Optimizing Programs; Block Data Transfers - HP AHA-8940 Configuration And User's Manual

Optimizing
Programs

Block Data Transfers

36 VXI Programming Using the IEEE 1394 Serial Bus
HP VISA
ViSession defaultRM, id;
//open device (VISA) session to the HP E1563
viOpenDefaultRM (&defaultRM);
viOpen (defaultRM, "VXI0::24::INSTR",VI_NULL,VI_NULL,
&id);
SICL
INST id;
// open device (SICL) session to the HP E1563
id = iopen("vxi,24")
Or, to open an interface session to the HP E8491A:
INST id;
// open (SICL) session to the VXI interface
id = iopen("vxi")
The HP E8491A IEEE 1394 interconnect uses the interface name VXI (or
vxi). The interface number is assigned using the 'I_O Config' utility
(Chapter 2). In the examples above, the logical address of the HP E1563
digitizer is 24 and INSTR indicates a VISA instrument control resource.
Programs that run over the IEEE 1394 serial bus are optimized by
transferring data between the PC and the instrument in blocks. The
following section identifies HP VISA and SICL functions that perform
block transfers.
Note
Refer to "Chapter 4: IEEE 1394 Fundamentals and Interface Overview" for
detailed information on data transfers using the IEEE 1394 data transfer
protocol.
VXIplug&play drivers for selected instruments contain functions that
perform block transfers. You will need to consult the driver help file to
determine if the driver for a particular instrument supports block transfers.
The following HP VISA functions perform block transfers over the
IEEE 1394 serial bus:
viMoveIn8
viMoveIn16
viMoveIn32
viMoveOut8 viMove
viMoveOut16 viMoveAsync
viMoveOut32
Chapter 3