NI DAQMX Read Functions - ni/grpc-device GitHub Wiki
- DAQmxReadAnalogF64
- DAQmxReadAnalogScalarF64
- DAQmxReadBinaryI16
- DAQmxReadBinaryI32
- DAQmxReadBinaryU16
- DAQmxReadBinaryU32
- DAQmxReadCounterF64
- DAQmxReadCounterF64Ex
- DAQmxReadCounterScalarF64
- DAQmxReadCounterScalarU32
- DAQmxReadCounterU32
- DAQmxReadCounterU32Ex
- DAQmxReadCtrFreq
- DAQmxReadCtrFreqScalar
- DAQmxReadCtrTicks
- DAQmxReadCtrTicksScalar
- DAQmxReadCtrTime
- DAQmxReadCtrTimeScalar
- DAQmxReadDigitalLines
- DAQmxReadDigitalScalarU32
- DAQmxReadDigitalU8
- DAQmxReadDigitalU16
- DAQmxReadDigitalU32
- Advanced
int32 DAQmxReadAnalogF64 (TaskHandle taskHandle, int32 numSampsPerChan, float64 timeout, bool32 fillMode, float64 readArray[], uInt32 arraySizeInSamps, int32 *sampsPerChanRead, bool32 *reserved);
Reads multiple floating-point samples from a task that contains one or more analog input channels.
Input | ||
---|---|---|
Name | Type | Description |
taskHandle | TaskHandle | The task to read samples from. |
numSampsPerChan | int32 | The number of samples, per channel, to read. The default value of -1 (DAQmx_Val_Auto) reads all available samples. If readArray does not contain enough space, this function returns as many samples as fit in readArray. NI-DAQmx determines how many samples to read based on whether the task acquires samples continuously or acquires a finite number of samples. If the task acquires samples continuously and you set this parameter to -1, this function reads all the samples currently available in the buffer. If the task acquires a finite number of samples and you set this parameter to -1, the function waits for the task to acquire all requested samples, then reads those samples. If you set the Read All Available Samples property to TRUE, the function reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples. |
timeout | float64 | The amount of time, in seconds, to wait for the function to read the sample(s). To specify an infinite wait, pass -1 (DAQmx_Val_WaitInfinitely). This function returns an error if the timeout elapses. A value of 0 indicates to try once to read the requested samples. If all the requested samples are read, the function is successful. Otherwise, the function returns a timeout error and returns the samples that were actually read. |
fillMode | bool32 | Specifies whether or not the samples are interleaved. |
Value | Description | |
---|---|---|
DAQmx_Val_GroupByChannel | Group by channel (non-interleaved) | |
DAQmx_Val_GroupByScanNumber | Group by scan number (interleaved) |
arraySizeInSamps | uInt32 | The size of the array, in samples, into which samples are read. |
reserved | bool32 * | Reserved for future use. Pass NULL to this parameter. |
Output | ||
Name | Type | Description |
readArray | float64 [] | The array to read samples into, organized according to fillMode. |
sampsPerChanRead | int32 * | The actual number of samples read from each channel. |
Name | Type | Description |
---|---|---|
status | int32 | The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error. |
int32 DAQmxReadAnalogScalarF64 (TaskHandle taskHandle, float64 timeout, float64 *value, bool32 *reserved);
Reads a single floating-point sample from a task that contains a single analog input channel.
Input | ||
---|---|---|
Name | Type | Description |
taskHandle | TaskHandle | The task to read the sample from. |
timeout | float64 | The amount of time, in seconds, to wait for the function to read the sample(s). To specify an infinite wait, pass -1 (DAQmx_Val_WaitInfinitely). This function returns an error if the timeout elapses. A value of 0 indicates to try once to read the requested samples. If all the requested samples are read, the function is successful. Otherwise, the function returns a timeout error and returns the samples that were actually read. |
reserved | bool32 * | Reserved for future use. Pass NULL to this parameter. |
Output | ||
Name | Type | Description |
value | float64 * | The sample read from the task. |
Name | Type | Description |
---|---|---|
status | int32 | The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error. |
int32 DAQmxReadBinaryI16 (TaskHandle taskHandle, int32 numSampsPerChan, float64 timeout, bool32 fillMode, int16 readArray[], uInt32 arraySizeInSamps, int32 *sampsPerChanRead, bool32 *reserved);
Reads multiple unscaled, signed 16-bit integer samples from a task that contains one or more analog input channels.
Input | ||
---|---|---|
Name | Type | Description |
taskHandle | TaskHandle | The task to read samples from. |
numSampsPerChan | int32 | The number of samples, per channel, to read. The default value of -1 (DAQmx_Val_Auto) reads all available samples. If readArray does not contain enough space, this function returns as many samples as fit in readArray. NI-DAQmx determines how many samples to read based on whether the task acquires samples continuously or acquires a finite number of samples. If the task acquires samples continuously and you set this parameter to -1, this function reads all the samples currently available in the buffer. If the task acquires a finite number of samples and you set this parameter to -1, the function waits for the task to acquire all requested samples, then reads those samples. If you set the Read All Available Samples property to TRUE, the function reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples. |
timeout | float64 | The amount of time, in seconds, to wait for the function to read the sample(s). To specify an infinite wait, pass -1 (DAQmx_Val_WaitInfinitely). This function returns an error if the timeout elapses. A value of 0 indicates to try once to read the requested samples. If all the requested samples are read, the function is successful. Otherwise, the function returns a timeout error and returns the samples that were actually read. |
fillMode | bool32 | Specifies whether or not the samples are interleaved. |
Value | Description | |
---|---|---|
DAQmx_Val_GroupByChannel | Group by channel (non-interleaved) | |
DAQmx_Val_GroupByScanNumber | Group by scan number (interleaved) |
arraySizeInSamps | uInt32 | The size of the array, in samples, into which samples are read. |
reserved | bool32 * | Reserved for future use. Pass NULL to this parameter. |
Output | ||
Name | Type | Description |
readArray | int16 [] | The array to read samples into, organized according to fillMode. |
sampsPerChanRead | int32 * | The actual number of samples read from each channel. |
Name | Type | Description |
---|---|---|
status | int32 | The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error. |
int32 DAQmxReadBinaryI32 (TaskHandle taskHandle, int32 numSampsPerChan, float64 timeout, bool32 fillMode, int32 readArray[], uInt32 arraySizeInSamps, int32 *sampsPerChanRead, bool32 *reserved);
Reads one or more unscaled 32-bit signed integer samples from a task that contains one or more analog input channels.
