remove unneeded commands

Change-Id: I2b3a343a117fced0195f23c3051902c1387e6bcc

secop/datatypes.py

@@ -480,6 +480,7 @@ class StructOf(DataType):
         return self.validate(dict(value))
 
 
+# idea to mix commands and params, not yet used....
 class Command(DataType):
     IS_COMMAND = True
 

secop/modules.py

@@ -503,19 +503,3 @@ class Drivable(Readable):
     }
     # XXX: CMDS ???? auto deriving working well enough?
 
-    def do_start(self):
-        """normally does nothing,
-
-        but there may be modules which _start_ the action here
-        """
-
-    def do_stop(self):
-        """Testing command implementation
-
-        wait a second"""
-        time.sleep(1)  # for testing !
-
-    def do_pause(self):
-        """if implemented should pause the module
-        use start to continue movement
-        """

secop_demo/modules.py

@@ -177,6 +177,9 @@ class MagneticField(Drivable):
             time.sleep(max(0.01, ts + loopdelay - time.time()))
         self.log.error(self, 'main thread exited unexpectedly!')
 
+    def do_stop(self):
+        self.write_target(self.read_value())
+
 
 class CoilTemp(Readable):
     """a coil temperature