Chapter 2 Hardware Overview ofthe NI 783xR
© National Instruments Corporation 2-19 NI 783xR User Manual
Caution Do not drive the same RTSI trigger bus line with the NI783xR 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 www.pxisa.org for more information about
PXI triggers.
PXI Local Bus (for NI PXI-783xR only)
The NI PXI-783xR 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-783xR. The PXI local
bus right lines on the NI PXI-783xR are PXI/LBR<0..12>. The PXI local
bus left lines on the NI PXI-783xR are PXI/LBLSTAR<0..12>.
The NIPXI-78 3xR 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 NIP XI-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 NIPXI-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 NIPXI-783xR local bus lines are only compatible w ith 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 NIPXI-783xR. Enabling the lines
in this way can damage the NI PXI-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,