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FANUC Series 0i-MODEL C, Series 0i Mate-MODEL C. MAINTENANCE MANUAL - page 18

8. TROUBLESHOOTING

B-64115EN/02

8.12

ALARM 90

(REFERENCE

POSITION RETURN

IS ABNORMAL)

Contents

Reference position return was executed when the following condition is

not satisfied:

The CNC received one rotation signal at least one time when the axis is

moving to the reference position at a speed higher than a speed equivalent

to 128 pulses of position error amount(DGN300).

Countermeasures

(START)

Position error

Check whether position gain is greater than 128 pulses

amount : DGN 300

(DGN 300) before or during reference position return.

YES

128 or more

(1) Next page

NO

Raise the speed

Check feed rate command:

PRM 1420 F : Rapid traverse rate

(mm/min)

PRM 1424

Manual rapid traverse rate (mm/min)

PRM 1825 G : Servo loop gain

(0.01sec^-1)

F

5000/3

Position error=

G detection unit[µm/PLUSE]

Detection unit : Move amount to a command pulse (usually 1µm)

In metric machine, if the no. of digits below decimal point is 4 on the position

display screen, detection unit is 0.1 µm.

Check rapid traverse override signals :

ROV1

DGN

014.0

ROV1

ROV2

Override

1014.0 (For two-

path control)

0

0

100%

ROV2

DGN

014.1

0

1

50%

1014.1 (For two-

1

0

25%

path control)

1

1

Fo rate

PRM

1421

Fo rate

Check reference position return deceleration signal

DEC1 to DEC8 DGN 009.0 to 009.7

When reference position return is started from deceleration signal 0, feed rate

becomes FL rate.

PRM 1425 FL rate

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8. TROUBLESHOOTING

(1)

Check whether the motor ratated more than one rota-

tion (one rotation signal is issued ) at faster than 128

pulses of position error amount.

NO

Return start position is too close

Rotated ?

· Chagne the return start position.

· Move the machine at faster that 128

YES

pulses for more than one rotation to

wards RP.

Check that voltage of pulse coder is higher than 4.75 V.

To measure pulse coder voltage, remove the motor cover and measure on

pulse coder PCB at across + and - or +5V and 0V terminals.

NO

More than 4.75V

YES

Hardware failure

Pulse coder power voltage is low

· Pulse coder is faulty

Change pulse coder or motor

CAUTION

After the pulse coder or motor is exchanged, reference

position or machine’s standard point may be different from

former one. Please set it correctly.

D Reference

A speed more than 128 pulses is required because if speed is lower that

this, one-rotation signal does not function stably, causing improper

position detection.

If bit 0 of parameter No. 2000 is set to 1, a speed corresponding to a

positional deviation of 1280 pulses or more is required.

Parameter No. 1836 can be set to 128 or less, as the minimum positional

deviation with which reference position return is possible.

(If the

parameter is set to 0, 128 is assumed as the minimum positional deviation.

If bit 0 of parameter No. 2000 is set to 1, a value equal to ten times the

set value is used for checking.)

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8. TROUBLESHOOTING

B-64115EN/02

Absolute position data in the serial pulse coder was lost.

8.13

(This alarm will be generated when serial pulse coder is exchanged or

ALARM 300

position feedback signal cable of the serial pulse coder is disconnected).

(REQUEST FOR

REFERENCE

POSITION RETURN)

Remedies

Machine position must be memorized using the following method:

D When reference position

(1) Execute manual reference position return only for an axis for which

return function is

this alarm was generated.When manual reference position return

present

cannot be executed because of an another alarm, set parameter 1815#5

to 0 and release the alarm and perform manual operation.

(2) Press

RESET

key at the end of reference position return to release the

alarm.

D When reference position

Execute dogless reference position setting to memorize the reference

return function is not

position.

present

D When serial pulse coder

Since the reference position is different from the former one, change the

is changed

grid shift value (PRM 1850) to correct the position.

Related parameters

#7

#6

#5

#4

#3

#2

#1

#0

1815

APC x

APZx

#5(APCx)

0 : Position detector is incremental pulse coder.

1 : Position detector is absolute pulse coder.

