diff --git a/LJ.conf b/LJ.conf
index 598df2f..af428a1 100644
--- a/LJ.conf
+++ b/LJ.conf
@@ -2,7 +2,7 @@
 lasernumber = 1
 debug = 0
 rediserverip = 0.0.0.0
-wwwip = 192.168.1.14
+wwwip = 127.0.0.1
 nozoscip = 127.0.0.1
 oscserverip = 127.0.0.1
 autostart = artnet
@@ -10,22 +10,23 @@ wstype = ws
 wsport = 9001
 
 [laser0]
+dac_family = extern_cmd
+cmd = ./tracers/lj_rust/lj_rust ./tracers/lj_rust/settings.toml
 color = -1
-type = LOCAL
-dac_family = etherdream
-ip = 127.0.0.1
-kpps = 10000
-centerx = 7.0
-centery = 61.0
-zoomx = 312.0
-zoomy = 1039.0
-sizex = 32000.0
-sizey = 32000.0
-finangle = -0.02263757042605427
+type = DS1000
+ip = 192.168.1.35
+kpps = 25000
 intens = 255.0
 red = 100
 green = 100
 blue = 100
+centerx = -21504.0
+centery = 21504.0
+zoomx = 8.90625
+zoomy = 20.671875
+sizex = 32000.0
+sizey = 32000.0
+finangle = 0.0
 swapx = -1
 swapy = -1
 lsteps = [ (1.0, 8),(0.25, 3), (0.75, 3), (1.0, 10)]
diff --git a/configure.py b/configure.py
old mode 100644
new mode 100755
diff --git a/libs3/commands.py b/libs3/commands.py
index 3437fd3..7a1b924 100644
--- a/libs3/commands.py
+++ b/libs3/commands.py
@@ -14,13 +14,13 @@ Commands reference. Use commands from websocket (webUI) or OSC, do not set value
 DAChecks()
 UpdateAllwww()
 
-/forwardui "htmlid args" 
+/forwardui "htmlid args"
 
 /scale/X/lasernumber value  (0-200)
 /scale/Y/lasernumber value  (0-200)
 
 /client or note on < 8 : change client displayed for Current Laser
-23 < /noteon < 32 : PL number displayed on webUI simulator    
+23 < /noteon < 32 : PL number displayed on webUI simulator
 
 /grid/lasernumber value (0 or 1) : switch given laser with grid display on or off
 
@@ -34,15 +34,15 @@ Live change of kpps is not implemented in newdac.py. Change will effect next sta
 
 /angle/lasernumber value : angle correction for given laser by value (0-360)
 
-/intens/lasernumber value : increase/decrease intensity for given laser by value 
+/intens/lasernumber value : increase/decrease intensity for given laser by value
 
 /resampler/lasernumber lsteps : change resampling strategy (glitch art) for given laser
 lsteps is a string like "[ (1.0, 8),(0.25, 3), (0.75, 3), (1.0, 10)]"
- 
-/mouse/lasernumber value (0 or 1) 
 
-/swap/X/lasernumber value (0 or 1) 
-/swap/Y/lasernumber value (0 or 1) 
+/mouse/lasernumber value (0 or 1)
+
+/swap/X/lasernumber value (0 or 1)
+/swap/Y/lasernumber value (0 or 1)
 
 /loffset/X/lasernumber value : change X offset of given laser to value (-32000/32000)
 /loffset/Y/lasernumber value : change Y offset of given laser to value (-32000/32000)
@@ -50,10 +50,10 @@ lsteps is a string like "[ (1.0, 8),(0.25, 3), (0.75, 3), (1.0, 10)]"
 /order value : instruct tracer what to do.
 
 0 : display user pointlist with current client key. See below for client key.
-1 : pull in redis a new correction matrix (EDH) 
-2 : display black 
+1 : pull in redis a new correction matrix (EDH)
+2 : display black
 3 : display grid
-4 : resampler 
+4 : resampler
 5 : pull in redis a new client key
 6 : Max Intensity Change     = reread redis key /intensity
 7 : kpps change              = reread redis key /kpps
@@ -74,12 +74,12 @@ lsteps is a string like "[ (1.0, 8),(0.25, 3), (0.75, 3), (1.0, 10)]"
 
 Example : client 0 send 2 point lists one for laser 0 and one for laser 1 by sending in redis :
 /pl/0/0 and /pl/0/1
-The "client key" when client 0 is selected to be displayed by lasers is "/pl/0/". 
-Each tracer pull its pointlist by using the current client key "/pl/0/" 
+The "client key" when client 0 is selected to be displayed by lasers is "/pl/0/".
+Each tracer pull its pointlist by using the current client key "/pl/0/"
 and add its laser number at startup : /pl0/0 ant /pl/0/1
 
-"Client" is a concept. Imagine in a demoparty there is 4 lasers. 
-John and Paul want to draw on all lasers. 
+"Client" is a concept. Imagine in a demoparty there is 4 lasers.
+John and Paul want to draw on all lasers.
 Let's give John client 0, he will send points to /pl/0/0, /pl/0/1, /pl/0/2 and /pl/0/3.
 
 Paul is client 1, so he will use /pl/1/0, /pl/1/1, /pl/1/2 and /pl/1/3.
@@ -87,7 +87,7 @@ Paul is client 1, so he will use /pl/1/0, /pl/1/1, /pl/1/2 and /pl/1/3.
 Both can send their pointlists to redis server.
 When John get the lasers switch to client 0, when it's Paul turn switch to client 1.
 
-But say Bob and Lisa needs only 2 lasers each. Give them client 2. 
+But say Bob and Lisa needs only 2 lasers each. Give them client 2.
 Bob could use /pl/2/0 and /pl/2/1 and Lisa could use /pl/2/2 and /pl/2/3.
 
