IBM DU3 2104, Hardware Technical Information

Page: 26 / 36

Power Control
Each fan-and-power-supply assembly in the 2104 has a DC On/Standby switch.
The power to the 2104 is also controlled by the Power Control switch on the switch
card.
Power Sequencing
The power sequencing of the disk drive modules in a 2104 is controlled by the settings
of the Drive Auto-Start and Select Enclosure Services switches on the switch card.
These are:
Drive Auto-Start switch Select Enclosure
Services switch Power Sequence
OFF OFF Normal Start
ON OFF Command Start
OFF ON Delayed Start
ON ON Reserved
Auto Restart
2104s automatically restart when input power is restored within specification after a
power failure. The disk drive module motors start under the control of the using system.
18
2104 Models DU3 and TU3 Hardware Technical Information