D20/D200 Redundancy Failover; Rs-232 Switch Panel: Indicators; Active/Standby Switch - GE D20 Installation And Operation Manual

D20/D200
Installation and Operations Guide
Familiarization
, continued
D20/D200 In the example on page 39, if CCU A fails, CCU B becomes active, as shown below:
Redundancy
Failover
CCU A Serial
Communications
RS-232 Switch The RS-232 Switch Panel has two sets of indicator LEDs:
Panel:
•
PWR A/PWR B: When lit, power and communications are received from the
Indicators
designated CCU. Normally, both LEDs are lit.
•
CCU A/CCU B: Normally, one LED is lit, indicating the Active CCU.
RS-232 Switch The Active/Standby switch on the front of the RS-232 Switch Panel is used to:
Panel:
•
Restore a previously failed CCU to Active status, once it has been repaired.
Active/Standby
•
Manually force a CCU to Active status, so routine maintenance can be
Switch
performed on the other CCU.
For instructions on operating the Active/Standby switch, refer to "RS-232 Switch
Panel: Active/Standby Switch Operation" on page 117
40
To Field
Equipment
. . . . .
RS-232 Switch Panel
. . . . .
RS-232 Switch
Monitor and
Control
CCU A
(Failed)
Inter-CCU
Communications
Active/Standby
Switch
994-0078-2.00-7
GE Energy
CCU B Serial
. . . . .
Communications
CCU B
(Active)
Power Indicator
LEDs
CCU Indicator
LEDs
General
Full