Index: SDDs/HDF.puml
===================================================================
diff -u -r7a707330ea36ffc9b91f04b42122cc24a966388d -r547b0ce012983c956be2ee3e0e1a96c87b0dcb60
--- SDDs/HDF.puml	(.../HDF.puml)	(revision 7a707330ea36ffc9b91f04b42122cc24a966388d)
+++ SDDs/HDF.puml	(.../HDF.puml)	(revision 547b0ce012983c956be2ee3e0e1a96c87b0dcb60)
@@ -25,28 +25,120 @@
     '   TCH: User touches a button (RadioButton, CheckBox, ...)
     '   SCL: User scrolls a flip-able area
 
-
   == Main TX HDF ==
     UI ->o UI: ⟲: Main Treatment Screen
     US -> UI: TCH: HDF Menu Option
     UI -> US: ACT: Display HDF Screen   \
                     \n\t  - Pressures   \
                     \n\t  - Pressures Graph \
                     \n\t  - HDF
+
+    group Plot Timer (1 min)
+        UI --> UI: ...
+    end
+
     group Pressures Data
         TD --> UI: ...
     end
-    UI -> US: ACT: Show Pressures Data BroadCast
-    group Plot Timer (1 min)
-        UI --> UI: ...
+
+    group HDF Data
+        TD --> UI: ...
     end
-    UI -> SW: ACT: Request HDF Data
-    SW -> TD: ACT: Request HDF Data
-    TD -> SW: ACT: Response HDF Data
-    SW -> UI: ACT: Response HDF Data
-    UI -> US: ACT: Display HDF Data
 
+ == Pause/ Resume Button ==
+    US -> UI: TCH: Pause/ Resume HDF button
+    UI -> SW: ACT: : Pause/ Resume Command
+
+    alt Pause
+        SW -> TD: MSG: [xXX: Req #1] Pause/ Resume Command Request\n\
+            \t(U32) cmd=HDF_PAUSE_COMMAND (0)
+    else Resume 
+        SW -> TD: MSG: [xXX: Req #1] Pause/ Resume Command Request\n\
+            \t(U32) cmd=HDF_RESUME_COMMAND (1)
+    end
+
+    TD -> SW: MSG: [xXX: Rsp #2] \nPause/ Resume Command Response   \
+                        \n\t(U32)  mAccept                      \
+                        \n\t(U32)  mRejectionReason
+
+    SW -> UI: CMD: Pause/ Resume Command Response   \
+                        \n\t(U32)  mAccept                      \
+                        \n\t(U32)  mRejectionReason
+    alt Accept
+        UI -> US: ACT: Display status tags for paused or resumed
+    else #Pink Reject 
+        UI -> US: ACT: Show rejection reason
+    end         
+
+ == Auto-Substitution  Button ==
+    US -> UI: TCH: Auto-Substitution switch
+    UI -> SW: ACT: Auto-Substitution Command
+
+    alt Off
+        SW -> TD: MSG: [xXX: Req #1] Auto-Substitution Command Request\n\
+            \t(U32) cmd=HDF_AUTO_SUB_OFF_COMMAND (0)
+    else On 
+        SW -> TD: MSG: [xXX: Req #1] Auto-Substitution Command Request\n\
+            \t(U32) cmd=HDF_AUTO_SUB_ON_COMMAND (1)
+    end
+
+    TD -> SW: MSG: [xXX: Rsp #2] \nAuto-Substitution Command Response   \
+                        \n\t(U32)  mAccept                      \
+                        \n\t(U32)  mRejectionReason
+
+    SW -> UI: CMD: Auto-Substitution Command Response   \
+                        \n\t(U32)  mAccept                      \
+                        \n\t(U32)  mRejectionReason
+    alt Accept
+        group HDF Data
+            TD --> UI: (U32)autoSubState= OFF (0) / ON(1)
+        end
+        UI -> US: ACT: Display state of auto sub
+    else #Pink Reject 
+        UI -> US: ACT: Show rejection reason
+    end      
+
+ == Edit HDF  Button ==
+    US -> UI: TCH: Edit HDF Icon 
+    UI -> UI: ACT: Open HDF adjustment dialog
+    US -> UI: TCH: Edit : \
+                \n\t Treatment Mode \
+                \n\t Prescribed Substitution Fluid Volume
+    US -> UI: TCH: Confirm Button
+    UI -> SW: ACT: Adjust HDF Request
+    SW -> TD: MSG: [xXX: Req #2] Adjust HDF Request\
+            \n\t(U32) Treatment Mode   \
+            \n\t(F32) Prescribed Substitution Fluid Volume
+    TD -> SW: MSG: [xXX: Rsp #3] \nAdjust HDF Response   \
+                        \n\t(U32)  mAccept                              \
+                        \n\t(U32)  mTxModeRejectionReason               \
+                        \n\t(U32)  mPrescSubFluidVolumeRejectionReason
+    SW -> UI: CMD: Adjust HDF Response    \
+                        \n\t(U32)  mAccept                      \
+                        \n\t(U32)  mTxModeRejectionReason               \
+                        \n\t(U32)  mPrescSubFluidVolumeRejectionReason
+    alt Accept
+        UI -> US: ACT: Close Dialog
+    else #Pink Reject 
+        UI -> US: ACT: Highlight rejected parameter
+    end   
+
  == Pressures Data ==
     TD -> SW: MSG: [x24: #12] \nTD Pressures Data\n(F32) artPress, \n(F32) venPres\n(U32) limitState\n(S32) artMin\n(S32) artMax\n(S32) venMin\n(s32) venMax\n(F32) artLong\n(U32) venLong\n(F32) tmpPress\n(F32) tmpMin\n(F32) tmpMax 
     SW -> UI: CMD: Update TD Pressures\n(F32) artPress, \n(F32) venPres\n(U32) limitState\n(S32) artMin\n(S32) artMax\n(S32) venMin\n(s32) venMax\n(F32) artLong\n(U32) venLong\n(F32) tmpPress\n(F32) tmpMin\n(F32) tmpMax 
+
+ == HDF Data ==
+    TD -> SW: MSG: [xXX: #5]\nHDF Data      \
+            \n\t(F32) setSubVolume          \
+            \n\t(F32) subRate               \
+            \n\t(F32) subVolumeDelivered    \
+            \n\t(U32) state                 \
+            \n\t(U32) autoSubState
+    SW -> UI: CMD: Display HDF Data         \
+            \n\t(F32) setSubVolume          \
+            \n\t(F32) subRate               \
+            \n\t(F32) subVolumeDelivered    \
+            \n\t(U32) state                 \
+            \n\t(U32) autoSubState
+
 @enduml