FANUC Series 0i-MODEL F Plus. CONNECTION MANUAL (FUNCTION) - page 44

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Specify G81R3 to start synchronization. The block of G81R3 is immediately ended and the next
block is started.
When G81R3 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 EGB
mode signal SYNMOD<Fn065.6> becomes “1”.

When the M code for waiting for completion of EGB automatic phase synchronization is
commanded, the next block is not started until automatic phase synchronization is completed.

For cancellation, specify the M code for starting deceleration of EGB automatic phase
synchronization while the tool is moved away from the workpiece. The block of M code for starting
deceleration is immediately ended and the next block is started.

When M code for starting deceleration is issued, the EGB mode signal SYNMOD<Fn065.6>
becomes “0” and deceleration is started immediately according to the acceleration rate set in
parameter No.7778.

When G80R3 is issued, deceleration is continued. And the speed reaches 0, the G80R3 block
terminates.

NOTE

1 Do not specify EGB synchronization (G81/G81.5) command before automatic

phase synchronization is completed. If EGB synchronization command is issued,
alarm (PS1595), “ILL-COMMAND IN EGB MODE” is generated. Even when an
alarm (PS1595) occurs, automatic phase synchronization before the occurrence
of an alarm is continued.

2 Confirm the completion of phase synchronization by M code (parameter

No.7787) for waiting for completion of EGB automatic phase synchronization,
then issue a movement command or machining to work axis. Also, in the case of
helical gears, make sure that the phase synchronization is completed and then
issue a movement command for the axial feed axis.

3 Specify M code (parameter No.7787) for waiting for completion of EGB

automatic phase synchronization and M code (parameter No.7788) for starting
deceleration of EGB automatic phase synchronization in a single block.

4 As for M code (parameter No.7787) for waiting for completion of EGB automatic

phase synchronization and M code (parameter No.7788) for starting deceleration
of EGB automatic phase synchronization, the function code signal and strobe
signal are not output.

Program example

O1000 ;

G81 T_ L_ R3; Synchronization start command
G00 X_;

X-axis approach

Mxx;

M code for waiting for completion of EGB automatic phase synchronization command

G01 Z_ F_;

Machining start

:
G00 X_;

Release work and tool

Myy;

M code for starting deceleration of EGB automatic phase synchronization command

G00 X_;

X-axis retraction

G80 R3;

Synchronization cancellation command

:
M30;

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Signal

EGB mode signal SYNMOD< Fn065.6>

[Classification] Output signal

[Function] Reports that synchronization with the EGB is in progress.

[Operation] This signal becomes “1” if:

Synchronization with the EGB is in progress.

It becomes “0” if:
-

Synchronization with the EGB is canceled.

Signal address

Fn065

SYNMOD

Parameter

7787

M code for waiting for completion of EGB automatic phase synchronization

[Input type] Parameter input

[Data type] 2-word path

[Valid data range] 0 to 99999999

Set M code for waiting for completion of EGB automatic phase synchronization.
When 0 is set in this parameter, this parameter is invalid.

7788

M code for starting deceleration of EGB automatic phase synchronization

[Input type] Parameter input

[Data type] 2-word path

[Valid data range] 0 to 99999999

Set M code for starting deceleration of EGB automatic phase synchronization.
When 0 is set in this parameter, this parameter is invalid.

1.9.4

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 synchronization 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.

For an explanation of the electronic gear box, see the preceding Subsection, "Electronic Gear Box" in this
manual.

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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 512).

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.

Positional deviation

In skip function for EGB axis, when bit 5 (ESE) of parameter No.6216 is set to 1, positional deviation
when the skip signal and the high-speed skip signal are input is considered and compensated.
As a result, the measurement with high accuracy becomes possible in skip function for EGB axis.

Example

The pitch of a gear can be measured.

Fig. 1.9.4

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.

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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, “G31.9/G31.8
FORMAT ERROR” 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, "VARIABLE NO.
OUT OF RANGE" 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,

errors due to delay in acceleration/deceleration and the servo system are small.
In skip function for EGB axis, when bit 5 (ESE) of parameter No.6216 is set to 1,
positional deviation when the skip signal and the high-speed skip signal are input
is considered and compensated.

Signal

For details of skip signals, see the sections on "skip function" and "high-speed signal".

Parameter

6200

SRE

SLS

HSS

SK0

GSK

[Input type] Parameter input

[Data type] Bit path

#0 GSK

As a skip signal, the skip signal SKIPP is:

Invalid.

Valid.

#1 SK0

This parameter specifies whether the skip signal is made valid under the state of the skip

signal SKIP and the multistage skip signals SKIP2 to SKIP8.
0:

Skip signal is valid when these signals are “1”.

Skip signal is valid when these signals are “0”.

#4 HSS

The skip function does not use high-speed skip signals while skip signals are input.
(The conventional skip signal is used.)

The step skip function uses high-speed skip signals while skip signals are input.

#5 SLS

The multi-step skip function does not use high-speed skip signals while skip signals
are input. (The conventional skip signal is used.)

The multi-step skip function uses high-speed skip signals while skip signals are
input.

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NOTE

The skip signals (SKIP and SKIP2 to SKIP8) are valid regardless of
the setting of this parameter. They can also be disabled using bit 4
(IGX) of parameter No. 6201.

#6 SRE

When a high-speed skip signal or high-speed measurement position arrival signal is used:

The signal is assumed to be input on the rising edge (contact open

→

close).