 
@@ -96,17 +96,18 @@ Bob could use /pl/2/0 and /pl/2/1 and Lisa could use /pl/2/2 and /pl/2/3.
 import types, time, socket, math
 from libs3 import gstt
 import redis
-from libs3 import OSC3 
+from libs3 import OSC3
 from libs3 import settings, plugins, homographyp,log
 
 
 r = redis.StrictRedis(host=gstt.RediServerIP , port=6379, db=0)
 #r = redis.StrictRedis(host=gstt.RediServerIP , port=6379, db=0, password='-+F816Y+-')
 
+workers = []
 
 GenericCommands = ["start", "align", "ljclient", "scene", "addest", "deldest", "dest", "clientnumber", "vcvrack", "fft", "mitraille", "faceosc", "midigen", "viewgen", "audiogen", "noteon", "cc", "ljpong", "ljwars", "mouse", "emergency", "simu", "status", "run", "nozoid", "planet", "live", "words", "ai", "bank0", "pose", "lj", "cycl", "glyph", "pong", "maxw", "custom1", "square", "regen", "trckr", "aurora", "line1", "ForwardUI", "settings", "debug", "pl", "plugins"]
 
-    
+
 def UserOn(laser):
 
     print("User for laser ", laser)
@@ -130,7 +131,7 @@ def BlackOn(laser):
     plugins.sendWSall("/status Black on laser " + str(laser))
     sendOSCUI('/black/'+str(laser),1)
     r.set('/order/'+str(laser), 2)
-    
+
 
 def GridOn(laser):
 
@@ -164,7 +165,7 @@ def LasClientChange(clientnumber):
             r.set('/order/'+str(laserid), 5)
     else:
         print("ERROR :  Maximum number of scenes is set to ", gstt.MaxScenes)
-        
+
 
 def SceneChange(newscene):
 
@@ -190,7 +191,7 @@ def NoteOn(note):
     # Change laser client
     if note < 8:
         LasClientChange(note)
-    
+
     # Change PL displayed on webui
     if  note > 23 and note < 32:
         if note - 24 > gstt.LaserNumber -1:
@@ -198,8 +199,8 @@ def NoteOn(note):
             plugins.sendWSall("/redstatus No Laser"+str(note-24))
             plugins.sendWSall("/laser "+str(gstt.LaserNumber-1))
             plugins.SendAll("/laser "+str(gstt.LaserNumber-1))
-            
-        else: 
+
+        else:
             gstt.Laser = note -24
             print("Current Laser switched to", gstt.Laser)
             plugins.sendWSall("/status Laser " + str(gstt.Laser))
@@ -209,7 +210,7 @@ def NoteOn(note):
             plugins.sendWSall("/loffset/Y/" + str(gstt.Laser) +" " +str(gstt.centerY[gstt.Laser]))
             plugins.sendWSall("/scale/X/" + str(gstt.Laser) +" " + str(gstt.zoomX[gstt.Laser]))
             plugins.sendWSall("/scale/Y/" + str(gstt.Laser) +" " +str(gstt.zoomY[gstt.Laser]))
-            
+
 
 def Scim(path, tags, args, source):
 
@@ -223,7 +224,7 @@ def Scim(path, tags, args, source):
             plugins.sendWSall("/redstatus No Laser"+str(note-24))
             plugins.sendWSall("/laser "+str(gstt.LaserNumber-1))
 
-        else: 
+        else:
             gstt.Laser = laser -24
             plugins.sendWSall("/status Laser " + str(gstt.Laser))
             print("Current Laser switched to", gstt.Laser)
@@ -232,15 +233,15 @@ def Scim(path, tags, args, source):
 def Line1(path, tags, args, source):
 
     line1 = args[0]
-    print("OSC /line1", line1)   
+    print("OSC /line1", line1)
     plugins.sendWSall("/line1 " +"Fx "+line1)
 
 
-# forward 
+# forward
 def ForwardUI(path, tags, args, source):
 
     line = args[0]
-    print("OSC /forwardui to WebUI :", line)   
+    print("OSC /forwardui to WebUI :", line)
     print('from path', path, 'args', args)
     plugins.sendWSall(line)
     sendOSCUI('/status',line)
@@ -264,12 +265,12 @@ def handler(oscpath, args):
 
 
     # 2 incoming cases : generic or specific for a given lasernumber :
-    
+
     #
     # Generic : Commands without a laser number
     #
 
-    if oscpath[1] in GenericCommands:   
+    if oscpath[1] in GenericCommands:
 
         if gstt.debug > 0:
             print("GenericCommand :", oscpath[1], "with args", args)
@@ -286,7 +287,7 @@ def handler(oscpath, args):
             r.set("/"+oscpath[1]+"/"+oscpath[2]+"/"+oscpath[3], args[0])
 
 
-        if oscpath[0] == "pl" :    
+        if oscpath[0] == "pl" :
             r.set(oscpath, args[0])
 
 
@@ -314,7 +315,7 @@ def handler(oscpath, args):
             if gstt.debug >0:
                 print(("/" + args[0] + "/start 1"))
                 print(("/status got pong from "+ args[0] +"."))
-            
+
             plugins.sendWSall("/" + args[0] + "/start 1")
             #plugins.sendWSall("/status got pong from "+ args[0] +".")
 
