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FANUC Series 30i/300i/300is-MODEL A. Machining Center System. User's manual - page 99

21.AXIS CONTROL FUNCTIONS

PROGRAMMING

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- Acceleration/deceleration plus automatic phase synchronization type

Automatic phase

synchronization

Synchronization

cancellation command

Synchronization

start command

Workpiece-

axis speed

Synchronization

state

Acceleration

Deceleration

Spindle

speed

1. Move the workpiece axis to the position that corresponds to that

of the one-rotation signal of the spindle.

2. Specify G81R2 to start synchronization.

When G81R2 is specified, the workpiece axis is accelerated with
the acceleration according to the acceleration rate set in the
parameter No.7778. Upon completion of phase synchronization,
the G81R2 block terminates.

3. For cancellation, specify G80R2 while the tool is moved away

from the workpiece.

4. When G80R2 is issued, deceleration is started immediately

according to the acceleration rate set in parameter No. 7778.
When the speed reaches 0, the G80R2 block terminates.

CAUTION

1 Set the automatic phase synchronization speed in

parameter No. 7776 and the movement direction in
PHD, bit 7 of parameter No. 7702.

2 Phase synchronization acceleration/deceleration is

performed with the rapid traverse linear
acceleration/deceleration rate (time constant
specified in parameter No. 1620).

3 The workpiece axis speed is the speed

synchronized with spindle rotation with automatic
phase synchronization speed being superposed.
When setting the position deviation limit parameter
No. 1828, take the superposition into consideration.

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NOTE

1 The one-rotation signal used for automatic phase synchronization is issued not by

the spindle position coder but by the separate pulse coder attached to the spindle
and used to collect EGB feedback information. This means that the orientation
position based on the one-rotation signal issued by the spindle position coder does
not match the position used as the reference for the workpiece axis when
establishing phase synchronization for automatic phase synchronization based on
G81R2.

Moreover, the one-rotation signal of the separate pulse coder must be turned on
for each rotation of the spindle.

2 With the use of parameter No.7777, the position at which the phase of the

workpiece axis is matched can be shifted from the position corresponding to the
one-rotation signal in automatic phase matching.

3 In automatic phase synchronization, when a synchronization command is issued

again in a synchronization state, movement about the workpiece axis is performed
such that the position corresponding to the one-rotation signal of the spindle
matches the position about the workpiece axis specified in the G81R2
synchronization start command executed first.

4 In automatic phase synchronization, movement is performed about the workpiece

axis from the current position to the nearest phase position in the phase
synchronization movement direction specified by the parameter.

5 Linear acceleration/deceleration applies to synchronization start/cancellation.
6 The acceleration/deceleration plus automatic phase synchronization type can be

executed by the PHS parameter, bit 6 of No.7702, without specifying an R2
command in a G81 or G80 block.

7 In the automatic cancellation of synchronization due to one of the following causes,

deceleration is performed and synchronization canceled:
<1> Reset
<2> PW0000 (POWER MUST BE OFF)
<3> IO alarm

8 The acceleration rate parameter No.7778 must not be changed in the

synchronization mode.

9 If the acceleration/deceleration parameter No. 7778 is 0, alarm PS1598 is issued

when G81 is issued.

10 For the FS16

series, the acceleration/deceleration for automatic phase

synchronization is divided into acceleration/deceleration and time constant, which
are set in parameters Nos. 2135 and 2136. For the FS30i series,
acceleration/deceleration is directly set in parameter No. 7778.

11 If EFX, bit 0 of parameter No. 7731, is 0, the canned cycle for drilling cannot be

used. To use the canned cycle for drilling, set EFX, bit 0 of parameter No. 7731,
to 1 and use G81.4 instead of G81 and G80.4 instead of G80.

21.AXIS CONTROL FUNCTIONS

PROGRAMMING

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Program example
- Acceleration/deceleration type

M03 ;

Clockwise spindle rotation command

G81 T_ L_ R1 ; Synchronization start command
G00 X_ ;

Positions the workpiece at the machining
position.

Machining in the synchronous state

G00 X_ ;

Retract the workpiece from the tool.

G81 T_ L_ R1 ; Synchronization ratio change.
G00 X_ ;

Positions the workpiece at the machining
position.

