Power-state logic, Computer power – Pioneer 2 / PeopleBot User Manual

Page 70

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Appendix B: Motor-Power Board Connectors

which output controls the computer's DC:DC voltage converter. Designed to provide

for crash-less shutdown of the computer in the event of a power brownout or for
unattended shutdowns, if Vpp drops below 10 VDC, the comparator automatically

initiates a two-minute delay before computer power (not system-wide) shutdown.

Similarly, when the computer power is manually switched OFF, the comparator is
grounded (below 10 VDC, of course) and the same two minute-delayed shutdown

occurs.

In all cases, power shutdown, but not necessarily computer software shutdown, is

canceled if power is restored to above 10 VDC, either by connecting a battery charger

or by hot-swapping the batteries.

With older Motor-Power systems, you may disable the two-minute delay circuitry

(switched or low-voltage shutdown immediate) by moving the jumpers on both J3 and

J6 on the Motor-Power Board to the pins opposite their ON position.

Power-State Logic

A 9-pin DSUB receptacle (P1) on the Motor-Power board provides a logic-level shutdown
indicator (DCD pin 1) which state goes low when computer power shutdown is first

initiated. The onboard computer may use this line state to initiate software-mediated

shutdown, such as provided by genpowerd for RedHat

©

Linux PCs.

Table 24. Power State 9-pin DSUB receptacle (P1)

1

2 3 4

5 6

7 8 9

DCD

nc nc pin

6 nc pin

4 nc nc Gnd

10-20K

adj.

across 4 & 6

Computer Power

Table 25. Computer power connector

Pin #

Connection

1

Vpp

2

Gnd

3

Gnd

4

5VDC @ 7A

A common 4-conductor, bevel-keyed connector (J5) provides 5
VDC @ 7A power for the onboard computer, and battery power

for the optional 12VDC fan.

64

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