#4(APZx)

Reference position of absolute pulse coder is :

0 : not established

1 : established

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8. TROUBLESHOOTING

8.14

ALARM 401

(V READY OFF)

Causes and actions

This alarm is issued if the servo ready signal (VRDY) of a servo amplifier

does not turn on or if the signal turns off during operation.

There are cases in which this alarm is issued because another servo alarm

is issued. If this occurs, first take the action for the first alarm.

Check the power magnetic circuit around the amplifier. The servo

amplifier or the axis control cards on the CNC may be defective.

D VRDY

CNC (Main board)

Servo amplifier

MCON: From the CNC to the servo amplifier

(Turn MCC on to request the activation of the servo motor)

VRDY: From the servo amplifier to the CNC

(Notifies that the servo is ready)

The exchange of this information is performed via the FSSB (optical cable).

D Example of connection

around the amplifier

(Typical example)

CNC

SVM

SVM

SPM

PSM

(servo

(servo

amplifier)

amplifier)

Control

power

supply

FSSB

FSSB

ESP

Emergency stop

circuit

MCC

Serial spindle

Servo

Servo

Spindle

motor

motor

motor

3-phase

AC

AC200V

Breaker

MCC

reactor

Single-

phase

Breaker

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8. TROUBLESHOOTING

8.15

ALARM 404

(V READY ON)

Causes and actions

This alarm is issued if the servo ready signal (VRDY) of a servo amplifier

remains on.

The servo amplifier or the axis control cards on the CNC may be

defective.

D VRDY

CNC

Servo amplifier

(Main CPU board)

MCON: From the CNC to the servo amplifier

(Turn MCC on to request the activation of the servo motor)

VRDY: From the servo amplifier to the CNC

(Notifies that the servo is ready)

The exchange of this information is performed via the FSSB (optical

cable).

This alarm is issued if VRDY remains on when the CNC turns MCON

off or if VRDY turns on before the CNC turns MCON on.

D Replacing the servo

The servo amplifier may be defective. Replace the servo amplifier.

amplifier

D Replacing the axis

If replacing the servo amplifier does not solve the problem, replace the

control cards

axis control card.

See Section 2.4, “CONNECTOR AND CARD CONFIGURATIONS OF

PRINTED CIRCUIT BOARDS” for an explanation of the mounting

locations of the cards.

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Digital servo parameters are abnormal.

8.17

(Digital servo parameters are set incorrectly.)

ALARM 417 (DIGITAL

SERVO SYSTEM IS

ABNORMAL)

D Causes

1

Confirm the setting value of the following parameters:

PRM 2020 : Motor format number

PRM 2022 : Motor rotation direction

PRM 2023 : Number of pulses of velocity feedbacks

PRM 2024 : Number of pulses of position feedback

PRM 1023 : Servo axis number

PRM 2084 : Flexible feed gear ratio

PRM 2085 : Flexible feed gear ratio

Confirm the details with diagnosis function of CNC side.

2

Change the setting of this parameter to 0.

PRM 2047 : Observer parameter

3

Perform initial setting of digital servo parameters.

Refer to setcion 6.1 “Initial Setting of Servo Parameters” .

This data indicates the cause of servo alarm No. 417, detected by the NC.

If the alarm is detected by the servo, the PRM bit (bit 4 of DGN No. 0203)

is set to 1.

#7

#6

#5

#4

#3

#2

#1

#0

0280

AXS

DIR

PLS

PLC

MOT

#0(MOT) :

The motor type specified in parameter No. 2020 falls outside the

predetermined range.

#2(PLC) :

The number of velocity feedback pulses per motor revolution, specified in

parameter No. 2023, is zero or less. The value is invalid.

#3(PLS) :

The number of position feedback pulses per motor revolution, specified in

parameter No. 2024, is zero or less. The value is invalid.

#4(DIR) :

The wrong direction of rotation for the motor is specified in parameter No.

2022 (the value is other than 111 or -111).

#6(AXS) :

In parameter No. 1023 (servo axis number), a value that falls outside the

range of 1 to the number of controlled axes is specified. (For example, 4 is

specified instead of

3.)

Alternatively, the values specified in the

parameter are not consecutive.

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8. TROUBLESHOOTING

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Spindle speed changes abnormally due to load.

8.20

ALARM 704

(SPINDLE SPEED

FLUCTUATION

DETECTION ALARM)

Remedies

Check whether spindle speed is constant by view

of the speed meter on CRT.

