Owner`s manual

When the upper key switch is in the Secure position, the lower key switch
has the effect of Auto Start, regardless of its setting. (See Section 3.2.)
Table 3–3: Lower Key Switch
Position Effect Light Color
Update Enables writing to CPUs and adapters. Halts boot pro-
cessor in console mode on power-up or when Restart
button ispressed. Used for updating parameters stored
in EEPROMs (upper key switch must be set to En-
able). Prevents an auto restart.
Red
Halt Prevents an auto restart if a failure or tran-
sient power outage occurs.
Yellow
Auto Start
(Normal Position)
Allows restart or reboot. Used for normal opera-
tion of the system.
Green
The lower key switch has three positions: Update, Halt, and Auto Start.
A light to the right of each key position lights to indicate which mode is
engaged.
Each position engages the primary processor in a different way.
• Update readies the CPU for parameter changes to the EEPROM which
are entered from the console terminal. You must have the switch in the
Update position to use some console commands: UPDATE and most
SET commands (see Section 5.18.1 through Section 5.18.5). (The upper
key switch must be set to Enable.) Digital customer service engineers
and self-maintenance customers use Update for updates to the console,
self-test, and ROM diagnostics programs. See also Section 5.24. When
the key is in the Update position, an automatic restart is inhibited.
Figure 3–3 shows the lower key switch with the key in the Update
position and the Update light lit.
• Halt inhibits automatic restart when a failure or transient power
outage happens. It is the opposite of Auto Start. On power-up, the
system halts in console mode, and you can issue a BOOT command
(see Section 5.6).
• Auto Start is the key position for normal operation. The key must be in
this position for automatic rebooting or restarting the system following
a power failure.
Controls and Indicators 3–7