Utility Bus; Connections; Local Clusters - HP M2350A Service Manual

Understanding the Computer Module
The Backplane
Utility Bus
This is used for power and clock signal distribution. The clock signals are placed on the bus by
the Utility CPU for the synchronization of data acquisition. The power is placed on the bus by
the DC/DC converter. The DC/DC converter is used to produce voltages from the output of the
power supply and place them on the bus.
The power and clocks that are present on the utility bus are detailed in the following list:
Power
+ 12v
power supply (from the DC/DC converter).
-12v
power supply (from the DC/DC converter).
+5v
power supply (from the DC/DC converter).
+6OV power supply (from the display module via the DC/DC converter).
Clocks
2oMHz
system clock (from the Util-CPU).
32ms
frame clock (C32MS) (from the Util-CPU).
2ms
sample clock (COZMS) (from the Util-CPU).
Connections
This section first describes the way the backplane is physically clustered and then provides the
rules for the connection
of
function cards to the backplane.
Local Clusters
The local bus is connected to all the connectors in the backplane, but it is interrupted to
form clusters that share a connection to the same local bus. There are 10 local clusters in the
backplane with varying numbers of connectors.
The clusters are color-coded on the computer module, so they can be easily identified. The
connectors are grouped into the following clusters:
Yellow 3 connectors: 1 and 3 (on rear) and 2 (on the front of the backplane).
Gray
2 connectors: 4 (front) and 5 (rear).
Red 2 connectors: 6 (front) and 7 (rear).
Blue
2 connectors: 8 (front) and 9 (rear).
Green 3 connectors: 10 + 12 (front) and 11 (rear).
Gray stripes 1 connector: 13 (rear).
Yellow stripes 1 connector: 14 (front).
Red stripes 2 connectors: 16 (front) and 15 (rear).
Blue stripes 5 connectors: 18 + 20 (front) and 17 + 19 + 21 (rear).
Green stripes 2 connectors: 22 + 24 (front).
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