IBM DS4700 manual Seven-segment numeric display LEDs, Definition

Table 45. Host and drive channel LED definitions

L1	L2	Definition
Off	Off	When both LEDs for a host or drive channel are off, this indicates one or more
		of the following conditions:
		v The host or drive channel ports are bad or the SFPs are faulty.
		v An SFP module is inserted with no fibre channel cable attached.
		Note: If the SFP is inserted in a drive port with no fibre channel attached,
		the associated drive port bypassed LED will also be lit. In addition, the L1
		and L2 LEDs will be unlit.
		v No SFP module is inserted in one or both of the host or drive ports in the
		channel.
On	Off	The host or drive channel l is operating at 1 Gbps.
		Note: This pattern is not applicable in the drive port because the DS4700
		Express does not support 1 Gbps fibre channel speed.
Off	On	The host or drive channel is operating at 2 Gbps.
On	On	The host or drive channel is operating at 4 Gbps.

Seven-segment numeric display LEDs

The numeric display consists of two seven-segment LEDs that provide information about enclosure identification and diagnostics. Figure 102 shows the numeric display and the diagnostic LED.

Seven- segment display

ds48042

76041

Diagnostic LED

Figure 102. Numeric display LEDs

When you power on the storage subsystem, the seven-segment LEDs show 88 before the boot firmware starts to run. After the boot code starts, - - is displayed.

When the storage subsystem is operating normally, the numeric display shows the enclosure identification (enclosure ID) of the storage subsystem.

If an error has occurred and the Needs Attention LED is on, the numeric display shows diagnostic information. The numeric display indicates the information is diagnostic by illuminating an LED that appears as a decimal point between the

132IBM System Storage DS4700 Express Storage Subsystem: Installation, User’s and Maintenance Guide