Interface Card OL* Support Guide

Chapter 3
Attention Button - Direct Slot Control
Introduction to the Attention Button, Power LED, & Attention LED
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Introduction to the Attention Button, Power LED, & Attention LED
OL* compatible slots have key hardware features of a power LED, an attention LED, the Attention Button,
and a Manual Release Latch, all contained on an OLX Divider. The Attention Button is also the name of the
method for hardware triggered Hot-Plug operations, with minimum or no console interactions. The Attention
Button is a momentary-contact push button, located adjacent to each hot-plug slot, that is pressed by the user
to initiate a hot-insertion or hot-removal at that slot. The Manually-operated Retention Latches (MRL) are
referred to as “latch” in this document. Look closely at the OLX Divider to determine which specific slot is
associated with the divider. There is a light pipe on the divider to carry the LED light to another location on
the divider for easy viewing.
See your platform documentation for specifics on LED and Attention Button positioning as there are
differences between systems.
The power LED is used to indicate the power state of the slot. The power LED is also used to provide visual
feedback to the operator when the hot-plug operations are event-driven, initiated via the latch, or Attention
Button. The power LED will begin to blink when the event is initiated and will continue to blink until the hot
plug operation is concluded. At that point, the power LED will transition from blinking to off or on. The final
state of the power LED informs the user of the outcome of the operation. The power LED can be in one of
three states: off, blinking, or on. The states have the following meanings:
The attention LED is used to help a human operator locate a slot or to indicate an operational hardware
problem at the slot. The attention LED can be in one of three states: off, blinking, or on. The states have the
following meanings:
Locate operations have precedence over operational problems for the attention LED.
The success or failure of an event-driven hot plug operation is communicated to the user via the power LED.
Therefore, the meaning of the power LED state depends on the context. An event-driven OLA will start with
the power LED in the steady OFF state. When the latch is closed and the Attention Button is pressed, the
power LED will begin flashing. When the operation is completed, the power LED will enter its terminal state.
For an event-driven OLR, the operation begins with the power LED in the steady ON state. When the AB is
pressed, the power LED begins flashing. If the power LED transitions to the steady OFF state, then the
operation has succeeded. If the power LED transitions from blink to steady ON, then the operation has failed.
Table 3-1 OLX Divider - Power LED State
Power LED State
Steady OFF Power Off It is safe to add or remove a card.
Blinking Transition Operation in progress. Need to wait. It is not
safe to add or remove a card.
Steady ON Power On It is not safe to add or remove a card.
Table 3-2 OLX Divider - Attention LED State
Attention LED State
Steady OFF Normal Normal operating mode.
Blinking Locate Slot is being identified at user's request.
Steady ON Attention Operational hardware problem at this slot.