The signal is assumed to be input on the falling edge (contact close

→

open).

6201

SKPXE

CSE

IGX

[Input type] Parameter input

[Data type] Bit path

#4 IGX

When the high-speed skip function is used, SKIP, SKIPP, and SKIP2 to SKIP8 are:

Enabled as skip signals.

Disabled as skip signals.

#5 CSE

For the continuous high-speed skip command, high-speed skip signals are:

Effective at either a rising or falling edge (depending on the setting of bit 6 (SRE) of
parameter No. 6200).

Effective at both the rising and falling edges.

#7 SKPXE

For the skip function (G31), the skip signal SKIP is:

Enabled.

Disabled.

Whether the skip signals are enabled or disabled

Parameter

Bit 4 (IGX) of

parameter

No. 6201

Bit 0 (GSK)

of parameter

No. 6200

Bit 7 (SKPXE)

of parameter

No. 6201

Skip

signal

SKIPP

Skip

signal

SKIP

Multistage skip

signals

SKIP2-SKIP8

Setting

Disabled

Enabled

Disabled

Enabled

Disabled

Enabled

Disabled

Bit 4 (IGX) of parameter No. 6201 is valid for the skip function using high-speed skip
signals (when bit 4 (HSS) of parameter No. 6200 is set to 1) or for the multistage skip
function using high-speed skip signals (when bit 5 (SLS) of parameter No. 6200 is set to
1).

6208

9S8

9S7

9S6

9S5

9S4

9S3

9S2

9S1

[Input type] Parameter input

[Data type] Bit path

9S1 to 9S8

Specify which high-speed skip signal is enabled for the continuous high-speed skip

command G31P90 or the EGB skip command G31.8.

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The settings of each bit have the following meaning:
0:

The high-speed skip signal corresponding to the bit is disabled.

1: The high-speed skip signal corresponding to the bit is enabled.
The bits correspond to signals as follows:

Parameter

High-speed skip signal

Parameter

High-speed skip signal

9S1

HDI0

9S5

HDI4

9S2

HDI1

9S6

HDI5

9S3

HDI2

9S7

HDI6

9S4

HDI3

9S8

HDI7

6216

ESE

[Input type] Parameter input

[Data type] Bit path

#5 ESE

positional deviation when the skip signal and the high-speed skip signal are input:

is not considered.

1: is considered.

6220

Period during which skip signal input is ignored for the continuous high-speed skip function and EGB

axis skip function

[Input type] Parameter input

[Data type] Byte path

[Unit of data] 8msec

[Valid data range] 3 to 127(

8msec)

This parameter specifies the period from when a skip signal is input to when the next skip
signal can be input for the continuous high-speed skip function and EGB axis skip
function. This parameter is used to ignore chattering in skip signals.
If a value that falls outside the valid range is specified, the setting is assumed to be 24
msec.

Signal ignoring period (parameter No. 6220)

Skip signal

This signal is ignored.

When high-speed skip signals are used and bit 5 (CSE) of parameter No. 6201 is set to 1,
signals are handled as follows:

Signal ignoring period (parameter No. 6220)

High-speed skip
signals

These signals
are ignored.

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Alarm and message

Number

Message

Description

PS0115

VARIABLE NO. OUT OF
RANGE

A number that cannot be used for a local variable, common variable, or
system variable in a custom macro is specified.
In the EGB axis skip function (G31.8), a non-existent custom macro
variable number is specified. Or, the number of custom macro variables
used to store skip positions is not sufficient.

PS1152

G31.9/G31.8 FORMAT
ERROR

There is a format error in the G31.9 or G31.8 block as described below.
-  No axis address is specified in the G31.9 or G31.8 block.
-  More than axis address is specified in the G31.9 or G31.8 block.
-  P is not specified in the G31.9 or G31.8 block

1.9.5

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 electronic gear box is hereinafter called an EGB function.

1.9.5.1

Specification method (G80.5, G81.5)

Format

G81.5

























;

Synchronization start

↑

Amount of travel

along the master axis

along the slave axis

G80.5

0 ;

Synchronization cancellation

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.)

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

≤

5000)

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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.

Slave-axis speed

0 L

: Slave-axis address

: Slave axis speed(-250

≤

250,

= 0 is excluded, however.)

Synchronization cancellation

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.

Others

Synchronization is automatically canceled under the following conditions.
<1>  Emergency stop
<2>  Servo alarm
<3>  Alarm PW0000 (indicating that the power should be turned off)
<4>  An IO alarm is generated

How to reduce the synchronous error

When you use the Electronic gear box function, to reduce the synchronous error, please apply
feed-forward to the slave axis and set 100% to the parameter of feed-forward coefficient.
And please confirm the effectiveness of feed-forward by the following procedure.

[Procedure]

When the slave axis synchronizes only with the command from master axis (ie. When the slave
axis doesn’t use helical gear compensation), the position error of slave axis is regarded as the
synchronous error. Please check that the position error (DGN data No.300) of the slave axis
becomes 0 or so.

And also check the position error is near 0 even when the speed of the master axis is changed.

Set the following parameters to use Feed-forward function with 100% coefficient.

[Setting parameters]
Bit 3 (PIENx) of parameter No. 2003 = 1 (Slave axis)

Use PI control in velocity control

Bit 1 (FEEDx) of parameter No. 2005 = 1 (Slave axis)

Use Feed-forward function

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