Index: dialin/ui/hd_simulator.py
===================================================================
diff -u -rd55580ac0bef4e0c16ad6c6d9d0cff409ec67027 -r6190f606dd8ffb47962b6944487406640deb754d
--- dialin/ui/hd_simulator.py	(.../hd_simulator.py)	(revision d55580ac0bef4e0c16ad6c6d9d0cff409ec67027)
+++ dialin/ui/hd_simulator.py	(.../hd_simulator.py)	(revision 6190f606dd8ffb47962b6944487406640deb754d)
@@ -1184,17 +1184,19 @@
 
         self.can_interface.send(message, 0)
 
-    def cmd_set_treatment_heparin_data(self, cumulative: float) -> None:
+    def cmd_set_treatment_heparin_data(self, cumulative: float, required: float) -> None:
         """
         the Treatment Heparin Data message setter/sender method
-        | MSG  | CAN ID | Box | Type   | Ack | Src | Dst | Description            | #1:(F32)               |
-        |:----:|:------:|:---:|:------:|:---:|:---:|:---:|:-----------:           |:--:                    |
-        |0x4D00| 0x040  | 7   | 1 Hz   | N   | HD  | All | Treatment Heparin Data | \ref Data::mCumulative |
+        | MSG  | CAN ID | Box | Type   | Ack | Src | Dst | Description            | #1:(F32)               | #1:(F32)             |
+        |:----:|:------:|:---:|:------:|:---:|:---:|:---:|:-----------:           |:--:                    |:--:                  |
+        |0x4D00| 0x040  | 7   | 1 Hz   | N   | HD  | All | Treatment Heparin Data | \ref Data::mCumulative | \ref Data::mRequired |
 
         @param cumulative: (float) Heparin Cumulative Volume
+        @param required: (float) Heparin Volume required for treatment
         @return: none
         """
         payload = float_to_bytearray(cumulative)
+        payload += float_to_bytearray(required)
 
         message = DenaliMessage.build_message(channel_id=DenaliChannels.hd_sync_broadcast_ch_id,
                                               message_id=MsgIds.MSG_ID_HD_HEPARIN_DATA_BROADCAST.value,