FANUC Series 16 / 160 / 18 / 180 – Model B. Maintenance Manual

8. TROUBLESHOOTING

B-62445E/03

D LED display

Display

Meaning

Explanation

Power off

Power to the servo converter is not supplied.

NOT READY

Internal MMC (electro-magnetic contactor) is not

turned on.

READY

Internal MMC is turned on and the motor

becomes ready.

DC voltage for driving main circuit is considerabley

Excessive

high.

voltage alarm

LV5V

+5V of control power is abnormally low.

Control power

low alarm

LVDC

DC voltage for main circuit is extremely low.

DC link voltage

low alarm

DCSW

Regenerative discharge energy in short time is

Abnormal regen-

large or regenerative discharge circuit is faulty.

erative control cir-

cuit

DCOH

Average regenerative discharge energy is large or

Excessive regen-

frequency of acc./dec. is large.

erative discharge

Lights when thermostat in the servo amplifier func-

Servo amplifier

tions.

overheat

MCC

Contacts of electro-magnetic contactor is blown.

Electro magnetic

contactor

HCL

Lights when a large current flows through the main

L axis excess

circuit of L axis.

current

HCM

Lights when a large current flows through the main

M axis excess

circuit of M axis.

current

HCLM

Lights when alarge current flows throught the main

Excess current

circuit of L axis and M axis.

Note) 1st axis is L, 2nd axis is M.

D LVDC alarm

When the electro-magnetic contactor is turned on in the servo amp. or DC

voltage for the main circuit becomes low, this LED is lit.

Causes are;

1) Input voltage is insufficient.

2) Contacts of electro-magnetic contactor in servo amp. is poor.

3) Power circuit in servo amp. is abnormal.

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8.TROUBLESHOOTING

D DCSW alarm

This alarm is lit when the transistor for regenerative discharging turns on

more than 1 second.

Its causes are;

1) Mulfunction of servo amplifier such as regenerative discharge circuit.

2) Regenerative discharge energy is excessive due to cutting conditions.

D DCOH alarm

This alarm is lit when regenerative discharge registance is overheated and

the thermost operates.

Its causes are ;

1) Average discharge energy is excessive due to frequent acc./dec. or no

use of balancer in vertical axis

2) Functioning of a thermostat in the power transformer when thermostat

signal TH1 and TH2 are connected.

D MCC alarm

When turning on MCC, if the contacts are already on.

D Check terminals on

When you open the cover of the terminal board, you can see the check

servo amp.

terminal below LED.

D Terminal name and

meaning

Terminal name

Meaning

Control power +5V(+5"0.25)

IRL

R-phase motor current of L axis

ISL

S-phase motor current of L axis

IRM

R-phase motor current of M axis

ISM

S-phase motor current of M axis

D Current/volt

Type of unit

A/V

Type of unit

(A/V)

A06B-6066-H002

A06B-6066-H222

1/1

Left side L axis/

Right side M axis

A06B-6066-H003

A06B-6066-H223

1/3

A06B-6066-H004

A06B-6066-H224

1/10

A06B-6066-H006

A06B-6066-H233

3/3

A06B-6066-H234

3/10

A06B-6066-H244

10/10

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8.TROUBLESHOOTING

Position detection signal line is disconnected or short-circuited.

8.23

ALRAM 416

(DISCONNECTION

ALARM)

Point

Check the details using the CNC’s diagnostic fucntion.

DGN

0201

ALD

EXP

→

Built-in serial pulse coder

³ENC_X

disconnection

Separate type position

³SCALE_X

detector connection

Pulse coder disconnec-

Note

tion (software)

Note

This alarm is related with full-closed system.

Causes

Signal cable is disconnected or short-circuitted

Serial pulse coder or position detector is faulty Refer to Note 1

Main CPU board or option 2 board is faulty Refer to Note 2

Notes

After the pulse coder is replaced, reference position or

machine’s standard position is different from former one.

Adjust and set it correctly.

When the main board is replaced, all the data stroed in

memory is lost. Set NC data again, referring to chapter 3 ”

Data input/output” .

Main CPU

Linearscale

board or Option

2 board

ENCx

SCALEx

x is an axis number

From 1st axis to 4th axis are main CPU board. 5th axis or more are option

2 board.

365

8. TROUBLESHOOTING

B-62445E/03

Digital servo parameters are abnormal.

8.24

(Digital servo parameters are set incorrectly.)

ALARM 417 (DIGITAL

When alarm 315 is occured at the same time, check the cause of alarm 351

SERVO SYSTEM IS

of section 9.16.

ABNORMAL)

D Causes

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.

