diff --git a/libs3/settings.py b/libs3/settings.py
index cffc7f9..5e1ff95 100644
--- a/libs3/settings.py
+++ b/libs3/settings.py
@@ -32,6 +32,8 @@ def Write():
 		config.set(laser, 'ip', str(gstt.lasersIPS[i]))
 		config.set(laser, 'type', str(gstt.lasertype[i]))
 		config.set(laser, 'dac_family', str(gstt.dacfamily[i]))
+		if gstt.dacfamily[i] == "extern_cmd":
+		  config.set(laser, 'cmd', str(gstt.cmd[i]))
 		config.set(laser, 'kpps', str(gstt.kpps[i]))
 		config.set(laser, 'intens', str(gstt.intens[i]))
 		config.set(laser, 'red', str(gstt.red[i]))
diff --git a/main.py b/main.py
index ccd6a15..7d2bd95 100755
--- a/main.py
+++ b/main.py
@@ -528,16 +528,16 @@ if __name__ == '__main__':
     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
+            dac_worker = spawn(gstt.cmd[lasernumber])
+            dac_worker.name = f'ExternCmd{lasernumber}'
+            dac_worker.join = dac_worker.wait
         else:
-            dac_worker0= Process(target=dac_process, args=(lasernumber,0,))
-            dac_worker0.start()
+            dac_worker= Process(target=dac_process, args=(lasernumber,0,))
+            dac_worker.start()
 
         #commands.worker0 = dac_worker0 # ???
-        commands.workers.append(dac_worker0)
-        print("Tracer 0 : name", dac_worker0.name , "pid", dac_worker0.pid )
+        commands.workers.append(dac_worker)
+        print(f"Tracer {lasernumber} : name", dac_worker.name , "pid", dac_worker.pid )
         print("DAC Family:", gstt.dacfamily[lasernumber]);
 
     # if lasernumber >0: