MITSUBISHI ALARM LIST



ALARMS

If you have a Y03 Alarm, there will be an axis number displayed to the right of the alarm. This alarm means that the NC believes that axis is not connected to the system. First check that all of the servo amplifiers are connected and that they are all being supplied with AC voltage normally labeled R and S. Also check for the presence of the DC Link on all three axes. Make sure the Serial Buss is daisy chained to all of the amps and to the spindle. Check all of the rotary selector switches on the amps and the spindle to be sure they are in the correct position. The description of this alarm in the manual indicates a hardware fault as the likely culprit but in most cases you will probably find a parameter set wrong so if you have a copy of the parameters you might want to go ahead and reload them.

Alarm Y06 is basically the same deal and will always be a parameter If you have the alarm Y03 AMP UNEQUIPPED XYZA and alarm EMERGENCY STOP LIN, there is a good chance the CPU is not communicating with the amplifiers. In this case, the likely suspects are the serial cables, the terminator plug or the communication board QX721 or QX722. The control will have one of these boards are the other. It is a small board which is mounted piggyback on the CPU board. A good test for this case is to replace the cable that goes from the CPU to the first amplifier. In the field this may be difficult. You can take a cable from between two of the amps is long enough and connect it to port CN1A of the first amp and to the CPU. Place the terminator on port CN1B of this amp. If the cable was bad, when you power up this time the alarm should say something different depending on which amp you are connected to. For example, Y03 AMP UNEQUIPPED YZA or XZA. In this case, replacing the cable should solve the problem. The communication boards do go bad sometimes so don't be afraid to replace it if you cannot effect a change by moving cables around. Anytime you have the Y03 alarm along with other alarms there is a way to bypass the alarm so you can work on the other problems. Remove the cable from CSH21 on the CPU and insert the terminator plug into the port. Go to the Machine Base Parameter NOAMP and make it a 1. This will tell the NC that no amps are installed and the alarm will go away.

Also for the Y03 AMP UNEQUIPPED ALARM, if you get this after replacing or adding an amplifier, make sure the DIP switches on the amps are set correctly to identify the axes to the NC.

Often times you will have an alarm such as S52 Servo Warning 00E6 X. This does not always mean there is a problem with the X axis. Sometimes there will be a problem communicating with all of the servos but if X is the first in the string, the NC may issue this alarm. If you have an alarm like this in conjunction with an EMG Emergency PLC alarm the problem may have nothing to do with the servos at all. In this case the problem could be with something such as the Keypad Interface Card in the pendant. In particular, if the four pin cable that goes to J4 on the keypad interface card is removed, damaged, etc. this alarm will definitely occur. This cable uses two of the four wires. They connect to 24vdc on the external power supply.

MDS-A-SPJA-75RT

AL-30 on this amplifier is a regenerative alarm. It can occur if the AC Line exceeds 260 volts or if the regenerative braking system (resistor) fails. Experience has shown that it usually means that the amplifier is bad. AL-24 is a Ground Fault alarm, it normally occurs if a motor is grounded or one of the AC power leads is accidentally swapped with a motor lead.

The following is a nearly complete list of Mitsubishi Alarms as displayed on the drives. Depending on the specific drive, the LED display may show an A or an AL along with the number but the meaning is the same. Some alarm numbers shown here may appear on other Mitsubishi drives and their meanings may be other than indicated here. Also, an effort is made here to distinguish Servo alarms from Spindle alarms by entering SV or SP after the description. Due to the various uses and configurations of drives as well as typing errors etc., you have to use your best judgment when applying these alarms to your situation.

The following are for MDS drives.

10 UNDERVOLTAGE The P-N Bus voltage is 200V or less.
SV, SP

11 AXES SELECTION
ERROR (ASE) The axis setting rotary switch was set illegally in the two axis integrated amp (dual amp).
SV

12 MEMORY ERROR 1 The memory IC (SRAM or FROM) check sum was illegal.
(ME1)
SV, SP

13 SOFTWARE PROCESS The software data processing was not completed within the normal time.
ERROR (SWE)
SV, SP

14 UNDEFINED

15 MEMORY ERROR 2 Memory error on the servo drive.
(ME2)
SV

16 POLE POSITION The differential input of the U, V or W phase of the pole position detection signal of the OHE type
ERROR (RD1) type detector were both "H" or "L".


