diff --git a/charon_vna/vna.py b/charon_vna/vna.py
index ad34309..d23022b 100644
--- a/charon_vna/vna.py
+++ b/charon_vna/vna.py
@@ -4,7 +4,8 @@ from pathlib import Path
 from typing import Any, Dict, Tuple
 
 import adi
-import iio
+
+# import iio
 import numpy as np
 import skrf as rf
 import xarray as xr
@@ -229,158 +230,159 @@ class Charon:
 
 
 # %%
-sdr = Charon("ip:192.168.3.1", frequency=np.linspace(1e9, 1.1e9, 11))
+if __name__ == "__main__":
+    pass
 
-# %% initialization
-config = sdr.get_config()
-# print(sdr.ctrl.debug_attrs["adi,rx-rf-port-input-select"].value)
-# print(sdr.ctrl.debug_attrs["adi,tx-rf-port-input-select"].value)
-config
+    # %%
+    sdr = Charon("ip:192.168.3.1", frequency=np.linspace(1e9, 1.1e9, 11))
 
-# %% generate tone
-fc = 1e9
-sdr.set_output(frequency=fc + sdr.FREQUENCY_OFFSET, power=-5)
+    # %% initialization
+    config = sdr.get_config()
+    # print(sdr.ctrl.debug_attrs["adi,rx-rf-port-input-select"].value)
+    # print(sdr.ctrl.debug_attrs["adi,tx-rf-port-input-select"].value)
+    config
 
-# %% capture data
-data = sdr._rx(1, fc=fc)
+    # %% generate tone
+    fc = 1e9
+    sdr.set_output(frequency=fc + sdr.FREQUENCY_OFFSET, power=-5)
 
-# %% Plot in time
-fig, axs = plt.subplots(2, 1, sharex=True, tight_layout=True)
-axs[0].plot(np.real(data).T)
-axs[1].plot(np.imag(data).T)
-axs[0].set_ylabel("Real")
-axs[1].set_ylabel("Imag")
-axs[0].grid(True)
-axs[1].grid(True)
-axs[-1].set_xlabel("Sample")
-axs[-1].set_xlim(0, data.shape[-1])
-fig.show()
+    # %% capture data
+    data = sdr._rx(1, fc=fc)
 
-# %%
-fig, ax = plt.subplots(1, 1, tight_layout=True)
-ax.plot(np.real(data).T, np.imag(data).T)
-ax.grid(True)
-ax.set_aspect("equal")
-ax.set_xlabel("Real")
-ax.set_ylabel("Imag")
-ax.set_xlim(np.array([-1, 1]) * (2 ** (12 - 1) - 1))
-ax.set_ylim(ax.get_xlim())
-fig.show()
+    # %% Plot in time
+    fig, axs = plt.subplots(2, 1, sharex=True, tight_layout=True)
+    axs[0].plot(np.real(data).T)
+    axs[1].plot(np.imag(data).T)
+    axs[0].set_ylabel("Real")
+    axs[1].set_ylabel("Imag")
+    axs[0].grid(True)
+    axs[1].grid(True)
+    axs[-1].set_xlabel("Sample")
+    axs[-1].set_xlim(0, data.shape[-1])
+    fig.show()
 
