fix: handle connection exceptions and show message box

Python_script/VNA.py

@@ -17,6 +17,8 @@ class Vna:
                 Implements the basic operation of the VNA
 
         """
+        self.vna = None
+
         # open connection here
 
         # store the credentials so that methods can access them
@@ -233,7 +235,8 @@ class Vna:
         self.vna.write('*CLS')
     
     def close(self):
-        self.vna.close()
+        if self.vna is not None:
+            self.vna.close()
 
     def __del__(self):
         self.close()

Python_script/almemo2490.py

@@ -62,10 +62,8 @@ class err_hdl(Exception):
                         time.sleep(mdelay)
                         mtries -= 1
                         mdelay += backoff
-                print('maximum number of retries [%d] reached\nfunction: %s\nmodule: %s' \
-                      % (tries, function.__name__,function.__module__))
- 
-                return default_response
+                raise Exception('maximum number of retries [%d] reached\nfunction: %s\nmodule: %s' \
+                      % (tries, function.__name__,function.__module__)) 
                 
             return function_retry # true decorator
             
@@ -111,6 +109,7 @@ class almemo2490:
     
     # constructor of class
     def __init__(self, ip = '192.168.115.44', timeout = 10):
+        self.tn = None
         
         # set class variabel with ip adress given in parameter list of constructor
         self.ip_adress = ip 
@@ -463,7 +462,8 @@ class almemo2490:
     
     # close telenet connection
     def close(self):
-        self.tn.close()
+        if self.tn is not None:
+            self.tn.close()
         
     def __exit__(self):
         self.close()
@@ -477,4 +477,4 @@ class almemo2490:
 
 
     
-    
+    
\ No newline at end of file

Python_script/almemo710.py

@@ -62,10 +62,8 @@ class err_hdl(Exception):
                         time.sleep(mdelay)
                         mtries -= 1
                         mdelay += backoff
-                print('maximum number of retries [%d] reached\nfunction: %s\nmodule: %s' \
-                      % (tries, function.__name__,function.__module__))
- 
-                return default_response
+                raise Exception('maximum number of retries [%d] reached\nfunction: %s\nmodule: %s' \
+                      % (tries, function.__name__,function.__module__)) 
                 
             return function_retry # true decorator
             
@@ -112,6 +110,7 @@ class almemo710:
     
     # constructor of class
     def __init__(self, ip = '192.168.115.94', timeout = 10):
+        self.tn = None
         
         # set class variabel with ip adress given in parameter list of constructor
         self.ip_adress = ip 
@@ -460,7 +459,8 @@ class almemo710:
         
     # close telenet connection
     def close(self):
-        self.tn.close()
+        if self.tn is not None:
+            self.tn.close()
     
     def __exit__(self):
         self.close()
@@ -476,4 +476,4 @@ class almemo710:
 
 
     
-    
+    
\ No newline at end of file

Python_script/climate-lab-gui.py

@@ -91,8 +91,9 @@ class TestStandMainWindow(QMainWindow):
             self.setEnabled(True)
             return
 
-        meas = prototype.Measurements(config_data, output_basename,False, ext_sensor_channels)
+        meas = None
         try:
+            meas = prototype.Measurements(config_data, output_basename,False, ext_sensor_channels)
             if self.tempSweepButton.isChecked():
                 temperatures = meas.perform_sweep(self.startParameter.value(), self.stopParameter.value(),
                                                   self.stepParameter.value(), self.fixedParameter.value(),
@@ -138,9 +139,14 @@ class TestStandMainWindow(QMainWindow):
                 except FileNotFoundError as e:
                     QtWidgets.QMessageBox.warning(self, 'Warning', str(e))
 
+        except Exception as e:
+            print('ERROR: Exception during measurement: '+str(e))
+            QtWidgets.QMessageBox.critical(self, 'Error', str(e))
+
         finally:
-            meas.chamber.close()
-            meas.ext_sensors.close()
+            if meas is not None:
+                meas.chamber.close()
+                meas.ext_sensors.close()
             
             self.setEnabled(True)
 

Python_script/prototype.py

@@ -51,6 +51,13 @@ class MeasurementData:
 
 class Measurements:
     def __init__(self, config_data, output_basename, standby, ext_sensor_channels):
+        #create all members that need to be closed to be able to write a close function
+        #which does not throw because of unknown variables
+        self.chamber = None
+        self.instr_chamber = None
+        self.dut = None
+        self.ext_sensors = None
+        
         self.max_delta_temp = config_data['delta_temp']
         self.max_delta_hum = config_data['delta_hum']
 
@@ -375,7 +382,19 @@ class Measurements:
         return (target_hum-self.max_delta_hum <= float(readback_hum)) and \
                (float(readback_hum) <= target_hum+self.max_delta_hum)
 
-
+    #convecinece function to close everything in case an exception escapes
+    #FIXME: needs to be called by code using the Measurements object
+    def close(self):
+        if self.chamber is not None:
+            self.chamber.close()
+        if self.instr_chamber is not None:
+            self.inst_chamber.close()
+        if self.dut is not None:
+            self.dut.close()
+        if self.ext_sensors is not None:
+            self.ext_sensors.close()
+        
+    
 def plot_output(output_basename, measurements_appendices, show_blocking_plot, config_data, ext_sens_data,
                 measurement_set_names, reference_signal_names, title=''):
     
@@ -466,8 +485,9 @@ if __name__ == '__main__':
     with open('ext_sensor_channels.json', 'r') as f2:
         ext_sensor_channels = json.load(f2)
 
-    mes = Measurements(config_data, output_basename, args.standby, ext_sensor_channels)
+    mes = None
     try:
+        mes = Measurements(config_data, output_basename, args.standby, ext_sensor_channels)
         if args.file:
             n_measurements = mes.perform_measurements(args.file)
             plot_output(output_basename, range(n_measurements), args.plot, config_data, ext_sensor_channels,
@@ -489,7 +509,7 @@ if __name__ == '__main__':
                         output_basename + ': Temperature sweep ' +
                         str(temperatures[0]) + ' degC to ' + str(temperatures[-1]) + ' degC')
     finally:
-        mes.chamber.close()
-        mes.ext_sensors.close()
+        if mes is not None:
+            mes.close()
 
     # mes.plot_output(output)