Update factory coefficient script with SNA5000A example

Software/Scripts/FactoryCoefficients/VNA.py

@@ -33,8 +33,8 @@ def measure():
     
     Measurements are returned as a dictionary:
         Key: S parameter name (e.g. "S11")
-        Value: List of tuples: [frequency, real, imaginary]
+        Value: List of tuples: (frequency, complex S parameter)
     
     :return: Measurements
     """
-    return {}
+    return {}

Software/Scripts/FactoryCoefficients/VNA_Example_LibreVNA/VNA.py

@@ -73,7 +73,7 @@ def measure():
     
     Measurements are returned as a dictionary:
         Key: S parameter name (e.g. "S11")
-        Value: List of tuples: [frequency, complex]
+        Value: List of tuples: (frequency, complex)
     
     :return: Measurements
     """

Software/Scripts/FactoryCoefficients/VNA_Example_SNA5000A/SNA5000A.py

@@ -0,0 +1,119 @@
+import pyvisa
+from enum import Enum
+
+class SNA5000A:
+    # Class to control a siglent SNA5000A vector network analyzer
+
+    def __init__(self, ip="192.168.22.8"):
+        rm = pyvisa.ResourceManager('@py')
+        dev_addr = "TCPIP0::"+ip+"::INSTR"
+        self.inst = rm.open_resource(dev_addr)
+        # check ID
+        id = self.inst.query('*IDN?')
+        if not id.startswith('Siglent Technologies,SNA50'):
+            raise RuntimeError("Wrong device ID received:"+id)
+        self.num_ports = int(self.read(":SERVICE:PORT:COUNT?"))
+        self.excited_ports = self.num_ports
+
+    def set_excited_ports(self, portlist):
+        if len(portlist) == 0:
+            # disabling all ports is not allowed
+            return
+        # enable traces for the specified ports
+        for i in range(1, self.num_ports+1):
+            if i in portlist:
+                # enable the trace
+                self.write(":DISP:WIND:TRAC" + str(i) + " 1")
+                # set the parameter
+                self.write(":CALC:PAR" + str(i) + ":DEF S" + str(i) + str(i))
+            else:
+                # disable the trace
+                self.write(":DISP:WIND:TRAC" + str(i) + " 0")
+        self.excited_ports = len(portlist)
+
+    def set_start_freq(self, freq):
+        self.write(":SENS:FREQ:STAR "+str(freq))
+
+    def set_stop_freq(self, freq):
+        self.write(":SENS:FREQ:STOP "+str(freq))
+
+    def set_IF_bandwidth(self, bandwidth):
+        self.write(":SENS:BWID "+str(bandwidth))
+
+    def set_source_power(self, power):
+        self.write(":SOUR:POW "+str(power))
+
+    def set_points(self, points):
+        self.write(":SENS:SWEEP:POINTS "+str(points))
+
+    def get_trace_data(self, parameters: set):
+        # example call: get_trace_data({"S11", "S21"})
+        xdata = self.read(":CALC:DATA:XAXIS?")
+        rawdata = {}
+        for p in parameters:
+            rawdata[p] = self.read(":SENS:DATA:CORR? "+p)
+        # parse received data
+        freqList = []
+        for val in xdata.split(","):
+            freqList.append(float(val))
+        parsedData = {}
+        for param in rawdata.keys():
+            real = []
+            imag = []
+            doubleValues = rawdata[param].split(",")
+            for i in range(0, len(doubleValues), 2):
+                real.append(float(doubleValues[i]))
+                imag.append(float(doubleValues[i+1]))
+            if len(real) != len(freqList):
+                raise Exception("X/Y data vectors with different lengths, unable to parse data")
+            parsedData[param+"_real"] = real
+            parsedData[param+"_imag"] = imag
+        ret = {}
+        for p in parameters:
+            trace = []
+            for i in range(len(freqList)):
+                freq = freqList[i]
+                real = parsedData[p + "_real"][i]
+                imag = parsedData[p + "_imag"][i]
+                trace.append((freq, complex(real, imag)))
+            ret[p] = trace
+        return ret
+
+    def start_single_sweep(self):
+        self.start_continuous_sweep()
+        self.write(":INIT:IMM")
+
+    def blocking_single_sweep(self, data=set()):
+        self.write(":TRIG:SOUR MAN")
+        self.start_continuous_sweep()
+
+        # Sweep may take a long time, so we need to adjust the timeout of the visa connection
+        sweeptime = float(self.read(":SENS:SWE:TIME?"))
+        timeout = self.excited_ports * sweeptime + 10
+        self.write("TRIG:SING")
+        old_timeout = self.inst.timeout
+        self.inst.timeout = timeout * 1000
+        self.read("*OPC?")
+        self.inst.timeout = old_timeout
+        ret = self.get_trace_data(data)
+        self.write(":TRIG:SOUR INT")
+        return ret
+
+    def start_continuous_sweep(self):
+        self.write(":INIT:CONT 1")
+
+    def stop_sweep(self):
+        self.write(":INIT:CONT 0")
+
+    def sweep_complete(self) -> bool:
+        print(self.read(":SENS:AVER:COUN?"))
+        return True
+
+    def write(self, command):
+        self.inst.write(command)
+
+    def read(self, command):
+        return self.inst.query(command)
+
+    def reset(self):
+        self.inst.write("*RST")

