LabJack U12, Руководство пользователя, Страница: 23 / 36

•
*scanRate – Returns the actual scan rate, which due to clock resolution is not
always exactly the same as the desired scan rate.
• *voltages – Pointer to a 4096 by 4 array where voltage readings are returned.
Unused locations are filled with 9999.0.
• *stateIOout – Pointer to a 4096 element array where IO states are returned.
Unused locations are filled with 9999.0.
• *overVoltage – If >0, an overvoltage has been detected on at least one sample
of one of the selected analog inputs.
ActiveX Function Differences:
The “channels” and “gains” arrays are replaced with “channelsPacked” and “gainsPacked”. The
OCX has a function “FourPack” (4.23) which will convert 4 elements to a packed value. The
packed value is determined as: element[0] + (element[1] * 2^8) + (element[2] * 2^16) +
(element[3] * 2^24).
The parameters “demo”, “ledOn”, “disableCal”, “transferMode”, “updateIO”, and “stateIOin”, are
replaced by an “optionBits” parameter. Call the OCX function “BuildOptionBits” (4.22) to
determine this parameter.
The “voltages” and “stateIOout” arrays are represented as strings. Floating point data is
returned as 13 characters per number (XXXX.XXXXXXXX) and integers are returned as 10
characters per number (XXXXXXXXXX). Zeros are used for padding where necessary.
Declaration (ActiveX):
long AIBurstX (
long FAR* idnum,
long numChannels,
long channelsPacked,
long gainsPacked,
float FAR* scanRate,
long triggerIO,
long triggerState,
long numScans,
long timeout,
BSTR FAR* voltages,
BSTR FAR* stateIOout,
long FAR* overVoltage,
long optionBits)
4.3 AIStreamStart
Starts a hardware timed continuous acquisition where data is sampled and stored in the
LabJack RAM buffer, and can be simultaneously transferred out of the RAM buffer to the PC
application. A call to this function should be followed by periodic calls to AIStreamRead, and
eventually a call to AIStreamClear.
If the LED is enabled (ledOn>0), it will toggle every 40 samples during acquisition and turn on
when the stream operation stops.
Declaration:
long __cdecl AIStreamStart (
long *idnum,
long demo,
long stateIOin,
long updateIO,
long ledOn,