Initial commit

.gitignore

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+.virtenv
+__pycache__

ssa3032tmc.py

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+#!/bin/env python3
+
+import usbtmc
+
+READ_CHUNK_SIZE = 256
+
+class SSA3023(object):
+    def __init__(self):
+        self.instr =  usbtmc.Instrument(0xf4ec, 0x1300)
+        #TODO: Check if ID number matches
+        #id_str = self.instr.ask("*IDN?")
+
+        self.instr.write(":FORMat:TRACe:DATA ASCii")
+
+    def get_start_freq(self):
+        return float(self.instr.ask(":SENSe:FREQuency:STARt?"))
+
+    def get_stop_freq(self):
+        return float(self.instr.ask(":SENSe:FREQuency:STOP?"))
+
+    def get_ref_level(self):
+        return float(self.instr.ask(":DISPlay:WINDow:TRACe:Y:SCALe:RLEVel?"))
+
+    def get_norm_ref_level(self):
+        return float(self.instr.ask(":DISPlay:WINDow:TRACe:Y:NRLevel?"))
+
+    def is_displayed_trace(self, num):
+        if num < 1 or num > 4:
+            raise ValueError("%d is not a valid trace %d", num)
+        res = self.instr.ask(":TRACe%d:MODE?" % num)
+
+        return res != "BLANk"
+
+    def get_trace(self, num):
+        if num < 1 or num > 4:
+            raise ValueError("%d is not a valid trace %d", num)
+
+        self.instr.write(":TRACe:DATA? %d" % num)
+        data = b''
+        while not data.endswith(b'\n'):
+            chunk = self.instr.read_raw(num=READ_CHUNK_SIZE)
+            data = data + chunk
+
+        data = data.decode("utf-8").split(',')[:-1]
+        data = map(lambda x: float(x), data)
+
+        return list(data)

trace-grab.py

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+#!/usr/bin/env python3
+
+import usbtmc
+
+import numpy as np
+import matplotlib.pyplot as plt
+from matplotlib.ticker import EngFormatter
+
+from ssa3032tmc import SSA3023
+
+def main():
+
+    ssa = SSA3023()
+
+    start_freq = ssa.get_start_freq()
+    stop_freq = ssa.get_stop_freq()
+    norm_level = ssa.get_norm_ref_level()
+
+    fig = plt.figure()
+    ax = fig.add_subplot(111)
+    formatterHz = EngFormatter(unit='Hz')
+    ax.xaxis.set_major_formatter(formatterHz)
+
+    ax.set_xlim(start_freq, stop_freq)
+    ax.grid()
+
+    min_level = norm_level
+
+    for i in [1,2,3,4]:
+        if ssa.is_displayed_trace(i):
+            samples = np.array(ssa.get_trace(i))
+            min_level = min(np.min(samples), min_level)
+            freqs = np.linspace(start_freq, stop_freq, len(samples))
+            ax.plot(freqs, samples, label="Trace %d" % i)
+
+    ax.set_ylim(min_level - 10, norm_level)
+    ax.legend()
+    plt.show()
+
+
+
+
+    plt.show()
+
+
+if __name__ == '__main__':
+    main()

trace-live.py

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+#!/usr/bin/env python3
+
+import usbtmc
+
+import numpy as np
+import matplotlib.pyplot as plt
+from matplotlib.ticker import EngFormatter
+
+from ssa3032tmc import SSA3023
+
+def main():
+
+    ssa = SSA3023()
+
+    fig = plt.figure()
+    ax = fig.add_subplot(111)
+
+
+    while True:
+        ax.clear()
+        start_freq = ssa.get_start_freq()
+        stop_freq = ssa.get_stop_freq()
+        norm_level = ssa.get_norm_ref_level()
+
+        formatterHz = EngFormatter(unit='Hz')
+        ax.xaxis.set_major_formatter(formatterHz)
+            
+        ax.set_xlim(start_freq, stop_freq)
+        ax.grid()
+
+        min_level = norm_level
+
+        for i in [1,2,3,4]:
+            if ssa.is_displayed_trace(i):
+                samples = np.array(ssa.get_trace(i))
+                min_level = min(np.min(samples), min_level)
+                freqs = np.linspace(start_freq, stop_freq, len(samples))
+                ax.plot(freqs, samples, label="Trace %d" % i)
+
+        ax.set_ylim(min_level - 10, norm_level)
+        ax.legend()
+
+        plt.pause(0.250)
+
+
+if __name__ == '__main__':
+    main()