User guide

Introduction 13
PXIS-2719A
Figure 1-8: Instrument Signal Routing
1.5.5 Local Bus
The local bus on a PXI backplane is a daisy-chained bus that con-
nects each peripheral slot with adjacent peripheral slots to the left
and right. Each local bus has 13 lines and can transmit analog or
digital signals between modules. It can also provide a high-speed
sideband communication path that does not affect the PCI band-
width.
In accordance with the PXI specification, the local bus connects all
adjacent slots except slots 1 and 2.
1.5.6 Trigger Bus
The trigger bus is an 8-line bus that connects all PXI slots in the
same PCI segment. The trigger bus can be used to provide inter-
module synchronization. PXI modules can transmit trigger or
clock signals to one another through the trigger bus, allowing pre-
cisely timed responses to asynchronous external events the sys-
tem is monitoring or controlling.
The PXIS-2719A provides three trigger bus segments, connected
by two trigger bus buffers. The first segment is from slot 1 to slot 6,