Measurement Computing STLITE-CPCI-xxx - Manual (Page 9)

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4. POWERING-UP
4.1 SEQUENCE FOR APPLYING POWER
It is important that higher-numbered PCI buses in your system’s hierarchy be powered-up and in a stable state at
the time the host computer comes up and issues a master power-on bus reset. In systems that perform automatic
PCI bus configuration, this allows the configuration software to recognize the PCI bus hierarchy and all attached
devices.
NOTE: It is desirable for the host computer and the CPCI Expansion Chassis to receive their AC power
from the same, protected, local AC power source.
1. POWER-ON – Place the AC power switch on the rear panel of the CPCI Expansion Chassis ON ( I )
2. Apply power to the host system.
NOTE: If you have multiple (daisy-chained) CPCI Expansion Chassis, apply power to the most
“downstream” unit first, then the next ‘upstream” unit, etc., and finally, power-up the host computer.
4.2 POWERING DOWN
There is no requirement for sequential powering-down of the system. You can shut down system units in any
order you wish.
5. MULTIPLE CHASSIS INSTALLATION
5.1 INTRODUCTION
The PCI Local Bus Specification defines the PCI bus as a hierarchical bus where PCI-to-PCI Bridges (PPBs)
can be used to add “levels” to the PCI bus hierarchy.
Thus, you can add two or more STLITE-CPCI-8R/16R chassis to your system configuration. It can be done in
either a “daisy-chain” (serial) manner or a fan-out (serial/parallel) fashion. Each configuration has its own
advantages and applications.
In a daisy chain configuration (Figure 5-1), expansion chassis are added serially at the end of the PCI bus
hierarchy, one PPB after another. This adds “depth” to the local PCI bus by increasing the number of active
local bus levels in the system configuration.
Each PCI bridge has a primary side and a secondary side. Take, for example, the addition of a bridge to existing
PCI Bus 0. The new bridge is attached to the secondary side of the first bridge and the new bridges secondary
side becomes Local Bus 1. The primary side is defined as the side attached to the lower numbered, or upstream
PCI Local Bus. A bridge attached to the secondary side of the new bridge (Bus 1) would be assigned a higher
number (Bus 2) and considered downstream of Bus 1.
5.2 DAISY-CHAIN CONFIGURATION
The PCI bus in your host computer is typically numbered “0”. Each new PPB adds a new bus level into the
hierarchy. The Host Bridge card, when plugged into the host computer, has as its primary side, Bus 0. Its
downstream side (the cable) is Bus 1 (Figure 5-1).
The first expansion chassis also has one or two PPBs (for an eight- or 16-slot rack). The first PPB has its
primary side connected to Bus 1 (the cable) and its downstream feeds Bus 2 on the chassis motherboard.
In a 16-slot rack (STLITE-CPCI-16R), the second PPB has Bus 2 as its primary side and Bus 3 is the secondary.
If you were to insert another Host CPCI Bridge card in an open slot in first expansion rack, its primary side
would be attached to Bus 2 or Bus 3 depending on the slot chosen (Figure 5-1). Its cable (secondary side) will be