Index: leahi_dialin/td/modules/air_trap.py
===================================================================
diff -u -rb4e77cdb95bebe6ba3fc49c2389d7e6127a81e9c -rdf2b51a17a2ccdaf3587f631de7623fa7fcae624
--- leahi_dialin/td/modules/air_trap.py	(.../air_trap.py)	(revision b4e77cdb95bebe6ba3fc49c2389d7e6127a81e9c)
+++ leahi_dialin/td/modules/air_trap.py	(.../air_trap.py)	(revision df2b51a17a2ccdaf3587f631de7623fa7fcae624)
@@ -234,7 +234,7 @@
 
         vlv = integer_to_bytearray(valve)
         sts = integer_to_bytearray(valve_state)
-        payload = sts + vlv
+        payload = vlv + sts
 
         message = DenaliMessage.build_message(channel_id=DenaliChannels.dialin_to_td_ch_id,
                                               message_id=MsgIds.MSG_ID_TD_2_WAY_VALVE_SET_STATE_REQUEST.value,
@@ -245,7 +245,34 @@
         # If there is content...
         if received_message is not None:
             # response payload is OK or not OK
+            self.logger.debug("Air trap valve " + str(valve) + " set to " + str(valve_state))
             return received_message['message'][DenaliMessage.PAYLOAD_START_INDEX]
         else:
             self.logger.debug("timeout!!")
             return False
+
+    def cmd_set_td_air_trap_control(self, control: int = 0) -> int:
+        """
+        Constructs and sends a set control command to the TD air trap.
+
+        @param control: start/stop for air trap control (0=stop, 1=start)
+        @returns 1 if successful, zero otherwise
+        """
+
+        ctl = integer_to_bytearray(control)
+        payload = ctl
+
+        message = DenaliMessage.build_message(channel_id=DenaliChannels.dialin_to_td_ch_id,
+                                              message_id=MsgIds.MSG_ID_TD_SET_AIR_TRAP_CONTROL.value,
+                                              payload=payload)
+        # Send message
+        received_message = self.can_interface.send(message)
+
+        # If there is content...
+        if received_message is not None:
+            # response payload is OK or not OK
+            self.logger.debug("Air trap control set to " + str(control))
+            return received_message['message'][DenaliMessage.PAYLOAD_START_INDEX]
+        else:
+            self.logger.debug("timeout!!")
+            return False
\ No newline at end of file