-# %% Plot in frequency
-f = np.fft.fftfreq(data.shape[-1], 1 / sdr.sdr.sample_rate)
-RX_BITS = 12  # for each of i, q (including sign bit)
-fft_data = np.fft.fft(data, axis=-1, norm="forward") / (2 ** (RX_BITS - 1))
-plt.figure()
-for cc, chan in enumerate(sdr.sdr.rx_enabled_channels):
-    plt.plot(
-        np.fft.fftshift(f),
-        db20(np.fft.fftshift(fft_data[cc])),
-        label=f"Channel {chan}",
+    # %%
+    fig, ax = plt.subplots(1, 1, tight_layout=True)
+    ax.plot(np.real(data).T, np.imag(data).T)
+    ax.grid(True)
+    ax.set_aspect("equal")
+    ax.set_xlabel("Real")
+    ax.set_ylabel("Imag")
+    ax.set_xlim(np.array([-1, 1]) * (2 ** (12 - 1) - 1))
+    ax.set_ylim(ax.get_xlim())
+    fig.show()
+
+    # %% Plot in frequency
+    f = np.fft.fftfreq(data.shape[-1], 1 / sdr.sdr.sample_rate)
+    RX_BITS = 12  # for each of i, q (including sign bit)
+    fft_data = np.fft.fft(data, axis=-1, norm="forward") / (2 ** (RX_BITS - 1))
+    plt.figure()
+    for cc, chan in enumerate(sdr.sdr.rx_enabled_channels):
+        plt.plot(
+            np.fft.fftshift(f),
+            db20(np.fft.fftshift(fft_data[cc])),
+            label=f"Channel {chan}",
+        )
+    plt.legend()
+    plt.ylim(-100, 0)
+    plt.xlabel("Frequency [Hz]")
+    plt.ylabel("Power [dBfs]")
+    plt.title(f"Fc = {sdr.sdr.rx_lo / 1e9} GHz")
+    plt.gca().xaxis.set_major_formatter(EngFormatter())
+    plt.grid(True)
+    plt.show()
+
+    # %%
+    s = sdr.vna_capture(frequency=np.linspace(70e6, 200e6, 101))
+
+    # %% Plot Logmag
+    fig, axs = plt.subplots(2, 1, sharex=True, tight_layout=True)
+
+    axs[0].plot(s.frequency, db20(s), label="Measured")
+    axs[1].plot(s.frequency, np.rad2deg(np.angle((s))), label="Measured")
+
+    axs[0].grid(True)
+    axs[1].grid(True)
+
+    axs[0].set_ylim(-80, 0)
+    axs[1].set_ylim(-200, 200)
+    axs[1].set_xlim(np.min(s.frequency), np.max(s.frequency))
+    axs[1].xaxis.set_major_formatter(EngFormatter(places=1))
+    axs[1].set_xlabel("Frequency")
+
+    axs[0].set_ylabel("|S11| [dB]")
+    axs[1].set_ylabel("∠S11 [deg]")
+
+    reference_sparams = None
+    reference_sparams = dir_ / "RBP-135+_Plus25degC.s2p"
+    if reference_sparams is not None:
+        ref = rf.Network(reference_sparams)
+        rbp135 = net2s(ref)
+
+        axs[0].plot(rbp135.frequency, db20(rbp135.sel(m=1, n=1)), label="Datasheet")
+        axs[1].plot(rbp135.frequency, np.rad2deg(np.angle(rbp135.sel(m=2, n=1))), label="Datasheet")
+        axs[0].legend()
+        axs[1].legend()
+
+    plt.show()
+
+    # %% SOL calibration
+    cal_frequency = np.linspace(70e6, 600e6, 101)
+    ideal_cal_frequency = rf.Frequency(np.min(cal_frequency), np.max(cal_frequency), len(cal_frequency))
+    input("Connect SHORT and press ENTER...")
+    short = sdr.vna_capture(frequency=cal_frequency)
+    input("Connect OPEN and press ENTER...")
+    open = sdr.vna_capture(frequency=cal_frequency)
+    input("Connect LOAD and press ENTER...")
+    load = sdr.vna_capture(frequency=cal_frequency)
+
+    short_net = s2net(short)
+    open_net = s2net(open)
+    load_net = s2net(load)
+
+    cal_ideal = rf.media.DefinedGammaZ0(frequency=ideal_cal_frequency)
+    calibration = rf.calibration.OnePort(
+        [short_net, open_net, load_net],
+        [cal_ideal.short(), cal_ideal.open(), cal_ideal.load(0)],
     )
-plt.legend()
-plt.ylim(-100, 0)
-plt.xlabel("Frequency [Hz]")
-plt.ylabel("Power [dBfs]")
-plt.title(f"Fc = {sdr.sdr.rx_lo / 1e9} GHz")
-plt.gca().xaxis.set_major_formatter(EngFormatter())
-plt.grid(True)
-plt.show()
 
+    # %%
+    s = sdr.vna_capture(frequency=cal_frequency)
 
-# %%
-s = sdr.vna_capture(frequency=np.linspace(70e6, 200e6, 101))
+    # %%
+    s_calibrated = calibration.apply_cal(s2net(s))
 
-# %% Plot Logmag
-fig, axs = plt.subplots(2, 1, sharex=True, tight_layout=True)
+    plt.figure()
+    s_calibrated.plot_s_smith()
+    # ref.plot_s_smith(m=1, n=1)
+    plt.show()
 
-axs[0].plot(s.frequency, db20(s), label="Measured")
-axs[1].plot(s.frequency, np.rad2deg(np.angle((s))), label="Measured")
+    plt.figure()
+    for start, stop in HAM_BANDS:
+        plt.axvspan(start, stop, alpha=0.1, color="k")
+    s_calibrated.plot_s_db()
+    # ref.plot_s_db(m=1, n=1)
+    plt.gca().xaxis.set_major_formatter(EngFormatter())
+    plt.grid(True)
+    plt.xlim(s_calibrated.f[0], s_calibrated.f[-1])
+    plt.show()
 
