NonStop S-Series Planning and Configuration Guide (G06.29+)

System Components
HP NonStop S-Series Planning and Configuration Guide—523303-021
4-8
Power Monitor and Control Units (PMCUs)
Power Monitor and Control Units (PMCUs)
Two power monitor and control units (PMCUs) are located in slots 21 and 22 behind
the battery retainer.
Each PMCU connects to:
•
One battery
•
One fan
•
One power supply (only in enclosures with power shelves)
•
The backplane
•
One DC power distribution bus
The PMCU:
•
Disconnects the batteries when powering off the system
•
Connects the batteries to the DC power distribution buses (when the system is
plugged in or enabled by the service processor)
•
Communicates with the service processors (SPs) using the serial maintenance bus
(SMB) so that the SPs can diagnose the condition of:
°
Batteries
°
Fans
°
Power supplies
•
Powers the fans
•
Provides the interface to:
°
Group ID switches
°
Group service LEDs
°
Emergency power-off (EPO) circuitry
VST104.vst
PMCU