Warns when not using 16 worker

DSSC.py

@@ -43,9 +43,9 @@ class DSSC:
         self.aspect = self.px_pitch_v/self.px_pitch_h # aspect ratio of the DSSC images
         self.geom = None
         self.mask = None
-        self.max_fraction_memory = 0.8
+        self.max_fraction_memory = 0.4
         self.filter_mask = None
-        self.Nworker = 6
+        self.Nworker = 16
         
         print('DSSC configuration')
         print(f'Topic: {self.topic}')
@@ -321,6 +321,13 @@ class DSSC:
             do_pulse_mean=do_pulse_mean
             ))
             
+        if self.Nworker != 16:
+            with warnings.catch_warnings():
+                warnings.simplefilter("default")
+                warnings.warn(('Nworker other than 16 known to cause issue' +
+                    '(https://in.xfel.eu/gitlab/SCS/ToolBox/merge_requests/76)'),
+                    RuntimeWarning)
+
         timestamp = strftime('%X')
         print(f'start time: {timestamp}')