
No. DescriptionFaulty location and remedy
SPM in-
dica-
tion(*1)
Message
7n47 SPN_n_ : POS–CODER
SIGNAL AB-
NORMAL
47 1 Replace the cable.
2Re–adjust the BZ sensor signal.
3 Correct the cable layout (vicinity of
the power line).
1 The A/B phase signal of the
spindle position coder (connector
JY4) is abnormal.
2 The A/B phase signal (connector
JY2) of the MZ or BZ sensor is ab-
normal.
The relationship between the A/B
phase and 1–rotation signal is incor-
rect (Pulse interval mismatch).
7n49 SPN_n_ : HIGH CONV.
DIF. SPEED
49 Check whether the calculated differ-
ential speed value exceeds the maxi-
mum motor speed.
In differential speed mode, the speed
of the other spindle converted to the
speed of the local spindle has ex-
ceeded the allowable limit (the differ-
ential speed is calculated by multiply-
ing the speed of the other spindle by
the gear ratio).
7n50 SPN_n_ : SPNDL CON-
TROL OVER-
SPEED
50 Check whether the calculated value
exceeds the maximum motor speed.
In spindle synchronization, the speed
command calculation value exceed-
ed the allowable limit (the motor
speed is calculated by multiplying the
specified spindle speed by the gear
ratio).
7n51 SPN_n_ : LOW VOLT DC
LINK
51 1 Check and correct the power sup-
ply voltage.
2 Replace the MC.
Input voltage drop was detected.
(PSM alarm indication: 4) (Momen-
tary power failure or poor MC contact)
7n52 SPN_n_ : ITP SIGNAL
ABNORMAL I
52 1 Replace the SPM control printed
circuit board.
2 Replace the spindle interface
printed circuit board in the CNC.
NC interface abnormality was de-
tected (the ITP signal stopped).
7n53 SPN_n_ : ITP SIGNAL
ABNORMAL II
53 1 Replace the SPM control printed
circuit board.
2 Replace the spindle interface
printed circuit board in the CNC.
NC interface abnormality was de-
tected (the ITP signal stopped).
7n54 SPN_n_ : OVERLOAD
CURRENT
54 Review the load state. An overload current was detected.
7n55 SPN_n_ : POWER LINE
SWITCH ER-
ROR
55 1 Replace the magnetic contactor.
2 Check and correct the sequence.
The power line state signal of the
magnetic contactor for selecting a
spindle or output is abnormal.
7n56 SPN_n_ : INNER COOL-
ING FAN STOP
56 Replace the SPM unit. The cooling fan in the SPM control cir-
cuit stopped.
7n57 SPN_n_ : EX DECEL-
ERATION
POWER
57 1 Decrease the acceleration/decel-
eration duty.
2 Check the cooling condition (pe-
ripheral temperature).
3 If the cooling fan stops, replace the
resistor.
4 If the resistance is abnormal, re-
place the resistor.
An overload was detected in the re-
generative resistance. (PSMR alarm
indication: 8)
Thermostat operation or short–time
overload was detected.
The regenerative resistor was dis-
connected, or an abnormal resis-
tance was detected.
APPENDIXA. ALARM LIST
GFKE-0222-EN
904