Update

script/correlation_stream.py

@@ -0,0 +1,162 @@
+"""
+Run as:
+pshell_be -l -test -c -f="users/edwin/correlation_stream.py" -args="PREFIX:'SLAAR-LBSTREAM1'"
+
+or with additional parameters:
+pshell_be -l -test -c -f="users/edwin/correlation_stream.py" -args="PREFIX:'SLAAR-LBSTREAM1',VERBOSE:False,TIME_INTERVAL:2.0"
+"""
+
+if not "PREFIX" in globals():
+    PREFIX = "SLAAR-LBSTREAM1"    
+if not "VERBOSE" in globals():
+    VERBOSE = True
+if not "TIME_INTERVAL" in globals():
+    TIME_INTERVAL = 1.0
+
+EMPTY_VALUE = 1112223330    
+    
+    
+if PREFIX[-1] != ":":
+    PREFIX = PREFIX + ":"
+
+def get_channel_list():
+    ch=[]
+    try:
+        for i in range(20):
+           v= caget(PREFIX + "NAME" + str(i+1))
+           if v.strip()=="":
+                break
+           ch.append(str(v.strip()))
+    except:
+        pass
+    return ch 
+
+def ack_channel_list(channel_list):
+    try:
+        s=""
+        for c in channel_list:
+            s=s+c+"\n"
+        s=s+"\x00"
+        caput(PREFIX + "PACK_LIST",[ord(c) for c in s])    
+    except:
+        pass
+        
+def start_stream(channel_list):
+    try:    
+        st=None    
+        print "Starting stream"
+        if len(channel_list)==0:
+            raise Exception ("No channel defined")
+        st = Stream("pulse_id", dispatcher)
+        for c in channel_list:
+            st.addScalar(c, c, 1, 0)   
+        st.initialize()
+        st.start()
+        st.waitCacheChange(10000)    #Wait stream be running before starting scan
+        if st.take() is None:
+            raise Exception("Error initializing data stream")   
+        ack_channel_list(channel_list)
+        print "Stream started"                    
+    except:
+        stop_stream(st)
+        print sys.exc_info()[1]     
+    return st
+        
+def stop_stream(st):
+    try:        
+        if st:
+            st.close()    
+            st=None
+            print "Stream closed"   
+    except:
+        print sys.exc_info()[1]  
+    finally:
+        ack_channel_list([])
+
+#def on_start_change(val):
+#    fork(start_stream if (val==1) else stop_stream)
+#start = Channel(PREFIX + "START_STOP", type = 'i', monitored = True, callback=on_start_change)
+
+t0=None
+pid=None
+def handle_message(msg, channel_list, buf):
+    global t0, pid
+    if t0 is None:
+        t0  = time.time()
+    now=time.time()
+    num_channels = len(channel_list)
+    size_buffer= 300 #int((len(buf)-100)/(len(channel_list)+1))  
+    buf[0] = msg.pulseId
+    buf[1] = num_channels
+    buf[4] = EMPTY_VALUE
+    if (pid is not None) and ((pid+1) != msg.pulseId):
+        print "Missing pid: ", (pid+1)
+    pid = msg.pulseId
+    #Count
+    if buf[2] < size_buffer:
+        buf[2] = buf[2]+1    
+    #Index    
+    buf[3] = buf[3]+1    
+    if buf[3] == size_buffer:
+         buf[3]=0 
+    index = int(buf[3])*(num_channels+1) + 10    
+    buf[index] = msg.pulseId
+    index = index+1
+    for v in msg.values():
+        buf[index] = EMPTY_VALUE if ((v is None) or (math.isnan(v)))else v                       
+        index = index+1    
+    if now >= (t0 + TIME_INTERVAL):        
+        if VERBOSE:                
+            print to_list(buf[0:5])        
+        t0  = time.time()
+        return True
+    return False
+
+def run():    
+    channel_list = []   
+    st=None 
+    start = Channel(PREFIX + "START_STOP", type = 'i')
+    outp = Channel(PREFIX + "PACK_DATA", type = '[d')
+    buf = to_array([0]*outp.get_size(),'d')
+    buf[2] = 0
+    buf[3]= -1  
+
+    try:        
+        while True:
+            started = (start.get()==1)
+            if started and not st:
+                print "Started"
+                channel_list=get_channel_list()
+                print "Channel list: ", channel_list
+                st = start_stream(channel_list)                         
+                
+                class StreamListener (DeviceListener):                
+                    def onValueChanged(self, device, value, former): 
+                        if handle_message(value, channel_list, buf):
+                            outp.putq(buf)   
+                listener = StreamListener()                
+                st.addListener(listener)
+                
+            elif st and not started:
+                print "Stopped"
+                channel_list=[]
+                stop_stream(st)
+                st = None
+            """
+            if st:
+                st.waitCacheChange(0)
+                if handle_message(st.take(), channel_list, buf):
+                    outp.putq(buf)                    
+                time.sleep(0.001)
+            else:            
+                time.sleep(0.1)
+            """
+            time.sleep(0.1)                    
+    finally:
+        stop_stream(st)
+        if outp: outp.close()
+        if start: start.close()
+
+        
+if __name__ == "__main__":
+    run()