Input | ||
---|---|---|
Name | Type | Description |
taskHandle | TaskHandle | The task used in this function. |
numSampsPerChan | int32 | The number of samples, per channel, to read. The default value of -1 (DAQmx_Val_Auto) reads all available samples. If readArray does not contain enough space, this function returns as many samples as fit in readArray. NI-DAQmx determines how many samples to read based on whether the task acquires samples continuously or acquires a finite number of samples. If the task acquires samples continuously and you set this parameter to -1, this function reads all the samples currently available in the buffer. If the task acquires a finite number of samples and you set this parameter to -1, the function waits for the task to acquire all requested samples, then reads those samples. If you set the Read All Available Samples property to TRUE, the function reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples. |
timeout | float64 | The amount of time, in seconds, to wait for the function to read the sample(s). To specify an infinite wait, pass -1 (DAQmx_Val_WaitInfinitely). This function returns an error if the timeout elapses. A value of 0 indicates to try once to read the requested samples. If all the requested samples are read, the function is successful. Otherwise, the function returns a timeout error and returns the samples that were actually read. |
fillMode | bool32 | Specifies whether or not the samples are interleaved. |
Value | Description | |
---|---|---|
DAQmx_Val_GroupByChannel | Group by channel (non-interleaved) | |
DAQmx_Val_GroupByScanNumber | Group by scan number (interleaved) |
arraySizeInSamps | uInt32 | The size of the array, in samples, into which samples are read. |
reserved | bool32 * | Reserved for future use. Pass NULL to this parameter. |
Output | ||
Name | Type | Description |
readArray | int32 [] | The array to read samples into, organized according to fillMode. |
sampsPerChanRead | int32 * | The actual number of samples read from each channel. |
Name | Type | Description |
---|---|---|
status | int32 | The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error. |
int32 DAQmxReadBinaryU16 (TaskHandle taskHandle, int32 numSampsPerChan, float64 timeout, bool32 fillMode, uInt16 readArray[], uInt32 arraySizeInSamps, int32 *sampsPerChanRead, bool32 *reserved);
Reads multiple unscaled, unsigned 16-bit integer samples from a task that contains one or more analog input channels.
Input | ||
---|---|---|
Name | Type | Description |
taskHandle | TaskHandle | The task to read samples from. |
numSampsPerChan | int32 | The number of samples, per channel, to read. The default value of -1 (DAQmx_Val_Auto) reads all available samples. If readArray does not contain enough space, this function returns as many samples as fit in readArray. NI-DAQmx determines how many samples to read based on whether the task acquires samples continuously or acquires a finite number of samples. If the task acquires samples continuously and you set this parameter to -1, this function reads all the samples currently available in the buffer. If the task acquires a finite number of samples and you set this parameter to -1, the function waits for the task to acquire all requested samples, then reads those samples. If you set the Read All Available Samples property to TRUE, the function reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples. |
timeout | float64 | The amount of time, in seconds, to wait for the function to read the sample(s). To specify an infinite wait, pass -1 (DAQmx_Val_WaitInfinitely). This function returns an error if the timeout elapses. A value of 0 indicates to try once to read the requested samples. If all the requested samples are read, the function is successful. Otherwise, the function returns a timeout error and returns the samples that were actually read. |
fillMode | bool32 | Specifies whether or not the samples are interleaved. |
Value | Description | |
---|---|---|
DAQmx_Val_GroupByChannel | Group by channel (non-interleaved) | |
DAQmx_Val_GroupByScanNumber | Group by scan number (interleaved) |
arraySizeInSamps | uInt32 | The size of the array, in samples, into which samples are read. |
reserved | bool32 * | Reserved for future use. Pass NULL to this parameter. |
Output | ||
Name | Type | Description |
readArray | uInt16 [] | The array to read samples into, organized according to fillMode. |
sampsPerChanRead | int32 * | The actual number of samples read from each channel. |
Name | Type | Description |
---|---|---|
status | int32 | The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error. |
int32 DAQmxReadBinaryU32 (TaskHandle taskHandle, int32 numSampsPerChan, float64 timeout, bool32 fillMode, uInt32 readArray[], uInt32 arraySizeInSamps, int32 *sampsPerChanRead, bool32 *reserved);
Reads one or more unscaled 32-bit unsigned integer samples from a task that contains one or more analog input channels.
