Add and update AO examples

examples/analog_out/analog_out_helper.py

@@ -0,0 +1,24 @@
+"""Helper functions for the analog_out example."""
+
+import numpy
+import numpy.typing
+
+np = numpy
+
+
+def create_sine_wave(
+    frequency: float, amplitude: float, sampling_rate: float, duration: float
+) -> numpy.typing.NDArray[numpy.double]:
+    """Generate a sine wave."""
+    t = np.arange(0, duration, 1 / sampling_rate)
+
+    return amplitude * np.sin(2 * np.pi * frequency * t)
+
+
+def create_voltage_sample(voltage: float, number_of_samples: int) -> float:
+    """Generate a voltage sample."""
+    data = []
+    for i in range(number_of_samples):
+        data.append(voltage * i / number_of_samples)
+
+    return data

examples/analog_out/cont_gen_voltage_wfm_int_clk.py

@@ -4,29 +4,22 @@
 waveform using an internal sample clock.
 """
 
-import numpy as np
+from analog_out_helper import create_sine_wave
 
 import nidaqmx
 from nidaqmx.constants import AcquisitionType
 
 with nidaqmx.Task() as task:
-    frequency = 10
-    amplitude = 1
-    sampling_rate = 100
-    duration = 1
-
-    # generate the time array
-    t = np.arange(0, duration, 1 / sampling_rate)
-    # Generate the sine wave
-    data = amplitude * np.sin(2 * np.pi * frequency * t)
+    sampling_rate = 1000.0
+    data = create_sine_wave(
+        frequency=10.0, amplitude=1.0, sampling_rate=sampling_rate, duration=1.0
+    )
 
     task.ao_channels.add_ao_voltage_chan("Dev1/ao0")
-    task.timing.cfg_samp_clk_timing(
-        1000, sample_mode=AcquisitionType.CONTINUOUS, samps_per_chan=100
-    )
+    task.timing.cfg_samp_clk_timing(sampling_rate, sample_mode=AcquisitionType.CONTINUOUS)
     task.write(data)
     task.start()
 
-    input("Running task. Press Enter to stop.\n")
+    input("Generating voltage continuously. Press Enter to stop.\n")
 
     task.stop()

examples/analog_out/cont_gen_voltage_wfm_int_clk_every_n_samples_event.py

@@ -6,35 +6,29 @@
 the specified number of samples generation is complete.
 """
 
-import numpy as np
+from analog_out_helper import create_sine_wave
 
 import nidaqmx
 from nidaqmx.constants import AcquisitionType
 
 with nidaqmx.Task() as task:
-    frequency = 10
-    amplitude = 1
-    sampling_rate = 100
-    duration = 1
-
-    # generate the time array
-    t = np.arange(0, duration, 1 / sampling_rate)
-    # Generate the sine wave
-    data = amplitude * np.sin(2 * np.pi * frequency * t)
+    sampling_rate = 1000.0
+    data = create_sine_wave(
+        frequency=10.0, amplitude=1.0, sampling_rate=sampling_rate, duration=1.0
+    )
 
     def callback(task_handle, every_n_samples_event_type, number_of_samples, callback_data):
         """Callback function for written data."""
-        print(f"transferred {number_of_samples} samples event invoked.")
+        print("Transferred N samples")
+
         return 0
 
     task.ao_channels.add_ao_voltage_chan("Dev1/ao0")
-    task.timing.cfg_samp_clk_timing(
-        1000, sample_mode=AcquisitionType.CONTINUOUS, samps_per_chan=100
-    )
-    task.register_every_n_samples_transferred_from_buffer_event(100, callback)
+    task.timing.cfg_samp_clk_timing(sampling_rate, sample_mode=AcquisitionType.CONTINUOUS)
+    task.register_every_n_samples_transferred_from_buffer_event(1000, callback)
     task.write(data)
     task.start()
 
-    input("Running task. Press Enter to stop.\n")
+    input("Generating voltage continuously. Press Enter to stop.\n")
 
     task.stop()

examples/analog_out/cont_gen_voltage_wfm_int_clk_non_regen.py

@@ -1,50 +1,37 @@
 """Example of analog output voltage generation.
 
