FANUC Series 0i-MODEL F Plus. CONNECTION MANUAL (FUNCTION) - page 136

6. INTERPOLATION FUNCTION

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of the spindle and Y-axis specified by P and Q. So, a position coder needs to be attached to the spindle.
This control will be maintained until the polygon turning cancel command is executed (G50.2). Polygon
turning is cancelled by any of the following in addition to the G50.2 command:
(1)  Power off
(2)  Emergency stop
(3)  Servo alarm

(4) Reset (external reset signal ERS <Gn008.7>, reset/rewind signal RRW <Gn008.6>, and

key

on the MDI panel)

(5) Occurrence of alarm PS0217 to PS0221, PS0314, and PS5018

NOTE

1 Before polygon turning, reference position return operation on the Y-axis needs

to be specified to determine the rotation start position of the tool. This reference
position return operation is performed by detecting a deceleration limit as in the
case of manual reference position return operation. (By setting bit 7 (PLZ) of
parameter No. 7600, reference position return operation can be performed
without detecting a deceleration limit.)

2 The rotation direction on the Y-axis is determined by the sign of Q, and is not

affected by the rotation direction of the position coder.

3 Among Y-axis position indications, the indication of a machine coordinate

(MACHINE) changes within the amount of movement for 0 to 1 revolution as a
movement is made on the Y-axis. The absolute coordinate and relative
coordinate are not updated. So, when specifying an absolute-position command
for the Y-axis after polygon turning mode cancellation, set a workpiece coordinate
system after reference position return operation.

4 For the Y-axis engaged in polygon turning, jog feed and handle feed are disabled.
5 For the Y-axis not engaged in polygon turning, a move command can be

specified as in the case of other controlled axes.

6 The Y-axis engaged in polygon turning is not counted in the number of

simultaneously controlled axes.

7 One workpiece must be machined using a fixed spindle speed until the workpiece

is finished.

8 G50.2 is the G code for suppressing buffering.
9 The following functions must be commanded with polygon turning cancel mode.

-  Inch/metric conversion
-  AI contour control
-  Tilted working plane indexing
-  Flexible path axis assignment

Spindle connection

A position coder must be mounted on the spindle. However, polygon turning requires no additional
changes to the spindle connection.
Polygon turning uses the position coder feedback signal to control the positional relationship (cutting
position) between the spindle and tool rotation axis, and the ratio of speed.

Tool rotation axis (servo axis) connection

Parameter No. 7610 specifies the controlled axis (servo axis) to be used as the tool rotation axis.
The same parameter setting as for ordinary servo axes applies to the servo axis connection for polygon
turning except for some parameters.
When the machine is not in the polygon turning mode, the servo axis specified as the rotation tool axis
functions as a feed axis. So, the servo axis can be:

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Used as a subspindle under PMC axis control

Positioned by a move command from a machining program.

However, be careful about the angle to rotate through and feedrate.
Refer to the concrete example of the following a parameter setting.

Principle of polygon turning

The principle of polygon turning is explained below. In the Fig. 6.9.1 (a), the radius of tool and workpiece
are A and B, and the angular speeds of tool and workpiece are

and

. The origin of XY Cartesian

coordinates is assumed to be the center of the workpiece.
Simplifying the explanation, consider that the tool center exists at the position Po (A, 0) on the workpiece
periphery, and the tool nose starts from position Pto (A-B, 0).

: (A,0)

: (A-B,0)

Tool

Angular
speed

(0,0)

Workpiece

Angular speed

Fig. 6.9.1 (a)

Pt(X

)

(0,0)

Start point

Fig. 6.9.1 (b)

In this case, the tool nose position Pt (Xt, Yt) after time t is expressed by equations 1 and 2:

cos

cos(

)

(Equation 1)

sin

sin(

)

(Equation 2)

Assuming that the rotation ration of workpiece to tool is 1:2, namely,

, equations 1 and 2 are

modified as follows:

cos

-Bcos

A-B

)cos

(Equation 1)'

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sin

+Bsin

A+B

)sin

(Equation 2)'

These equations indicate that the tool nose path draws an ellipse with longer diameter A+B and shorter
diameter A-B.
Then consider the case when one tool is set at 180

symmetrical positions, for a total of two. A square can

be machined with these tools as shown Fig. 6.9.1 (c).

