handover of self.value as float + software averaging function impleme…

…nted

Bugfix: self.value is now handed over explizitly as float. This fix was necessary for the "Test Field" function to work properly as contrary tp values out of the sweep list, the text field hands over its content in string format.

Added Feature: the SMU class offers the option of averaging values. The E36xxA instruments offer a read-back resolution (model dependend) down to 1mA, often saving the use of an additional DMM. By sampling multiple measurement values, the readout can be stabilized conderable, making these PSUs suitable for recording DC curves on their own for many simple parts. This is now implemented, offering the option of averaging with a simple click of an options box within the SMU class GUI.

src/SMU-Keysight_E3632A/main.py

@@ -75,6 +75,7 @@ def set_GUIparameter(self):
             "RouteOut": ["Front"],
             "Compliance": 1,
             "RangeVoltage": ["15 V / 7 A", "30 V / 4 A"],
+            "Average": 1,
         }
 
         return gui_parameter
@@ -90,7 +91,12 @@ def get_GUIparameter(self, parameter={}):
         # self.channel = int(parameter["Channel"])
 
         self.voltage_range = parameter["RangeVoltage"]
-
+        self.average = int(parameter["Average"])
+
+        if self.average == 0:
+            msg = ("Average of 0 not possible. Disable average by setting it to 1.")
+            raise Exception(msg)
+
     def initialize(self):
         self.port.write("*IDN?")
         identifier = self.port.read()
@@ -148,7 +154,7 @@ def poweroff(self):
         self.port.write("OUTP:STAT OFF")
 
     def apply(self):
-        if self.value > 15.45 and float(self.currentlimit) > 4.12:
+        if float(self.value) > 15.45 and float(self.currentlimit) > 4.12:
             msg = ("The next requested step would exceed 15.45 V with current limit higher than 4.12 A.\n\n"
                    "Please either stop at 15.45 V max or lower current compliance limit to 4.12 A max.")
             raise Exception(msg)
@@ -159,10 +165,16 @@ def apply(self):
             time.sleep(0.1)
 
     def measure(self):
-        self.port.write("MEAS:VOLT?")
-        self.v = float(self.port.read())
-        self.port.write("MEAS:CURR?")
-        self.i = float(self.port.read())
+        self.v = 0
+        self.i = 0
+        for n in range(self.average): 
+            self.port.write("MEAS:VOLT?")
+            self.v = self.v + float(self.port.read())
+            self.port.write("MEAS:CURR?")
+            self.i = self.i + float(self.port.read())
+
+        self.v = self.v / self.average
+        self.i = self.i / self.average
 
     def call(self):
         return [self.v, self.i]