Change the setting of this parameter to 0.

PRM 2047 : Observer parameter

Perform initial setting of digital servo parameters.

”Refer to setcion 5.1 ”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

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

Because an ambient temperature of the control unit becomes high, a

8.25

thermostat mounted on the back panel of NC functions and informs an

ALARM 700

alarm.

(OVERHEAT AT

CONTROL SIDE)

Remedies

(START)

Check fan on the top of the control unit is oper-

ating when power is on.

Operating

YES

Check temperature around the control unit is

Fun motor is faulty

high (more than 45 degrees)

Replace fan motor

YES

High tempera-

ture ?

Thermostat on the back panel of NC is

Lower temperature around

faulty.

the control unit

Replace the back panel of NC.

367

8. TROUBLESHOOTING

B-62445E/03

Spindle speed changes abnormally due to load.

8.26

ALARM 704 (SPINDLE

SPEED

FLUCTUATION

DETECTION ALARM)

Remedies

Check whether spindle speed is constant by view

of the speed meter on CRT.

YES

Constant ?

Is a heavy cutting being per-

formed ? Confirm spindle load

on CRT.

Confirm the follow-

ing parameter :

YES

Heavy cutting?

PRM 4911

PRM 4912

PRM 4913

Reduce cutting condition

PRM 4914

Doesn’t the cutting tool worn ?

YES

Worn ?

Replace tool

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

Communication error has generated in serial spindle

8.27

ALARM 749

(SERIAL SPINDLE

COMMUNICATION

ERROR)

Causes and Remedies

Improper connection between the main CPU board and the serial spindle.

The following reason is considered.

For Series 16 main CPU A20B-2901-0980,0981,0982

For Series 16 option A20B-2901-0984,0985,0986

Main

CPU

ROM

Calendar clock

Optical I/O link

adaptor

Spindle

RAM

Spindle control

amplifier

D/A converter

Optical cable

System control module is faulty.(Bold line in the figure below indicates

module mounting position.)

A cable between the main CPU board and optical I/O link adapter is

disconnected or short-circuited.

Optical I/O link adapter is faulty.

Optical cable is disconnected.

Serial spindle amplifier is faulty.

<Location of spindle module> Main CPU board

Specification

of spindle module

A20B-2901-0980 to

A20B-2901-0982

A16B-3200-0010

A16B-3200-0170

(1)

(2)

(3)

(4)

(5)

(2)

(3)

(4)

(5)

(6)

(7)

(8)

(9)

(10)

369

8. TROUBLESHOOTING

B-62445E/03

When the spindle amplifier does not become normal state immediately

8.28

after power is turned on in the serial spindle system, this alarm is

ALARM 750 (SPINDLE

informed.

SERIAL LINK

CANNOT BE

STARTED)

Points

This alarm does not occur once the system becomes ready including the

spindle system .

This alarm occurs during power on sequence before the system becomes

ready.

After the system becomes ready, serial spindle alarm is issued by alarm

749.

Causes

(1) Optical cable is in poor contact or spindle amplifier power is off.

(2) When display of spindle amplifier shows SU-01 or an alarm other than

AL-24 is displayed, power to the NC is turned on.

In this case, this alarm usually occurs when the NC’s power is turned

off while the serial spindle is operating. Turn off the power of serial

spindle once, then turn it on and starts the system.

(3) Combination of hardware is wrong.

(4) When the 2nd spindle is at the state of (1) to (3).

When the 2nd spindle is used, parameter is set as follows :

Bit 4 of parameter no.3701 is 1: No. of serial spindles connected is 2.

Details of Alarms

Confirm the details of troubles on diagnostic 409.

DGN

0409

SPE

S2E

S1E

SHE

#3(SPE)

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

starting conditions for spindle amplifier.

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

the starting conditions for spindle amplifier.

#2(S2E)

0 : At the start of spindle serial control, the spindle is normal.

1 : At the start of spindle serial control, the spindle is abnormal.

#1(S1E)

0 : The serial communication module of the CNC side is normal.

1 : The serial communication module of the CNC side is abnormal.

#0(SPE)

0 : Serial communication module on the CNC side is normal.

1 : Serial communication module was detected to be abnormal on the

CNC side.

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8.TROUBLESHOOTING

Remedies

Reform the following countermeasures based on the above

configurations:

(1) #3(SPE)1: In spindle serial control, the serial spindle parameters does

not satisfy the starting conditions for spindle amplifier.

↓

Confirm the settings of parameters 4000s.

Especially checks the parameters those are changed from the standard

parameters.

(2) #2(S2E)1: At the start of spindle serial control, when an abnormality

is found in the 2nd spindle side.