YES

Constant ?

NO

Is a heavy cutting being per-

formed ? Confirm spindle load

on CRT.

Confirm the follow-

ing parameter :

YES

Heavy cutting?

PRM 4911

PRM 4912

Reduce cutting condition

PRM 4913

NO

PRM 4914

Doesn’t the cutting tool worn ?

YES

Worn ?

Replace tool

NO

Spindle servo unit is faulty

Spindle motor is faulty

Remedies

PRM 4911 : A ratio of spindle speed at which actual spindle speed is

regarded as arrived at a command spindle speed.

PRM 4912 : Spindle speed fluctuation ratio up to which the spindle

speed fluctuation detection alarm is not issued.

PRM 4913 : Spindle speed fluctuation that is not regarded as the spindle

speed fluctuation alarm.

PRM 4914 : Time when a spindle speed changed to when spindle speed

fluctuation detection is started.

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8. TROUBLESHOOTING

8.21

ALARM 749

(SERIAL SPINDLE

COMMUNICATION

ERROR)

Causes and actions

An error occurred in the communication between the serial spindle

amplifier (SPM) and the CNC. The probable causes include:

D Contact failure of the connection cable

D Defective printed circuit board on the CNC

D Defective spindle amplifier

D Noise

D Connection cable

Check that the cable connecting the serial spindle amplifier (SPM) to the

CNC is in contact.

Check that the cable is inserted firmly into the connectors and that it does

not have any conductors likely to be cut off.

Check that the cable used is a twisted-pair cable and that it is connected

as described in the connection manual.

D Printed circuit boards on

A spindle control circuit for the CNC is installed on the main board. If

the CNC

this alarm is issued, replace the main board.

D Spindle amplifier module

When an error occurred on the spindle amplifier module (SPM) side, a

(SPM)

code of A, A1, or A2 is indicated on the SPM depending on the nature of

the error.

In this case, take appropriate actions in the Maintenance Manual of your

servo motor.

D Noise environment

If any of the above actions does not solve the problem, examine the noise

environment of the connection cable.

See the section on the measures against noise, take appropriate actions

such as the reinforcement of the cable shield and the separation of the

cable from the power line.

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8. TROUBLESHOOTING

B-64115EN/02

8.22

ALARM 750

(SPINDLE SERIAL

LINK STARTUP

FAILURE)

Causes and actions

This alarm is issued if a serial spindle amplifier (SPM) does not enter the

normal startup state when the CNC is turned on.

This alarm is not issued once the CNC system including the spindle

amplifiers has started up normally. It is issued if a fault occurs in the

power-on process.

The probable causes include the following:

D Contact failure, wiring error, or connection error of the connection

cable

D The CNC is turned on when a spindle amplifier is in the alarm state.

D Parameter setting error

D Defective printed circuit board on the CNC

D Detective spindle amplifier

D Connection

Up to two serial spindle amplifiers (SPMs) can be connected per path.

Note, however, the number of amplifiers that can be connected differs

depending on the model, number of paths, and configuration. Refer to the

Connection Manual (Hardware).

Main board

SPM (first)

JA7A

JA7B

JA7A

SPM (second)

JA7B

JA7A

Check that the cables are connected as shown in the figure above. Check

that JA7Bs and JA7As are connected correctly.

Check that the cables are latched firmly and are not loose.

Refer to the Connection Manual (Hardware) to check that the cables are

connected correctly.

D States of the spindle

This alarm is issued if the CNC is turned on when the LED of a spindle

amplifiers

amplifier indicates a number other than “24”.

On the spindle amplifier, remove the cause of the alarm. Turn off the

spindle amplifier and the CNC, then turn on the system again.

D Details of the alarm

If this alarm is issued, its details can be checked with diagnosis numbers

409 and 439.

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8. TROUBLESHOOTING

D 1st and 2nd spindles

#7

#6

#5

#4

#3

#2

#1

#0

0409

SPE

S2E

S1E

SHE

SPE:

0 : In the spindle serial control, the serial spindle parameters fulfill the

spindle unit startup conditions.

1 : In the spindle serial control, the serial spindle parameters do not fulfill

the spindle unit startup conditions.

