Content .. 100 101 102 103 ..

FANUC Series 0i-MODEL F Plus. CONNECTION MANUAL (FUNCTION) - page 102

4. REFERENCE POSITION ESTABLISHMENT

B-64693EN-1/01

- 770 -

1884

Distance 2 from the scale zero point to reference position

NOTE

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

[Input type] Parameter input

[Data type] 2-word axis

[Unit of data] Detection unit

[Valid data range] -999 to 999

When a linear scale with absolute address reference marks is used, set the distance from
the scale zero point to reference position in parameter Nos. 1883 and 1884).

Distance from the zero point to the reference position of a linear scale
= No. 1884

1,000,000,000 + No. 1883

The  scale  zero point  represents  a  point  where mark 1 and mark 2 match. Usually, this
point  is a virtual point  that does not physically exist on the scale. (See the following
figure.)
If the reference position  is placed in the + direction  when viewed from the scale  zero
point, set a positive value. If the reference position  is placed in the -  direction  when
viewed from the scale zero point, set a negative value.

Mark 1

Mark 2

Mark 1

Mark 2

Zero point of encoder

Encoder end

Reference position

……..

Mark 1 = mark 2

41.8

8.2

42.0

8.0

PRM.1821

PRM.1882

PRM.1884

1,000,000,000 + PRM.1883

B-64693EN-1/01

4. REFERENCE POSITION ESTABLISHMENT

- 771 -

[Example of parameter settings]

When an encoder as shown the following figure is used with an IS-B, millimeter
machine:

20.000

19.980

9.940

10.060

9.960

10.040

9.980

10.020

5.000

20.000mm

20.020mm

-[9960/(20020-20000)*20000+5000] =

-9965000

Mark 1

Mark 2

Mark 1

Mark 2

Mark 1

Mark 2

Mark 1

Mark

Mark 2

Mark 1 = mark 2

Scale zero point

+ direction

- direction

Reference

position

Parameters

No.1821 (interval of mark 1)

= 20000

No.1882 (interval of mark 2)

= 20020

No.1883 (reference position) = position of point A + 5.000
= distance between A and B/(mark 2

mark 1)

mark 1 + 5000

= 9960/(20020-20000)

20000 + 5000

= 9965000
= -9965000 (the reference position is on the negative side)

[Setting parameter No. 1883]
When it is difficult to measure the distance  from the scale  zero point  to the reference
position  (parameter No.  1883), the method  described  below can be used to find the
distance.

<1>  Set parameter No. 1815 to enable this function.

Set an appropriate value in parameter No. 1821 and No. 1882.

Parameter No. 1240 is set to 0.

Parameters Nos. 1883 and 1884 are set to 0.

<2> At an appropriate position, establish a reference position.

(As a result, the machine coordinate represents the distance from the scale zero point
to the current position.)

<3> By jog feed or handle feed, place the machine at the accurate reference position.
<4> In parameter No. 1883, set the machine coordinate of that time converted to the

detection unit (machine coordinate

CMR).

<5> If necessary, set parameter No. 1240.

NOTE

1 Set parameter Nos. 1883 and 1884 so that the distance from the

scale zero point to the reference position is within the range from
-999,999,999,999 to +999,999,999,999. If a value beyond this
range is set, an alarm DS1448, "ILLEGAL PARAMETER (D.C.S.)",
is issued.

2 The scale area on the scale cannot be extended across the scale

zero point. Make parameter settings not to cause the scale area to
extend beyond the scale zero point.

4. REFERENCE POSITION ESTABLISHMENT

B-64693EN-1/01

- 772 -

Alarm and message

Number

Message

Description

PS5220

REFERENCE POINT ADJUSTMENT
MODE

In case of distance coded linear scale I/F, the reference
point auto setting bit 2 (DATx) of parameter No. 1819 is set
to 1. Move the machine to reference position by manual
operation and execute manual reference return.

