Hot-swap capability
33
Model 6276 User Guide
3 • System architecture
External power connections
The chassis provides a rear DC interface panel with -48 VDC power interfaces for N+1 power operation and
dual ground lugs, as shown in
figure 5
on page 19. The connectors are described in
table 6
.
.
Front panel keying for power supplies
Power supply keying options have been registered with PICMG. Since power supplies use a different type of
connector than other CompactPCI slots, there is no possibility of mating problems with 2mm connectors. The
power supply key options are independent of the 2mm application card keys, and may duplicate key codes that
are used for different purposes elsewhere in the system.
Specific front panel keying is defined to prevent damaging an AC power supply inserted into a backplane wired
for DC and vice versa.
Hot-swap capability
Hot-swapping is the capability of removing and replacing components without turning off the system. Hot-swap
capability is becoming increasingly important in systems requiring continuous operation at some level. Because
boot times of many popular operating systems are long, the hot-swap capability is crucial for high-end PC servers,
and even more so for telecommunication systems, such as base stations, where board-level exchanges must be
made without any downtime. CompactPCI supports dynamic configuration to allow hot removal/insertion of
boards without interrupting backplane transactions or disturbing DC voltages in the power system.
The hot-swap feature is implemented on the CPCI boards, not on the backplane. The backplane remains pas-
sive. Therefore, CompactPCI boards either are or are not hot-swappable.
Signal lines must be precharged to 1V before being plugged into the backplane to maintain ongoing bus trans-
actions. Also, power must be ramped up or down in a controlled manner to allow the power supply to adjust to
Table 6. Description of rear interface panel connectors
Item
Description
-48 VDC power
terminal
DC rear-entry module accepts 36–75 VDC at 7.0 A max input via Phoenix connector.
Polarity should be applied as marked (negative—top position, positive—bottom posi-
tion).
AC power
interface
The AC power interface accepts 115 - 230 VAC (50–60 Hz), 5 amp maximum.
Ground lugs
The dual frame ground lugs must be used to connect the chassis to earth ground on
DC interfaces. Failure to do this will cause excessive RF emissions and could possibly
create a safety hazard. The double ground lug meets NEBS and will accept Amp part
# 606209-1. NEBS requires a double lug on DC chassis to ensure that the ground
connection will not rotate and become loose.
The dual frame ground lugs on DC interfaces must be used to connect the chas-
sis to earth ground. Failure to do this will cause excessive RF emissions and
could possibly create a safety hazard.
WARNING