S2E:

0 : The second spindle is normal during the spindle serial control startup.

1 : The second spindle was detected to have a fault during the spindle

serial control startup.

S1E:

0 : The first spindle is normal during the spindle serial control startup.

1 : The first spindle was detected to have a fault during the spindle axis

serial control startup.

SHE:

0 : The serial communications circuit in the CNC is normal.

1 : The serial communications circuit in the CNC was detected to have a

fault.

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8. TROUBLESHOOTING

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8.23

ALARM 5134

(FSSB: OPEN

READY TIME OUT)

ALARM 5135 (FSSB:

ERROR MODE)

ALARM 5137 (FSSB:

CONFIGURATION

ERROR)

ALARM 5197 (FSSB:

OPEN TIME OUT)

ALARM 5198 (FSSB:

ID DATA NOT READ)

Causes and actions

These alarms are issued if any of the axis control cards and the slaves

(such as servo amplifiers) and optical cables connected to the FSSB is

defective.

No.

Message

Description

5134

FSSB: OPEN READY TIME

The FSSB did not become ready to

OUT

open during initialization.

5135

FSSB: ERROR MODE

The FSSB entered an error mode.

5137

FSSB: CONFIGURATION

The FSSB detected a configuration er-

ERROR

ror.

5197

FSSB: OPEN TIME OUT

The FSSB did not open when the CNC

had allowed the FSSB to open.

5198

FSSB: ID DATA NOT READ

The initial ID information for the amplifi-

er cannot be read because of a failure

in the temporary assignment.

D Processing of the FSSB

The processing of the FSSB at power on is as described below:

at power on

1

The CNC initializes the FSSB and the servo.

2

The servo returns the first ready signal.

3

The first ITP interrupt is generated.

4

The CNC waits for the FSSB to become ready to open.

5

The CNC checks that the FSSB did not detect a configuration error.

6

The CNC allows the FSSB to open.

7

The CNC checks that the FSSB has opened.

8

The servo returns the second ready signal.

9

Normal operation

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8. TROUBLESHOOTING

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8.28

ALARM 926

(FSSB ALARM)

Causes and actions

A fault occurred on the FSSB (serial servo bus) that connects servo

amplifiers to the CNC.

This alarm is issued if a fault occurs in any of the axis control cards

making up the FSSB, optical cables, and servo amplifiers.

D Identifying the defective

Use the LEDs on the servo amplifiers.

location

Using the

7-segment LEDs installed on the servo amplifiers, the

defective location can be identified.

FSSB connection

example

Amplifier

Amplifier

Amplifier

Amplifier

Amplifier

Amplifier

CNC

0

1

2

3

4

5

B

A

If portion A, indicated by dotted line, contains the defective location, the

LEDs on the servo amplifiers will be as shown in the table below.

Amplifier

Amplifier

Amplifier

Amplifier

Amplifier

Amplifier

Amplifier

No.

0

1

2

3

4

5

“L”

LED

“-”

“-”

or

“U”

“U”

“U”

display

“-”

In this case, any of the following locations may be defective:

(1) Optical cable connecting together the servo amplifier whose LED is

“L” or “-” and that whose LED is “U”. In the above figure, the optical

cable in portion A may be defective.

(2) Either of the servo amplifier whose LED is “L” or “-” and that whose

LED is “U”. In the above figure, either amplifier 2 or 3 may be defective.

If portion B, indicated by dotted line, contains the defective location, the

LEDs on the servo amplifiers will be as follows:

Amplifier

Amplifier

Amplifier

Amplifier

Amplifier

Amplifier

Amplifier

No.

0

1

2

3

4

5

LED

“-” or “U”

display

In this case, any of the following locations may be defective:

(1) Optical cable connected to the CNC. In the above figure, the optical

cable in portion B may be defective.

(2) Any of the axis control cards in the CNC

(3) First servo amplifier connected. In the above figure, amplifier 0 may

be defective.

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8. TROUBLESHOOTING

D Identifying the defective

Use the display on the CNC screen

location

If alarm 926 is issued, information such as the following is displayed at

the bottom of the CNC screen. It can be used to identify the defective

location.

