Operation

35

 

 

 

Table 7. Switches and indicators

Switch or Indicator

Function

Power supply

 

On/standby switch

Applies DC operating voltages to the drive electronics and

(on/

 

)

power supply fan when placed in the on ( l ) position.

 

Drive control board

 

Ready LED

This LED flashes during the power on sequence until the

(green)

discs are up to speed and the heads are loaded.

It is on steady with power on complete, assuming that there are no fault conditions.

It flashes during a power off sequence. This occurs when the drive receives a Start/Stop Unit command after it has once been started.

Heartbeat LED

This LED blinks when the SCSI controller is operating

(green)

properly.

 

If the LED is constantly on or off, it indicates one of two

 

things:

 

• The SCSI controller is not functioning properly.

 

• The SCSI controller is executing diagnostics and

 

should be ready in a few seconds.

Active LED

This LED socket is provided for units which do not use

(socket)

the optional bezel. When the active LED is inserted into

 

this socket, it indicates SCSI command activity.

 

When it is on, the drive is executing a SCSI command.

 

When it is off, the drive does not have a SCSI command

 

to execute.

Optional bezel on drive

 

Active LED

This LED indicates command activity by the drive.

(color unspecified)

 

 

When it is on, the drive is executing a SCSI command.

 

When it is off, the drive does not have a SCSI command

 

to execute.

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Seagate ST43400N/ND user manual Switch or Indicator Function