Machining in the synchronous state

G00 X_ ;

Retract the workpiece from the tool.

G80 R1 ;

Synchronization cancel command

- Acceleration/deceleration plus automatic phase synchronization type

M03 ;

Clockwise spindle rotation command

G00 G90 C_ ;

C-axis positioning

G81 T_ L_ R2 ; Synchronization start command
G00 X_ ;

Positions the workpiece at the machining
position.

Machining in the synchronous state

G00 X_ ;

Retract the workpiece from the tool.

G81 T_ L_ R2 ; Synchronization ratio change.
G00 X_ ;

Positions the workpiece at the machining
position.

Machining in the synchronous state

G00 X_ ;

Retract the workpiece from the tool.

G80 R2 ;

Synchronization cancel command

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21.7.3

Skip Function for EGB Axis

Overview

This function enables the skip or high-speed skip signal (these signals
are collectively called skip signals in the remainder of this manual) for
the EBG slave axis in synchronization mode with the EGB (electronic
gear box ).
This function has features such as the following:

1

If a skip signal is input while an EGB axis skip command block
is being executed, this block does not terminate until the
specified number of skip signals have been input.

If a skip signal is input while an EGB axis skip command block
is being executed, the tool remains in synchronous mode and
moves, not stopping on the EGB slave axis.

The machine coordinates assumed when skip signals are input
and the number of input skip signals are stored in specified
custom macro variables.

Format

G81 T_ L_ ;

EGB mode ON

G31.8 G91

0 P_ Q_ ( R_ ) ; EGB skip command

: Specify an EGB slave axis. The specified value

must always be "0".

P: Number of the first one of the custom macro

variables used to store the machine coordinates
assumed when skip signals are input.

Q: Number of skip signals that can be input during the

execution of G31.8
(permissible range: 1 to 200).

R: Number of the custom macro variable used to store

the number of input skip signals.

Specify it to check the number of input signals.

Explanation

G31.8 is a one-shot G code.
When G31.8 is executed, the machine coordinates assumed when skip
signals are input are written in as many custom macro variables as the
number specified in Q, starting with the one having the number
specified in P, when the skip command block terminates.
Also, the number of input skip signals is written to the custom macro
variable specified in R each time a skip signal is input.

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PROGRAMMING

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Example

G81 T200 L2 ;

EGB mode ON

X   ;
Z   ;
G31.8 G91 C0 P500 Q200 R1 ;  EGB skip command

After 200 skip signals have been input, the 200 skip positions on the
C-axis that correspond to the respective skip signals are stored in
custom macro variables #500 to #699.
Also, the number of input skip signals is stored in custom macro
variable #1.

NOTE

1 When specifying this function, specify only a single

EGB slave axis. If no axis is specified for two or
more axes are specified, alarm PS1152 is
generated.

2 If P is not specified, alarm PS1152 is generated.
3 If R is not specified, the number of input skip

signals is not written to a custom macro variable.

4 The custom macro variable numbers specified in P

and R must be existing ones. If a non-existent
variable number is specified, alarm PS0115 is
generated.
If a variable shortage occurs, alarm PS0115 is
generated.

5 Whether to use conventional skip signals or

high-speed skip signals with this function can be
specified with HSS, bit 4 of parameter No. 6200.
If deciding to use high-speed skip signals, specify
which high-speed signals to enable with 9S1 to
9S8, bits 0 to 7 of parameter No. 6208).

6 Skip positions are calculated from feedback pulses

from the machine. Thus, they are free from errors
due to delay in acceleration/deceleration and the
servo system

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21.7.4

Electronic Gear Box 2 Pair

Overview

The Electronic Gear Box is a function for rotating a workpiece in sync
with a rotating tool, or to move a tool in sync with a rotating
workpiece. With this function, the high-precision machining of gears,
threads, and the like can be implemented. A desired synchronization
ratio can be programmed.
Up to two sets of axes can be synchronized. A gear grinding machine
can be controlled, for instance, by using one axis for rotating the
workpiece in sync with the tool and another axis for performing
dressing in sync with the tool.
The specification method differs depending on the configuration of
the machine. For details, refer to the relevant manual provided by
the machine tool builder.
The electronic gear box is hereinafter called an EGB function.