↓

Check the 2nd spindle parameters and connections to see whether the

spindle is mechanically and electronically connected to the spindle.

↓

If the above settings and connections are right, the module of (4) or the

spindle amplifier itself may be defective.

(3) #1(SIE)1: When an abnormality is found in the 1st spindle at the start

of serial spindle control, exchange the unit if the following

check items are not concerned.

↓

Check the parameters and connections at the 1st spindle to see whether

the 1st spindle is mechanically and electrically connected.

↓

If the parameters and connections are correct, the system control

module shown below or the spindle amplifier itself is faulty.

(4) #0(SPE)1: The serial communication module is detected to be

abnormal. Exchange the following module :

373

8. TROUBLESHOOTING

B-62445E/03

<Location of spindle module> Main CPU board

Specification

of spindle module

A20B-2901-0980 to

A20B-2901-0982

A16B-3200-0010

A16B-3200-0170

(1)

(2)

(3)

(4)

(5)

(2)

(3)

(4)

(5)

(6)

(7)

(8)

(9)

(10)

A16B-3200-0110

A16B-2202-0860

(1)

(1)(2)

(3)

(4)

(5)(6)

(7)

(2)

(3)

(4)

(5)

(6)

(8)(9)

(7)

(8)

(10)

(9)

(11)

(10)

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8.TROUBLESHOOTING

With serial spindle system, an alarm on the spindle unit is informed to the

8.29

CNC.

ALARM 751,761

751 ( Alarm detection by 1st spindle )

(SPINDLE ALARM)

761( Alarm detection by 2nd spindle )

The alarm contents is displayed by AL-xx on the display of spindle amp.

Refer to appendix 2.3 or 2.4 for the contents.

The CNC holds an alarm number display (AL-xx).

D Point

This alarm informs of trouble of spindle control unit.

Repair the spindle side by the method of remedy for each alarm.

D Causes and Remedies

Refer to Appendix 2.3 or 2.4 for details.

377

8. TROUBLESHOOTING

B-62445E/03

ROM parity error occurred.

8.30

ALARM 900 (ROM

PARITY ERROR)

Causes and Remedies

(1) ROM module mounted on the main CPU board or ROM is defective.

SYSTEM ALARM

B0A1-02

900

ROM PARITY

CNC ROM MODULE : FC0

Defective file

or ROM is displayed

MACRO ROM MODULE

SERVO ROM

Confirm the series and versions of control software those are displayed

on upper right of the screen.

*FROM module may be written data by machine tool builder.

*Mounting position of ROM/FROM module

378

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8.TROUBLESHOOTING

A16B-3200-0010

A16B-3200-0170

(1)

(2)

(3)

(4)

(5)

(2)

(3)

(4)

(5)

(6)

(7)

(8)

(9)

(10)

(1) FROM module

(3) FROM module

Specification

: A20B-2902-0080X0082

Specification

: A20B-2902-0341,0343

A20B-2902-0090X0094

(10)

BOOT ROM

(9) BOOT ROM

A16B-3200-0110

A16B-2202-0860

(1)

(1)(2)

(3)

(4)

(5)(6)

(7)

(2)

(3)

(4)

(5)

(6)

(8)(9)

(7)

(8)

(10)

(9)

(11)

(10)

(2) FROM module

(3) FROM module

Specification

: A20B-2902-0341,0343

Specification

: A20B-2902-0341,0343

(11)

BOOT ROM

A20B-2902-0410,0411

(10)

BOOT ROM

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8.TROUBLESHOOTING

Parity error of RAM module that stores part programs.

8.31

ALARM 910 TO 915

(SRAM PARITY)

Points

A parity bit is prepared for writing data in memory correctly. There are

odd-number parity and even-number parity.

(Parity bit)

(Even-number

parity)

Causes and Remedies

(1) Causes are faults of RAM on the main board or RAM module, or fault

of data memorized in RAM. When this alarm occurs immediately

after power is turned on, once turn off power, then turn on power while

pushing

RESET

and

DELETE

key to perform memory all clear

If parity error is not released by clearing all memory, RAM on the main

board or RAM module may be faulty. Change (4)RAM module on

main CPU board.

Set all the data again, referring to chapter 3 “data input/output”.

