The 4302, 4303, 4304, and 4305 have four timing engines. Each of these timing engines can have its own configuration settings for timing, triggering, and the sample mode (either buffered or hardware timed single point).

Each timing engine can use any AI channel and can control up to eight channels. Each channel can only be used once across all timing engines.

By default, NI-DAQmx automatically selects an available timing engine when reserving the task. Use the DAQmx Timing attribute/property SampTimingEngine to specify the timing engine to use or to determine which timing engine NI-DAQmx automatically selected.

Note You must reserve the task before querying the timing engine unless you explicitly specified the timing engine.

The SampTimingEngine attribute/property is an integer value corresponding to one of the four analog input timing engines available on the device:

SampTimingEngine Value Timing Engine Used
0 te0
1 te1
2 te2
3 te3

If a task has more than eight channels, NI-DAQmx automatically uses multiple timing engines, synchronizing and sharing settings across all timing engines. All timing engines in a single task must share the same settings.

For example, if a task has 10 channels, NI-DAQmx uses two timing engines, which leaves two timing engines for other tasks. If the task has 32 channels, all four timing engines are used.

Each channel's digital filter settings can be configured independently if the channel is used in a task in buffered sample mode. For tasks using HWTSP sample mode, all channels in the task must have the same digital filter configuration.