-This example demonstrates how to output a continuous periodic
-waveform with new data using an internal sample clock while
-the task is running.
+This example demonstrates how to continuously generate an
+analog output waveform by providing new data to the output buffer
+as the task is running.
+
+This example is useful if you want to generate a non-repeating waveform,
+make updates on-the-fly, or generate a frequency that is not an
+even divide-down of your sample clock. In this example,
+the default frequency value is 17.0 to demonstrate that non-regenerative output
+can be used to create a signal with a frequency that is not an even divide-down
+of your sample clock.
 """
 
-import time
-
-import numpy as np
+from analog_out_helper import create_sine_wave
 
 import nidaqmx
 from nidaqmx.constants import AcquisitionType, RegenerationMode
 
 
-def get_sine_wave_data(cycle):
-    """Generate a sine wave data."""
-    frequency = (10, 50)
-    amplitude = (1, 3)
-    sampling_rate = (100, 500)
-    duration = 1
-    selection = cycle % 2
-
-    # generate the time array
-    t = np.arange(0, duration, 1 / sampling_rate[selection])
-    # Generate the sine wave
-    data = amplitude[selection] * np.sin(2 * np.pi * frequency[selection] * t)
-    return data
-
-
 with nidaqmx.Task() as task:
     is_first_run = True
+    sampling_rate = 1000.0
     task.ao_channels.add_ao_voltage_chan("Dev1/ao0")
     task.out_stream.regen_mode = RegenerationMode.DONT_ALLOW_REGENERATION
-    task.timing.cfg_samp_clk_timing(
-        1000, sample_mode=AcquisitionType.CONTINUOUS, samps_per_chan=100
-    )
+    task.timing.cfg_samp_clk_timing(sampling_rate, sample_mode=AcquisitionType.CONTINUOUS)
 
     try:
-        cycle = 1
-        print("Starting task. Press Ctrl+C to stop.")
-        time.sleep(1.0)
-
+        print("Generating voltage continuously. Press Ctrl+C to stop.")
         while True:
-            data = get_sine_wave_data(cycle)
+            data = create_sine_wave(
+                frequency=17.0, amplitude=1.0, sampling_rate=sampling_rate, duration=1.0
+            )
             task.write(data)
-            cycle = cycle + 1
             if is_first_run:
                 is_first_run = False
                 task.start()

examples/analog_out/gen_voltage_wfm_int_clk.py

@@ -5,13 +5,21 @@
 sample clock.
 """
 
+from analog_out_helper import create_voltage_sample
+
 import nidaqmx
 from nidaqmx.constants import AcquisitionType
 
 with nidaqmx.Task() as task:
+    data = []
+    total_samples = 1000
     task.ao_channels.add_ao_voltage_chan("Dev1/ao0")
-    task.timing.cfg_samp_clk_timing(1000, sample_mode=AcquisitionType.FINITE, samps_per_chan=1000)
+    task.timing.cfg_samp_clk_timing(
+        1000.0, sample_mode=AcquisitionType.FINITE, samps_per_chan=total_samples
+    )
 
-    print(f"Generate {task.write([1.1, 2.2, 3.3, 4.4, 5.5])} voltage samples.")
+    data = create_voltage_sample(5.0, total_samples)
+    number_of_samples_written = task.write(data, auto_start=True)
+    print(f"Generate {number_of_samples_written} voltage samples.")
     task.wait_until_done()
     task.stop()

examples/analog_out/gen_voltage_sample.py → examples/analog_out/voltage_update.py

@@ -10,4 +10,3 @@
     task.ao_channels.add_ao_voltage_chan("Dev1/ao0")
 
     print(f"Generate {task.write(1.1)} voltage sample.")
-    task.stop()

tests/acceptance/test_examples.py

@@ -1,8 +1,10 @@
 from __future__ import annotations
 
 import contextlib
+import os
 import re
 import runpy
+import sys
 import warnings
 from pathlib import Path
 
@@ -29,6 +31,8 @@ def test___shipping_example___run___no_errors(example_path: Path, system):
                 )
     if example_path.name == "ci_pulse_freq.py":
         pytest.skip("Example times out if there is no signal.")
+    if example_path.name == "analog_out_helper.py":
+        pytest.skip("Helper for analog output.")
     if re.search(r"\binput\(|\bKeyboardInterrupt\b", example_source):
         pytest.skip("Example waits for keyboard input.")
     if example_path.name == "nidaqmx_warnings.py":
@@ -38,6 +42,12 @@ def test___shipping_example___run___no_errors(example_path: Path, system):
         context_manager = contextlib.nullcontext()
 
     with context_manager:
+        example_dir = os.path.dirname(os.path.abspath(example_path))
+        if example_dir not in sys.path:
+            # Solving ModuleNotFoundError.
+            # Add the example directory to sys.path so that the
+            # helper module can be found.
+            sys.path.append(example_dir)
         runpy.run_path(str(example_path))