Adding Continuous Acquisition Chart Multiple Samples example in NI-DMM

CHANGELOG.md

@@ -800,6 +800,7 @@
 #### [nidmm] Unreleased
 - Added
   - Added the `nidmm_measure_ac_volts.py` example.
+  - Added the `nidmm_cont_acq_chart_multiple_samples.py` example.
   - Added the `nidmm_diode_test.py` example.
   - Added the `nidmm_measure_capacitance.py` example.
   - Added the `nidmm_measure_temperature_rtd.py` example.

docs/nidmm/examples.rst

@@ -3,6 +3,15 @@ Examples
 
 `You can download all nidmm examples for latest version here <https://github.com/ni/nimi-python/releases/download/nidmm-1.5.0/nidmm_examples.zip>`_
 
+nidmm_cont_acq_chart_multiple_samples.py
+----------------------------------------
+
+.. literalinclude:: ../../src/nidmm/examples/nidmm_cont_acq_chart_multiple_samples.py
+   :language: python
+   :linenos:
+   :encoding: utf8
+   :caption: `(nidmm_cont_acq_chart_multiple_samples.py) <https://github.com/ni/nimi-python/blob/master/src/nidmm/examples/nidmm_cont_acq_chart_multiple_samples.py>`_
+
 nidmm_diode_test.py
 -------------------
 

src/nidmm/examples/nidmm_cont_acq_chart_multiple_samples.py

@@ -0,0 +1,61 @@
+#!/usr/bin/python
+
+import argparse
+import nidmm
+import sys
+
+
+# Maximum points a single fetch_multi_point call can return in a continuous acquisition, per the array_size documentation
+MAX_SAMPLES_PER_FETCH = 100000
+
+
+def example(resource_name, options, function, measurement_range, digits, samples_to_fetch, total_samples):
+    print(f'Starting acquisition on resource {resource_name}, for {total_samples} samples.')
+    with nidmm.Session(resource_name=resource_name, options=options) as session:
+        session.configure_measurement_digits(measurement_function=nidmm.Function[function], range=measurement_range, resolution_digits=digits)
+        # A sample_count of 0 configures a continuous acquisition
+        session.configure_multi_point(trigger_count=1, sample_count=0)
+
+        samples_fetched = 0
+        with session.initiate():
+            while samples_fetched < total_samples:
+                # Fetch the whole backlog when it exceeds samples_to_fetch so the buffer does not overflow
+                backlog, _ = session.read_status()
+                samples_in_this_fetch = min(max(samples_to_fetch, backlog), MAX_SAMPLES_PER_FETCH)
+
+                new_samples = session.fetch_multi_point(array_size=samples_in_this_fetch)
+
+                samples_fetched += len(new_samples)
+
+        print(f'Fetched {samples_fetched} measurements')
+
+
+def _main(argsv):
+    parser = argparse.ArgumentParser(description='Acquires measurements and prints a summary using the NI-DMM API.', formatter_class=argparse.ArgumentDefaultsHelpFormatter)
+    parser.add_argument('-n', '--resource-name', default='PXI1Slot2', help='Contains the resource_name of the device to initialize.')
+    parser.add_argument('-f', '--function', default='DC_VOLTS', choices=nidmm.Function.__members__.keys(), type=str.upper, help='Specifies the measurement_function used to acquire the measurement.')
+    parser.add_argument('-r', '--range', default=10, type=float, help='Specifies the range for the function specified in the Measurement_Function parameter.')
+    parser.add_argument('-d', '--digits', default=5.5, type=float, help='Specifies the resolution of the measurement in digits.')
+    parser.add_argument('-s', '--samples-to-fetch', default=4, type=int, help='Specifies the minimum number of measurements to fetch at a time.')
+    parser.add_argument('--total-samples', default=100, type=int, help='Number of measurements to fetch before stopping.')
+    parser.add_argument('-op', '--option-string', default='', type=str, help='Sets the initial value of certain attributes for the session.')
+    args = parser.parse_args(argsv)
+    example(args.resource_name, args.option_string, args.function, args.range, args.digits, args.samples_to_fetch, args.total_samples)
+
+
+def main():
+    _main(sys.argv[1:])
+
+
+def test_example():
+    options = {'simulate': True, 'driver_setup': {'Model': '4082', 'BoardType': 'PXIe', }, }
+    example('PXI1Slot2', options, 'DC_VOLTS', 10, 5.5, 4, 10)
+
+
+def test_main():
+    cmd_line = ['--option-string', 'Simulate=1, DriverSetup=Model:4082; BoardType:PXIe', '--total-samples', '10', ]
+    _main(cmd_line)
+
+
+if __name__ == '__main__':
+    main()