17 A/D CONVERTER The A/D converter for current detection did not function properly during initialization.
(ADE)
SV, SP

18 INITIAL COMM. ERROR The Absolute position or pole position data from the type detector was not correctly sent.
(WAT)
SV

19 UNDEFINED


1A SERIAL DETECTOR Initial communication with the serial encoder installed on the ballscrew end was not possible.
COMM. ERROR
(STE1)
SV

1B CPU ERROR SUB An error was detected in the data stored in the of the serial pulse coder installed on the ball
(SCPU) EEPROM screw end.
SV
1C LED ERROR SUB Deterioration of the LEDs in the serial pulse (SLED) coder installed on the ball screw end was
SV detected.

1D DATA ERROR SUB An error was detected in the per rotation (SDAT) position data of the serial pulse coder installed
SV on the ball screw end.

1E SERIAL DETECTOR The thermal protector built in the detector operated in the serial pulse coder installed on
ERROR SUB the ball screw end.
(SOHE) SV

1F SERIAL DETECTOR Communication with the detector in the serial pulse coder installed on
COMMUNICATION the ball screw end was cut off.
ERROR SUB (STRE)
SV

20 NO SIGNAL DETECTED The differential input of the A, B or Z phase 1 signal from the motor end installed detector
(NS1) were both H or L.
SV

21 NO SIGNAL DETECTED The differential input of the A, B or Z phase 2 signal from the machine end installed detector
(NS2) were both H or L.
SV, SP

22 NO SIGNAL DETECTED The serial input of the A, B or Z phase signal 3 from the motor end installed detector were
(NS3) both H or L.
SV

23 SPEED DEFLECTION The speed command and motor speed deflection exceeded the specified value and the state
EXCESSIVE for a specified time.
(OSE) SP

24 GROUND FAULT A motor cable ground fault was detected.
SV, SP

25 ABSOLUTE POSITION A serial data counter error received from the absolute value detector (excluding scale) was detected
LOST (ABSE) during creation of the absolute position after the NC power was turned on.
SV

26 NOT-USED AXIS ERROR The rotary switch was set to F and an IPM error occurred in an axis not being controlled.
(NAE)
SV

27 ABSOLUTE POSITION An error was detected in the CPU of the absolute position linear scale.(Alarm output
DETECTION SCALE by the detector. CPU by the detector)
ERROR SV
(SCCPU)


28 ABSOLUTE POSITION The scale moved at 45 mm/sec or higher when the NC power was turned on for the absolute
OVERSPEED position linear scale or the detector rotated at 500 rpm or higher when the drive power was
(SOSP) off with the HA-FA motor.
SV

29 ABSOLUTE POSITION An error occurred in the absolute position detection circuit of the absolute position
DETECTOR CIRCUIT linear scale or HA-FH motor built-in detector.
ERROR
(SABS) SV

2A INCREMENTAL POSITION The movement speed exceeded 60 m/min in the absolute position linear scale.
DETECTOR CIRCUIT
ERROR SV
(SINC)

2B CPU ERROR The CPU for the absolute position linear scale or HA-FH motor built-in detector did not
(SCPU) operate correctly.
SV


2C LED ERROR An LED error was detected by the HA-FH motor built-in detector.
(SLED)
SV

2D DATA ERROR An error was detected in the per rotation position data of the serial pulse coder
(SDAT) installed on the motor end.
SV

2E UNDEFINED

2F SERIAL DETECTOR Communication error with the high speed serial detector.
COMMUNICATION
ERROR SV
(STRE)