SV1051

ILLEGAL SYNCHRONOUS AXIS

In axis synchronous control, the parameter setting for the
axis for which distance coded linear scale I/F is used, is
incorrect. Set the following parameters to the same values
for the master axis and slave axis.
-

Parameter No. 1821 (mark-1 interval)

Parameter No. 1882 (mark-2 interval)

Bit 2 (DC2x) and Bit 1 (DC4x) of parameter No.1802
(the number of marks)

DS0020

REFERENCE RETURN INCOMPLETE

An attempt was made to perform an automatic return to the
reference position on the perpendicular axis before the
completion of a return to the reference position on the
angular axis.
However, this attempt failed because a manual return to the
reference position during angular axis control or an
automatic return to the reference position after power-up
was not commanded. First, return to the reference position
on the angular axis, then return to the reference position on
the perpendicular axis.

DS0026

MISMATCH OF ANGULAR AXIS(D.C.S)

On angular axis control, one of the angular/perpendicular
axes is the scale with ref-pos, and the other of them is not
the scale with ref-pos. Such system is not admired.

DS0027

MISMATCH OF SYNCHRONOUS
AXIS(D.C.S)

Master/slave axes of axis synchronous control, one of
them is the linear scale with distance-coded reference
marks, and the other of them is not the linear scale with
distance-coded reference marks. Please establish
reference position with the input signal
SYNCn<Gn138>, SYNCJn<Gn140> or parameter
setting to 0.

The slave axis of the axis synchronous control is two or
more settings. Such system is not admired.

DS1448

ILLEGAL PARAMETER (D.C.S.)

The setting value of parameter for distance coded linear
scale I/F is satisfied the following any conditions.
-

The absolute-position detection function is enabled.

Either parameter No. 1821 (mark-1 interval) or
parameter 1882 (mark-2 interval) is set to 0.

Parameters Nos. 1821 and 1882 have identical
settings.

The difference between the settings made for
parameters Nos. 1821 and 1882 is greater than or
equal to twice either setting.

The setting value of parameters 1883 and 1884 are
over the valid data range.

In case of Rotary axis (B type), the values other than 0
are set to the parameter No.1868 and No.1869 or bit 0
(RVSx) of parameter No.1815 is set to 1.

DS1449

REFERENCE MARK ARE DIFFERENT
FROM PARAMETER

In case of distance coded linear scale I/F, the actual
interval of reference marks is different from setting value in
parameters Nos. 1821 and 1882.

B-64693EN-1/01

4. REFERENCE POSITION ESTABLISHMENT

- 773 -

Diagnosis data

3545

Measurement point 1 of the reference marks of distance coded linear scale

3546

Measurement point 2 of the reference marks of distance coded linear scale

3547

Measurement point 3 of the reference marks of distance coded linear scale

3548

Measurement point 4 of the reference marks of distance coded linear scale

[Data type]

2-word axis

[Unit of data] Detection unit

[Valid data range] -999999999 to 999999999

3549

Internal status of the reference marks of distance coded linear scale

3550

Scale counter value of the reference marks of distance coded linear scale

[Data type]

2-word axis

[Unit of data] Detection unit

[Valid data range] -999999999 to 999999999

3551

Scale counter value of the reference marks of distance coded linear scale (high)

[Data type]

2-word axis

[Unit of data] Detection unit

[Valid data range] -999 to 999

Scale counter value of the reference marks of distance coded linear scale = diagnosis data
No.3551

1,000,000,000 + diagnosis data No.3550

4.9

LINEAR SCALE WITH DISTANCE-CODED REFERENCE
MARKS (SERIAL)

Overview

By using High-resolution serial output circuit for the linear scale with distance-coded reference marks
(serial), the CNC measures the interval of referenced mark by axis moving of short distance and
determines the absolute position.
This function enables high-speed high-precision detection by using High-resolution serial output circuit.
It is available that using maximum stroke 30 meters length.

Explanation

The linear scale with distance-coded reference marks (serial) is combined the irregular reference marked
linear scale with the High-resolution serial output circuit, it can detect the accurate position.

Reference mark signal

10.02

10.04

10.06

The CNC measures the interval of referenced mark by axis moving of short distance and determines the
absolute position, because of the interval of each reference mark is different with regular interval.