Fig. 6.9.1 (c)

If three tools are set at every 120

, the machining figure will be a hexagon as shown Fig. 6.9.1 (d).

Fig. 6.9.1 (d)

WARNING

For the maximum rotation speed of the tool, see the instruction manual supplied
with the machine. Do not specify a spindle speed higher than the maximum tool
speed or a ratio to the spindle speed that results in a speed higher than the
maximum tool speed.

Examples of parameter setting

The following descriptions exemplify typical parameter setting for polygon turning using a serial pulse
coder (with a million pulse capability).
(1) Tool rotation axis setting

This example uses the CNC's fourth axis (connected as the Y-axis) as a rotation tool axis for
polygon turning.

Parameter No. 7610 = 4 (controlled axis number for the tool rotation axis)

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The following description assumes that the axis type parameter is set to the fourth axis.

(2) Servo parameter setting

Set the servo parameters as listed below:

CMR=1

DMR=36/100

(With the above setting, the reference counter capacity is 360000.)

Parameter No.1820=2

(CMR)

Parameter No.1821=360000 (reference counter capacity)

Parameter No.2084=36

(DMR numerator)

Parameter No.2085=100

(DMR denominator)

For the other servo parameters, specify typical values.

(3) Parameter setting for polygon turning

The least command increment, detection unit, the angle to rotate through per rotation for the Y axis
are as follows:

Least command increment=

DMR

CMR

Detection unit=

DMR

CMR

increment

command

Least

Angle to rotate through per tool axis rotation=

increment

command

Least

360

where
L:

Tool axis rotation angle per motor rotation (degrees),
(360

speed increment ratio)

When the servo motor is connected directly to the rotation tool, for example, L = 360. When the tool
speed is doubled, L = 720.
Q: Number of pulses per pulse coder rotation

(For a serial pulse coder, Q = 1000000.)

The least command increment specified here is specific to the Y axis. It is determined regardless of
what is specified in parameter No. 1013#0,#1 (ISA/ISC). However, both ISA and ISC must be set to
0 for IS-B setting.

If the servo motor is connected directly to the rotation tool:

Least command increment=

0.001

36/100

1000000

360

[deg]

Detection unit=0.001 [deg]

Angle to rotate through per tool axis rotation=

360000

001

360

The upper limit to the tool rotation axis speed is:

Maximum servo motor speed

speed increment ratio

Therefore, if the maximum servo motor speed is 1000 [min

-1

], and the servo motor is directly

connected to the servo motor:

Upper limit to the tool rotation axis speed = 1000

1 = 1000 [min

-1

]

This means the parameters must be set as follows:

Parameter No. 7620 = 360000 (angle to rotate through per tool axis rotation)

Parameter No. 7621 = 1000 (upper limit to tool rotation axis speed)

(4) Feedrate parameter setting

Because the least command increment is 0.01 [deg], the input unit for the feedrate is 1 [deg/min].

To obtain a rapid traverse speed of 1000 [min

-1

], for example, specify as follows:

Parameter No. 1420 = 360000 (= 1000

360)

Other feedrate parameters must be set in degrees per minute.

(5) Commands from the NC program

When the machine is not performing polygon turning, the machining program can issue move
commands to the Y-axis.

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Such commands can be issued in the same way as for ordinary axes. However, note the travel
increment and feedrate.

The Y-axis rotates through 0.003[deg] by the following command:

V3;

Likewise, the polygon axis rotates through 1.000[deg] by the following command:

V1.0;

The current position of the Y-axis in the machine coordinate system is normalized according to the
value specified by parameter No. 7620.

Typical values range from 0.000 to 359.999.

Signal

Polygon synchronization under way signal PSYN<Fn063.7>

[Classification] Output signal

[Function] Informs the PMC that the machine is in the polygon turning mode.

