmZYX
ll
F
L
T
ClBlZYXL
CB
CB
=
++++=
ππ
- Usable functions
This function can be used with the following functions:
- Linear interpolation
- Dry run
- Tool length compensation in a specified direction (when bit 2
(FWR) of parameter No. 7711) is set to 1)
- Acceleration/deceleration before look-ahead interpolation
Acceleration/deceleration before look-ahead interpolation is applied to
the feedrate on a virtual circle. However, parameters such as for an
allowable feedrate difference (parameter No. 1478) and a maximum
allowable acceleration (parameter No. 1660) are to be set for each
rotation axis.
- Parameter setting
For a rotation axis for which this function is to be used, set the
following parameters:
- Bit 0 (ROT) of parameter No. 1006 = 1
- Bit 1 (RFD) of parameter No. 1010 = 1
- Parameter No. 2524 = Virtual circle radius
- Setting for excluding rotation axes from feedrate calculation
With the following parameter settings (virtual circle radius = 0.0),
rotation axes are excluded from feedrate calculation:
- Bit 0 (ROT) of parameter No. 1006 = 1
- Bit 1 (RFD) of parameter No. 1010 = 1
- Parameter No. 2524 = 0.0
If only a rotation axis is specified when the parameter settings above
are made, the rotation axis is moved at a maximum cutting feedrate.
- Rewriting of parameters with G10
The following parameters can be rewritten with G10 in the part
program:
- Bit 1 (RFD) of parameter No. 1010
- Parameter No. 2524