4. REFERENCE POSITION ESTABLISHMENT

B-64693EN-1/01

- 774 -

It is not necessary that the axis is moved to the reference position for establishment of reference position.

This function enables high-speed high-precision detection by using High-resolution serial output circuit.
It is available that using maximum stroke 30 meters length.

Connection

It is available under linear motor system and full closed system.

Linear motor system

CNC

Servo

amplifier

Linear motor

Linear Motor

Position Detection

Circuit C

Pole sensor

Linear scale with distance-coded

reference marks (serial)

CNC

Servo

amplifier

Separate

Detector

Interface

Unit

Table

High

Resolution

Serial Output

Circuit C

Full Closed System

Linear scale with distance-coded

reference marks (serial type)

Procedure for reference position establishment through manual operation

(1) Select the JOG mode, and set the manual reference position return selection signal ZRN to "1".
(2) Set the feed axis and direction selection signal (+J1, -J1, +J2, -J2, …) of a target axis to “1” and feed

toward the reference position.

(3) The axis is fed at a constant low speed (reference position return FL feedrate specified by parameter

No.1425 setting).

(4) When the absolute position of linear scale with distance-coded reference marks (serial) is detected,

the axis stops. Then the absolute position of CNC is calculated and the reference position
establishment signal (ZRF1, ZRF2, ZRF3, …) turns to "1".

The timing chart for this procedures is given below.

FL rate

JOG

ZRN

+J1

Reference mark

ZRF1

Feedrate

B-64693EN-1/01

4. REFERENCE POSITION ESTABLISHMENT

- 775 -

Procedure for reference position establishment through automatic operation

If an automatic reference position return (G28) is specified before a reference position is not established,
steps (3) to (4) above are performed automatically.
After the reference position is established, the automatic reference position return is performed by setting
of bit 0 (RFS) of parameter No. 1818.

Stopping the operation for establishing a reference position

The operation for establishing a reference position is stopped if any of
the following operations is performed in steps (3) to (4), described above.

•

Reset

•

Setting the feed axis and direction selection signal (+J1, -J1, +J2, -J2, etc.) to "0"

•

Setting the Servo off signals (SVF1, SVF2, etc.) to "1"

If any of the following operations is performed during the operation of automatic reference position
return (G28) before a reference position is not established, the operation for establishing a reference
position stops:

•

Reset

•

Performing feed hold during movement from an intermediate position to the reference position

•

Setting the Servo off signals (SVF1, SVF2, etc.) to "1"

If the operation for establishing a reference position is stopped by an operation other than a reset, the
operation for establishing a reference position must be reset and resumed.

Establishing a reference position and moving to the reference position

By following operation, establishing a reference position and moving to the reference position is
performed.

Moving through manual

operation in REF mode

Moving through automatic operation by automatic

reference position return (G28)

The reference
position is not
established.

Establishing the reference
position

Firstly, moving to the intermediate position, and
establishing the reference position.
Secondly, whether moving to the reference position or not
is performed by setting bit 0 (RFS) of parameter No.1818.

The reference
position is
established.

Moving to the reference position

Whether moving to the intermediate position and the
reference position or not is performed by setting bit 1
(RF2) of parameter No.1818.

Axis synchronous control

In case of using the axis synchronous control, please confirm the following items.

•

When this function is used with axis synchronous control axes, the linear scale with distance-coded
reference marks (serial) used for the master axis and that used for the slave axis must have reference
marks placed at identical intervals.

•

The linear scale with distance-coded reference marks (serial) can be installed on the master and slave
axes either in the same or opposite direction.

•

To the axis parameters, which relate to this function (except No.1883, No.1884) (distance from the
scale zero point to reference position), the same value must be set for the master axis and for the
slave axis.

•

The linear scale with distance-coded reference marks (serial) should be applied for the master axis
and the slave axis.
If either of the master axis or the slave axis is not the linear scale with distance-coded reference
marks (serial), alarm DS0018, "SERIAL DCL:MISMATCH (SSYNC CTRL)", occurs when
reference position establishment is tried by the axis synchronous control.

