Index: dialin/common/msg_defs.py
===================================================================
diff -u -r15ac4efc414bb043b7a3d5af0be099389e8a4bd4 -r342405f045e63fafeaee5406be24312498950a28
--- dialin/common/msg_defs.py	(.../msg_defs.py)	(revision 15ac4efc414bb043b7a3d5af0be099389e8a4bd4)
+++ dialin/common/msg_defs.py	(.../msg_defs.py)	(revision 342405f045e63fafeaee5406be24312498950a28)
@@ -101,6 +101,7 @@
     MSG_ID_HD_RINSEBACK_CMD_RESPONSE = 0x53                     # HD rinseback request response
     MSG_ID_HD_RECIRC_CMD_RESPONSE = 0x55                        # HD re-circ request response
     MSG_ID_HD_RINSEBACK_PROGRESS = 0x56                         # HD broadcast of rinseback progress
+    MSG_ID_HD_BLOOD_PRIME_PROGRESS = 0x59                         # HD broadcast of blood prime progress
 
 
     MSG_ID_CAN_ERROR_COUNT = 0x999                              # test code in support of EMC testing
Index: dialin/ui/hd_simulator.py
===================================================================
diff -u -r15ac4efc414bb043b7a3d5af0be099389e8a4bd4 -r342405f045e63fafeaee5406be24312498950a28
--- dialin/ui/hd_simulator.py	(.../hd_simulator.py)	(revision 15ac4efc414bb043b7a3d5af0be099389e8a4bd4)
+++ dialin/ui/hd_simulator.py	(.../hd_simulator.py)	(revision 342405f045e63fafeaee5406be24312498950a28)
@@ -1579,6 +1579,27 @@
 
         self.can_interface.send(message, 0)
 
+    def cmd_send_treatment_blood_prime_data(self, vTarget, vCurrent):
+        """
+        the bloodprime state change Response message method
+        | MSG  | CAN ID | Box | Type   | Ack | Src | Dst | Description              | #1:(F32)           | #2:(F32)            | #2:(U32)         |
+        |:----:|:------:|:---:|:------:|:---:|:---:|:---:|:-----------:             |:--:                |:--:                 |:--:              |
+        |0x5900| 0x020  | 6   | 1Hz    | N   | HD  | UI  | bloodprime progress data | \ref Data::mTarget | \ref Data::mCurrent | \ref Data::mRate |
+
+        :param vTarget  : (float) the target  volume in mL
+        :param vCurrent : (float) the current volume in mL
+        :return: None
+        """
+
+        payload  = float_to_bytearray(vTarget)
+        payload += float_to_bytearray(vCurrent)
+
+        message = DenaliMessage.build_message(channel_id=DenaliChannels.hd_to_ui_ch_id,
+                                              message_id=MsgIds.MSG_ID_HD_BLOOD_PRIME_PROGRESS.value,
+                                              payload=payload)
+
+        self.can_interface.send(message, 0)
+
     def cmd_send_treatment_adjust_recirculate_response(self, vAccepted, vReason):
         """
         the recirculate state change Response message method