User`s guide

Status and Error Messages
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Upstream devices (for example, rack display, console, and modem) provide control
for the system, initiate commands for the downstream devices, and act on the
messages that they receive from downstream devices.
Downstream devices (for example, C-bricks, the USB hub of the R-brick, and L1
controllers of the bricks) perform the actions that are specified by the L2 controller
commands, send responses to the L2 controller that indicate the status of the
commands, and send error messages to the L2 controller.
• Allows remote maintenance.
You use the L2 controller touch display to do the following:
• Power the system on and off.
• Monitor voltage margins.
• Reset the system
• Enter a non-maskable interrupt (NMI).
The L2 controller also monitors and generates status and error messages related to the
rack chassis items, such as the power bay and other rack items. The L2 controller also
displays status and error messages generated by each individual brick’s L1 controller.
(See “L1 Controller Tasks and Messages” on page 31 for L1 controller message
descriptions.)
The L2 controller information is displayed on the L2 controller touch display located in
the front door of your server system. (The actual L2 controller is located on the top of
your rack enclosure.)
Note: If you have a system console, you can also see the L2 controller messages on the
system console.