30 OVER REGENERATION Overheating of the regenerative resistor was detected.
(OR)
SV, SP

31 OVERSPEED Motor speed exceeded the tolerable speed.
(OS) SV, SP

32 POWER MODULE ERROR The IPM used in the amplifier detected over current.
IOC (PME)
SV, SP

33 OVERVOLTAGE The PN buss wire voltage exceeded 400V.
SV, SP

34 CRC ERROR There was an error in the communication data from the NC.
(DP)
SV, SP

35 CNC COMMUNICATION The movement command data sent from the NC was excessive.
DATA ERROR
SV, SP

36 CNC COMMUNICATION There was an error in the communication data from the NC.
ERROR
(TE) SV, SP

37 INITIAL PARAMETER Parameter error.
ERROR SV, SP
(PE)

38 CNC COMMUNICATION A protocol error occurred in the communication with the NC (Framing Error).
PROTOCOL ERROR 1
(TP1) SV, SP

39 CNC COMMUNICATION A protocol error occurred in the communication with the NC(Information Error).
PROTOCOL ERROR 2
(TP2) SV, SP

3A OVERCURRENT The current (detection value) for motor drive is excessive.
(OC)
SP

3B POWER MODULE ERROR The IPM overheat detection functioned.
(PMOH) SV, SP

3C REGENERATIVE CIRCUIT An error was detected in the regenerative transistor or resistor.
ERROR 3C

3D UNDEFINED

3E UNDEFINED

3F UNDEFINED

40 A-TK UNIT Detected when the changeover input sequence was mistaken during use of the TK unit with
CHANGEOVER ERROR the one amplifier, two motor function.
(KE)
SP

41 A-TK UNIT Detected when an error occurs in the data communication during use of the TK unit with the one
COMMUNICATION amplifier, two motor function.
ERROR 2
(KE2) SP

42 FEEDBACK ERROR 1 A skip of the detector feedback signal pulse occurred in the OHE type or OHA type detector
(FE1) used in the semi-closed loop system and ballscrew end closed loop system. A skip of the
SV detector feedback signal pulse in the low speed type serial type absolute position linear scale.

43 FEEDBACK ERROR 2 A deviation occurred in the feedback amount from the motor end detector and machine
(FE2) end detector in the closed loop system.
SV

44 C AXIS CHANGEOVER When using the coil changeover motor, C axis control was carried out without the H coil.
ALARM
(CAXC) SP

45 UNDEFINED

46 MOTOR OVERHEAT Check motor temperature, check overheat sensor.
(OHM)
SV, SP

47 UNDEFINED

48 UNDEFINED

49 UNDEFINED

4A UNDEFINED

4B UNDEFINED

4C UNDEFINED

4D UNDEFINED

4E UNDEFINED

4F INSTANTANEOUS STOP The power was cut off for 50 milliseconds or more.
SV, SP

50 OVERLOAD DETECTION 1 The time that motor current exceeded the parameter (overload detection level) in the stall
OLL ratio conversion was longer than parameter OLT (overload level).
(OL1)
SV, SP

51 OVERLOAD DETECTION 2 A current command exceeding 95% of the amplifier's maximum current continued for one
(OL2) second or more.
SV, SP

52 EXCESSIVE ERROR 1 The actual position droop for the ideal droop exceeded the parameter setting value OD1
DURING SERVO ON (excessive error width during servo on).
(OD1)
SV, SP

53 EXCESSIVE ERROR 2 The actual position droop for the ideal droop exceed ed the parameter setting value OD2
DURING SERVO OFF (excessive error width during servo off).
(OD2)
SV, SP


54 EXCESSIVE ERROR 3 The motor current did not flow when the excessive error 1 alarm was detected
(OD3) (added with the B series).
SV

55 UNDEFINED

56 UNDEFINED

57 UNDEFINED

58 COLLISION A collision detection type 1 error was detected during the G0 modal (rapid traverse).
DETECTION 0
(CLE0) SV


59 COLLISION A collision detection type 1 error was detected during the G1 modal (cutting feed).
DETECTION 1
(CLE1) SV


5A COLLISION A collision detection type 2 error was detected.
DETECTION 2
(CLT2) SV

5B UNDEFINED

5C ORIENT FEEDBACK The pulse miss value was higher than the parameter set value (SP114:OPER)
ERROR when orientation positioning was completed.
(ORFE)
SP