@@ -333,25 +334,25 @@ def handler(oscpath, args):
 
         elif oscpath[1] == "mouse":
             Mouse(int(args[0]),int(args[1]),int(args[2]),int(args[3]))
-        
 
-        # /emergency value (0 or 1) 
+
+        # /emergency value (0 or 1)
         elif oscpath[1] == "emergency":
-        
+
             if args[0] == "1":
-                
+
                 for laser in range(gstt.lasernumber):
                     print("Black requested for laser ", laser)
                     BlackOn(laser)
                 print("EMERGENCY MODE")
-                plugins.sendWSall("/status EMERGENCY MODE")  
+                plugins.sendWSall("/status EMERGENCY MODE")
 
             else:
                 for laser in range(gstt.lasernumber):
                     print("Back to normal for laser ", laser)
                     UserOn(laser)
 
-        # Plugins commands : 
+        # Plugins commands :
         elif oscpath[1] == "plugins":
             # /plugins/start pluginame
             if oscpath[2] == "start":
@@ -373,9 +374,9 @@ def handler(oscpath, args):
                 print("Restarting plugin :",args[0])
                 print()
                 plugins.Restart(args[0])
-        
-        
-        # Settings commands : 
+
+
+        # Settings commands :
         elif oscpath[1] == "settings":
             if oscpath[2] == "lasers":
                 print()
@@ -420,7 +421,7 @@ def handler(oscpath, args):
                 print("** RESTART LJ **")
                 #LJautokill()
 
-            
+
             if oscpath[2] == "restart":
                 print()
                 print("Restarting", args[0], "...")
@@ -457,25 +458,25 @@ def handler(oscpath, args):
 
         else:
             laser = int(oscpath[3])
-    
+
         #print "args[0] :",args[0]," ", type(args[0])
 
-        # /black/lasernumber value (0 or 1) 
+        # /black/lasernumber value (0 or 1)
         if oscpath[1] == "black":
-        
+
             if args[0] == "1":
                 print("Black requested for laser ", laser)
-                BlackOn(laser)     
+                BlackOn(laser)
             else:
                 print("User mode for laser ", laser)
                 UserOn(laser)
-                
-        # /grid/lasernumber value (0 or 1) 
+
+        # /grid/lasernumber value (0 or 1)
         if oscpath[1] == "grid":
-        
+
             if args[0] == "1":
                 print("Grid requested for laser ", laser)
-                GridOn(laser)     
+                GridOn(laser)
             else:
                 print("No grid for laser ", laser)
                 UserOn(laser)
@@ -485,7 +486,7 @@ def handler(oscpath, args):
             print("New IP for laser ", laser)
             gstt.lasersIPS[laser]= args[0]
             settings.Write()
-    
+
         # /kpps/lasernumber value
         # Live change of kpps is not implemented in newdac.py. Change will effect next startup.
         if oscpath[1] == "kpps":
@@ -495,59 +496,59 @@ def handler(oscpath, args):
             sendOSCUI('/kpps/' + str(laser), args[0])
             r.set('/kpps/' + str(laser), str(args[0]))
             r.set('/order/'+str(laser), 7)
-    
-        # /angle/lasernumber value 
+
+        # /angle/lasernumber value
         if oscpath[1] == "angle":
             print("New Angle modification for laser ", oscpath[2], ":",  float(args[0]))
             gstt.finANGLE[laser] = math.radians(float(args[0]))
             sendOSCUI('/angle/' + str(laser), gstt.finANGLE[laser])
             NewEDH(laser)
             print("New angle", gstt.finANGLE[laser])
-            
-        # /intens/lasernumber value 
+
+        # /intens/lasernumber value
         if oscpath[1] == "intens":
             print("LJ2 : New intensity requested for laser ", laser, ":",  int(args[0]))
             plugins.sendWSall("/status Intensity " + str(args[0]))
             sendOSCUI('/intens/' + str(laser), args[0])
             r.set('/intensity/' + str(laser), str(args[0]))
             r.set('/order/'+str(laser), 6)
-    
 
-    
+
+
         # /resampler/lasernumber lsteps
         # lsteps is a string like "[ (1.0, 8),(0.25, 3), (0.75, 3), (1.0, 10)]"
         if oscpath[1] == "resampler":
             #print"resampler with args", args
             Resampler(laser,args)
-            
-    
-        # /mouse/lasernumber value (0 or 1) 
+
+
+        # /mouse/lasernumber value (0 or 1)
         if oscpath[1] == "mouse":
-        
+
             if args[0] == "1":
                 print("Mouse requested for laser ", oscpath[2])
                 gstt.Laser = oscpath[2]
             else:
                 print("No mouse for laser ",  oscpath[2])
-    
-    
-        # /swap/X/lasernumber value (0 or 1) 
+
+
+        # /swap/X/lasernumber value (0 or 1)
         if oscpath[1] == "swap" and oscpath[2] == "X":
-        
+
             print("swapX was", gstt.swapX[laser])
             if args[0] == "0":
                 print("swap X -1 for laser ", laser)
                 gstt.swapX[laser]= -1
                 NewEDH(laser)
-    
+
             else:
                 print("swap X 1 for laser ",  laser)
                 gstt.swapX[laser]= 1
                 NewEDH(laser)
-    
-        # /swap/Y/lasernumber value (0 or 1) 
+
+        # /swap/Y/lasernumber value (0 or 1)
         if oscpath[1] == "swap" and oscpath[2] == "Y":
-    
+
             print("swapY was", gstt.swapX[laser])
             if args[0] == "0":
                 print("swap Y -1 for laser ",  laser)
@@ -557,7 +558,7 @@ def handler(oscpath, args):
                 print("swap Y 1 for laser ",  laser)
                 gstt.swapY[laser]= 1
                 NewEDH(laser)
-    
+
 
         # /loffset/X/lasernumber value
         if oscpath[1] == "loffset" and oscpath[2] == "X":
@@ -565,7 +566,7 @@ def handler(oscpath, args):
                 print("offset/X laser", laser, "modified to",  args[0])
                 gstt.centerX[laser] =  float(args[0])
                 NewEDH(laser)
-        
+
 