Software/Scripts/FactoryCoefficients/VNA_Example_SNA5000A/VNA.py

@@ -0,0 +1,59 @@
+# A VNA is needed to measure and create the factory coefficients.
+# This file contains the necessary function to extract data from this VNA.
+# Please implement all functions according to the VNA you are using.
+
+from VNA_Example_SNA5000A.SNA5000A import SNA5000A
+import time
+
+vna = None
+
+def checkIfReady() -> bool:
+    """
+    checkIfReady checks if the VNA is connected and ready to be used
+    
+    This function can also be used for initiliazing the VNA. It is called only
+    once at the beginning
+       
+    :return: True if VNA is ready. False otherwise
+    """
+    global vna
+    try:
+        vna = SNA5000A()
+    except:
+        print("Failed to detect VNA")
+        return False
+
+    vna.stop_sweep()
+    vna.set_start_freq(9000)
+    vna.set_stop_freq(8500000000)
+    vna.set_points(801)
+    vna.set_source_power(0)
+    vna.set_IF_bandwidth(10000)
+
+    return True
+
+def getPorts() -> int:
+    """
+    getPorts returns the number of ports the VNA has
+    
+    Creation of factory coefficients if faster if more ports are available.
+    The VNA needs at least 2 ports and at most 4 ports can be utilized.
+    
+    :return: Number of ports on the VNA
+    """
+    return vna.num_ports
+
+def measure():
+    """
+    measure starts a measurement and returns the S parameter data
+    
+    This function should start a new measurement and block until the data
+    is available. No previous measurements must be returned.
+    
+    Measurements are returned as a dictionary:
+        Key: S parameter name (e.g. "S11")
+        Value: List of tuples: (frequency, complex)
+    
+    :return: Measurements
+    """
+    return vna.blocking_single_sweep({"S11","S12","S13","S14","S21","S22","S23","S24","S31","S32","S33","S34","S41","S42","S43","S44"})

Software/Scripts/FactoryCoefficients/createFactoryCoefficients.py

@@ -4,7 +4,8 @@
 import subprocess
 import time
 #import VNA
-from VNA_Example_LibreVNA import VNA
+#from VNA_Example_LibreVNA import VNA
+from VNA_Example_SNA5000A import VNA
 
 def SCPICommand(ser, cmd: str) -> str:
     ser.write((cmd+"\r\n").encode())
@@ -47,10 +48,10 @@ def SCPICommand(ser, cmd: str) -> str:
 print("Found LibreCAL device on port " + port.device)
 
 ser = serial.Serial(port.device, timeout = 1)
-idn = SCPICommand(ser, "*IDN?").split("_")
+idn = SCPICommand(ser, "*IDN?").split(",")
 if idn[0] != "LibreCAL":
-    raise Exception("Invalid *IDN response: "+idn[0])
-print("Detected LibreCAL device has serial number "+idn[1])
+    raise Exception("Invalid *IDN response: "+idn)
+print("Detected LibreCAL device has serial number "+idn[2])
 
 # Enable writing of the factory partition
 SCPICommand(ser, ":FACT:ENABLEWRITE I_AM_SURE")