-axs[0].grid(True)
-axs[1].grid(True)
+    plt.figure()
+    for start, stop in HAM_BANDS:
+        plt.axvspan(start, stop, alpha=0.1, color="k")
+    # s_calibrated.plot_s_vswr()
+    # drop invalid points
+    vswr = copy.deepcopy(s_calibrated.s_vswr[:, 0, 0])
+    vswr[vswr < 1] = np.nan
+    plt.plot(s_calibrated.f, vswr)
+    plt.axhline(1, color="k", linestyle="--")
+    plt.ylabel("VSWR")
+    plt.xlabel("Frequency [Hz]")
+    # ref.plot_s_vswr(m=1, n=1)
+    plt.gca().xaxis.set_major_formatter(EngFormatter())
+    plt.grid(True)
+    plt.ylim(0, 10)
+    plt.xlim(s_calibrated.f[0], s_calibrated.f[-1])
+    plt.show()
 
-axs[0].set_ylim(-80, 0)
-axs[1].set_ylim(-200, 200)
-axs[1].set_xlim(np.min(s.frequency), np.max(s.frequency))
-axs[1].xaxis.set_major_formatter(EngFormatter(places=1))
-axs[1].set_xlabel("Frequency")
-
-axs[0].set_ylabel("|S11| [dB]")
-axs[1].set_ylabel("∠S11 [deg]")
-
-reference_sparams = None
-reference_sparams = dir_ / "RBP-135+_Plus25degC.s2p"
-if reference_sparams is not None:
-    ref = rf.Network(reference_sparams)
-    rbp135 = net2s(ref)
-
-    axs[0].plot(rbp135.frequency, db20(rbp135.sel(m=1, n=1)), label="Datasheet")
-    axs[1].plot(rbp135.frequency, np.rad2deg(np.angle(rbp135.sel(m=2, n=1))), label="Datasheet")
-    axs[0].legend()
-    axs[1].legend()
-
-plt.show()
-
-
-# %% SOL calibration
-cal_frequency = np.linspace(70e6, 600e6, 101)
-ideal_cal_frequency = rf.Frequency(np.min(cal_frequency), np.max(cal_frequency), len(cal_frequency))
-input("Connect SHORT and press ENTER...")
-short = sdr.vna_capture(frequency=cal_frequency)
-input("Connect OPEN and press ENTER...")
-open = sdr.vna_capture(frequency=cal_frequency)
-input("Connect LOAD and press ENTER...")
-load = sdr.vna_capture(frequency=cal_frequency)
-
-short_net = s2net(short)
-open_net = s2net(open)
-load_net = s2net(load)
-
-cal_ideal = rf.media.DefinedGammaZ0(frequency=ideal_cal_frequency)
-calibration = rf.calibration.OnePort(
-    [short_net, open_net, load_net],
-    [cal_ideal.short(), cal_ideal.open(), cal_ideal.load(0)],
-)
-
-
-# %%
-s = sdr.vna_capture(frequency=cal_frequency)
-
-# %%
-s_calibrated = calibration.apply_cal(s2net(s))
-
-plt.figure()
-s_calibrated.plot_s_smith()
-# ref.plot_s_smith(m=1, n=1)
-plt.show()
-
-plt.figure()
-for start, stop in HAM_BANDS:
-    plt.axvspan(start, stop, alpha=0.1, color="k")
-s_calibrated.plot_s_db()
-# ref.plot_s_db(m=1, n=1)
-plt.gca().xaxis.set_major_formatter(EngFormatter())
-plt.grid(True)
-plt.xlim(s_calibrated.f[0], s_calibrated.f[-1])
-plt.show()
-
-plt.figure()
-for start, stop in HAM_BANDS:
-    plt.axvspan(start, stop, alpha=0.1, color="k")
-# s_calibrated.plot_s_vswr()
-# drop invalid points
-vswr = copy.deepcopy(s_calibrated.s_vswr[:, 0, 0])
-vswr[vswr < 1] = np.nan
-plt.plot(s_calibrated.f, vswr)
-plt.axhline(1, color="k", linestyle="--")
-plt.ylabel("VSWR")
-plt.xlabel("Frequency [Hz]")
-# ref.plot_s_vswr(m=1, n=1)
-plt.gca().xaxis.set_major_formatter(EngFormatter())
-plt.grid(True)
-plt.ylim(0, 10)
-plt.xlim(s_calibrated.f[0], s_calibrated.f[-1])
-plt.show()
-
-# %%
+    # %%