         # /loffset/Y/lasernumber value
         if oscpath[1] == "loffset" and oscpath[2] == "Y":
@@ -573,18 +574,18 @@ def handler(oscpath, args):
                 print("offset/Y laser", laser, "modified to",  args[0])
                 gstt.centerY[laser] =  float(args[0])
                 NewEDH(laser)
-    
-    
+
+
         # /scale/X/lasernumber value
         if oscpath[1] == "scale" and oscpath[2] == "X":
-            
+
                 gstt.zoomX[laser] = float(args[0])
                 print("scale/X laser", laser , "modified to",  gstt.zoomX[laser])
                 NewEDH(laser)
-    
+
         # /scale/Y/lasernumber value
         if oscpath[1] == "scale" and oscpath[2] == "Y":
-           
+
                 gstt.zoomY[laser] = float(args[0])
                 print("scale/Y laser",  laser, "modified to",  gstt.zoomY[laser])
                 NewEDH(laser)
@@ -592,22 +593,22 @@ def handler(oscpath, args):
 
 # OSC UI feedback
 def sendOSCUI(oscaddress,oscargs=''):
-    
+
     if gstt.TouchOSCUI == True:
         oscmsg = OSC3.OSCMessage()
         oscmsg.setAddress(oscaddress)
         oscmsg.append(oscargs)
-    
+
         oscui = OSC3.OSCClient()
-        oscui.connect((gstt.TouchOSCIP, 8001)) 
+        oscui.connect((gstt.TouchOSCIP, 8001))
         #print("main sending OSC UI message :", oscmsg, "to", gstt.TouchOSCIP, ":8001")
         if gstt.debug >0:
             print("main sending OSC UI message :", oscmsg, "to", gstt.TouchOSCIP, ":8001")
-    
+
         try:
             oscui.sendto(oscmsg, (gstt.TouchOSCIP, 8001))
             oscmsg.clearData()
-        
+
         except:
             print ('Connection to OSC UI refused : died ?')
             pass
@@ -639,7 +640,7 @@ def UpdateOSCUI(laserid):
         sendOSCUI("/swap/Y/" + str(laserid), 0)
 
 
-# 
+#
 # Different useful codes for some commands
 #
 
@@ -700,7 +701,7 @@ def isOpen(ip):
       time.sleep(1)
 
     finally:
-     
+
       dacksock.close()
       return istate
 
@@ -726,22 +727,27 @@ def LJautokill():
                 print('Shutdown order for tracer '+str(laser), 9)
             r.set('/order/'+str(laser), 9)
 
+    for (n,dac_worker) in enumerate(workers):
+        log.warn(f'Entering tracer{n} ...')
+        dac_worker.join()
+
     lasernumber= gstt.LaserNumber -1
-    log.warn("Ending tracer0...")
-    worker0.join()
-    if lasernumber >0:
-        log.warn("Ending tracer1...")
-        worker1.join()
-    if lasernumber >1:
-        log.warn("Ending tracer2...")
-        worker2.join()
-    if lasernumber >2:
-        log.warn("Ending tracer3...")
-        worker3.join()
-    
+    # log.warn("Ending tracer0...")
+    # worker0.join()
+    # if lasernumber >0:
+    #     log.warn("Ending tracer1...")
+    #     worker1.join()
+    # if lasernumber >1:
+    #     log.warn("Ending tracer2...")
+    #     worker2.join()
+    # if lasernumber >2:
+    #     log.warn("Ending tracer3...")
+    #     worker3.join()
+
+
     log.warn("Laser feedbacks resetting...")
     for laserid in range(0,lasernumber+1):
-        
+
         r.set('/lack/'+str(laserid),64)
         r.set('/lstt/'+str(laserid),64)
         r.set('/cap/'+str(laserid),0)
@@ -759,9 +765,9 @@ def DAChecks():
 
         if isOpen(gstt.lasersIPS[dac]):
             print("DAC", dac, "at", gstt.lasersIPS[dac], ": UP")
-            gstt.dacs[gstt.dacnumber] = dac 
+            gstt.dacs[gstt.dacnumber] = dac
             gstt.dacnumber +=1
-            
+
         else:
             print("DAC", dac, "at", gstt.lasersIPS[dac], ": DOWN")
 
@@ -786,19 +792,19 @@ For reference values of EDH modifier if assign to keyboard keys (was alignp)
 
         gstt.zoomX[gstt.Laser] += 0.1
          gstt.zoomY[gstt.Laser] -= 0.1
-       
+
         gstt.zoomY[gstt.Laser] += 0.1
-        
+
         gstt.sizeX[gstt.Laser] -= 50
-        
+
         gstt.sizeX[gstt.Laser] += 50
-        
+
         gstt.sizeY[gstt.Laser] -= 50
-        
+
         gstt.sizeY[gstt.Laser] += 50
-        
+
         gstt.finANGLE[gstt.Laser] -= 0.001
-        
+
         gstt.finANGLE[gstt.Laser] += 0.001
 
 Code for bit analysis 2 bits / laser to encode order.
@@ -813,7 +819,7 @@ Code for bit analysis 2 bits / laser to encode order.
     #order = r.get('/order')
     #neworder = order & ~(1<< laser*2)
     #neworder = neworder & ~(1<< 1+ laser*2)
-    #r.set('/order', str(neworder))  
+    #r.set('/order', str(neworder))
 
     # Laser bit 0 = 0 and bit 1 = 1 : New EDH
     #order = r.get('/order')
diff --git a/libs3/gstt.py b/libs3/gstt.py
index 188e4c2..2840c1b 100644
--- a/libs3/gstt.py
+++ b/libs3/gstt.py
@@ -49,13 +49,13 @@ Laser = 0
 # Can be changed with /noteon 24-31
 simuPL = 1
 
