National Instruments NI 785xR - Manual (Page 43)

Chapter 2 Hardware Overview of the NI 78xxR
R Series Intelligent DAQ User Manual 2-22 ni.com
The PXI local bus right lines on the NI PXI-781xR/783xR are
PXI/LBR<0..12>. The PXI local bus left lines on the NI PXI-781xR/783xR
are PXI/LBLSTAR<0..12>.
The NI PXI-781xR/783xR 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-781xR/783xR 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-781xR/783xR 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-781xR/783xR 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-781xR/783xR. Enabling
the lines in this way can damage the NI PXI-781xR/783xR. NI is not liable for any damage
resulting from enabling such lines.
The left local bus lines from the left peripheral slot of a PXI backplane
(Slot 2) are routed to the star trigger lines of up to 13 other peripheral slots
in a two-segment PXI system. This configuration provides a dedicated,
delay-matched trigger signal between the first peripheral slot and the
other peripheral slots for precise trigger timing signals. For example—as
shown in Figure 2-12—an NI PXI-781xR/783xR in Slot 2 can send an
independent trigger signal to each device plugged into Slots <3..15> using
the PXI/LBLSTAR<0..12>. Each device receives its trigger signal on its
own dedicated star trigger line.
Caution Do not configure the NI 781xR/783xR and another device to drive the same
physical star trigger line simultaneously. Such signal driving can damage the
NI 781xR/783xR and the other device. NI is not liable for any damage resulting from
such signal driving.