Input | ||
---|---|---|
Name | Type | Description |
taskHandle | TaskHandle | The task used in this function. |
numSampsPerChan | int32 | The number of samples, per channel, to read. The default value of -1 (DAQmx_Val_Auto) reads all available samples. If readArray does not contain enough space, this function returns as many samples as fit in readArray. NI-DAQmx determines how many samples to read based on whether the task acquires samples continuously or acquires a finite number of samples. If the task acquires samples continuously and you set this parameter to -1, this function reads all the samples currently available in the buffer. If the task acquires a finite number of samples and you set this parameter to -1, the function waits for the task to acquire all requested samples, then reads those samples. If you set the Read All Available Samples property to TRUE, the function reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples. |
timeout | float64 | The amount of time, in seconds, to wait for the function to read the sample(s). To specify an infinite wait, pass -1 (DAQmx_Val_WaitInfinitely). This function returns an error if the timeout elapses. A value of 0 indicates to try once to read the requested samples. If all the requested samples are read, the function is successful. Otherwise, the function returns a timeout error and returns the samples that were actually read. |
fillMode | bool32 | Specifies whether or not the samples are interleaved. |
Value | Description | |
---|---|---|
DAQmx_Val_GroupByChannel | Group by channel (non-interleaved) | |
DAQmx_Val_GroupByScanNumber | Group by scan number (interleaved) |
arraySizeInSamps | uInt32 | The size of the array, in samples, into which samples are read. |
reserved | bool32 * | Reserved for future use. Pass NULL to this parameter. |
Output | ||
Name | Type | Description |
readArray | uInt32 [] | The array to read samples into, organized according to fillMode. |
sampsPerChanRead | int32 * | The actual number of samples read from each channel. |
Name | Type | Description |
---|---|---|
status | int32 | The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error. |
int32 DAQmxReadCounterF64 (TaskHandle taskHandle, int32 numSampsPerChan, float64 timeout, float64 readArray[], uInt32 arraySizeInSamps, int32 *sampsPerChanRead, bool32 *reserved);
Reads multiple floating-point samples from a counter task. Use this function when counter samples are interleaved, and are scaled to a floating-point value, such as for frequency and period measurements.
Input | ||
---|---|---|
Name | Type | Description |
taskHandle | TaskHandle | The task to read samples from. |
numSampsPerChan | int32 | The number of samples, per channel, to read. The default value of -1 (DAQmx_Val_Auto) reads all available samples. If readArray does not contain enough space, this function returns as many samples as fit in readArray. NI-DAQmx determines how many samples to read based on whether the task acquires samples continuously or acquires a finite number of samples. If the task acquires samples continuously and you set this parameter to -1, this function reads all the samples currently available in the buffer. If the task acquires a finite number of samples and you set this parameter to -1, the function waits for the task to acquire all requested samples, then reads those samples. If you set the Read All Available Samples property to TRUE, the function reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples. |
timeout | float64 | The amount of time, in seconds, to wait for the function to read the sample(s). To specify an infinite wait, pass -1 (DAQmx_Val_WaitInfinitely). This function returns an error if the timeout elapses. A value of 0 indicates to try once to read the requested samples. If all the requested samples are read, the function is successful. Otherwise, the function returns a timeout error and returns the samples that were actually read. |
arraySizeInSamps | uInt32 | The size of the array, in samples, into which samples are read. |
reserved | bool32 * | Reserved for future use. Pass NULL to this parameter. |
Output | ||
Name | Type | Description |
readArray | float64 [] | The array to read samples into. |
sampsPerChanRead | int32 * | The actual number of samples read from each channel. |
Name | Type | Description |
---|---|---|
status | int32 | The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error. |
int32 DAQmxReadCounterF64Ex (TaskHandle taskHandle, int32 numSampsPerChan, float64 timeout, bool32 fillMode, float64 readArray[], uInt32 arraySizeInSamps, int32 *sampsPerChanRead, bool32 *reserved);
Reads multiple floating-point samples from a counter task. Use this function when counter samples are scaled to a floating-point value, such as for frequency and period measurements.
Input | ||
---|---|---|
Name | Type | Description |
taskHandle | TaskHandle | The task to read samples from. |
numSampsPerChan | int32 | The number of samples, per channel, to read. The default value of -1 (DAQmx_Val_Auto) reads all available samples. If readArray does not contain enough space, this function returns as many samples as fit in readArray. NI-DAQmx determines how many samples to read based on whether the task acquires samples continuously or acquires a finite number of samples. If the task acquires samples continuously and you set this parameter to -1, this function reads all the samples currently available in the buffer. If the task acquires a finite number of samples and you set this parameter to -1, the function waits for the task to acquire all requested samples, then reads those samples. If you set the Read All Available Samples property to TRUE, the function reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples. |
timeout | float64 | The amount of time, in seconds, to wait for the function to read the sample(s). To specify an infinite wait, pass -1 (DAQmx_Val_WaitInfinitely). This function returns an error if the timeout elapses. A value of 0 indicates to try once to read the requested samples. If all the requested samples are read, the function is successful. Otherwise, the function returns a timeout error and returns the samples that were actually read. |
fillMode | bool32 | Specifies whether or not the samples are interleaved. |
Value | Description | |
---|---|---|
DAQmx_Val_GroupByChannel | Group by channel (non-interleaved) | |
DAQmx_Val_GroupByScanNumber | Group by scan number (interleaved) |
arraySizeInSamps | uInt32 | The size of the array, in samples, into which samples are read. |
reserved | bool32 * | Reserved for future use. Pass NULL to this parameter. |
Output | ||
Name | Type | Description |
readArray | float64 [] | The array to read samples into. |
sampsPerChanRead | int32 * | The actual number of samples read from each channel. |
Name | Type | Description |
---|---|---|
status | int32 | The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error. |
int32 DAQmxReadCounterScalarF64 (TaskHandle taskHandle, float64 timeout, float64 *value, bool32 *reserved);
Reads a single floating-point sample from a counter task. Use this function when the counter sample is scaled to a floating-point value, such as for frequency and period measurement.