-# gstt.laserIPS. 
+# gstt.laserIPS.
 lasersIPS = ['192.168.1.5','192.168.1.6','192.168.1.3','192.168.1.4']
 
 maxdacs = 4
 
 # Autodetected by DAChecks() in main3 :
-# Store connected dacs. Maybe laser 1 in LJ.conf is not connected but Laser 2 is. 
+# Store connected dacs. Maybe laser 1 in LJ.conf is not connected but Laser 2 is.
 dacs = [-1, -1, -1, -1]
 # Actual number of connected DACs
 dacnumber = 0
@@ -63,8 +63,9 @@ dacnumber = 0
 # gstt.kpps stores kpps for each laser.
 # ** Will be overridden by LJ.conf file values **
 kpps = [25000,25000,25000,25000]
-lasertype = ["LOCAL","LOCAL","LOCAL","LOCAL"] 
-dacfamily = ["etherdream","etherdream","etherdream","etherdream"] 
+lasertype = ["LOCAL","LOCAL","LOCAL","LOCAL"]
+dacfamily = ["etherdream","etherdream","etherdream","etherdream"]
+cmd = [None,None,None,None]
 intensity = [-1,-1,-1,-1]
 intens = [-1,-1,-1,-1]
 red = [100,100,100,100]
@@ -74,17 +75,17 @@ blue = [100,100,100,100]
 # gstt.GridDisplay : if = 1 Curve points actually sent to PL are replaced by a grid
 GridDisplay = [0,0,0,0]
 
-# Transformation Matrix for each laser 
+# Transformation Matrix for each laser
 EDH = [[], [], [], []]
 
-# Etherdreams reports 
+# Etherdreams reports
 # ipconn is initial newdac to its etherdream
 lstt_ipconn = [[-1], [-1], [-1], [-1]]
 # dacstt is dac light engine state
 lstt_dacstt = [[-1], [-1], [-1], [-1]]
-# store last dac answers : ACK, not ACK,... 
+# store last dac answers : ACK, not ACK,...
 lstt_dacanswers = [[-1], [-1], [-1], [-1]]
-# store last number of points sent to etherdreams buffer 
+# store last number of points sent to etherdreams buffer
 lstt_points = [[0], [0], [0], [0]]
 
 swapX = [1,1,1,-1]
@@ -93,7 +94,7 @@ swapY = [1,1,1,-1]
 lsteps = [[],[],[],[]]
 
 # For glitch art : change position and number of points added by tracer.py
-# shortline is for distance with next point, shorter than 4000 (in etherdream coordinates) 
+# shortline is for distance with next point, shorter than 4000 (in etherdream coordinates)
 # i.e (0.25,3) means add 3 points at 25% on the line.
 stepshortline = [(1.0, 8)]
 stepslongline = [(0.25, 3), (0.75, 3), (1.0, 10)]
@@ -114,7 +115,7 @@ knob = [0] * 33
 cc[21]=60
 viewer_distance = cc[21] * 8
 
-# fov (cc 22) 
+# fov (cc 22)
 cc[22]= 60
 fov = 4 * cc[22]
 
@@ -130,7 +131,7 @@ nozoport=8001 #nozosc.py sending port to LJay (main.py)
 nozuport=0 #linux serial usb port connecting nozoid devices ACM0 by default
 
 
-angleX = 0 
+angleX = 0
 angleY = 0
 angleZ = 0
 
diff --git a/libs3/settings.py b/libs3/settings.py
index 8806330..cffc7f9 100644
--- a/libs3/settings.py
+++ b/libs3/settings.py
@@ -16,7 +16,7 @@ import ast
 import numpy as np
 
 
-def Write(): 
+def Write():
 
 	config.set('General', 'lasernumber', str(gstt.LaserNumber))
 	config.set('General', 'rediserverip', str(gstt.RediServerIP))
@@ -51,8 +51,8 @@ def Write():
 
 
 
-def Read(): 
-	
+def Read():
+
 	gstt.LaserNumber = config.getint('General', 'lasernumber')
 	gstt.RediServerIP= config.get('General', 'rediserverip')
 	gstt.wwwIP= config.get('General', 'wwwip')
@@ -69,6 +69,8 @@ def Read():
 		gstt.lasersIPS[i]= config.get(laser, 'ip')
 		gstt.lasertype[i]= config.get(laser, 'type')
 		gstt.dacfamily[i] = config.get(laser, 'dac_family')
+		if gstt.dacfamily[i] == "extern_cmd":
+		  gstt.cmd[i] = config.get(laser, 'cmd')
 		gstt.kpps[i] = config.getint(laser, 'kpps')
 		gstt.intens[i] = config.getfloat(laser, 'intens')
 		gstt.red[i] = config.getint(laser, 'red')
@@ -90,4 +92,3 @@ def Read():
 
 config = configparser.ConfigParser()
 config.read(gstt.ConfigName)
-
diff --git a/main.py b/main.py
index f37e951..ccd6a15 100755
--- a/main.py
+++ b/main.py
@@ -11,14 +11,14 @@ Laser server + webUI servers (ws + OSC)
 
 - get point list to draw : /pl/lasernumber
 - for report /lstt/lasernumber /lack/lasernumber /cap/lasernumber
-- a nice ws debug tool : websocat 
-- a "plugin" is a generator that send points to LJ. Plugins if they have an open OSC port can be checked and restart if in the same computer. 
+- a nice ws debug tool : websocat
+- a "plugin" is a generator that send points to LJ. Plugins if they have an open OSC port can be checked and restart if in the same computer.
 
