Operator`s manual

Power bus connectors — There are three power bus connectors

(MO, SO, and SI).

The main-out (MO) connector is the source for the

power control bus signal to the expander. One end

of a power-bus cable is connected here and the other

end is connected to the power supply secondary-in (SI)

connector of an R400X expander.

In the VAX 4000 Model 500, the secondary-in (SI)

connector receives the power bus control signal from

the front panel system ON/OFF switch. In a power

bus with more than one expander, the power control

bus signal is connected between expanders using the

secondary in and out connectors (see Section 2.7.4)

NOTE

The SI connector is not available for system expansion.

The secondary-out (SO) connector is not used on the

VAX 4000 system. It is used to send the signal down

the power bus for conﬁgurations with more than one

expander.

1–22 System Overview