Input | ||
---|---|---|
Name | Type | Description |
taskHandle | TaskHandle | The task to read the sample from. |
timeout | float64 | The amount of time, in seconds, to wait for the function to read the sample(s). To specify an infinite wait, pass -1 (DAQmx_Val_WaitInfinitely). This function returns an error if the timeout elapses. A value of 0 indicates to try once to read the requested samples. If all the requested samples are read, the function is successful. Otherwise, the function returns a timeout error and returns the samples that were actually read. |
reserved | bool32 * | Reserved for future use. Pass NULL to this parameter. |
Output | ||
Name | Type | Description |
value | float64 * | The sample read from the task. |
Name | Type | Description |
---|---|---|
status | int32 | The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error. |
int32 DAQmxReadCounterScalarU32 (TaskHandle taskHandle, float64 timeout, uInt32 *value, bool32 *reserved);
Reads a 32-bit integer sample from a counter task. Use this function when the counter sample is returned unscaled, such as for edge counting.
Input | ||
---|---|---|
Name | Type | Description |
taskHandle | TaskHandle | The task to read the sample from. |
timeout | float64 | The amount of time, in seconds, to wait for the function to read the sample(s). To specify an infinite wait, pass -1 (DAQmx_Val_WaitInfinitely). This function returns an error if the timeout elapses. A value of 0 indicates to try once to read the requested samples. If all the requested samples are read, the function is successful. Otherwise, the function returns a timeout error and returns the samples that were actually read. |
reserved | bool32 * | Reserved for future use. Pass NULL to this parameter. |
Output | ||
Name | Type | Description |
value | uInt32 * | The sample read from the task. |
Name | Type | Description |
---|---|---|
status | int32 | The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error. |
int32 DAQmxReadCounterU32 (TaskHandle taskHandle, int32 numSampsPerChan, float64 timeout, uInt32 readArray[], uInt32 arraySizeInSamps, int32 *sampsPerChanRead, bool32 *reserved);
Reads multiple 32-bit integer samples from a counter task. Use this function when counter samples are interleaved, and are returned unscaled, such as for edge counting.
Input | ||
---|---|---|
Name | Type | Description |
taskHandle | TaskHandle | The task to read samples from. |
numSampsPerChan | int32 | The number of samples, per channel, to read. The default value of -1 (DAQmx_Val_Auto) reads all available samples. If readArray does not contain enough space, this function returns as many samples as fit in readArray. NI-DAQmx determines how many samples to read based on whether the task acquires samples continuously or acquires a finite number of samples. If the task acquires samples continuously and you set this parameter to -1, this function reads all the samples currently available in the buffer. If the task acquires a finite number of samples and you set this parameter to -1, the function waits for the task to acquire all requested samples, then reads those samples. If you set the Read All Available Samples property to TRUE, the function reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples. |
timeout | float64 | The amount of time, in seconds, to wait for the function to read the sample(s). To specify an infinite wait, pass -1 (DAQmx_Val_WaitInfinitely). This function returns an error if the timeout elapses. A value of 0 indicates to try once to read the requested samples. If all the requested samples are read, the function is successful. Otherwise, the function returns a timeout error and returns the samples that were actually read. |
arraySizeInSamps | uInt32 | The size of the array, in samples, into which samples are read. |
reserved | bool32 * | Reserved for future use. Pass NULL to this parameter. |
Output | ||
Name | Type | Description |
readArray | uInt32 [] | The array to read samples into. |
sampsPerChanRead | int32 * | The actual number of samples read from each channel. |
Name | Type | Description |
---|---|---|
status | int32 | The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error. |
int32 DAQmxReadCounterU32Ex (TaskHandle taskHandle, int32 numSampsPerChan, float64 timeout, bool32 fillMode, uInt32 readArray[], uInt32 arraySizeInSamps, int32 *sampsPerChanRead, bool32 *reserved);
Reads multiple 32-bit integer samples from a counter task. Use this function when counter samples are returned unscaled, such as for edge counting.
Input | ||
---|---|---|
Name | Type | Description |
taskHandle | TaskHandle | The task to read samples from. |
numSampsPerChan | int32 | The number of samples, per channel, to read. The default value of -1 (DAQmx_Val_Auto) reads all available samples. If readArray does not contain enough space, this function returns as many samples as fit in readArray. NI-DAQmx determines how many samples to read based on whether the task acquires samples continuously or acquires a finite number of samples. If the task acquires samples continuously and you set this parameter to -1, this function reads all the samples currently available in the buffer. If the task acquires a finite number of samples and you set this parameter to -1, the function waits for the task to acquire all requested samples, then reads those samples. If you set the Read All Available Samples property to TRUE, the function reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples. |
timeout | float64 | The amount of time, in seconds, to wait for the function to read the sample(s). To specify an infinite wait, pass -1 (DAQmx_Val_WaitInfinitely). This function returns an error if the timeout elapses. A value of 0 indicates to try once to read the requested samples. If all the requested samples are read, the function is successful. Otherwise, the function returns a timeout error and returns the samples that were actually read. |
fillMode | bool32 | Specifies whether or not the samples are interleaved. |
Value | Description | |
---|---|---|
DAQmx_Val_GroupByChannel | Group by channel (non-interleaved) | |
DAQmx_Val_GroupByScanNumber | Group by scan number (interleaved) |
arraySizeInSamps | uInt32 | The size of the array, in samples, into which samples are read. |
reserved | bool32 * | Reserved for future use. Pass NULL to this parameter. |
Output | ||
Name | Type | Description |
readArray | uInt32 [] | The array to read samples into. |
sampsPerChanRead | int32 * | The actual number of samples read from each channel. |
Name | Type | Description |
---|---|---|
status | int32 | The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error. |
int32 DAQmxReadCtrFreq (TaskHandle taskHandle, int32 numSampsPerChan, float64 timeout, bool32 interleaved, float64 readArrayFrequency[], float64 readArrayDutyCycle[], uInt32 arraySizeInSamps, int32 *sampsPerChanRead, bool32 *reserved);
Reads one or more pairs of pulse frequency and duty cycle from a counter input task.