5D UNDEFINED

5E UNDEFINED

5F UNDEFINED

60 RESISTOR The resistor regeneration unit's DC24V voltage dropped.
REGENERATION 24V
VOLTAGE DROPPED
SP (0)

61 POWER MODULE An over current was detected with the power supply units IPM.
OVERCURRENT (1)
CV

62 (2) Not Used

63 AUXILIARY The auxiliary regeneration transistor in the power supply unit is short circuited.
REGENERATION
ERROR (3)
CV

64 GROUNDING 2 Regeneration actuated immediately after the ready on.
(4)
CV

65 RUSH CURRENT ERROR The rush relay in the power supply unit is excited but not turned on.
(5)
CV

66 (6) Not Used

67 OPEN PHASE The R, S or T input of the power supply unit is open.
(7)
CV

68 WATCH DOG The power supply software process did not end within the designated time.
​ (8)

69 GROUND FAULT A ground fault occurred in the motor.
(9) CV

6A CONTACTOR FUSE Welding of the power supply unit external contactor was detected.
(A)
CV

6B RUSH RELAY FUSE Welding of the rush relay in the power supply unit was detected.
(B)
CV

6C MAIN CIRCUIT ERROR The main circuit capacitor in the power supply could not be charged correctly.
(C)
CV


6D PARAMETER ERROR When NC power is turned on.
(D)
CV

6E MEMORY ERROR An error occurred in the power supply unit's memory circuit.
(E)
CV

6F A/D ERROR An error occurred in the power supply unit's A/D converter section.
(PS ERROR)
SP, CV

70 (G) UNDEFINED

71 POWER SUPPLY An instantaneous power failure exceeding 25ms was detected in the power supply unit.
INSTANTANEOUS
POWER FAILURE
(H)
CV


72 (I) UNDEFINED

73 OVER REGENERATION The regenerative load in the resistor regeneration unit exceeded the standard value.
(J)
CV

74 REGENERATIVE The regenerative resistor's thermal protector functioned.
RESISTOR OVERHEAT
(K)
CV

75 OVERVOLTAGE The power supply unit's PN buss voltage exceeded 410 volts.
(L)
CV

76 EXTERNAL EMERGENCY When NC power is turned on.
STOP SETTING ERROR
(M)
​ CV

77 POWER MODULE The IPM in the power supply unit detected an overheat.
(V)/FIN (R) OVERHEAT
(N)
CV

78 UNDEFINED

79 UNDEFINED

7A UNDEFINED

7B UNDEFINED

7C UNDEFINED

7D UNDEFINED

7E UNDEFINED

7F UNDEFINED

80 UNDEFINED

81 UNDEFINED

82 POWER SUPPLY A no signal was detected in the communication line with the power supply.
NO SIGNAL
(NSP)
SV, SP, CV

83 UNDEFINED

84 UNDEFINED

85 UNDEFINED

86 UNDEFINED

87 UNDEFINED

88 WATCH DOG The servo amplifier software process did not end within the designated time.
(WD)
SV

89 UNDEFINED

8A UNDEFINED

8B UNDEFINED

8C UNDEFINED

8D UNDEFINED

8E UNDEFINED

8F UNDEFINED

90 LOW SPEED SERIAL Communication with the absolute position linear scale was not possible when the
INITIAL COMMUNICATION NC power was turned on.
ERROR (WAT)
SV

91 LOW SPEED SERIAL During normal operation, the absolute position data was not transmitted from the low
COMMUNICATION speed serial detector
ERROR (WAS)
SV

92 LOW SPEED SERIAL During normal operation, the absolute position data transmitted from the low speed
PROTOCOL ERROR serial detector.
(WAF) SV

93 ABSOLUTE POSITION The absolute value counter could not be set when the power was turned on because
FLUCTUATION the absolute position had fluctuated.
(WAM)
SV

94 UNDEFINED

95 UNDEFINED

96 MP SCALE In the MP scale absolute detection system, an excessive deviation in the motor end
FEEDBACK ERROR installation detector and MP scale feedback amount was detected.
(MPE)
SV

97 MP SCALE OFFSET In the MP scale absolute position detection system, an error was detected in the offset
FLUCTUATION data read when the NC power was turned on.
(MPO)
SV

