User manual

Programmer’s Guide Page 21 of 66
// Initialize the digitizers
for (long i = 0; i < nbrInstruments; i++)
{
char resourceName[20];
sprintf(resourceName, "PCI::INSTR%d", i);
status = Acqrs_InitWithOptions(resourceName, VI_FALSE, VI_FALSE,
options, &(instrumentID[i]));
}
// Now combine the first 3 digitizers (in inverse order)
idList[0] = instrumentID[2];
idList[1] = instrumentID[1];
idList[2] = instrumentID[0];
ViSession multiInstrID;
ViSession masterIndex = instrumentID[1];
long nbrInList = 3;
status = AcqrsD1_multiInstrDefine(idList, nbrInList, masterIndex,
&multiInstrID);
status = Acqrs_calibrate(multiInstrID);
The first part of the code above finds and initializes all individual digitizers, as shown in section Error! Reference
source not found., Error! Reference source not found.. Of course, you could also use one of the other 2 methods of
identifying individual digitizers.
After AcqrsD1_multiInstrDefine has executed successfully, the instrumentID’s in the list idList become
unavailable for further operations. You must use the returned multiInstrID to refer to the newly defined
MultiInstrument.
You are responsible for making sure that
all participating digitizers are physically connected with AS bus bridges
the modules are of the same model type
the master module has no more memory than any other participating digitizer
an AcqGeo.map file is available if needed by the driver
If the master module has more memory than any other digitizer, the combined instrument will work as long as you
never request more memory than that available in the unit with the shortest memory.
The digitizers within the 'manually' defined MultiInstrument are numbered from 0 to (nbrInList – 1), exactly as
presented in the digitizer list idList. For details on channel and trigger source numbering, please refer to section 3.18,
AS BUS OPERATION.
3.2.9. AqGeo.map file positioning
For AS bus MultiInstruments in some systems the driver will need additional information about the physical ordering
of the modules. This information is stored in a file named AqGeo.map which the driver will load when an AS bus
instrument is defined. The driver will search for the AqGeo.map file as follows:
First the file will be searched for in the working directory of the application.
Then the working directory will be searched for a file "AqDrv4.ini"
Finally the directory pointed to by the environment variable "AcqirisDxDir" will be searched for a file
"AqDrv4.ini"
The "AqDrv4.ini" file should contain the name of a directory which will also be searched for the
AqGeo.map file. Here is a typical example of its contents:
[Acqiris]
GeoMapPath=C:\Program Files\Acqiris\bin