
2. HARDWARE
B–63835EN/03
156
D LED display when a system alarm occurs j: Off J: On l: Blink
(If CPU card A20B–3300–029X is used)
ALARM jJj System failure. The software detected an error and
stopped the system.
ALARM JJj An error occurred on the local bus in the main CPU
board.
Alternatively, a bus error occurred in the main CPU.
Alternatively, a DRAM parity error was detected.
ALARM jjJ System emergency. The hardware detected an error.
Alternatively, a bus error occurred in the main CPU.
Alternatively, a DRAM parity error was detected.
ALARM JjJ A disconnection was found in the optical
fiber cable between the CNC and LCD.
Alternatively, a printed circuit board on the
LCD side is defective.
If a disconnection occurs, the dot of the
7–segment LED is also lit.
If a disconnection occurs, the display of the
LCD unit blinks.
ALARM jJJ An SRAM parity error or SRAM ECC error was de-
tected.
NOTE
1 If any of the system alarms occurs, the hardware may be
defective.
2 If a disconnection is detected in the optical fiber cable
between CNC and LCD at power–up, the ALARM LEDs
alternately display these patterns: JjJ ³ jJj
D 7–segment LED display when a system alarm occurs
If a system alarm occurs, a number blinks as shown below, depending
on the system alarm number.
7–segment
LED
System
alarm num-
ber
System alarm type
0 900 to 909 ROM parity alarm.
System ROM parity stored in FROM
1 910 to 919 SRAM or DRAM parity alarm
2 920 to 929 Servo alarm
3 930 to 949 CPU interrupt or SRAM ECC error
5 950 to 959 PMC system alarm
7 970 to 979 Bus error or non–maskable interrupt
8 Others Other system alarms
NOTE
If any of the system alarms occurs, the hardware may be
defective.