98 UNDEFINED

99 UNDEFINED

9A UNDEFINED

9B UNDEFINED

9C UNDEFINED

9D UNDEFINED

9E HIGH SPEED An error was detected in the multi-rotation counter in the serial encoder installed on the
SERIAL DETECTOR the ballscrew end.
ERROR (WAN)
SV

9F BATTERY VOLTAGE The voltage of the battery supply to the absolute position detector dropped.
DROP (WAB)
SV

A0 UNDEFINED

A1 UNDEFINED

A2 UNDEFINED

A3 UNDEFINED

A4 UNDEFINED

A5 UNDEFINED

A6 UNDEFINED

A7 UNDEFINED

A8 TURRET INDEX NO DEFINITION
COMMAND ERROR SP
WARNING
(WTW)

A9 UNDEFINED

AA CNC INITIAL Waiting for NC power on after power off.
COMMUNICATION SV, SP
PHASE 1 WAIT CNC

AB CNC INITIAL Waiting for NC power on for the first time.
COMMUNICATION SV, SP
PHASE 1 WAIT

AC CNC INITIAL Initializing. Requisition parameter transmission.
COMMUNICATION SV, SP
PHASE 2 WAIT

AD CNC INITIAL Initializing. Requisition parameter conversion.
COMMUNICATION SV, SP
PHASE 3 WAIT

AE CNC INITIAL Initializing. Standby for main servo IT start.
COMMUNICATION SV, SP
PHASE 4 WAIT

AF RESERVED

B0 IN READY OFF DURING SERVO INITIALIZATION.
SV, SP

B1 " "

B2 " "

B3 " "

B4 " "

B5 " "

B6 " "

B7 " "

B8 " "

B9 " "

BA " "

BB " "

BC " "

BD " "

BE " "

BF " "

C0 READY ON AND Machine and control ready but servo not running.
SERVO OFF
SV, SP

C1 " "

C2 " "

C3 " "

C4 " "

F6 RESERVED FOR AXIS
NUMBER INDICATION.
SV, SP

F7 " "

F8 " "

F9 " "

FA UNDEFINED

FB UNDEFINED

FC UNDEFINED

FD UNDEFINED

FE UNDEFINED

FF UNDEFINED

0 UNDEFINED

1 FLASH PROGRAMMING During re-writing of software.
ERROR SV, SP

2 FLASH ERASE ERROR During re-writing of software.
SV, SP

3 VPP ERROR "

4 CHECK SUM ERROR "

5 COMPARE ERROR "

6 UNDEFINED

7 UNDEFINED

8 BANK DESIGNATION During re-writing of software.
ERROR
SV, SP

9 INITIAL ADDRESS "
ERROR

A BANK CHANGEOVER "
ERROR

B ADDRESS ERROR "

C RECEPTION TIME "
ERROR

D UNDEFINED

E UNDEFINED

F COMMAND SEQUENCE During re-writing of software.
ERROR
SV, SP

The following list of alarms are associated with regeneration problems. Some of the alarms are include in the list above but this listing supplies additional information. Also, the number or letter in the column to the right of the alarm code refers to what will be displayed on the resistance regeneration converter unit. In addition, the two digit letter code beneath the alarm code refers to how the alarm can be reset.

AR = By turning the converter unit power off and back on.
PR = By turning the NC power off and back on.
NR = By pressing the NC Reset.

60 0 INSTANTANEOUS STOP The 24vdc dropped.
PR

63 3 REGENERATION ERROR The regeneration transistor turned on while the regeneration command was off.
PR

65 5 RUSH RELAY ERROR The rush relay does not turn on and chattering occurs.
PR

68 8 WATCH DOG CPU runaway.
AR

69 9 GROUND FAULT Driver UVW ground fault.
PR

6B b RUSH RELAY MELT The rush relay did not turn off.
PR

6C C MAIN CIRCUIT ERROR The buss is short circuited, the charge to the main CIRCUIT IS ABNORMAL.
PR

6D d PARAMETER ERROR The regenerative resistor setting is not adequate.
PR ERROR

6E E MEMORY ERROR The memory cannot be read/written correctly.
AR

73 J OVER-GENERATION The regeneration load was exceeded.
PR

74 t REGENERATION The regenerative resistor thermal functioned.
RESISTOR OVERHEAT
PR