D RAM module mounting

: SRAM module (Part program editing, parameters)

position

A16B-3200-0010

A16B-3200-0170

(10)

(1)

(2)

(3)

(4)

(5)

(2)

(3)

(4)

(5)

(6)

(10)

(6)

(7)

(8)

(9)

(10)

(1) FROM/SRAM module

(2) Additional SRAM module

Specification

: A20B-2902-0080

Specification

: A20B-2902-0350X0352

A20B-2902-0090,0093,0094

(3) FROM/SRAM module

(10)

SRAM

Specification

: A20B-2902-0341,0343

mounted on main CPU board

381

8. TROUBLESHOOTING

B-62445E/03

A16B-3200-0110

A16B-2202-0860

(1)

(1)(2)

(3)

(4)

(5)(6)

(7)

(2)

(3)

(4)

(5)

(6)

(8)(9)

(7)

(8)

(10)

(9)

(11)

(10)

(1) Additional SRAM module

(2) Additional SRAM module

Specification

: A20B-2902-0350X0352

Specification

: A20B-2902-0350X0352

(2) FROM/SRAM module

FROM/SRAM module

Specification

: A20B-2902-0341,0343

Specificaiton

: A20B-2902-0341,0343

A20B-2902-0410,0411

A16B-3200-0160

(1)

(2)

(3)

(4)(5)

(6)(7)

(8)

(9)

(10)

(11)

(1) Addition SRAM module

Specification

: A20B-2902-0350X0352

(10)

FROM/SRAM module

Specification

: A20B-2902-0341,0343

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8.TROUBLESHOOTING

(2) Low voltage of memory back up battery. Battery alarm occurs if

voltage is 2.6V or less (3.0V rating).

When the memory back up battery voltage is lowered, BAT is

displayed at lower part of the screen.

When battery alarm is lit, replace with new lithium batteries as soon

as possible.

Refer to 2.8 battery replacing item and change the batteries.

(3) Power supply unit is faulty

When alarm turns off by an operation of clearing all the memory,

power supply unit may also be faulty.

383

8. TROUBLESHOOTING

B-62445E/03

A parity error occurred in the DRAM module.

8.32

ALARM 916 (DRAM

PARITY ERROR)

Cause and action

The DRAM module on the main CPU board may be faulty. Replace the

DRAM module.

<Location of DRAM module> Main CPU board

Specification: A20B-2901-0940 ~ 0942

A16B-3200-0010

A16B-3200-0170

(1)

(2)

(3)

(4)

(5)

(2)

(3)

(4)

(5)

(6)

(7)

(8)

(9)

(10)

A16B-3200-0110

A16B-2202-0860

(1)

(1)(2)

(3)

(4)

(5)(6)

(7)

(2)

(3)

(4)

(5)

(6)

(8)(9)

(7)

(8)

(10)

(9)

(11)

(10)

384

8. TROUBLESHOOTING

B-62445E/03

920: Watch dog alarm or RAM parity in servo control module

8.33

has occurred in the 1st or 2nd axis

ALARM 920 TO 923

921: Above alarm has occurred in the 3rd or 4th axis

(WATCH DOG OR

922: Above alarm has occurred in the 5th or 6th axis

RAM PARITY)

923: Above alarm has occurred in the 7th or 8th axis

points

The timer used to monitor the operation of CPU is called the watch dog

D Watch dog timer alarm

timer. The CPU resets timer time every time a constant time has passed.

When an error occurs in CPU or peripheral device, timer is not reset but

the alarm is informed.

D RAM parity error

Refer to alarm 910 to 915

Causes and Remedies

D Servo control module is

The servo module includes servo RAM, watch dog timer circuit, etc.

faulty

Defectiveness of hardware, abnormality or malfunctioning of detection

circuit or the like is considered. Therefore, replace servo module on the

main CPU board for alarm 920 and 921; replace servo module on the

option 2 board for alarm 922 and 923.

Main

CPU

ROM

Servo module

(A20B-2902-0060, A20B-2902-0061)

RAM

D Main CPU board is faulty

CPU or peripheral circuits may be faulty. Replace the main CPU board.

D CNC control software

Software may not work properly due to failure of FROM module. Change

ROM module is faulty

FROM module.

D Power supply unit is

DC output voltage of power supply unit may be faulty. Replace the power

faulty

supply unit.

