Filter
Top Products
VXI Programming Using the IEEE 1394 Serial Bus 35Chapter 3
Chapter 3
VXI Programming Using the IEEE 1394
Serial Bus
Using this Chapter
This chapter contains examples and general information for programming
VXI systems over the IEEE 1394 serial bus. The contents of the chapter
include:
• Programming Register-Based and Message-Based
Instruments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
• Opening Instrument Sessions . . . . . . . . . . . . . . . . . . . . . . . . 35
• Optimizing Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
• HP E8491A Triggering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
• Using HP E8491A Shared Memory . . . . . . . . . . . . . . . . . . . 47
Programming
Register-Based and
Message-Based VXI
Instruments
There are no SCPI instrument drivers for register-based instruments
installed in, or downloaded to the HP E8491A. Therefore, register-based
instruments are programmed over the IEEE 1394 bus using either their
VXIplug&play drivers, or through register-level peeks and pokes using
HP VISA or SICL.
Message-based instruments are programmed using HP VXIplug&play
drivers, or using SCPI commands embedded in HP VISA or SICL function
calls.
VXIplug&play drivers for HP register-based and message-based
instruments are contained on the HP Universal Instrument Drivers CD
which ships with each HP VXI instrument.
Opening Instrument
Sessions
Programs which run over the IEEE 1394 interface begin by opening a
session between the VXI instrument and the driver or I_O library (VISA or
SICL). An address that includes the interface name and number (described
in Chapter 2) and the instrument’s logical address is used in opening these
sessions.
Following are three segments that open sessions to an instrument in
HP VXIplug&play, HP VISA, and SICL programs.
HP VXIplug&play
ViSession vi;
// open device (VXIplug&play) session to the HP E1563
errStatus = hpe1563_init(“VXI0::24::INSTR”,VI_FALSE,
VI_FALSE, &vi);