FANUC Series 30i/300i/300is-MODEL A. Machining Center System. User's manual - page 153

5.TEST OPERATION

OPERATION

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5.2

FEEDRATE OVERRIDE

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. 5.2 (a) Feedrate override

Feedrate override

Procedure

Set the feedrate override dial to the desired percentage (%) on the
machine operator's panel, before or during automatic operation.
On some machines, the same dial is used for the feedrate override dial
and jog feedrate dial. Refer to the appropriate manual provided by the
machine tool builder for feedrate override.

Limitation
- Override range

The override that can be specified ranges from 0 to 254%. For
individual machines, the range depends on the specifications of the
machine tool builder.

- Override during thread

During the threading process, the override setting is ignored; it is
always regarded as 100% during the process.

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5.3

RAPID TRAVERSE OVERRIDE

An override of four steps (F0, 25%, 50%, and 100%) can be applied to
the rapid traverse rate. F0 is set by a parameter No. 1421.

Rapid traverse rate
10m/min

Override
50%

5m/min

Fig. 5.3 (a) Rapid traverse override

Rapid traverse override

Procedure

Select one of the four feedrates with the rapid traverse override switch
during rapid traverse. Refer to the appropriate manual provided by the
machine tool builder for rapid traverse override.

Explanation

The following types of rapid traverse are available. Rapid traverse
override can be applied for each of them.
(1)  Rapid traverse by G00
(2)  Rapid traverse during a canned cycle
(3)  Rapid traverse in G27, G28, G29, G30, G53
(4)  Manual rapid traverse
(5)  Rapid traverse of manual reference position return

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5.4

DWELL/AUXILIARY FUNCTION TIME OVERRIDE

An override can be applied to dwell and the auxiliary function
(M/S/T/B) in increments of 1

in the range from 0 to 100

For the auxiliary function, however, if the override is less than 100

the next block is started after a lapse of actual processing time plus
shortage time.

Dwell/auxiliary function time override

Procedure

Press the 1

rapid traverse override selection switch and turn the

rapid traverse override switch to select the desired percentage.

For details on 1

rapid traverse override, refer to the manual provided

by the machine tool builder.

Explanation
- Dwell

An override can be applied to dwell.
[Example]

Override and dwell time when G04 P10000; is executed

Override Dwell

time

25% 40.0

sec.

50% 20.0

sec.

75% 13.3

sec.

100% 10.0

sec.

NOTE

An override is disabled for dwell per revolution.

- AUXILIARY functions (M/S/T/B)

An override can be applied in the time from when M/S/T/B is sent
until the FIN signal is turned off (or until MFIN, SFIN, TFIN, and
BFIN are changed in the case of the high speed M/S/T/B). The time
required to communicate with PMC is included.
When the FIN signal is turned off and then shortage time elapses, the
next block is started.
[Example]

When the following program is executed with the override set to
60

N10

M03

;

N20

⋅

;

When the processing time of the N10 block is 80 msec, the N20
block is started approx. 56 msec after completion of the
processing.

Shortage time = 80 msec × 100/60 - 80 msec = 53.333

≅

56 msec

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NOTE

The time count is incremented every 4 msec or 8
msec and the fraction is rounded up. The counting
cycle of time may depend on the system.

The 1

rapid traverse override signal reads the value upon completion

of the auxiliary function. Accordingly, the value is not ensured if the
override value changes between before and after the reading.

When the movement command and auxiliary function are specified in
the same block:

(1) When the movement command is completed first

•

An override is enabled.

(2) When the auxiliary command is completed first

•

An override is disabled.

When auxiliary functions are specified in the same block, the shortage
time is calculated using the auxiliary function with the longest
processing time.

NOTE

1 This function is disabled for dwell by PMC axis

control (04H) and the auxiliary functions (12H, 14H,
15H).

2 For the dwell, when the 1

rapid traverse override

signal is 0

, a transition to the next block is not

performed.

3 The time when a feed hold is caused in the auxiliary

function during shortage time is not included in the
shortage time.

4 For the auxiliary function, when the 1

rapid

traverse override signal is 0

, the setting of

parameter No. 3018 is used as the override value.
When the setting of the parameter is 0, it is
assumed to be 10

. While the 1

rapid traverse

override signal is 0

, a transition to the next block

is not performed.