 
-All used ports: 
+All used ports:
 
 8002 OSC incoming
-9001 Websocket communication with WebGUI 
+9001 Websocket communication with WebGUI
 Plugins OSC Ports (see LJ.conf)
 
 '''
@@ -52,14 +52,14 @@ settings.Write()
 from multiprocessing import Process, set_start_method
 import random, ast
 from libs3 import plugins
-#from libs3 import lasytracer as tracer 
-from libs3 import tracer3 as tracer 
-#from libs3 import niptracer3 as tracer 
+#from libs3 import lasytracer as tracer
+from libs3 import tracer3 as tracer
+#from libs3 import niptracer3 as tracer
 from libs3 import homographyp, commands, font1
 #import subprocess
 import os
 #from libs3 import midi3
-from libs3 import OSC3 
+from libs3 import OSC3
 from websocket_server import WebsocketServer
 #import socket
 import types, _thread, time
@@ -82,7 +82,6 @@ elif os_name == "Darwin":  # macOS
 elif os_name == "Linux":
     print("Plateform: Linux")
 
-
 def dac_process(number, pl):
 
     import sys
@@ -90,6 +89,7 @@ def dac_process(number, pl):
 
     print("Starting dac process", number)
 
+
     while True:
         try:
             d = tracer.DAC(number,pl)
@@ -110,20 +110,20 @@ def dac_process(number, pl):
 
         except KeyboardInterrupt:
             sys.exit(0)
- 
+
 
 
 #
 # Init variables
 #
 
-debug = gstt.debug 
+debug = gstt.debug
 print("Debug :", debug)
 
 print("Start Scene number :",gstt.SceneNumber)
 print("Laser feedbacks resetting...")
 for laserid in range(0,gstt.LaserNumber):
-    
+
     r.set('/lack/'+str(laserid),64)
     r.set('/lstt/'+str(laserid),64)
     r.set('/cap/'+str(laserid),0)
@@ -156,13 +156,13 @@ import socket
 # oscserver
 oscserverIP = gstt.oscIPin
 
-# OSC Server : accept OSC message on port 8002 
+# OSC Server : accept OSC message on port 8002
 #oscIPin = "192.168.1.10"s
 oscserverIPin = serverIP
 oscserverPORTin = 8002
 
 # OSC Client : to send OSC message to an IP port 8001
-oscserverIPout = oscserverIP 
+oscserverIPout = oscserverIP
 oscserverPORTout = 8101
 
 oscserver = OSC3.OSCServer( (oscserverIPin, oscserverPORTin) )
@@ -200,7 +200,7 @@ def handler(path, tags, args, source):
     commands.handler(oscpath,args)
 
 
-# RAW OSC Frame available ? 
+# RAW OSC Frame available ?
 def osc_frame():
     #print 'oscframe'
     # clear timed_out flag
@@ -213,7 +213,7 @@ def PingAll():
 
     if gstt.debug > 0:
         print("Pinging all plugins...")
-        
+
     for plugin in list(gstt.plugins.keys()):
         if gstt.debug > 0:
             print("pinging", plugin)
@@ -223,28 +223,28 @@ def PingAll():
 
 '''
 gstt.lasertype[i
-gstt.sizeX[i] = 
-gstt.sizeY[i] = 
+gstt.sizeX[i] =
+gstt.sizeY[i] =
 '''
 '''
 # OSC UI feedback
 def sendOSCUI(oscaddress,oscargs=''):
-    
+
     if gstt.TouchOSCUI == True:
         oscmsg = OSC3.OSCMessage()
         oscmsg.setAddress(oscaddress)
         oscmsg.append(oscargs)
-    
+
         oscui = OSC3.OSCClient()
-        oscui.connect((gstt.TouchOSCIP, 8001)) 
+        oscui.connect((gstt.TouchOSCIP, 8001))
         print("main sending OSC UI message :", oscmsg, "to", gstt.TouchOSCIP, ":8001")
         if gstt.debug >0:
             print("main sending OSC UI message :", oscmsg, "to", gstt.TouchOSCIP, ":8001")
-    
+
         try:
             oscui.sendto(oscmsg, (gstt.TouchOSCIP, 8001))
             oscmsg.clearData()
-        
+
         except:
             print ('Connection to OSC UI refused : died ?')
             pass
@@ -276,7 +276,7 @@ def osc_thread():
 
                 if lstt == "2":                                 # Dac PLAYING (2) -> led is green (1)
                     sendWSall("/lstt/" + str(laserid) + " 1")
-            
+
 
                 ackstate = {'61': 'ACK', '46': 'FULL', '49': "INVALID", '21': 'STOP', '64': "NOCONNECTION ?", '35': "NOCONNECTION ?" , '97': 'ACK', '70': 'FULL', '73': "INVALID", '33': 'STOP', '100': "NOCONNECTION", '48': "NOCONNECTION", 'a': 'ACK', 'F': 'FULL', 'I': "INVALID", '!': 'STOP', 'd': "NOCONNECTION", '0': "NOCONNECTION"}
                 lack= r.get('/lack/'+str(laserid)).decode('ascii')
@@ -293,13 +293,13 @@ def osc_thread():
                 if chr(int(lack)) == 'I':                       # Dac sent INVALID ("I") -> led is yellow (4)
                     sendWSall("/lack/" + str(laserid)+" 4")
                 #print lack
-                
+
                 if lack == "64" or lack =="35":                 # no connection to dac -> leds are red (6)
-                    sendWSall("/lack/" + str(laserid) + " 6")   
-                    sendWSall("/lstt/" + str(laserid) + " 6")  
-                    #sendWSall("/lstt/" + str(laserid) + " 0")  
+                    sendWSall("/lack/" + str(laserid) + " 6")
+                    sendWSall("/lstt/" + str(laserid) + " 6")
+                    #sendWSall("/lstt/" + str(laserid) + " 0")
                     sendWSall("/points/" + str(laserid) + " 6")
-                    
+
                 else:
                     # last number of points sent to etherdream buffer
                     sendWSall("/points/" + str(laserid) + " " + str(r.get('/cap/'+str(laserid)).decode('ascii')))
@@ -322,17 +322,17 @@ def osc_thread():
 