Input | ||
---|---|---|
Name | Type | Description |
taskHandle | TaskHandle | The task to read samples from. |
numSampsPerChan | int32 | The number of samples, per channel, to read. The default value of -1 (DAQmx_Val_Auto) reads all available samples. If readArray does not contain enough space, this function returns as many samples as fit in readArray. NI-DAQmx determines how many samples to read based on whether the task acquires samples continuously or acquires a finite number of samples. If the task acquires samples continuously and you set this parameter to -1, this function reads all the samples currently available in the buffer. If the task acquires a finite number of samples and you set this parameter to -1, the function waits for the task to acquire all requested samples, then reads those samples. If you set the Read All Available Samples property to TRUE, the function reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples. |
timeout | float64 | The amount of time, in seconds, to wait for the function to read the sample(s). To specify an infinite wait, pass -1 (DAQmx_Val_WaitInfinitely). This function returns an error if the timeout elapses. A value of 0 indicates to try once to read the requested samples. If all the requested samples are read, the function is successful. Otherwise, the function returns a timeout error and returns the samples that were actually read. |
interleaved | bool32 | Specifies whether or not the samples are interleaved. |
Value | Description | |
---|---|---|
DAQmx_Val_GroupByChannel | Group by channel (non-interleaved) | |
DAQmx_Val_GroupByScanNumber | Group by scan number (interleaved) |
arraySizeInSamps | uInt32 | The size of the array, in samples, into which samples are read. |
reserved | bool32 * | Reserved for future use. Pass NULL to this parameter. |
Output | ||
Name | Type | Description |
readArrayFrequency | float64 [] | The array to read frequency samples into. |
readArrayDutyCycle | float64 [] | The array to read duty cycles into. The duty cycle is the pulse high time divided by the pulse period. |
sampsPerChanRead | int32 * | The actual number of samples read from each channel. |
Name | Type | Description |
---|---|---|
status | int32 | The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error. |
int32 DAQmxReadCtrFreqScalar (TaskHandle taskHandle, float64 timeout, float64 *frequency, float64 *dutyCycle, bool32 *reserved);
Reads a single pair of pulse frequency and duty cycle from a counter input task.
Input | ||
---|---|---|
Name | Type | Description |
taskHandle | TaskHandle | The task to read the sample from. |
timeout | float64 | The amount of time, in seconds, to wait for the function to read the sample(s). To specify an infinite wait, pass -1 (DAQmx_Val_WaitInfinitely). This function returns an error if the timeout elapses. A value of 0 indicates to try once to read the requested samples. If all the requested samples are read, the function is successful. Otherwise, the function returns a timeout error and returns the samples that were actually read. |
reserved | bool32 * | Reserved for future use. Pass NULL to this parameter. |
Output | ||
Name | Type | Description |
frequency | float64 * | The pulse frequency. |
dutyCycle | float64 * | The pulse high time divided by the pulse period. |
Name | Type | Description |
---|---|---|
status | int32 | The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error. |
int32 DAQmxReadCtrTicks (TaskHandle taskHandle, int32 numSampsPerChan, float64 timeout, bool32 interleaved, uInt32 readArrayHighTicks[], uInt32 readArrayLowTicks[], uInt32 arraySizeInSamps, int32 *sampsPerChanRead, bool32 *reserved);
Reads one or more pairs of pulse high and low tick counts from a counter input task.
Input | ||
---|---|---|
Name | Type | Description |
taskHandle | TaskHandle | The task to read samples from. |
numSampsPerChan | int32 | The number of samples, per channel, to read. The default value of -1 (DAQmx_Val_Auto) reads all available samples. If readArray does not contain enough space, this function returns as many samples as fit in readArray. NI-DAQmx determines how many samples to read based on whether the task acquires samples continuously or acquires a finite number of samples. If the task acquires samples continuously and you set this parameter to -1, this function reads all the samples currently available in the buffer. If the task acquires a finite number of samples and you set this parameter to -1, the function waits for the task to acquire all requested samples, then reads those samples. If you set the Read All Available Samples property to TRUE, the function reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples. |
timeout | float64 | The amount of time, in seconds, to wait for the function to read the sample(s). To specify an infinite wait, pass -1 (DAQmx_Val_WaitInfinitely). This function returns an error if the timeout elapses. A value of 0 indicates to try once to read the requested samples. If all the requested samples are read, the function is successful. Otherwise, the function returns a timeout error and returns the samples that were actually read. |
interleaved | bool32 | Specifies whether or not the samples are interleaved. |
Value | Description | |
---|---|---|
DAQmx_Val_GroupByChannel | Group by channel (non-interleaved) | |
DAQmx_Val_GroupByScanNumber | Group by scan number (interleaved) |
arraySizeInSamps | uInt32 | The size of the array, in samples, into which samples are read. |
reserved | bool32 * | Reserved for future use. Pass NULL to this parameter. |
Output | ||
Name | Type | Description |
readArrayHighTicks | uInt32 [] | The array to read the number of high ticks into. |
readArrayLowTicks | uInt32 [] | The array to read the number of low ticks into. |
sampsPerChanRead | int32 * | The actual number of samples read from each channel. |
Name | Type | Description |
---|---|---|
status | int32 | The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error. |
int32 DAQmxReadCtrTicksScalar (TaskHandle taskHandle, float64 timeout, uInt32 *highTicks, uInt32 *lowTicks, bool32 *reserved);
Reads one or more pairs of pulse high and low tick counts from a counter input task.
