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CHAPTER 4: Components
as the normal position. Then, when you press the N gang switch, all lines
switch to the normal position.
• LAMP TEST: This pushbutton lights all LEDs in the rack. You can use it to
determine if an LED is operating correctly.
• RESET: This switch performs a warm reset or a cold reset, depending on its
associated DIP switch setting. A warm reset reboots the CPU without affecting
the operator-programmed data that is stored in CPU RAM (for example, alarm
definitions). A cold reset reboots the CPU and deletes all operator-
programmed data that is stored in the CPU RAM, reinitializing the system.
4.2.2 LED
S
• OK (green): There is one OK LED for power supply 1 (PS1) and one for
power supply 2 (PS2). When lit, this LED indicates that the relevant power
supply is functioning.
• FAN FAIL (red): There is one FAN FAIL LED for PS1 and one for PS2. When
lit, this LED indicates that the fan in the relevant power supply is not
functioning.
• LINK ON (green): This LED, when lit, indicates that the control card is
functioning and capable of communicating with other racks and with the
central PC. When not lit, this LED indicates that the control card has failed.
When the control card fails, COMM IN is physically shorted to COMM OUT,
bypassing the failed control card.