5 For auxiliary functions M02 and M30, bit 7 (OVM) of

parameter No. 3002 can be used to enable or
disable an override.

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5.5

DRY RUN

The tool is moved at the feedrate specified by a parameter regardless
of the feedrate specified in the program. This function is used for
checking the movement of the tool under the state that the workpiece
is removed from the table.

Tool

Table

Fig. 5.5 (a) Dry run

Dry run

Procedure

Press the dry run switch on the machine operator's panel during
automatic operation.
The tool moves at the feedrate specified in a parameter. The rapid
traverse switch can also be used for changing the feedrate.
Refer to the appropriate manual provided by the machine tool builder
for dry run.

Explanation
- Dry run feedrate

The dry run feedrate changes as shown in the table below according to
the rapid traverse switch and parameters.

Table 5.5 (a)

Program command

Rapid traverse

switch

Rapid traverse

Cutting feed

Rapid traverse rate

Dry run feedrate

Jvmax

(*2)

OFF

Dry run feedrate

JV,

or rapid traverse rate

(*1)

Dry run feedrate

(*2)

Max. cutting feedrate ...........Setting by parameter No.1430
Rapid traverse rate ...............Setting by parameter No.1420
Dry run feedrate ...................Setting by parameter No.1410
(

1) Dry run feedrate

JV when parameter RDR (No. 1401#6) is 1.

Rapid traverse rate when parameter RDR is 0.

Jog feedrate override

(

2) Clamped to the maximum cutting feedrate

Jvmax

Maximum value of jog feedrate override

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5.6

SINGLE BLOCK

Pressing the single block switch starts the single block mode. When
the cycle start button is pressed in the single block mode, the tool
stops after a single block in the program is executed. Check the
program in the single block mode by executing the program block by
block.

Tool

Cycle start

Stop

Workpiece

Cycle start

Fig. 5.6 (a) Single block

Single block

Procedure

Press the single block switch on the machine operator's panel.

The execution of the program is stopped after the current block is
executed.

Press the cycle start button to execute the next block. The tool
stops after the block is executed.

Refer to the appropriate manual provided by the machine tool
builder for single block execution.

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Explanation
- Reference position return and single block

If G28, G29, and G30 are issued, the single block function is effective
at the intermediate point.

- Single block during a canned cycle

In a canned cycle, the single block stop points are the end of <1>, <2>,
and <6> shown below. When the single block stop is made after the
point <1> or <2>, the feed hold LED lights.

<6>

<1>

<2>

<4>

<5>

Rapid
traverse

Cutting feed

<3>

Fig. 5.6 (b) Single block during canned cycle

- Subprogram call and single block

Single block stop is not performed in a block containing M98P_;.
M99; or G65.
However, single block stop is even performed in a block with M98P_
or M99 command, if the block contains an address other than O, N, P,
L.

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5.7

HIGH SPEED PROGRAM CHECK FUNCTION

When the cycle start button is pressed with the high speed program
check mode set to be enabled, the program syntax and stroke limit are
checked without axis movement.
A program check is performed at the maximum speed that can be
specified by the CNC, regardless of the specified speed.

NOTE

This function is optional.

High speed program check

Procedure

1 Perform position of the machine at the start position of the

machining program in advance.
Set the workpiece coordinate system or tool compensation to the
same state as in actual machining.

Reset the CNC and press the high speed program check switch
on the machine operator's panel to enter the high speed program
check mode. In the high speed program check mode,
"PRG-CHK" blinks at the lower-left of the CNC screen.

Press the cycle start button to execute the program without axis
movement. The feedrate is the maximum speed that can be
specified by the CNC, regardless of the specified speed.
The program syntax and stroke limit are checked during
execution of the program.

Upon completion of the check, reset the CNC and release the
high speed program check mode with the switch on the machine
operator's panel.

Explanation
- Stroke Limit Check

Following the stroke limit check is executed without axes movements
during the high speed program check mode.

•

Stored stroke check 1

•

Stored stroke check 2, 3

•

Stroke limit check before move

•

Rotation area interference check

If an alarm about the stroke limit occurs in the high speed program
check mode, clear the alarm as described below.
(1) Change the mode to other than MEM or DNC.
(2) Reset the CNC.

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