Type: SystemAsyncCallback An optional asynchronous callback that is called when the read is complete. Specify if you do not want a callback when the read is complete.
state
Type: SystemObject A user-provided object that distinguishes this asynchronous read request from other requests. Use this parameter to provide information to the callback. Specify if you do not need to pass any additional information to the callback.
data
Type: SystemBoolean An initialized 1D array of Boolean samples that contains the read data. Each element in the array corresponds to a digital line in the channel.
Return Value
Type: IAsyncResult An IAsyncResult that represents the asynchronous call.
Remarks
If the data buffer is large enough to hold the number of samples requested, this overload attempts to reuse existing memory allocated from the array to acquire data. This results in more efficient memory allocation when performing multiple reads with a continuous digital input task.
To get the read data or any exceptions that occurred during an asynchronous read initiated with
this method, call EndReadSingleSampleMultiLine(IAsyncResult)
with the returned
IAsyncResult.
NI-DAQmx scales the returned data to the units of the measurement, including any custom scaling you apply to the channel. You specify these units with the create channel methods or the
DAQ Assistant.
NI-DAQmx read and write methods time out after the amount of time specified by the
Timeout
property on the task you are reading from or writing to.