test_stream_counter_readers_writers.py 文件源码

def test_one_sample_pulse_freq(self, x_series_device, seed):
        # Reset the pseudorandom number generator with seed.
        random.seed(seed)

        frequency = random.uniform(1000, 10000)
        duty_cycle = random.uniform(0.2, 0.8)

        # Select random counters from the device.
        counters = random.sample(self._get_device_counters(x_series_device), 2)

        with nidaqmx.Task() as write_task, nidaqmx.Task() as read_task:
            write_task.co_channels.add_co_pulse_chan_freq(
                counters[0], freq=frequency, duty_cycle=duty_cycle)
            write_task.timing.cfg_implicit_timing(
                sample_mode=AcquisitionType.CONTINUOUS)

            read_task.ci_channels.add_ci_pulse_chan_freq(
                counters[1], min_val=1000, max_val=10000)
            read_task.ci_channels.all.ci_pulse_freq_term = (
                '/{0}InternalOutput'.format(counters[0]))

            read_task.start()
            write_task.start()

            reader = CounterReader(read_task.in_stream)

            value_read = reader.read_one_sample_pulse_frequency()
            write_task.stop()

            assert numpy.isclose(value_read.freq, frequency, rtol=0.05)
            assert numpy.isclose(value_read.duty_cycle, duty_cycle, rtol=0.05)