Input | ||
---|---|---|
Name | Type | Description |
taskHandle | TaskHandle | The task to read the sample from. |
timeout | float64 | The amount of time, in seconds, to wait for the function to read the sample(s). To specify an infinite wait, pass -1 (DAQmx_Val_WaitInfinitely). This function returns an error if the timeout elapses. A value of 0 indicates to try once to read the requested samples. If all the requested samples are read, the function is successful. Otherwise, the function returns a timeout error and returns the samples that were actually read. |
reserved | bool32 * | Reserved for future use. Pass NULL to this parameter. |
Output | ||
Name | Type | Description |
highTicks | uInt32 * | The number of ticks the pulse is high. |
lowTicks | uInt32 * | The number of ticks the pulse is low. |
Name | Type | Description |
---|---|---|
status | int32 | The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error. |
int32 DAQmxReadCtrTime (TaskHandle taskHandle, int32 numSampsPerChan, float64 timeout, bool32 interleaved, float64 readArrayHighTime[], float64 readArrayLowTime[], uInt32 arraySizeInSamps, int32 *sampsPerChanRead, bool32 *reserved);
Reads one or more pairs of pulse high and low times from a counter input task.
Input | ||
---|---|---|
Name | Type | Description |
taskHandle | TaskHandle | The task to read samples from. |
numSampsPerChan | int32 | The number of samples, per channel, to read. The default value of -1 (DAQmx_Val_Auto) reads all available samples. If readArray does not contain enough space, this function returns as many samples as fit in readArray. NI-DAQmx determines how many samples to read based on whether the task acquires samples continuously or acquires a finite number of samples. If the task acquires samples continuously and you set this parameter to -1, this function reads all the samples currently available in the buffer. If the task acquires a finite number of samples and you set this parameter to -1, the function waits for the task to acquire all requested samples, then reads those samples. If you set the Read All Available Samples property to TRUE, the function reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples. |
timeout | float64 | The amount of time, in seconds, to wait for the function to read the sample(s). To specify an infinite wait, pass -1 (DAQmx_Val_WaitInfinitely). This function returns an error if the timeout elapses. A value of 0 indicates to try once to read the requested samples. If all the requested samples are read, the function is successful. Otherwise, the function returns a timeout error and returns the samples that were actually read. |
interleaved | bool32 | Specifies whether or not the samples are interleaved. |
Value | Description | |
---|---|---|
DAQmx_Val_GroupByChannel | Group by channel (non-interleaved) | |
DAQmx_Val_GroupByScanNumber | Group by scan number (interleaved) |
arraySizeInSamps | uInt32 | The size of the array, in samples, into which samples are read. |
reserved | bool32 * | Reserved for future use. Pass NULL to this parameter. |
Output | ||
Name | Type | Description |
readArrayHighTime | float64 [] | The array to read the high time pulses into. |
readArrayLowTime | float64 [] | The array to read the low time pulses into. |
sampsPerChanRead | int32 * | The actual number of samples read from each channel. |
Name | Type | Description |
---|---|---|
status | int32 | The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error. |
int32 DAQmxReadCtrTimeScalar (TaskHandle taskHandle, float64 timeout, float64 *highTime, float64 *lowTime, bool32 *reserved);
Reads one or more pairs of pulse high and low times from a counter input task.
Input | ||
---|---|---|
Name | Type | Description |
taskHandle | TaskHandle | The task to read the sample from. |
timeout | float64 | The amount of time, in seconds, to wait for the function to read the sample(s). To specify an infinite wait, pass -1 (DAQmx_Val_WaitInfinitely). This function returns an error if the timeout elapses. A value of 0 indicates to try once to read the requested samples. If all the requested samples are read, the function is successful. Otherwise, the function returns a timeout error and returns the samples that were actually read. |
reserved | bool32 * | Reserved for future use. Pass NULL to this parameter. |
Output | ||
Name | Type | Description |
highTime | float64 * | The amount of time the pulse is high. |
lowTime | float64 * | The amount of time the pulse is low. |
Name | Type | Description |
---|---|---|
status | int32 | The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error. |
int32 DAQmxReadDigitalLines (TaskHandle taskHandle, int32 numSampsPerChan, float64 timeout, bool32 fillMode, uInt8 readArray[], uInt32 arraySizeInBytes, int32 *sampsPerChanRead, int32 *numBytesPerSamp, bool32 *reserved);
Reads multiple samples from each digital line in a task. Each line in a channel gets one byte per sample.
Input | ||
---|---|---|
Name | Type | Description |
taskHandle | TaskHandle | The task to read samples from. |
numSampsPerChan | int32 | The number of samples, per channel, to read. The default value of -1 (DAQmx_Val_Auto) reads all available samples. If readArray does not contain enough space, this function returns as many samples as fit in readArray. NI-DAQmx determines how many samples to read based on whether the task acquires samples continuously or acquires a finite number of samples. If the task acquires samples continuously and you set this parameter to -1, this function reads all the samples currently available in the buffer. If the task acquires a finite number of samples and you set this parameter to -1, the function waits for the task to acquire all requested samples, then reads those samples. If you set the Read All Available Data property to TRUE, the function reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples. |
timeout | float64 | The amount of time, in seconds, to wait for the function to read the sample(s). To specify an infinite wait, pass -1 (DAQmx_Val_WaitInfinitely). This function returns an error if the timeout elapses. A value of 0 indicates to try once to read the requested samples. If all the requested samples are read, the function is successful. Otherwise, the function returns a timeout error and returns the samples that were actually read. |
fillMode | bool32 | Specifies whether or not the samples are interleaved. |
Value | Description | |
---|---|---|
DAQmx_Val_GroupByChannel | Group by channel (non-interleaved) | |
DAQmx_Val_GroupByScanNumber | Group by scan number (interleaved) |
arraySizeInBytes | uInt32 | The size of the array, in samples, into which samples are read. |
reserved | bool32 * | Reserved for future use. Pass NULL to this parameter. |
Output | ||
Name | Type | Description |
readArray | uInt8 [] | The array to read samples into. Each numBytesPerSamp corresponds to one sample per channel, with each element in that grouping corresponding to a line in that channel, up to the number of lines contained in the channel. |
sampsPerChanRead | int32 * | The actual number of samples read from each channel. |
numBytesPerSamp | int32 * | The number of elements in readArray that constitutes a sample per channel. For each sample per channel, numBytesPerSamp is the number of bytes that channel consists of. |
Name | Type | Description |
---|---|---|
status | int32 | The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error. |
int32 DAQmxReadDigitalScalarU32 (TaskHandle taskHandle, float64 timeout, uInt32 *value, bool32 *reserved);
Reads a single 32-bit integer sample from a task that contains a single digital input channel. Use this function for devices with up to 32 lines per port. The sample is returned in unsigned integer format.