75 L OVERVOLTAGE The buss voltage rose.
NR

77 n PCB OVERHEAT Overheating of the thermal in the amplifier.
PR

E8 o OVER-REGENERATION 80% of the over regeneration alarm level.
REGENERATION
WARNING


The following list of alarms can be found in the manual,
MITSUBISHI
AC SPINDLE DRIVE
MDS-1-SPJA SERIES
SPECIFICATIONS AND MAINTENANCE MANUAL


Z MEMORY A Check Sum or RAM error occurred in the spindle drive
ERROR 1 control card ROM.


S04 Alarms:

S04 SERVO ALARM: AR 00?? ?
The two numbers after the two zeros are the actual alarm number and are typically displayed on the amplifier or power supply. If you see a number between 60 and 80 it is normally a power supply (CV unit) problem. The letter display ed after the alarm number is normally an axis designation such as X, Y, etc. If the letter is S or T, refer to the spindle alarm section. These alarms always require that the drive (main) power must be cycled to remove the alarm.

11 ASE Spindle Selection Error
In MDS-B-B24 driver, the rotary selector switches for both axes are set to the same axis number when using the 2 axis
integrated amplifier. Otherwise, the switches are set to an illegal value.

12 ME Memory Error
An error was detected in a memory IC or FB IC by self-check to be made during driver power-on.

25 ABSE Absolute Position Data Lost
The backup voltage in the absolute position detector dropped. The absolute position cannot be compensated.

68 PWD Power Supply Watchdog
The S/W process did not complete in a specified time.

6E PME Power Supply Memory Error
Memory error was detected on the power supply unit. (Alarm E on the power supply unit.) An error occurred in the memory
circuit.

6F PSE Power Supply Alarm
The power supply unit is not connected. Otherwise, an error was detected in the A/D converter of the power supply.

76 Power Supply External Emergency Stop
Setting Abnormal
External emergency stop setting abnormal alarm is generated in the power supply unit. (M on the power supply display).
The rotary switch setting and parameter (PYTP) setting do not match.

77 Power Module or PC Board Overheated
Power module or PC overheated alarm is generated on the power supply unit. (n on the power supply unit).

84 HCPU HR Unit CPU Error
The CPU of MDS-B-HR connected with the motor and does not operate properly.

88 WD Watch Dog
Servo system operation is abnormal.

8D Hcpu HR Unit CPU Error
The CPU of MDS-B-HR connected with the (SUB) machine and does not operate properly.


When AL-25 is displayed on an amplifier, it means the Absolute Position has been erased. Normally, if you turn the power off then back on it will go away. Sometimes it helps to hold the NC power on button while the control is powering up. On some machines it will be necessary to reset the axes zero positions once the alarm is gone.


Alarm AL-A1 is normal sometimes when you swap servo amplifiers. It means that when the amplifier powers up it sees an absolute position other than what it expects to see. In other words the amplifier stores the position of the axis relative to the marker pulses of the encoder and when it powers up and compares this to the position of the pulse coder and sees a difference, the alarm is generated. This is a fairly low priority alarm and will not be displayed if other pulse coder alarms are present such as AL-16 which is a communication problem between the pulse coder and amp.


For alarm E51 FILE OPEN ERROR, check how much memory is available. In some cases the memory may get reset to 0 for the amount Free and the amount Used. This is more or less common if you change an Option Parameter, especially the memory size parameter (prosiz). To resolve the problem, change fix_p to 1 and Format the control.

P461 FILE I/O ERROR will normally result from not re-loading the Fixed Cycles after formatting the control.


If alarm S52 M01 0102 is issued when taking a cut, check Machine Servo Parameters SV021 and SV022. SV022 specifies the current detection level of overload 1 (OL1) with respect to the stall rating (%). Setting range is 1-500%. Parameter SV021 specifies a time constant for detection of of overload 1 (OL1). The setting range is 1-1800 seconds. What all this means is that if you have an axis which the axis faults or alarms during a cut parameter SV022 tells the control what level of current or motor load is allowable, SV021 tells the control how long the motor is allowed to pull this amount of current.

