Measurement Computing WaveBook rev.3.0 - Manual (Page 214)

D-18 daqX API - Command Reference, 6-24-99 WaveBook User’s Manual
daqAdcTransferStop
DLL Function daqAdcTransferStop(DaqHandleT handle);
C daqAdcTransferStop(DaqHandleT handle);
Visual BASIC VBdaqAdcTransferStop&(ByVal handle&)
Delphi daqAdcTransferStop( handle:DaqHandleT )
Parameters handle Handle to the device for which the Adc data transfer is to be stopped
Returns DerrNoError No error (see the API Error Codes table at the end of this chapter).
See Also daqAdcTransferSetBuffer, daqAdcTransferStart, daqAdcTransferGetStat
Program References None
Used With All devices
Description
daqAdcTransferStop
allows you to stop a current ADC buffer transfer, if one is active. The current transfer will be halted and no more
data will transfer into the transfer buffer. Though the transfer is stopped, the acquisition will remain active. Transfers can be re-initiated
with daqAdcStartTransfer after the stop, as long as the current acquisition remains active. The acquisition can be halted by calling
the daqAdcDisarm function.
daqCalGetConstants
DLL Function daqCalGetConstants(DaqHandleT handle, DWORD channel, DaqAdcGain gain, DaqAdcRangeT
range, PWORD gainConstant, PSHORT offsetConstant );
C daqCalGetConstants(DaqHandleT handle, DWORD channel, DaqAdcGain gain, DaqAdcRangeT
range, PWORD gainConstant, PSHORT offsetConstant );
Visual BASIC VBdaqCalGetConstants(ByVal handle&, ByVal channel&, ByVal gain&, ByVal range&, al
gainConstant%, offsetConstant% );
Delphi daqCalGetConstants(handle: DaqHandleT;channel:DWORD; gain: DaqAdcGain; range:
DaqAdcRangeT; gainConstant:PWORD; offsetConstant:PSHORT );
handle Handle to the device for which ADC transfer status is to be retrieved
channel Channel number to apply the calibration settings
gain Gain range to apply the calibration settings
range A/D input range to apply the calibration settings
gain Pointer to the gain value for the current entry
Parameters
offset Pointer to the offset value for the current entry
Returns DerrNoError No error (see the API Error Codes table at the end of this chapter).
See Also daqCalSetConstants,daqCalSelectCalTable,daqCalSelectInputSignal,daqCalSaveConstants
Program References None
Used With WaveBook/512, WaveBook/516 series
Description
daqCalGetConstants
gets the calibration constants from the currently selected calibration table chosen by the daqCalSetConstants
command.
The user-calibration constants are gains and offsets that are applied to the input data. The data comes in, is multiplied by the gain, then
the offset is added to it. The resulting data is the conversion between the raw A/D data and the data that is presented during the
acquisition. Each channel, gain, and bipolar/unipolar setting has a different pair of gain and offset values. The first three parameters of
the daqCalGetConstants function specify which set of constants are to be retrieved. The last two parameters are the actual constants.
These constants are in a particular binary format. The gain constant is 32768 times the gain. For a gain of ×1, the gain constant is 32768
or 0x8000. The maximum gain is approximately ×2 (65535/32768), and the minimum gain is ×0 (0/32768). The offset (a left-justified
signed 12-bit number) is added to the final result. A single least-significant bit has an integer value of 16 or 0x0010.