Chapter 2
Hardware Overview of the NI 7831R
2-20
ni.com
the remaining devices on that PXI bus segment must have PXI/TRIG0
configured as an input.
Caution
Do
not
drive the same RTSI trigger bus line with the NI 7831R and another device
simultaneously. Such signal driving can damage both devices. NI is
not
liable for any
damage resulting from such signal driving.
For more information on using and configuring triggers, select
Help»VI,
Function, & How-To 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
pxisa.org
for more information about PXI
triggers.
PXI Local Bus (for NI PXI-7831R only)
The NI PXI-7831R can communicate with other PXI devices using the PXI
local bus. The PXI local bus is a daisy-chained bus that connects each PXI
peripheral slot with its adjacent peripheral slot on either side. For example,
the right local bus lines from a PXI peripheral slot connect to the left local
bus lines of the adjacent slot on the right. Each local bus is 13 lines wide.
All of these lines connect to the FPGA on the NI PXI-7831R. The PXI local
bus right lines on the NI PXI-7831R are PXI/LBR<0..12>. The PXI local
bus left lines on the NI PXI-7831R are PXI/LBLSTAR<0..12>.
The NI PXI-7831R can configure each PXI local bus line either as an input
or an output signal. Only one device can drive the same physical local bus
line at a time. For example, if the NI PXI-7831R is configured to drive a
signal on PXI/LBR 0, the device in the slot immediately to the right must
have its PXI/LBLSTAR 0 line configured as an input.
Caution
Do
not
drive the same PXI local bus line with the NI PXI-7831R and another
device simultaneously. Such signal driving can damage both devices. NI is
not
liable for
any damage resulting from such signal driving.
The NI PXI-7831R local bus lines are only compatible with 3.3 V signaling
LVTTL and LVCMOS levels.
Caution
Do
not
enable the local bus lines on an adjacent device if the device drives
anything other than 0–3.3V LVTTL signal levels on the NI PXI-7831R. Enabling the lines
in this way can damage the NI PXI-7831R. NI is
not
liable for any damage resulting from
enabling such lines.
