DC Power Connection
7.4.3 POWER FAIL DETECT SIGNAL
Pin 2 on connector J4 is an optional power fail detect signal.
This signal allows the MD21 to detect failing DC power. When the
signal is asserted (active low), a latch is set. When the MD21
microprocessor senses the latch, it inhibits disk drive activity.
The signal must be asserted at least 2 milliseconds before the +5
VDC power falls below +4.75 VDC.
To use this power fail detect option, the power supply used in the
subsystem in which the MD21 resides must contain a power fail
signal. Connect pin 2 to the power fail signal in the power
supply.
7.5 DC POWER CONNECTION
The MD21 Controller power supply, designated J7, (see Figure 7-8)
is an AMP P/N 641737-1. Table 7-7 lists the power connections for
this connector.
LED 4 LED 3
Figure 7-8.
Pin Locations for Power Connector
JUMPERS
MD2103-0776
7-20 Interfaces
Содержание MD21/S2
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