def DetectorThunk(conn,dir='C:/PAPA Control/',datacount=1000):
"""An infinite loop for controlling the detector
Keyword arguments:
conn -- a connection stream for communicating with the main process
dir -- the directory in which to save data
datacount -- the number of data points to attempts to read at a time
The function loops through, either sleeping or recording data. It polls
its communication stream and expects a two element tuple. The first
element is an event code and the second is a tuple with the arguments for
the event.
"""
det = Detector() #detector object
running = False
paused = False
runnumber = -1
stream = None
count = 0
while True:
if (not running) and (not conn.poll()):
sleep(0.01)
continue
if conn.poll():
cmd,args=conn.recv()
if cmd==QUIT:
break
elif cmd==START:
if runnumber<=0:
logging.error("Error: Invalid Run #")
continue
if not running:
stream = open(dir+("%04d"%runnumber)+'.pel','wb')
stream.write(det.makeHeader())
det.start()
running = True
count=0
elif cmd==STOP:
if running:
det.stop()
det.clear()
running = False
stream.close()
stream=None
continue
elif cmd==PAUSE:
logging.info("Pausing Detector")
det.stop()#Do NOT clear
running = False
paused = True
elif cmd==RESUME:
if paused:
logging.info("Resuming")
det.start()
running = True
else:
logging.warning("Cannot resume: detector not paused")
elif cmd==RUNNUMBER:
runnumber = args[0]
conn.send("Run # set to %d"%runnumber)
elif cmd==DIRECTORY:
dir = args[0]
elif cmd == N_COUNT:
conn.send(count/2)#Correction Needed for 64 Bit Mode
elif cmd==PARAM:
opt,val=args
det.setParam(opt,val)
elif cmd == QUERY:
conn.send(det.status[args[0]])
#print det.status[args[0]]
else:
logging.warning("Did not recognize command %d"%cmd)
if running:
if stream is None: continue
try:
#Get the number of data points and the data
#note that num is the number of 32 bit data
#points given by the detector, which may or
#may not be the actual number of neutrons,
#depending on if the detector is in 32 or
#64 bit mode
(num,data)=det.read(datacount)
except RuntimeError,(err):
logging.error(err)
break
count += num
#Pull only the actual data from the buffer
if num < datacount:
data=data[:num]
stream.write(data.tostring())
if num < datacount:
stream.flush()
sleep(0.01)