Input | ||
---|---|---|
Name | Type | Description |
taskHandle | TaskHandle | The task to read the sample from. |
timeout | float64 | The amount of time, in seconds, to wait for the function to read the sample. The default value is 10.0 seconds. To specify an infinite wait, pass -1 (DAQmx_Val_WaitInfinitely). This function returns an error if the timeout elapses. A value of 0 indicates to try once to read the requested sample. If the entire requested sample is read, the function is successful. Otherwise, the function returns a timeout error and returns what was actually read. |
reserved | bool32 * | Reserved for future use. Pass NULL to this parameter. |
Output | ||
Name | Type | Description |
value | uInt32 * | The sample read from the task. |
Name | Type | Description |
---|---|---|
status | int32 | The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error. |
int32 DAQmxReadDigitalU8 (TaskHandle taskHandle, int32 numSampsPerChan, float64 timeout, bool32 fillMode, uInt8 readArray[], uInt32 arraySizeInSamps, int32 *sampsPerChanRead, bool32 *reserved);
Reads multiple 8-bit integer samples from a task that has one or more multiple digital input channels. Use this function for devices with up to 8 lines per port. The samples are returned in unsigned byte format.
Input | ||
---|---|---|
Name | Type | Description |
taskHandle | TaskHandle | The task to write samples to. |
numSampsPerChan | int32 | The number of samples, per channel, to read. The default value of -1 (DAQmx_Val_Auto) reads all available samples. If readArray does not contain enough space, this function returns as many samples as fit in readArray. NI-DAQmx determines how many samples to read based on whether the task acquires samples continuously or acquires a finite number of samples. If the task acquires samples continuously and you set this parameter to -1, this function reads all the samples currently available in the buffer. If the task acquires a finite number of samples and you set this parameter to -1, the function waits for the task to acquire all requested samples, then reads those samples. If you set the Read All Available Samples property to TRUE, the function reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples. |
timeout | float64 | The amount of time, in seconds, to wait for the function to read the sample(s). To specify an infinite wait, pass -1 (DAQmx_Val_WaitInfinitely). This function returns an error if the timeout elapses. A value of 0 indicates to try once to read the requested samples. If all the requested samples are read, the function is successful. Otherwise, the function returns a timeout error and returns the samples that were actually read. |
fillMode | bool32 | Specifies whether or not the samples are interleaved. |
Value | Description | |
---|---|---|
DAQmx_Val_GroupByChannel | Group by channel (non-interleaved) | |
DAQmx_Val_GroupByScanNumber | Group by scan number (interleaved) |
arraySizeInSamps | uInt32 | The size of the array, in samples, into which samples are read. |
reserved | bool32 * | Reserved for future use. Pass NULL to this parameter. |
Output | ||
Name | Type | Description |
readArray | uInt8 [] | The array to read samples into, organized according to fillMode. |
sampsPerChanRead | int32 * | The actual number of samples read from each channel. |
Name | Type | Description |
---|---|---|
status | int32 | The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error. |
int32 DAQmxReadDigitalU16 (TaskHandle taskHandle, int32 numSampsPerChan, float64 timeout, bool32 fillMode, uInt16 readArray[], uInt32 arraySizeInSamps, int32 *sampsPerChanRead, bool32 *reserved);
Reads multiple 16-bit integer samples from a task that contains one or more digital input channels. Use this function for devices with up to 16 lines per port. The samples are returned in unsigned integer format.
Input | ||
---|---|---|
Name | Type | Description |
taskHandle | TaskHandle | The task to read samples from. |
numSampsPerChan | int32 | The number of samples, per channel, to read. The default value of -1 (DAQmx_Val_Auto) reads all available samples. If readArray does not contain enough space, this function returns as many samples as fit in readArray. NI-DAQmx determines how many samples to read based on whether the task acquires samples continuously or acquires a finite number of samples. If the task acquires samples continuously and you set this parameter to -1, this function reads all the samples currently available in the buffer. If the task acquires a finite number of samples and you set this parameter to -1, the function waits for the task to acquire all requested samples, then reads those samples. If you set the Read All Available Samples property to TRUE, the function reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples. |
timeout | float64 | The amount of time, in seconds, to wait for the function to read the sample(s). To specify an infinite wait, pass -1 (DAQmx_Val_WaitInfinitely). This function returns an error if the timeout elapses. A value of 0 indicates to try once to read the requested samples. If all the requested samples are read, the function is successful. Otherwise, the function returns a timeout error and returns the samples that were actually read. |
fillMode | bool32 | Specifies whether or not the samples are interleaved. |
Value | Description | |
---|---|---|
DAQmx_Val_GroupByChannel | Group by channel (non-interleaved) | |
DAQmx_Val_GroupByScanNumber | Group by scan number (interleaved) |
arraySizeInSamps | uInt32 | The size of the array, in samples, into which samples are read. |
reserved | bool32 * | Reserved for future use. Pass NULL to this parameter. |
Output | ||
Name | Type | Description |
readArray | uInt16 [] | The array to read samples into, organized according to fillMode. |
sampsPerChanRead | int32 * | The actual number of samples read from each channel. |
Name | Type | Description |
---|---|---|
status | int32 | The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error. |
int32 DAQmxReadDigitalU32 (TaskHandle taskHandle, int32 numSampsPerChan, float64 timeout, bool32 fillMode, uInt32 readArray[], uInt32 arraySizeInSamps, int32 *sampsPerChanRead, bool32 *reserved);
Reads multiple 32-bit integer samples from a task that contains one or more digital input channels. Use this function for devices with up to 32 lines per port. The samples are returned in unsigned integer format.