386

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8.TROUBLESHOOTING

<Location of module> Main CPU board

A16B-3200-0010

A16B-3200-0170

(1)

(2)

(3)

(4)

(5)

(2)

(3)

(4)

(5)

(6)

(7)

(8)

(9)

(10)

(1) FROM module

(3) FROM module

Specification

: A20B-2902-0080X0082

Specification

: A20B-2902-0341,0343

A20B-2902-0090X0094

A20B-2902-0410X0411

(7) Servo module of 1st, 2nd axis

Specification

: A20B-2902-0060X0061

Specification

: A20B-2902-0060X0061

(6) Servo module of 3rd, 4th axis

Specification

: A20B-2902-0060X0061

Specification

: A20B-2902-0060X0061

A16B-3200-0110

A16B-2202-0860

(1)

(1)(2)

(3)

(4)

(5)(6)

(7)

(2)

(3)

(4)

(5)

(6)

(8)(9)

(7)

(8)

(10)

(9)

(11)

(10)

(2) FROM Module

(3) FROM module

Specification

: A20B-2902-0341,0343

Specification

: A20B-2902-0341,0343

(7) Servo module of 1st, 2nd axis

A20B-2902-0410X0411

Specification

: A20B-2902-0060X0061

(8) Servo module of 1st, 2nd axis

(9) Servo module of 3rd, 4th axis

Specification

: A20B-2902-0060X0061

Specification

: A20B-2902-0060X0061

(7) Servo module of 3rd, 4th axis

(8) Servo module of 5th, 6th axis

Specification

: A20B-2902-0060X0061

Specification

: A20B-2902-0060X0061

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8.TROUBLESHOOTING

<Location of module> Option 2 board

A16B-2202-0400,0401

A16B-2202-0890,0891

(1)

(2)

(3)

(4)

(5)

(1)

(2)

(3)

(4)

(5)

(6)

(7)

(6)

(7)

(7) Servo module of 5th, 6th axis

Specification

: A20B-2902-0060X0061

Specification

: A20B-2902-0060X0061

(6) Servo module of 7th, 8th axis

Specification

: A20B-2902-0060X0061

Specification

: A20B-2902-0060X0061

A16B-2202-0850,0851,0853

(1)

(2)

(3)

(4)

(5)

(6)

(7)

(8)

(6) Servo module of 5th, 6th axis

Specification

: A20B-2902-0060X0061

(7) Servo module of 3rd, 4th axis

Specification

: A20B-2902-0060X0061

(8) Servo module of 1st, 2nd axis

Specification

: A20B-2902-0060X0061

389

8. TROUBLESHOOTING

B-62445E/03

The digital servo module is not mounted.

8.34

ALARM 924 (SERVO

MODULE MOUNTING

ERROR)

Note

This alarm may not occur during normal operaion.

This alarm may be generated when a PCB is changed for

maintenance.

D Causes and remedies

Check installation of servo module on main CPU or option 2 board.

For location of servo module, refer to an installation diagram of alarm 920

to 923.

1st to 4th axis servo module

(A20B-2902-0060 or A20B-2902-0061)

5th to 8th axis servo module

(A20B-2902-0060 or A20B-2902 -0061)

Unless these boards are mounted correctly, if this alarm still generates,

change main CPU board, option 2 board and/ or servo module.

D Kinds of servo module

A20B-2902-0060

Standard

A20B-2902-0061

For Learning control

390

B-62445E/03

8.TROUBLESHOOTING

CPU error (illeagal interrupt) has generated.

8.35

ALARM 930 (CPU

ERROR)

Causes and Remedies

Main CPU board is faulty

An interrupt which will not occur during usual operation has

generated.

Peripheral circuit of the CPU may be abnormal. Change the main

CPU board. If operation is performed normally by power off and

on, noise may be a cause. Refer to 8. Suppressing Noise.

391

8. TROUBLESHOOTING

B-62445E/03

An error occurred when RAM test is being executed.

8.36

ALARM 950 (PMC

SYSTEM ALARM)

Causes and Remedies

The following causes are considered :

D For PMC-RB

Fault on Main CPU board

⋅

PMC control module (3) is faulty.

⋅

DRAM module (2) is faulty.

⋅

FROM module (1) is faulty.

D For PMC-RC

Fault on Main CPU board

⋅

PMC control module (5) is faulty.

⋅

DRAM module (4) is faulty (Option 3 board)

⋅

Option 3 board is faulty.

Module mounting

position

(Main CPU)

A16B-3200-0010

A16B-3200-0170

(1)

(2)

(3)

(4)

(5)

(2)

(3)

(4)

(5)

(6)

(7)

(8)

(9)

(10)

(1) FROM module

(1) DRAM modle

Specification

: A20B-2902-0080X0082

Specification

: A20B-2901-0040X0942

A20B-2902-0090X0094

(3) FROM module

(2) DRAM module

Specification

: A20B-2902-0341,0343

Specification

: A20B-2901-0940X0942

: A20B-2902-0410X0411

(3) PMC control module

(4) PMC control module

Specification

: A20B-2901-0960X0961

Specification

: A20B-2901-0960X0961

392

FANUC Series 16 / 160 / 18 / 180 – Model B. Maintenance Manual - page 13