•

During operating the establishment of reference position, the state of synchronous control axis
selection signals (SYNCn<Gn138> or SYNCJn<Gn140>) should be kept.

4. REFERENCE POSITION ESTABLISHMENT

B-64693EN-1/01

- 776 -

Both of synchronous axes (master axis and slave axis) are fed on the reference position return FL feedrate
until distance coded scales of both axes detect the absolute position.
Then absolute position of both axes are calculated and the reference position establishment signal (ZRF1,
ZRF2, ...) turn to "1".

NOTE

When this function is used by the axis synchronous control, only one axis is
available for the slave axis.

Angular axis control

In case of using the angular axis control, please confirm the following items.

•

It is necessary to use the linear scale with distance-coded reference marks (serial) for both the
perpendicular axis and the angular axis.
If not, the alarm DS0019, "2SERIAL DCL:MISMATCH(ANGL-AXIS)", occurs when reference
position establishment is commanded.

•

Please set so that whenever the reference position establishment of angular axes is tried,
perpendicular axes are fed (bit 2 (AZR) of parameter No. 8200 to 0 and input signal NOZAGC
<G063.5> to "0").
If not, the alarm DS0019 occurs when reference position establishment is commanded.

•

When the reference point of the perpendicular axis is established, it is necessary to establish the
reference point of the angular axis previously. When the perpendicular axis is commanded
previously or the perpendicular axis and the angular axis are commanded simultaneously, the alarm
DS0020, "REFERENCE RETURN INCOMPLETE", occurs.

•

On angular axis control, if you use automatic setting of parameter Nos.1883 and 1884 on reference
position establishment (bit 2 (DATx) of parameter No.1819=1) for both the perpendicular axis and
the angular axis, please establish reference point of perpendicular axis after reference position auto
establishment and return of angular axis.

In manual reference position return, the perpendicular axis cannot be specified while the angular axis
reference point is being established. The perpendicular axis, if specified, is ignored.

Parameters

1815

DCLx

OPTx

[Input type] Parameter input

[Data type] Bit axis

NOTE

When at least one of these parameters is set, the power must be
turned off before operation is continued.

#1 OPTx

The separate position detector is:

Not to be used (semi-closed system)

To be used (full-closed system)

NOTE

Set this parameter to 1 when using a linear scale with
distance-coded reference marks (serial) (full-closed system).

#2 DCLx

As a separate position detector, a linear scale with reference marks or a linear scale with

an absolute address zero point is:
0:

Not used.

B-64693EN-1/01

4. REFERENCE POSITION ESTABLISHMENT

- 777 -

Used.

1818

SDCx

RF2x

RFSx

[Input type]

Parameter input

[Data type]

Bit axis

#0 RFSx

If G28 is specified for an axis for which a reference position is not established (ZRF = 0)

when a linear scale with an absolute address zero point is used:
0:

A movement is made to the reference position after reference position establishment
operation.

No movement is made after reference position establishment operation, but the
operation is completed.

NOTE

This parameter disables movement based on the G28 command to
a reference position. So, use this parameter only in special cases.

#1 RF2x

If G28 is specified for an axis for which a reference position is already established (ZRF

= 1) when a linear scale with an absolute address zero point is used:
0:

A movement is made to the reference position.

No movement is made to the intermediate position and reference position, but the
operation is completed.

NOTE

This parameter disables movement based on the G28 command to
a reference position. So, use this parameter only in special cases.

#3 SDCx

A linear scale with an absolute address zero point is:

Not used.

Used.

NOTE

1 When the parameter SDCx is set, the power must be turned off

before operation is continued. Alarm PW0000, “POWER MUST BE
OFF ” does not occur.

2 Please set bit 1 (SDC) of parameter No. 1815 to 1 when the full

closed system. But please set this parameter to 0 when the Linear
motor system.

1819

DATx

[Input type]

Parameter input

[Data type]

Bit axis

#2 DATx

The automatic setting of parameters Nos. 1883 and 1884 at manual reference position

return time is:
0:

Not performed.

Performed.

Content .. 100 101 102 103 ..