Technical data

3-16 Power Subsystem
Figure 3-15 Power Subsystem Voltage Monitoring
The System Controller monitors the midplane/backplane voltages: +1.5, +5, +12, -5.2, -12,
and 48 volts. Any voltage out of the specified range is recorded in the history file and the
system shut down. A warning is issued to the operating system (IRIX) and logged in the
system controller log for voltage levels approaching out-of-spec levels.
Offline
Switcher
(OLS A,B,C)
Monitors the 48 V at output of OLSs.
Shuts down if below 45 V or above 50 V
and sends Power Fail Warning (PFW).
Also shuts down for loss of AC.
Monitors backplane voltages generated by VCAM,
OLSs, 505 and 512 power boards. Also monitors
internal 1.5V power brick. Does not monitor IP19,
IP21, MC3, IO4 or SCSIBox. Shuts system down
if voltages are out of range.
48 V
REMOTE_INHIBIT
PFW (A, B, or C)
PENx
POKx
PFW
REMOTE_INHIBIT
OVERTEMP
External
Control
PENE
POKE
Shuts down if Voltage is out of range.
Sends POK signal and turns on POKLED.
IP19/IP21/MC3
Boards
PENA and B
POKA and B
OVERTEMP
Pwr
Brick
3.3 V
Pwr
Brick
5.0 V
Each power brick has a monitor circuit.
Shuts down of voltage is out of range.
Sends POK signal and turns on POKLED.
PENA
POKA
System
Controller
505/512/512x2
Power Boards
Shuts down if voltage is out of range.
Sends POK signal and turns on POKLED.
GE10
Board
1.5 V
Reg
PENB
POKB
IO4/VCAM
PENA and B
POKA and B
OVERTEMP
−12 V
Reg
1.5 V
Reg
−5.2 V
Reg
PENx (C or D)
POKx (C or D)
SCSIBoxes
Each power brick has a monitor circuit.
Shuts down if voltage is out of range.
Sends POK signal and turns on POKLED.
Pwr
Brick
5 V
Pwr
Brick
5/12 V