Fail the measurement when InstrJob timeout

exopy_hqc_legacy/instruments/drivers/visa/cryomagnetics_cs4.py

@@ -32,7 +32,7 @@ class CS4(VisaInstrument):
     #: Typical fluctuations at the output of the instrument.
     #: We use a class variable since we expect this to be identical for all
     #: instruments.
-    OUTPUT_FLUCTUATIONS = 2e-4
+    OUTPUT_FLUCTUATIONS = 5e-4
 
     caching_permissions = {'heater_state': True,
                            'target_field': True,
@@ -116,6 +116,10 @@ def sweep_to_field(self, value, rate=None):
 
         # Start ramping.
         self.target_field = value
+        # Added a pause and then sweep up due to a buggy behavior of the source
+        sleep(1)
+        self.activity = 'Hold'
+        sleep(1)
         self.activity = 'To set point'
 
         # Create job.
@@ -124,11 +128,14 @@ def sweep_to_field(self, value, rate=None):
         job = InstrJob(self.is_target_reached, wait, cancel=self.stop_sweep)
         return job
 
+    @secure_communication()
     def stop_sweep(self):
-        """Stop the field sweep at the current value.
+        """Stop the field sweep at the current value, and turn of the switch heater.
 
         """
         self.activity = 'Hold'
+        driver.heater_state = 'Off'
+        sleep(self.post_switch_wait)
 
     def check_connection(self):
         pass

exopy_hqc_legacy/instruments/drivers/visa/cryomagnetics_g4.py

@@ -76,6 +76,16 @@ def target_field(self, target):
         # can't reuse CS4 class because a semi-colon is needed
         self.write('ULIM {};'.format(target * 10))
 
+    @instrument_property
+    @secure_communication()
+    def field_sweep_rate(self):
+        """Rate at which to ramp the field (T/min).
+
+        """
+        # converted from A/s to T/min
+        rate = float(self.ask('RATE? 0'))
+        return rate * (60 * self.field_current_ratio)
+
     @field_sweep_rate.setter
     @secure_communication()
     def field_sweep_rate(self, rate):

exopy_hqc_legacy/tasks/tasks/instr/apply_mag_field_task.py

@@ -59,41 +59,47 @@ def perform(self, target_value=None):
 
         driver = self.driver
         normal_end = True
-        if (abs(driver.read_persistent_field() - target_value) >
-                driver.output_fluctuations):
+        # Only if driver.heater_state == 'Off' otherwise we wait for 
+        # post_switch_wait no matter what
+        if driver.heater_state == 'Off':
             job = driver.sweep_to_persistent_field()
             if job.wait_for_completion(self.check_for_interruption,
-                                       timeout=60, refresh_time=1):
+                                       timeout=60, refresh_time=3):
                 driver.heater_state = 'On'
                 sleep(self.post_switch_wait)
             else:
                 return False
 
+        if (abs(driver.read_persistent_field() - target_value) > 
+            driver.output_fluctuations):
             # set the magnetic field
             job = driver.sweep_to_field(target_value, self.rate)
             normal_end = job.wait_for_completion(self.check_for_interruption,
                                                  timeout=60,
                                                  refresh_time=10)
+            print('field:', driver.read_persistent_field())
 
         # Always close the switch heater when the ramp was interrupted.
         if not normal_end:
-            job.cancel()
-            driver.heater_state = 'Off'
-            sleep(self.post_switch_wait)
+            job.cancel() # stops the sweep and turn off the switch heater
             self.write_in_database('field', driver.read_persistent_field())
-            return False
+            # if not normal_end, fail the measurement
+            self.root.should_stop.set()
+            raise ValueError(cleandoc('''Field source did not set the field to 
+                                         {}'''.format(target_value)))
 
-        # turn off heater
+        # turn off heater if required
         if self.auto_stop_heater:
             driver.heater_state = 'Off'
             sleep(self.post_switch_wait)
-            job = driver.sweep_to_field(0)
+            # sweep down to zero at the fast sweep rate
+            job = driver.sweep_to_field(0, driver.fast_sweep_rate)
             job.wait_for_completion(self.check_for_interruption,
-                                    timeout=60, refresh_time=1)
+                                    timeout=60, refresh_time=3)
 
         self.write_in_database('field', target_value)
 
-        
+
 class ApplyMagFieldAndDropTask(InstrumentTask):
     """Use a supraconducting magnet to apply a magnetic field. Parallel task.