 #
 # Websocket part
-# 
+#
 def get_Host_name_IP():
     try:
-        host_name = socket.gethostname()
+        host_name = "localhost" #socket.gethostname()
         host_ip = socket.gethostbyname(host_name)
         print("Hostname : ", host_name)
         print("IP : ", host_ip)
     except:
         print("Unable to get Hostname and IP")
     return host_ip
-    
+
 # Called for every WS client connecting (after handshake)
 def new_client(client, wserver):
 
@@ -340,7 +340,7 @@ def new_client(client, wserver):
     sendWSall("/status Hello " + str(client['id']))
     #commands.sendOSCUI("/status", "Hello " + str(client['id']))
 
-    for laserid in range(0,gstt.LaserNumber):    
+    for laserid in range(0,gstt.LaserNumber):
 
         sendWSall("/ip/" + str(laserid) + " " + str(gstt.lasersIPS[laserid]))
         sendWSall("/kpps/" + str(laserid)+ " " + str(gstt.kpps[laserid]))
@@ -348,8 +348,8 @@ def new_client(client, wserver):
         sendWSall("/laser "+str(laserid))
         #print("/laser "+str(laserid))
         sendWSall("/lack/" + str(laserid) + " 6")
-        #print("/lack/" + str(laserid) + " 6") 
-        sendWSall("/lstt/" + str(laserid) + " 6")  
+        #print("/lack/" + str(laserid) + " 6")
+        sendWSall("/lstt/" + str(laserid) + " 6")
         #print("/lstt/" + str(laserid) + " 6")
         sendWSall("/points/" + str(laserid) + " 0")
         #print("/points/" + str(laserid) + " 0")
@@ -379,25 +379,25 @@ def client_left(client, wserver):
 def message_received(client, wserver, message):
 
     #if len(message) > 200:
-    #    message = message[:200]+'..'    
+    #    message = message[:200]+'..'
 
     #if gstt.debug >0:
     #    print ("")
     #    print("WS Client(%d) said: %s" % (client['id'], message))
-    
+
     oscpath = message.split(" ")
     #print "WS Client", client['id'], "said :", message, "splitted in an oscpath :", oscpath
     if gstt.debug > 0:
         print("WS Client", client['id'], "said :", message, "splitted in an oscpath :", oscpath)
-    
+
     PingAll()
     message4plugin = False
 
     # WS received Message is for a plugin ?
     for plugin in list(gstt.plugins.keys()):
-    
+
         if oscpath[0].find(plugin) != -1:
-    
+
             message4plugin = True
             #print(oscpath)
             if plugins.Send(plugin, oscpath):
@@ -411,13 +411,13 @@ def message_received(client, wserver, message):
         if len(oscpath) == 1:
             args[0] = "noargs"
             #print "noargs command"
-    
+
         elif len(oscpath) > 1:
-            args[0] = str(oscpath[1]) 
+            args[0] = str(oscpath[1])
             #print "arg",oscpath[1]
-        
+
         commands.handler(oscpath[0].split("/"),args)
-    
+
 
     # if needed a loop back : WS Client -> server -> WS Client
     #sendWSall("ws"+message)
@@ -431,7 +431,7 @@ def sendWSall(message):
     #if gstt.debug >0:
         #print("WS sending %s" % (message))
     wserver.send_message_to_all(message)
-    
+
     if gstt.TouchOSCUI == True:
         if message[:7] == '/status':
             print("Main WSall", message, message[:6])
@@ -440,8 +440,8 @@ def sendWSall(message):
             print("Main WSall", message, message[:6])
             commands.sendOSCUI('/line1', message[6:])
 
- 
-'''   
+
+'''
 print ("")
 log.info("Midi Configuration...")
 midi3.check()
@@ -462,7 +462,7 @@ log.info("Creating startup point lists...")
 
 if r.set("/clientkey","/pl/"+str(gstt.SceneNumber)+"/")==True:
     print("sent clientkey : /pl/"+str(gstt.SceneNumber)+"/")
-    
+
 #pdb.set_trace()
 for sceneid in range(0,gstt.MaxScenes+1):
     print("Scene "+ str(sceneid))
@@ -480,10 +480,32 @@ for sceneid in range(0,gstt.MaxScenes+1):
         r.set('/order/'+str(laserid), 0)
 
 
+#
+# For tracer as external command
+#
+import subprocess
+import select
+def spawn(cmd):
+    p = subprocess.Popen(cmd,
+        shell=True,
+        stdin=subprocess.DEVNULL,
+        stdout=subprocess.DEVNULL,
+        stderr=subprocess.DEVNULL)
+    return p
 #
 # Starts one DAC process per requested Laser
 #
 
+import signal
+import sys
+
+def signal_handler(sig, frame):
+    print('You pressed Ctrl+C!')
+    commands.LJautokill()
+    sys.exit(0)
+
+signal.signal(signal.SIGINT, signal_handler)
+
 if __name__ == '__main__':
 
     # Bug in 3.8.4 MacOS default multiprocessing start method is spawn. Spawn doesn't work properly
@@ -495,44 +517,55 @@ if __name__ == '__main__':
         commands.DAChecks()
         print("dacs", gstt.dacs)
 
-    else: 
+    else:
         log.infog("Resquested DACs mode")
 
