National Instruments Multifunction RIO NI R Series, Руководство пользователя

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Chapter 2 Hardware Overview of the NI 78xxR
© National Instruments Corporation 2-21 R Series Multifunction RIO User Manual
RTSI Trigger Bus
The NI 78 xx R can send and receive triggers thro
u
gh the RTSI trigger b
u
s.
The RTSI b
u
s provides eight shared trigger lines that connect to all the
devices on the b
u
s. In PXI, the trigger lines are shared between all the PXI
slots in a b
u
s segment. In PCI, the RTSI b
u
s is implemented thro
u
gh a
ribbon cable connected to the RTSI connector on each device that needs to
access the RTSI b
u
s.
Yo
u
can
u
se the RTSI trigger lines to synchronize the NI 78 xx R to any other
device that s
u
pports RTSI triggers. On the NI PCI-781 x R/783 x R and
NI PCIe-784 x R/785 x R, the RTSI trigger lines are labeled
RTSI/RTSI<0..6> and RTSI/RTSI7. On the NI PXI-78 xx R, the RTSI
trigger lines are labeled PXI/PXI_Trig<0..7>. In addition, the
NI PXI-78
xx R can
u
se the PXI star trigger line to send or receive triggers
from a device pl
u
gged into Slot 2 of the PXI chassis. The PXI star trigger
line on the NI PXI-78 xx R is PXI/PXI_Star.
The NI 78 xx R can config
u
re each RTSI trigger line either as an inp
u
t or an
o
u
tp
u
t signal. Beca
u
se each trigger line on the RTSI b
u
s is connected in
parallel to all the other RTSI devices on the b
u
s, only one device
sho
u
ld drive a partic
u
lar RTSI trigger line at a time. For example, if
one NI PXI-78 xx R is config
u
red to send o
u
t a trigger p
u
lse on
PXI/PXI_Trig0, the remaining devices on that PXI b
u
s segment m
u
st have
PXI/PXI_Trig0 config
u
red as an inp
u
t.
Caution Do not drive the same RTSI trigger b
u
s line with the NI 78 xx R and another device
sim
u
ltaneo
u
sly. S
u
ch signal driving can damage both devices. NI is not liable for any
damage res
u
lting from s
u
ch signal driving.
For more information on
u
sing and config
u
ring triggers, select Help»
Search the LabVIEW Help in LabVIEW to view the LabVIEW Help .
Refer to the PXI Hardware Specification Revision 2.1 and PXI Software
Specification Revision 2.1 at
www.pxi
s
a.org
for more information abo
u
t
PXI triggers.
PXI Local Bus (NI PXI-781
x
R/783
x
R Only)
The NI PXI-781 x R/783 x R can comm
u
nicate with other PXI devices
u
sing
the PXI local b
u
s. The PXI local b
u
s is a daisy-chained b
u
s that connects
each PXI peripheral slot with its adjacent peripheral slot on either side. For
example, the right local b
u
s lines from a PXI peripheral slot connect to the
left local b
u
s lines of the adjacent slot on the right. Each local b
u
s is 13 lines