Index: dialin/common/hd_defs.py
===================================================================
diff -u -r5b56b39677e922b19fa1046810486d2b1848056e -rd4087de260713b981854e29ae831a0ee13d3d598
--- dialin/common/hd_defs.py	(.../hd_defs.py)	(revision 5b56b39677e922b19fa1046810486d2b1848056e)
+++ dialin/common/hd_defs.py	(.../hd_defs.py)	(revision d4087de260713b981854e29ae831a0ee13d3d598)
@@ -385,8 +385,18 @@
     TREATMENT_PARAM_HEPARIN_BOLUS_VOLUME_ML                 = 16                                                               
     TREATMENT_PARAM_DIALYSATE_TEMPERATURE_C                 = 17                                                               
     TREATMENT_PARAM_UF_VOLUME_L                             = 18                                                   
-    NUM_OF_TREATMENT_PARAMS                                 = 19                                                                                
+    NUM_OF_TREATMENT_PARAMS                                 = 19
 
+class Acid_Concentrates(DialinEnum):
+   ACID_CONC_TYPE_FRESENIUS_08_1251_1                       = 0
+   ACID_CONC_TYPE_FRESENIUS_08_2251_0                       = 1
+   ACID_CONC_TYPE_FRESENIUS_08_3251_9                       = 2
+   NUM_OF_ACID_CONC_TYPES                                   = 3
+
+class Bicarb_Concentrates(DialinEnum):
+    BICARB_CONC_TYPE_FRESENIUS_CENTRISOL                    = 0
+    NUM_OF_BICARB_CONC_TYPES                                = 1
+
 @unique
 class PowerOffCommands(DialinEnum):
     """
Index: dialin/dg/hd_proxy.py
===================================================================
diff -u -racd09d02879e8add4cf7f694f5db8e423a76c341 -rd4087de260713b981854e29ae831a0ee13d3d598
--- dialin/dg/hd_proxy.py	(.../hd_proxy.py)	(revision acd09d02879e8add4cf7f694f5db8e423a76c341)
+++ dialin/dg/hd_proxy.py	(.../hd_proxy.py)	(revision d4087de260713b981854e29ae831a0ee13d3d598)
@@ -145,14 +145,16 @@
             self.logger.debug("Timeout!!!!")
             return False
 
-    def cmd_start_stop_dg(self, start: bool = True) -> int:
+    def cmd_start_stop_dg(self, start: bool = True, acid: int = 0, bicarb: int = 0) -> int:
         """
         Constructs and sends the start/stop DG command
         Constraints:
             DG must be in idle state of standby mode if start command given.
             DG must be in re-circulate mode if stop command given.
 
         @param start:  boolean - True = start DG, False = stop DG.
+        @param acid: integer - identifier for selected acid concentrate type
+        @param bicarb: integer - identifier for selected bicarbonate concentrate type
         @return: 1 if successful, zero otherwise
         """
 
@@ -162,7 +164,10 @@
         else:
             cmd = 0
             cmd_str = "stop "
-        payload = integer_to_bytearray(cmd)
+        start = integer_to_bytearray(cmd)
+        act = integer_to_bytearray(acid)
+        bct = integer_to_bytearray(bicarb)
+        payload = start + act + bct
 
         message = DenaliMessage.build_message(channel_id=DenaliChannels.dialin_to_dg_ch_id,
                                               message_id=MsgIds.MSG_ID_STARTING_STOPPING_TREATMENT_CMD.value,