Generating a simple Hahn echo sequence

Support & Troubleshooting
1

Moku model: Moku Pro
Operating system: Windows
Software version:

Bug or support request description: I am trying to generate a simple Hahn echo sequence

Where 2 pulses are separated by 20microseconds, and the pulses are 2microseconds each.

My cose is

import time
import numpy as np
from moku.instruments import ArbitraryWaveformGenerator
IP = 'xx.xx.xx.xx'

f_mw = 10e6          # carrier frequency [Hz]
vpp = 1.0            # output amplitude [Vpp]
tau = 2          # free evolution time [s]

t_pi_over_2 = 2e-6
t_pi = 2e-6
n_pi_over_2 = max(1, int(f_mw * t_pi_over_2))
n_pi = max(1, int(f_mw * t_pi))
print(n_pi_over_2, n_pi)
awg = ArbitraryWaveformGenerator(IP, force_connect=True)

try:
    # A basic sinusoidal LUT. Moku normalizes LUT data to [-1, 1]
    # and then scales it with amplitude and offset.
    t = np.linspace(0, 1, 100)
    lut = list(np.sin(2*np.pi*t))

    awg.generate_waveform(
        channel=1,
        sample_rate="Auto",
        lut_data=lut,
        frequency=f_mw,
        amplitude=vpp,
        offset=0.0,
        interpolation=True
    )

    # Configure manual-triggered burst output
    awg.enable_output(channel=1, enable=True)
    awg.burst_modulate(
        channel=1,
        trigger_source="Manual",
        trigger_mode="NCycle",
        burst_cycles=n_pi_over_2
    )

    awg.enable_output(channel=1, enable=True)

    # ---- First pulse: pi/2 ----
    awg.manual_trigger()

    # ---- Free evolution ----
    time.sleep(tau)

    # ---- Second pulse: pi ----
    awg.burst_modulate(
        channel=1,
        trigger_source="Manual",
        trigger_mode="NCycle",
        burst_cycles=n_pi
    )
    awg.manual_trigger()

    # ---- Wait for echo time ----
    time.sleep(tau)

    # Read out echo on your detector here
    print("Hahn echo sequence launched.")

finally:
    awg.relinquish_ownership()

the output is not at all what I gave in.
How do I go abou this pulse sequence operation.