Index: firmware/App/Services/SystemCommMessages.c
===================================================================
diff -u -rba71bd3e4403e328e3e75e8e14069d954cc9db8f -r3662494c8f383acfe63a9fa09d9e1a63ec5c5aec
--- firmware/App/Services/SystemCommMessages.c	(.../SystemCommMessages.c)	(revision ba71bd3e4403e328e3e75e8e14069d954cc9db8f)
+++ firmware/App/Services/SystemCommMessages.c	(.../SystemCommMessages.c)	(revision 3662494c8f383acfe63a9fa09d9e1a63ec5c5aec)
@@ -1535,11 +1535,17 @@
     BOOL result;
     MESSAGE_T msg;
     DG_START_STOP_TX_CMD_REQUEST_T cmd;
+    cmd.acidType   = 0;
+    cmd.bicarbType = 0;
 
-    cmd.start      = start;
-    cmd.acidType   = getTreatmentParameterU32( TREATMENT_PARAM_ACID_CONCENTRATE );
-    cmd.bicarbType = getTreatmentParameterU32( TREATMENT_PARAM_BICARB_CONCENTRATE );
+    cmd.start = start;
 
+    if ( TRUE == start )
+    {
+        cmd.acidType   = getTreatmentParameterU32( TREATMENT_PARAM_ACID_CONCENTRATE );
+        cmd.bicarbType = getTreatmentParameterU32( TREATMENT_PARAM_BICARB_CONCENTRATE );
+    }
+
     // Create a message record
     blankMessage( &msg );
     msg.hdr.msgID      = MSG_ID_STARTING_STOPPING_TREATMENT_CMD_REQUEST;