[Output cond.] The polygon synchronization signal is set to logical “1” by the polygon turning mode

command (G51.2) and stays at 1 during the polygon turning mode.
The signal is reset to logical “0” by the polygon turning mode reset command (G50.2) or
a reset. It stays at logical 0 when the machine is not in the polygon turning mode.

NOTE

This signal uses the same address for both polygon turning (using
the servo axis) and polygon turning with two spindles.

Other signals

Some signals related to the CNC controlled axis used as the tool rotation axis may be made ineffective
depending on whether the machine is in the polygon turning mode.

Signal

Valid / invalid for the

Y-axis of polygon

turning mode

All-axis machine lock signal MLK<Gn044.1>
Each-axis machine lock signal MLK1~MLK8 <Gn108>

Valid

Servo off signal SVF1~SVF8<Gn126>

Valid

Automatic operation stop signal *SP<Gn008.5>

Invalid

Interlock signal for all axes *IT <Gn008.0>
Interlock signal for each axis *IT1~*IT8 <Gn130>
Interlock signal for each axis direction +MIT1~+MIT8<Gn132>, -MIT1~-MIT8<Gn134>

Invalid

Feedrate override signal *FV0~*FV7 <Gn012>

Invalid

Dry run signal DRN<Gn046.7>

Invalid

Signal address

Fn063

PSYN

Diagnosis data

478

Speed of the tool rotating axis during polygon turning (1/min)

This indication is the speed of the tool rotating axis during polygon turning.

Parameter

7600

PLZ

PFF

[Input type] Parameter input

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[Data type] Bit path

#0 PFF

In spindle-servo polygon turning, feed forward for the tool rotation axis (servo axis)

during polygon turning is always:
0:

Disabled.

Enabled.

#7 PLZ

Reference position return based on a G28 command on the tool rotation axis for polygon

turning is:
0:

Performed in the same sequence as manual reference position return.

Performed by positioning using the rapid traverse rate.

The synchronous axis returns to the reference position in the same sequence as the
manual reference position return when no return-to-reference position is performed after
the power is turned on.

7603

PLROT

RPL

[Input type] Parameter input

[Data type] Bit path

#0 RPL

Upon reset, polygon turning mode is:

Released.

Not released.

NOTE

1 When an emergency stop occurs, the polygon turning mode is

released regardless of whether this parameter is set to 0 or 1.

2 When any of the following PS alarms is issued, the polygon turning

mode is released regardless of whether this parameter is set to 0 or
1:

- Alarm PS0217, "DUPLICATE G51.2(COMMANDS)"

- Alarm PS0219, "COMMAND G51.2/G50.2 INDEPENDENTLY"

- Alarm PS0220, "ILLEGAL COMMAND IN SYNCHR-MODE"

- Alarm PS0221, "ILLEGAL COMMAND IN SYNCHR-MODE"

- Alarm PS5018, "POLYGON SPINDLE SPEED ERROR"

3 If an SV alarm is issued, the polygon turning mode is released

regardless of whether this parameter is set to 0 or 1.

4 When this parameter is set to 1, polygon turning modal information

is kept regardless of whether bit 6 (CLR) of parameter No. 3402 is
set to 0 or 1.

5 Set bit 4 (C20) of parameter No. 3408 to 0.

#3 PLROT

The machine coordinates of a tool rotation axis for polygon turning are:

Rounded by the setting in parameter No.7620.

Rounded by 360

(or the setting in parameter No. 1260 when bit 0 (ROA) of

parameter No. 1008 is set to 1).

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7610

Control axis number of tool rotation axis for polygon turning

NOTE

When this parameter is set, the power must be turned off before
operation is continued.

[Input type] Parameter input

[Data type] Byte path

[Valid data range] 1 to number of controlled axes

This parameter sets the control axis number of a rotation tool axis used for polygon
turning.
However, when a G51.2 command is executed by setting 0 in this parameter, operation
stops with the alarm PS0314.

7620

Movement of tool rotation axis per revolution for polygon turning

NOTE

When this parameter is set, the power must be turned off before
operation is continued.