The alarms on the M300 control are almost identical to the M500.


Alarm E10 MEMORY OVER means that a value was set in the parameter PROSIZ that exceeds the hardware memory capacity of the control.

You cannot put a negative value in the Grid Shift parameter (G28sft). If you try to the control will issue the E02 DATA OVER alarm.

Regardless of which alarm is displayed on the CRT, the important thing is the four numbers at the end of the line (i.e. 006C), this tells the story of what the control thinks is wrong.

Not every manual lists or explains the S04 servo alarms, below is a partial list.

11 ASE Spindle Selection Error
In MDS-B-B24 driver, the rotary switches for both axes are set to the same axis number when using the 2 axis integrated
amplifier or the switches are set an illegal value.

12 ME Memory Error
An error was detected in a memory IC or FB IC by self-check to be made during driver power up sequence.

25 ABSE Absolute Position Data Lost
The backup voltage in the absolute position detector dropped. The absolute position cannot be compensated.

68 PWD Power Supply Watchdog
The software process did not complete in the specified time.


6E PME Power Supply Memory Error
"Memory Error" was detected on the power supply unit side (Alarm E on the power supply unit). An error occurred in the
memory circuit.

6F PSE Power Supply Alarm
The power supply unit is not connected or an error was detected in the A/D converter of the power supply.

76 Power Supply External Emergency Stop
Setting Abnormal
E-Stop Setting Abnormal alarm is generated on the power supply unit side. (M on the power supply unit) or the rotary
switch setting and parameter (PTYP) setting do not match.

77 Power Module or PC Board Overheated
Power module or PC board overheated alarm is generated on the power supply unit side (n on the power supply unit).

84 HCPU HR Unit CPU Error
The CPU of MDS-B-HR connected with the motor end does not operate properly.

88 WD Watch Dog
Servo system operation is abnormal.

8D Hcpu HR Unit CPU Error (SUB)
The CPU of MDS-B-HR connected with the machine end does not operate properly.

When adjusting for spindle orientation position shift (OPST) on an M520 or M530 control, it is sometimes not necessary to orient the spindle after adjustment to check the shift amount. If the machine uses a magsensor for orientation, when you change the parameter and press INPUT, the spindle will move the shift amount difference.

When the EDIT LOCK (hardware) of a machine with an M520 control is switched on and off, the Main Program display will switch from ABC, etc. to blank. Parameter will switch from ON to OFF.

Typically, if the spindle motor is phased wrong on a machine with a Mitsubishi drive the motor will run slower than commanded, may move jerkedly, may run one direction when M03 commanded the other direction when M03 commanded again, eventually will generate alarm S03 PR 23.

For alarm S01 PR 16 check the motor lead connections. What normally happens is the military style connector backs off the motor. You may check the leads and the windings will appear normal but the higher resistance causes the alarm. This alarm can also be hard to get rid of even once a good connection has been established. I have found that the main power sometimes has to be turned off for up to 30 minutes to reset the alarm or in some cases must be cycled several times.


When adjusting for spindle orientation position shift (OPST) on an M520 or M530 control, it is sometimes not necessary to orient the spindle after adjustment to check the shift amount. If the machine uses a magsensor for orientation, when you change the parameter and press INPUT, the spindle will move the shift amount difference.



When the EDIT LOCK (hardware) of a machine with an M520 control is switched on and off, the Main Program display will switch from ABC, etc. to blank. Parameter will switch from ON to OFF.


Typically, if the spindle motor is phased wrong on a machine with a Mitsubishi drive the motor will run slower than commanded, may move jerkedly, may run one direction when M03 commanded the other direction when M03 commanded again, eventually will generate alarm S03 PR 23.

For alarm S01 PR 16 check the motor lead connections. What normally happens is the military style connector backs off the motor. You may check the leads and the windings will appear normal but the higher resistance causes the alarm. This alarm can also be hard to get rid of even once a good connection has been established. I have found that the main power sometimes has to be turned off for up to 30 minutes to reset the alarm or in some cases must be cycled several times.