-    lasernumber = gstt.LaserNumber -1
+    #lasernumber = gstt.LaserNumber -1
     print("LaserNumber = ", gstt.LaserNumber)
     log.info("Starting "+str(gstt.LaserNumber) + " DACs process...")
-    
-    # Launch one process (a tracer3 instance) by laser
-    dac_worker0= Process(target=dac_process, args=(0,0,))
-    dac_worker0.start()
-    commands.worker0 = dac_worker0
-    print("Tracer 0 : name", dac_worker0.name , "pid", dac_worker0.pid )
-    
-    if lasernumber >0:
-        dac_worker1= Process(target=dac_process, args=(1,0,))
-        commands.worker1 = dac_worker1
-        print("Tracer 1 : name", dac_worker1.name , "pid", dac_worker1.pid )
-        dac_worker1.start()
-    
-    if lasernumber >1:
-        dac_worker2= Process(target=dac_process, args=(2,0,))
-        dac_worker2.start()
-        commands.worker2 = dac_worker2
-        print("Tracer 2 : name", dac_worker2.name , "pid", dac_worker2.pid )
-    
-    if lasernumber >2:
-        dac_worker3= Process(target=dac_process, args=(3,0,))
-        print("Tracer 3 : name", dac_worker3.name , "pid", dac_worker3.pid )
-        commands.worker3 = dac_worker3
-        dac_worker3.start()
+
+    commands.workers = []
+    for lasernumber in range(0,gstt.LaserNumber):
+        # Launch one process (a tracer3 instance) by laser
+        if gstt.dacfamily[lasernumber] == "extern_cmd":
+            dac_worker0 = spawn(gstt.cmd[lasernumber]) #Process(target=spawn, args=(gstt.cmd[0],))
+            dac_worker0.name = f'ExternCmd{lasernumber}'
+            dac_worker0.join = dac_worker0.wait
+        else:
+            dac_worker0= Process(target=dac_process, args=(lasernumber,0,))
+            dac_worker0.start()
+
+        #commands.worker0 = dac_worker0 # ???
+        commands.workers.append(dac_worker0)
+        print("Tracer 0 : name", dac_worker0.name , "pid", dac_worker0.pid )
+        print("DAC Family:", gstt.dacfamily[lasernumber]);
+
+    # if lasernumber >0:
+
+    #     dac_worker1= Process(target=dac_process, args=(1,0,))
+    #     commands.worker1 = dac_worker1
+    #     print("Tracer 1 : name", dac_worker1.name , "pid", dac_worker1.pid )
+    #     dac_worker1.start()
+
+    # if lasernumber >1:
+    #     dac_worker2= Process(target=dac_process, args=(2,0,))
+    #     dac_worker2.start()
+    #     commands.worker2 = dac_worker2
+    #     print("Tracer 2 : name", dac_worker2.name , "pid", dac_worker2.pid )
+
+    # if lasernumber >2:
+    #     dac_worker3= Process(target=dac_process, args=(3,0,))
+    #     print("Tracer 3 : name", dac_worker3.name , "pid", dac_worker3.pid )
+    #     commands.worker3 = dac_worker3
+    #     dac_worker3.start()
     print("")
-    
+
     #
     #  start WS and OSC servers
     #
-    
+
     try:
-        
+
         log.info("Starting servers...")
         hostIP= get_Host_name_IP()
         if hostIP != gstt.wwwIP:
@@ -542,8 +575,8 @@ if __name__ == '__main__':
             print("python3 configure.py")
             log.err('Exiting...')
             #gstt.wwwIP = hostIP
-            commands.LJautokill()
-            sys.exit()
+            #commands.LJautokill()
+            #sys.exit()
 
         # Launch OSC thread listening to oscserver
         print("OSC server to receive messages (UI,...)")
@@ -559,13 +592,13 @@ if __name__ == '__main__':
         #print()
         # Websocket listening port
         print("WebUI WS server...")
-        
+
         #hostIP= get_Host_name_IP()
         if hostIP != gstt.wwwIP:
             log.err("wwwIP in config is not set to "+str(hostIP))
             gstt.wwwIP = hostIP
             #commands.LJautokill()
-        
+
         print("binded at", gstt.wwwIP, "port",str(gstt.wsPORT))
         wserver = WebsocketServer(gstt.wsPORT,host= gstt.wwwIP)
         plugins.Init(wserver)
@@ -575,43 +608,40 @@ if __name__ == '__main__':
 
         print("")
         log.info("Resetting all Homographies...")
-        for laserid in range(0,gstt.LaserNumber):  
+        for laserid in range(0,gstt.LaserNumber):
             homographyp.newEDH(laserid)
-    
+
         #midi3.check()
         # plugins autostart
         #print("")
         log.info("Plugins startup...")
-    
+
         if gstt.autostart != "":
-         
+
             for pluginname in gstt.autostart.split(","):
                 print("Autostarting", pluginname, "...")
                 plugins.Start(pluginname)
-        
+
         print("")
         log.infog("LJ server running...")
-        
+
         # websocket loop
 
         wserver.run_forever()
-        
-    
+
+
     except Exception:
         log.err("Exception")
         traceback.print_exc()
-    
+
     # Gently stop on CTRL C
-    
+
     finally:
 
         commands.LJautokill()
 
     '''
     Some code previously used, for reference :
-    
+
     random_points = [(300.0+random.randint(-100, 100), 200.0+random.randint(-100, 100), 0), (500.0+random.randint(-100, 100), 200.0+random.randint(-100, 100), 65280), (500.0+random.randint(-100, 100), 400.0+random.randint(-100, 100), 65280), (300.0+random.randint(-100, 100), 400.0+random.randint(-100, 100), 65280), (300.0+random.randint(-100, 100), 200.0+random.randint(-100, 100), 65280)]
     '''
-
-
-