Measurement Computing Personal Daq rev.6.0 - Manual (Page 142)

B-10 API Commands Appendix B, 887095 Personal Daq User’s Manual
daqAdcSetDataFormat
DLL Function daqAdcSetDataFormat(DaqHandleT handle, daqAdcRawDataFormatT rawFormat,
daqAdcPostProcDataFormatT postProcFormat);
C daqAdcSetDataFormat(DaqHandleT handle, DaqAdcRawDataFormatT rawFormat,
DaqAdcPostProcDataFormatT postProcFormat);
Visual BASIC VBdaqAdcSetDataFormat&(ByVal handle&, ByVal rawFormat&, ByVal postProcFormat&)
Delphi daqAdcSetDataFormat(Handle:DaqHandleT; rawFormat:daqAdcRawDataFormatT rawFormat;
postProcFormat:daqAdcPostProcDataFormatT);
Handle The handle to the device for which to set the option
RawFormat Specifies the raw data format
Parameters
PostProcFormat Flags specifying the options to use
Returns DerrNoError No error
See Also daqCvtRawDataFormat,daqCvtRawDataFormat
Program References None
Used With All devices
Description
daqAdcSetDataFormat allows the setting of the raw and the post-acquisition data formats which will be returned by the acquisition
transfer functions.
Note: Certain devices may be limited to the types of raw and post-acquisition data formats that can be presented.
The rawFormat parameter indicates how the raw data format is to be presented. Normally, the raw-data format represents the data from
the A/D converter. The default value for this parameter is DardfNative where the raw-data format follows the native-data format of the
A/D for the particular device.
The Personal Daq requires that the rawFormat parameter be set to DardfFloat. This format indicates that the driver should return the
raw data in floating point format. In this case the floating point data returned will be indicative of the type of channel configured. For
instance, if the channel is configured as a volts/mvolts/uvolts channel then the floating point value returned for the channel will be in volts.
If the channel is configured as temperature (thermocouple) then the floating point value returned for that channels will be in degrees C.
The postProcFormat parameter specifies the format for which post-acquisition data will be presented. This format is used by the one-
step functions of the form daqAdcRd…. The default value is DappdfRaw where the post-acquisition data format will follow the rawFormat
parameter.
daqAdcSetDiskFile
DLL Function daqAdcSetDiskFile(DaqHandleT handle, LPSTR filename, daqAdcOpenMode openMode,
DWORD preWrite);
C daqAdcSetDiskFile(DaqHandleT handle, LPSTR filename, DaqAdcOpenMode openMode,
DWORD preWrite);
Visual BASIC VBdaqAdcSetDiskFile&(ByVal handle&, ByVal filename$, ByVal openMode&, ByVal
preWrite&)
Delphi daqAdcSetDiskFile(handle:DaqHandleT; filename:PChar; openMode:daqAdcOpenMode;
preWrite:DWORD)
handle Handle to the device for which direct to disk ADC acquisition is to be performed.
filename String representing the path and name of the file to place the raw ADC acquisition data.
openMode Specifies how to open the file for writing
Parameters
preWrite Specifies the number of bytes to pre-write in the file
Returns DerrNoError No error
See Also daqAdcTransferGetStat, daqAdcTransferSetBuffer, daqAdcTransferStart,
daqAdcTransferStop
Program References None
Used With All devices
Description
daqAdcSetDiskFile allows you to set a destination file for data transfers. Data transfers will be directed to the specified disk file. The
filename parameter is a string representing the path\name of the file to be opened. The openMode parameter indicates how the file is to
be opened for writing data. Valid file open modes are defined as follows:
•
DaomAppendFile - Open an existing file to append subsequent data transfers. This mode should only be used when the existing
file has a similar channel scan group configuration as the subsequent transfers.
•
DaomWriteFile - Rewrite or write over an existing file. This operation will destroy the original contents of the file.
•
DaomCreateFile - Create a new file for subsequent data transfers. This mode does not require that the file exist beforehand.
The preWrite parameter may, optionally, be used to specify the amount that the file is to be pre-written before the actual data collection
begins. Specifying the pre-write amount may increase the data-to-disk performance of the acquisition if it is known beforehand how much
data will be collected. If no pre-write is to be done, then the preWrite parameter should be set to 0.