PCI Bus System

The Programmable Communication Interface (PCI) bus is a single wire connected between modules receiving and delivering coded information. This wire is primarily identified as White with a Violet tracer. An additional tracer may be added to identify the different module connections. The coded information identifies the message and its importance. When multiple messages attempt to access PCI bus at once, code assigns priority ranking.

Modules along the PCI bus communicate at approximately 10800 bps (bits per second) for approximately 500 ms (milliseconds). Voltage is only present when modules are communicating. Measuring voltage on the PCI bus cannot be performed using a conventional DVOM. A lab scope should be used. Voltage on the PCI bus will switch from zero to 7.5 volts.