
B–62075E/04
2. HARDWARE
92
If an alarm condition occurs, an alarm message is usually displayed on the
CRT screen. The state of the PCB when the alarm occurred is indicated
by the LEDs on the front panel of each control unit PCBs, as shown below.
When a system alarm occurs, the alarm message displayed on the screen,
together with the LED indications on each PCB, help you to determine
the cause. Record the LED indications for each PCB to enable rapid
recovery of the system.
STATUS
ALARM
LEDs (Green) indicating
states of the processors on
printed circuit boards
LEDs (Red) indicating alarms
of the printed circuit boards
1234
Fig. 2.5 LED display for the printed circuit boards in the control unit
Name Code Remarks
A16B–1212–0471 Conventional type
Power supply unit AI
A16B–1212–0901 CE marking compatible
type
A16B–1212–0531 Conventional type
Power supply unit BI
A16B–1212–0871 CE marking compatible
type
PIL (Green) This LED is lit when the input AC power voltage is sup-
plied to CP1.
ALM (Red) This LED is lit when overcurrent, overvoltage, or low
voltage occurs in direct current output voltage.
2.5
LIGHTING OF ALARM
LEDS ON PCBS
2.5.1
Configuration of the
Power Supply Unit
D LED display