[Input type] Parameter input

[Data type] Real path

[Unit of data] deg

[Min. unit of data] Depend on the increment system of the applied axis
[Valid data range] 0 or positive 9 digit of minimum unit of data (refer to the standard parameter setting table

(B))
(When the increment system is IS-B, 0.0 to +999999.999)
This parameter sets the movement of a tool rotation axis per revolution.

7621

Maximum allowable speed for the tool rotation axis for polygon turning

[Input type] Parameter input

[Data type] 2-word path

[Unit of data] min

-1

[Valid data range] 0 or positive 9 digit of minimum unit of data (refer to the standard parameter setting table

(B))
(When the increment system is IS-B, 0.0 to +999999.999)
This parameter sets the maximum allowable speed of the tool rotation axis.

NOTE

If the speed of the tool rotation axis exceeds the set maximum
allowable speed during polygon turning, the synchronization
between the spindle and tool rotation axis is lost, and operation
stops with alarm PS5018.

Alarm and message

Number

Message

Description

PS0217

DUPLICATE
G51.2(COMMANDS)

G51.2 is further commanded in the G51.2 mode. Modify the program.

PS0218

NOT FOUND P/Q COMMAND

P or Q is not commanded in the G51.2 block, or the command value
is out of the range. Modify the program. For a polygon turning
between spindles, more information as to why this alarm occurred is
indicated in diagnosis data No. 471.

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Number

Message

Description

PS0219

COMMAND G51.2/G50.2
INDEPENDENTLY

G51.2 and 50.2 were specified in the same block for other
commands. Modify the program in another block.

PS0220

ILLEGAL COMMAND IN
SYNCHR-MODE

In polygon turning, movement is commanded by the NC program or
PMC axis control interface for the polygon axis. Modify the program
or check the PMC ladder.

PS0221

ILLEGAL COMMAND IN
SYNCHR-MODE

Polygon turning and Cs contour control or balance cutting are
executed at a time. Modify the program.

PS0314

ILLEGAL SETTING OF
POLYGONAL AXIS

An axis was specified invalidly in polygon turning.
For polygon turning:

A tool rotation axis is not specified. (Parameter No. 7610)

For polygon turning with two spindles:

Valid spindles are not specified. (Parameter Nos. 7640 to 7643)
-

A spindle other tan the serial spindle.

A spindle is not connected.

For concurrent use of polygon turning and polygon turning with two
spindles:

In the polygon turning mode, the value of parameter No.
7605 (selecting the type of polygon turning) was changed.

An attempt is made to use a spindle used for polygon turning
also for polygon turning with two spindles.

PS5018

POLYGON SPINDLE SPEED
ERROR

In G51.2 mode, the speed of the spindle or polygon synchronous
axis either exceeds the clamp value or is too small. The specified
rotation speed ratio thus cannot be maintained.
For polygon turning with two spindles:
More information as to why this alarm occurred is indicated in
diagnosis data No. 471.

Reference item

Manual name

Item name

OPERATOR’S MANUAL (B-64694EN)

Polygon turning

6.9.2

Polygon Turning with Two Spindles

Overview

When two or more serial spindles are used, the workpiece rotation axis (master axis) and tool rotation
axis (polygon synchronization axis) are synchronized at a certain speed ratio.
With this function, it is also possible to specify the phase difference between the master and polygon
synchronization axes.

The polygon turning with two spindles can use different spindle speeds for the same workpiece, because
it performs automatic phase compensation when a polygon synchronization mode command is issued or
the S command is changed during polygon synchronization mode.

With a multiple path system, polygon turning is possible on each path.

By default, the first and second spindles in each system are selected as the master axis and polygon
synchronization axis for each system. By setting parameters No. 7640 and No. 7641, however, any
spindles belonging to the same system can be selected as the master axis and polygon synchronization
axis. By setting parameters No. 7642 and No. 7643, however, any spindles belonging to different systems
can be selected as the master axis and polygon synchronization axis.

Command format

The following shows the program command format for polygon turning with two spindles. This is the
same as the program command format for polygon turning except for the following points.

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