![NI PXI-6682 Скачать руководство пользователя страница 29](http://html1.mh-extra.com/html/ni/pxi-6682/pxi-6682_user-manual_1685518029.webp)
Chapter 3
Hardware Overview
NI PXI-6682 User Manual
3-14
ni.com
PXI Trigger signals do not reach each slot at precisely the same time. A
difference of several nanoseconds between slots can occur in an eight-slot
chassis. However, this delay is not a problem for many applications. If your
application requires tighter synchronization, use the PXI_STAR triggers.
You can independently select the output signal source for each PXI trigger
line from one of the following sources:
•
PFI <0..2>
•
PXI_TRIG <0..7>
•
PXI_STAR <0..12>
•
Future time events
•
PXI_CLK10
•
Ground
The PXI Trigger outputs may be synchronized to CLK10 except when
routing future time events. Refer to the
Choosing the Type of Routing
section for more information about the synchronization clock.
Using the PXI Star Triggers
There are up to 13 PXI star triggers per chassis. Each trigger line
is a dedicated connection between Slot 2 and one other slot. The
PXI Specification
, Revision 2.1, requires that the propagation delay along
each star trigger line be matched to within 1 ns. A typical upper limit for
the skew in most NI PXI chassis is 500 ps. The low skew of the PXI star
trigger bus is useful for applications that require triggers to arrive at several
modules nearly simultaneously. The NI PXI-6682 is able to route low skew
triggers to the PXI_Star lines from any PFI line.
The star trigger lines are bidirectional, so signals can be sent to Slot 2 from
a module in another slot or from Slot 2 to the other module.
You can independently select the output signal source for each PXI star
trigger line from one of the following sources:
•
PFI <0..2> (low skew)
•
PXI_TRIG <0..7>
•
Another PXI star trigger line (PXI_STAR <0..12>)
•
Synchronized time event
•
PXI_CLK10
•
Ground
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com