Input | ||
---|---|---|
Name | Type | Description |
taskHandle | TaskHandle | The task to read samples from. |
numSampsPerChan | int32 | The number of samples, per channel, to read. The default value of -1 (DAQmx_Val_Auto) reads all available samples. If readArray does not contain enough space, this function returns as many samples as fit in readArray. NI-DAQmx determines how many samples to read based on whether the task acquires samples continuously or acquires a finite number of samples. If the task acquires samples continuously and you set this parameter to -1, this function reads all the samples currently available in the buffer. If the task acquires a finite number of samples and you set this parameter to -1, the function waits for the task to acquire all requested samples, then reads those samples. If you set the Read All Available Samples property to TRUE, the function reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples. |
timeout | float64 | The amount of time, in seconds, to wait for the function to read the sample(s). To specify an infinite wait, pass -1 (DAQmx_Val_WaitInfinitely). This function returns an error if the timeout elapses. A value of 0 indicates to try once to read the requested samples. If all the requested samples are read, the function is successful. Otherwise, the function returns a timeout error and returns the samples that were actually read. |
fillMode | bool32 | Specifies whether or not the samples are interleaved. |
Value | Description | |
---|---|---|
DAQmx_Val_GroupByChannel | Group by channel (non-interleaved) | |
DAQmx_Val_GroupByScanNumber | Group by scan number (interleaved) |
arraySizeInSamps | uInt32 | The size of the array, in samples, into which samples are read. |
reserved | bool32 * | Reserved for future use. Pass NULL to this parameter. |
Output | ||
Name | Type | Description |
readArray | uInt32 [] | The array to read samples into, organized according to fillMode. |
sampsPerChanRead | int32 * | The actual number of samples read from each channel. |
Name | Type | Description |
---|---|---|
status | int32 | The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error. |
int32 DAQmxGetNthTaskReadChannel (TaskHandle taskHandle, uInt32 index, char buffer[], int32 bufferSize);
Returns the Nth channel of the channels that are configured to be read by the DAQmxSetReadChannelsToRead property. This function takes the taskHandle, index, and bufferSize you specify and returns the Nth channel.
Input | ||
---|---|---|
Name | Type | Description |
taskHandle | TaskHandle | The task used in this function. |
index | uInt32 | The Nth channel to return. The index starts at 1. |
bufferSize | int32 | The size, in bytes, of buffer. If you pass 0, this function returns the number of bytes needed to allocate. |
Output | ||
buffer | char [] | The Nth channel in the index. If you pass NULL, this function returns the number of bytes needed to allocate. |
Name | Type | Description |
---|---|---|
status | int32 | The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A negative value indicates an error. For this function, if you pass NULL for the buffer or 0 for the buffer size, this function returns the number of bytes needed to allocate. |
int32 DAQmxReadRaw (TaskHandle taskHandle, int32 numSampsPerChan, float64 timeout, void *readArray, uInt32 arraySizeInBytes, int32 *sampsRead, int32 *numBytesPerSamp, bool32 *reserved);
Reads raw samples directly from the input lines. There is no scaling, parsing, or separation of the samples. Refer to the specifications for your device to determine the format of the incoming samples.
Input | ||
---|---|---|
Name | Type | Description |
taskHandle | TaskHandle | The task to read samples from. |
numSampsPerChan | int32 | The number of samples, per channel, to read. If you set this parameter to -1 (DAQmx_Val_Auto), NI-DAQmx determines how many samples to read based on whether the task acquires samples continuously or acquires a finite number of samples. If the task acquires samples continuously and you set this parameter to -1, this function reads all the samples currently available in the buffer. If readArray does not contain enough space, this function returns as many samples as fit in readArray. If the task acquires a finite number of samples and you set this parameter to -1, the function waits for the task to acquire all requested samples, then reads those samples. If you set the Read All Available Data property to TRUE, the function reads the samples currently available in the buffer and does not wait for the task to acquire all requested samples. |
timeout | float64 | The amount of time, in seconds, to wait for the function to read the sample(s). To specify an infinite wait, pass -1 (DAQmx_Val_WaitInfinitely). This function returns an error if the timeout elapses. A value of 0 indicates to try once to read the requested samples. If all the requested samples are read, the function is successful. Otherwise, the function returns a timeout error and returns the samples that were actually read. |
arraySizeInBytes | uInt32 | The size of the array into which samples are read. |
reserved | bool32 * | Reserved for future use. Pass NULL to this parameter. |
Output | ||
Name | Type | Description |
readArray | void * | The array into which samples are read. |
sampsRead | int32 * | The actual number of samples read into the array per scan. |
numBytesPerSamp | int32 * | The number of elements in readArray that constitutes a sample. This value takes into account all channels that are read. For example, five channels giving 12 bytes for one entire scan return 12 bytes. The value is not divided along channel lines. |
Name | Type | Description |
---|---|---|
status | int32 | The error code returned by the function in the event of an error or warning. A value of 0 indicates success. A positive value indicates a warning. A negative value indicates an error. |