Chapter 1
Introduction
PXI-846x and NI-CAN for Windows 98/95
1-2
ni.com
Hardware Overview
The PXI-8460 or PXI-8461 (one port and two port) and PXI-8462 are
software configurable and compliant with the
PXI Specification and
CompactPCI Specification
. With a PXI-8460, PXI-8461, or PXI-8462
board, you can make your PXI or CompactPCI chassis communicate with
and control CAN devices.
The PXI-8461 physical layer fully conforms to the ISO 11898 physical
layer specification for CAN and is optically isolated to 500 V. The
PXI-8460 physical layer conforms to the ISO 11519-2 physical layer
specification for CAN and is also optically isolated to 500 V. CAN
interfacing is accomplished using the Intel 82527 CAN controller chip.
The PXI-8461 supports a wide variety of transfer rates up to 1 Mb/s. The
PXI-8460 supports rates up to 125 kb/s. The PXI-8462 is a dual-speed
board, with port one configured as a high-speed port (ISO 11898), and port
two configured as a low-speed port (ISO 11519-2). The CAN physical layer
on the PXI-8460, PXI-8461, and PXI-8462 can be powered either
internally (from the board) or externally (from the bus cable power).
The power source for the CAN physical layer for each port is configured
with a jumper.
PXI-8461 boards are available with two physical connector types:
•
DB-9 D-Sub
•
Combicon-style pluggable screw terminals
PXI-8460 and PXI-8462 boards are available with DB-9 D-Sub connectors.
The PXI-846
x
series boards use the Real-Time System Integration (RTSI)
bus to solve the problem of synchronizing several functions across multiple
boards to a common trigger or timing event. The RTSI bus is implemented
by using the National Instruments PXI trigger bus to route timing and
trigger signals between the CAN hardware and National Instruments DAQ
hardware or additional CAN hardware. Although a PXI-846
x
series board
RTSI bus is available in a PXI chassis, there are important issues to consider
when using it in a CompactPCI chassis. Please refer to Appendix E,
, for detailed information about the PXI-846x series RTSI interface.
The PXI-8460, PXI-8461 and PXI-8462 boards use the Intel 386EX
embedded processor to implement time-critical features provided by the
NI-CAN software. The PXI-8460, PXI-8461 and PXI-8462 communicate
with the NI-CAN driver through on-board shared memory and an interrupt.
