Digital Equipment DECmpp 12000/Sx 100, Руководство по обслуживанию оборудования

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2.1 Overview of Controls and Indicators
2.1 Overview of Controls and Indicators
Several of the DECmpp 12000/Sx controls and indicators are described briefly in
the list below. The rest are described in more detail in the following sections.
• POWER (keyswitch) — Controls power to the DPU and enables the VMEbus
RESET button.
• VMEbus RESET pushbutton — Pushing this button resets the VMEbus only
if the POWER keyswitch is set at DIAGNOSTIC.
• MODEM switch — At CONNECT, it enables the internal system modem
(USA only). At DISCONNECT, it disables the modem.
• POWER indicator — Provides information about the power supplies and fan
assembly, part of the front indicators.
• Power Selector — A three-position toggle switch, part of the rear controls.
• Service Indicators — Service indicators are described in detail in Section 2.3.
ACU Indicators — Provides information about the ACU PCB.
MVIB Indicator — Provides information about the Front-end VME
interface (T6000) PCB.
PVME Indicators — Provides information about the PVME PCB.
PE and Router PCB Indicators — Provides information about the PE
array and router.
2.2 DPU Power System
The DPU power system is complex, and you should understand it thoroughly
before changing any settings.
Caution
To avoid system problems, do not turn the DPU off before bringing the
front-end server to console or single-user mode.
The power system includes indicators that show the status of the various power
supplies and a power sequencer that ensures the power supplies start in the
correct order.
The DPU power system includes the following controls:
• The POWER keyswitch, shown in Figure 2–3, has three settings:
OFF (straight up) turns DPU power off.
ON (middle position) turns DPU power on when the power selector switch
is set to LOCAL.
DIAGNOSTIC (lower position) is similar to ON, but also enables the
VMEbus RESET button.
DPU Controls and Indicators 2–5