21.7.4.1

Specification method (G80.5, G81.5)

Format

G81.5

























;

Synchronization start

↑

Amount of travel Amount of travel
along the master

along the slave axis

axis

G80.5

0 ;

Synchronization end

Explanation
- Master axis, slave axis, and dummy axis

The synchronization reference axis is called the master axis, while the
axis along which movement is performed in synchronization with the
master axis is called the slave axis.  For example, if the workpiece
moves in synchronization with the rotating tool as in a hobbing
machine, the tool axis is the master axis and the workpiece axis is the
slave axis.
Which axes to become the master and slave axes depends on the
configuration of the machine.    For details, refer to the manual issued
by the machine tool builder.
A single servo axis is used exclusively so that digital servo can
directly read the rotation position of the master axis.  (This axis is
called the EGB dummy axis.)

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- Synchronization start

When the ratio of the master-axis travel to the slave-axis travel is
specified, synchronization starts.

Specify the master-axis travel in either of the following ways.
1 Master-axis

speed

T t: Master-axis speed (1

≤

1000)

Master-axis pulse count
P p : Master-axis pulse count (1

≤

999999999)

Specify a pulse count on the condition that four pulses
correspond to one period in the A and B phases.

Specify the slave-axis travel in either of the following ways.
1 Slave-axis

travel

j : Slave-axis address

j : Slave-axis travel indicated in units of the minimum travel

increments(the range of valid settings for usual axis
movement applies)
When j = 0, the specified command is regarded as being a
command for the slave-axis speed, described below. In this
case, if L is not specified, an alarm is output.

2 Slave-axis

speed

0 L

: Slave-axis address

: Slave axis speed(1

≤

200)

- Synchronization end

Canceling synchronization for each axis by issuing a command
With a G80.5

0 command, synchronization is canceled.

is the address of the slave axis. Synchronization of the slave

axis specified by

is canceled.

A cancellation command can be issued only for one axis in one
block.

When

0 is not specified, the synchronization of all currently

synchronized axes is canceled.

When a synchronization cancellation command is issued, the
absolute coordinates for the slave axis are updated according to
the amount of travel during synchronization. For a rotation axis,
the value obtained by rounding off the amount of travel during
synchronization to the nearest 360 degrees is added to the
absolute coordinates.

Canceling synchronization by a reset
By setting HBR, bit 0 of parameter No. 7700, to 0,
synchronization is canceled with a reset. If the manual absolute
signal is ON, the absolute coordinates are updated.

3 Others

Synchronization is automatically canceled under the following
conditions.

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<1> Emergency stop
<2> Servo alarm
<3> Alarm PW0000 (indicating that the power should be turned

off)

<4> An IO alarm is generated

CAUTION

1 Feed hold, interlock, and machine lock are invalid

to a slave axis in EGB synchronization.

2 Even if an OT alarm is issued for a slave axis in

EGB synchronization, synchronization will not be
canceled.

3 During synchronization, it is possible to execute a

move command for a slave axis and other axes,
using a program. The move command for a slave
command must be an incremental one.

NOTE

1 If bit 0 (HBR) of parameter No. 7700 is set to 1,

EGB synchronization will not be canceled due to a
reset. Usually, set this parameter bit to 1.

2 In synchronous mode, it is not possible to specify

G27, G28, G29, G30, G30.1, and G53 for a slave
axis.

3 It is not possible to use controled axis detach for a

slave axis.

4 During synchronization, manual handle interruption

can be performed on the slave and other axes.

5 In synchronization mode, no inch/metric conversion

commands (G20 and G21) cannot be issued.

6 In synchronous mode, only the machine

coordinates on a slave axis are updated.

7 If bit 0 (EFX) of parameter No. 7731 is 0, no drilling

canned cycle can be used. To use a drilling canned
cycle, set bit 0 (EFX) of parameter No. 7731 to 1.

8 If, during synchronization, G81.5 is issued again,

alarm PS1594 is issued if bit 3 (ECN) of parameter
No. 7731 is 0. If bit 3 (ECN) of parameter No. 7731
is 1, the synchronization coefficient can be
changed to a newly specified one.

9 Actual cutting feedrate display does not take

synchronization pulses into consideration.

10 For an EGB slave axis, synchronous and

cpmposite control cannot be executed.

11 In EGB synchronization mode, AI contour control

mode is temporarily canceled.

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