RamanScanUI also works with the more stable dataqueue setup.

WITecCOM.py

@@ -208,8 +208,9 @@ class WITecCOM(RamanBase):
             while distance > epsxy:# and (lastpos is None or lastpos!=curpos):
                 curpos = self.getPosition()
                 distance = max(abs(curpos[0]-x), abs(curpos[1]-y))
-                if ((time()-t0>0.5) and max(abs(curpos[0]-initpos[0]), abs(curpos[1]-initpos[1]))<epsxy) or (time()-t0>10.):
-                    print("WARNING: signal ignored:", time()-t0, x, y, curpos, initpos)
+#                if ((time()-t0>0.5) and max(abs(curpos[0]-initpos[0]), abs(curpos[1]-initpos[1]))<epsxy) or (time()-t0>10.):
+                if ((time()-t0>2) and max(abs(curpos[0]-initpos[0]), abs(curpos[1]-initpos[1]))<epsxy) or (time()-t0>10.):
+                    print("WARNING: signal ignored; time: {} s, x, y: {}, {}, curPos: {}, initPos: {}".format((time()-t0), x, y, curpos, initpos))
                     sys.stdout.flush()
                     break
                 sleep(.01)

helperfunctions.py

@@ -24,6 +24,10 @@ import cv2
 import os
 
 def cv2imread_fix(fname, flags=cv2.IMREAD_COLOR):
+        if not os.path.exists(fname):    #This seems to be a source of potential errors. Having these lines here probably aids finding errors for other groups?
+            print('Error, image file not found\Please check if the used save-Image command returns before the image was fully written to disk.')
+            return
+        
         with open(fname, "rb") as fp:
             cont = fp.read()
             img = cv2.imdecode(np.fromstring(cont, dtype=np.uint8), flags)    

ramanscanui.py

@@ -21,10 +21,11 @@ If not, see <https://www.gnu.org/licenses/>.
 
 from PyQt5 import QtCore, QtWidgets
 import numpy as np
-from multiprocessing import Process, Pipe
-from time import sleep, time
-from externalmodules import tsp
+from multiprocessing import Process, Queue, Event
+import queue
+from time import sleep, time, localtime, strftime
 import datetime
+from externalmodules import tsp
 import sys
 
 def reorder(points, N=20):
@@ -45,7 +46,8 @@ def reorder(points, N=20):
     assert np.unique(newind).shape[0]==allind.shape[0]
     return newind
 
-def scan(name, accu, inttime, positions, controlclass, connection):
+def scan(name, accu, inttime, positions, controlclass, dataqueue, stopevent):
+    
     with open("ramanscanlog.txt", "a") as fp:
         sys.stderr = fp
         sys.stdout = fp
@@ -53,22 +55,20 @@ def scan(name, accu, inttime, positions, controlclass, connection):
         ramanctrl = controlclass()
         ramanctrl.connect()
         ramanctrl.initiateTimeSeriesScan(name, len(positions), accu, inttime)
+        print("starting Raman Scan at: " + strftime("%d %b %Y %H:%M:%S", localtime()))
         for i, p in enumerate(positions):
             x, y, z = p
-            print("time:", time())
-            print("position:", x, y, z)
+            
+            print('Measuring particle index {} at location {}, time = {}'.format(i, (x, y, z), strftime("%H:%M:%S", localtime())))
+            sys.stdout.flush()          #remove after testing
             ramanctrl.moveToAbsolutePosition(x, y, z)
             ramanctrl.nextTimeSeriesScan(i)
-            if connection.poll():
-                instruction = connection.recv()
-                if instruction=="stop":
+
+            if stopevent.is_set():
                 ramanctrl.disconnect()
                 return
-            connection.send(i)
+            dataqueue.put(i)
         ramanctrl.disconnect()
-        while not connection.poll():
-            sleep(.1)
-        connection.recv()
 
 class RamanScanUI(QtWidgets.QWidget):
     imageUpdate = QtCore.pyqtSignal(name='imageUpdate')
@@ -148,8 +148,11 @@ class RamanScanUI(QtWidgets.QWidget):
                                 QtWidgets.QMessageBox.No, QtWidgets.QMessageBox.No)
             if reply == QtWidgets.QMessageBox.Yes:
                 self.timer.stop()
-                self.connection.send("stop")
+#                self.connection.send("stop")
+                self.processstopevent.set()
                 self.process.join()
+                self.dataqueue.close()
+                self.dataqueue.join_thread()
                 self.view.unblockUI()
             else:
                 return
@@ -205,9 +208,9 @@ class RamanScanUI(QtWidgets.QWidget):
             self.progressbar.setRange(0, len(scanpoints))
             self.progressbar.setValue(0)
             self.ramanctrl.disconnect()
-            parent_conn, child_conn = Pipe()
-            self.connection = parent_conn
-            self.process = Process(target=scan, args=(self.dataset.name, accu, inttime, scanpoints, self.ramanctrl.__class__, child_conn))
+            self.processstopevent = Event()
+            self.dataqueue = Queue()
+            self.process = Process(target=scan, args=(self.dataset.name, accu, inttime, scanpoints, self.ramanctrl.__class__, self.dataqueue, self.processstopevent))
             self.process.start()
             self.starttime = time()
             self.timer = QtCore.QTimer(self)
@@ -217,8 +220,11 @@ class RamanScanUI(QtWidgets.QWidget):
     
     @QtCore.pyqtSlot()      
     def checkOnScan(self):
-        if self.connection.poll():
-            i = self.connection.recv()
+        try:
+            i = self.dataqueue.get_nowait()
+        except queue.Empty:
+            i = -1
+        if i >= 0:
             self.progressbar.setValue(i+1)
             self.view.highLightRamanIndex(i+1)
             Npoints = len(self.dataset.ramanpoints)
@@ -228,9 +234,9 @@ class RamanScanUI(QtWidgets.QWidget):
                 time2go = ttot - timerunning
                 self.progresstime.setText(self.timelabeltext + str(datetime.timedelta(seconds=round(time2go))))
             if i==Npoints-1:
-                self.connection.send("stop")
                 self.process.join()
-                self.connection.close()
+                self.dataqueue.close()
+                self.dataqueue.join_thread()
                 self.dataset.ramanscandone = True
                 self.view.saveDataSet()
                 self.view.unblockUI()