User`s guide

2 007-3938-003
1: Introducing the L1 and L2 Controllers
You monitor the system with the L1 controller either at the L1 controller’s liquid crystal
display (LCD) or at a system console.
See Chapter 2, “Using the L1 and L2 Controllers,” for details on using the L1 controller,
and see Chapter 3, “L1 and L2 Controller Commands,” for a list of L1 controller
commands.
The following are some of the functions performed by the L1 controller. (For a list of
functions that are specific to a product or component, see your server or graphics system
user’s guide.
• Drives the L1 controller display.
• Reports all failure conditions.
• Monitors and controls LEDs.
• Monitors the power On/Off switch.
• Monitors the reset switch, and the nonmaskable interrupt (NMI) switch.
• Monitors and acts on the state of the power, reset, and NMI switches.
• Drives the reset, soft reset, and NMI signals to the local node electronics on
command from software.
• Provides the time of day (TOD).
• Reads and reports memory and processor configuration within the node. Reads
dual inline memory module (DIMM) and system identification (ID) PROMs.
• Reads and writes contents of module identification EEPROMs.
• Controls voltage regulator modules (VRMs).
• Monitors voltage and reports failures.
• Controls and sequences DC power output of voltage regulators. Monitors failures
and reports them. Drives DC on and failure LEDs.
• Controls voltage margining within the brick or server.
• Controls and monitors fan speed and reports the number of the failed fan.
• Monitors and reports operating temperature and status of 48 VDC input power and
DC power.
• Provides a USB hub chip that has six master ports: one port connects internally to
the R-brick’s L1 controller, four ports connect to the L1 controllers of four C-bricks
(via the NUMAlink3 cable), and a master port connects to the L2 controller.