MODE

STATUS

information

information

Bits

Bits

Bits 12 to 15 of the MODE information indicate the number of the slave

in which the alarm occurred. The unit nearest the CNC (such as a servo

amplifier) is assigned a slave number of “0”. For a 2-axis amplifier, for

example, one number is assigned for the first axis, and the next number

is assigned for the second.

Details of the MODE information

Bit

15

14

13

12

11

0

De-

Number of the slave in

No meaning

scrip-

which the alarm oc-

tion

curred

0000: Indicates that the alarm occurred in slave 0.

0001: Indicates that the alarm occurred in slave 1.

:

:

1001: Indicates that the alarm occurred in slave 9.

Using the bits of the STATUS information, the fault can be estimated.

Details of the STATUS information

Bit

15

12

11

10

9

87

6

5

4

3

0

A

xxxx

0

0

0

xxx

1

x

0

xxxx

A

xxxx

0

1

0

xxx

0

x

1

xxxx

B

xxxx

0

0

1

xxx

0

x

1

xxxx

C

xxxx

1

0

0

xxx

0

x

1

xxxx

The STATUS information matches any of the patterns A, B, and C.

(x indicates a bit that may be either 0 or 1.)

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8. TROUBLESHOOTING

8.31

ALARM 950

(PMC SYSTEM

ALARM)

Causes and actions

This alarm is issued if a fault is detected in the PMC.

The probable causes include an I/O link communication error and a

defective PMC control circuit

The I/O Link is a serial interface that connects the CNC to various I/O

D Connecting the I/O Link

devices and allows transfers of I/O signals between devices at high speed.

When multiple devices are connected using the I/O Link, there forms a

relationship that a certain device is a master and the other devices are

slaves. The states of the input signals from the slaves are transferred to

the master at fixed intervals. The output signals from the master are

transferred to the slaves at fixed intervals. In a CNC system, the master

is the CNC (main board).

The I/O signals transferred via the I/O link can be used with the PMC

Ladder.

Master station (CNC)

Slave station #0

Group 0

JA1A

JD1B

JD1A

Slave station #1

JD1B

Group 1

JD1A

Up to 16 groups

D I/O Link communication

If alarm 950 is issued, displaying “PC050” on the screen, an I/O link

error PC050

communication error may have occurred.

Screen display example

SYSTEM ALARM

950 PMC SYSTEM ALARM

PC050 I/OLINK(CH1)

xx:yy-aa:bb

or

PC050 I/OLINK(CH2)

aa:bb-xx:yy

or

PC050 IOLINK CH1

aabb-xxyy:aabb

or

PC050 IOLINK CH2

aabb:aabb-xxyy

In this screen display example, the cause of the alarm can be estimated

using xx:yy. xx and yy are hexadecimal representations. CH1 and CH2

are channels on which communication failed.

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8. TROUBLESHOOTING

In this case, check the following:

(1) If bit 5 of yy is “1”

Perform examination with the same procedure as that in 1).

(2) If bit 6 of yy is “1” or if bit 7 of yy is “1”

First, replace the device of the slave station of the indicated group

number.

If the problem is not solved, perform examination with the same

procedure as that in 1) to identify the defective location.

3)

If bit 2 of the binary representation of xx is “1”, this indicates that the

link between the master station (CNC) and the slave station was

canceled. For example, assume that the following is displayed on the

screen:

SYSTEM ALARM

950 PMC SYSTEM ALARM

PC050 IOLINK CH1

aabb-8400:aabb

xx is equal to 84, or “1000100” in binary notation. Bit 2, which is the

third bit from the right, is “1”.

In this case, check the following:

(1) Disconnection of the slave station from the power supply

Check that the slave station is not turned off, that there are no

instantaneous power failures, and that the capacity of the power

supply is enough.

(2) Disconnection of the I/O link cable

Check that the I/O link cable has not fallen off or has not been

disconnected.

(3) If the problem is not solved, perform a check with the same

procedure as that in 1).

4)

If bit 3 or 4 of the binary representation of xx is “1”, this indicates that

a parity error occurred in the PMC control circuit on the main board.

In this case, replace the motherboard (main board).

D Other cases

The main board may be defective. Replace the main board.

See Section 2.4, “CONNECTOR AND CARD CONFIGURATIONS OF

PRINTED CIRCUIT BOARDS” for an explanation of the mounting

locations of the cards.

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