Data format deals with the type of the data that is read or written.
For input tasks, you can use the additional information for a variety of purposes. For example, you can update graphs to show the timing information and include labels with the channel names. Analysis routines can use the timing information for calculations such as FFTs. Because there is overhead associated with including this additional information, NI-DAQmx allows you to configure the information you want to include.
For output tasks, the timing information is the primary field that is useful. A waveform generated by a library may include timing information that you can use to set up the timing for your output task.
When reading data, the waveform data includes the time when the first sample in the waveform was acquired, t0, and the amount of time that elapsed between each sample, dt. However, there are limitations on these two values.
The dedicated digital format represents digital data similar to logic analyzers and digital simulation tools. Each channel has no limits on the number of lines. In addition, the digital format allows for additional states beyond basic 1s and 0s. The ADE can take advantage of this format by tailoring data and graph displays for the digital data.
For input tasks, you can use the additional information for a variety of purposes. For example, you can update graphs to show the timing information and include labels with the channel names. Because there is overhead associated with including this additional information, NI-DAQmx allows you to configure the information you want to include.
For output tasks, the timing information is the primary field that is useful. A waveform generated by a library may include timing information that you can use to set up the timing for your output task.
When reading data, the waveform data includes the time when the first sample in the waveform was acquired, t0, and the amount of time that elapsed between each sample, dt. However, there are limitations on these two values.
Use the line format when it is convenient for manipulating or displaying the digital data. A typical application is controlling or reading back relay states. For high-speed digital applications, you should generally not use the line format.
The port format is the most efficient in terms of space, as it requires only a bit of memory per line. In addition, the port format is often the most efficient in time as it matches the native format of many devices.
The largest integer supported is 32 bits; therefore, you can read and write digital channels with no more than 32 lines when using the port format.