Index: dialin/dg/dialysate_flow_sensor.py
===================================================================
diff -u
--- dialin/dg/dialysate_flow_sensor.py	(revision 0)
+++ dialin/dg/dialysate_flow_sensor.py	(revision ecca3e1c3c23264c32aad0edb6c1ff89bd253ac0)
@@ -0,0 +1,144 @@
+###########################################################################
+#
+# Copyright (c) 2019-2021 Diality Inc. - All Rights Reserved.
+#
+# THIS CODE MAY NOT BE COPIED OR REPRODUCED IN ANY FORM, IN PART OR IN
+# WHOLE, WITHOUT THE EXPLICIT PERMISSION OF THE COPYRIGHT OWNER.
+#
+# @file load_cells.py
+#
+# @author (last) H. Nguyen
+# @date (last) 25-Oct-2021
+# @author (original) H. Nguyen
+# @date (original) 25-Oct-2021
+#
+############################################################################
+import struct
+from enum import unique
+from logging import Logger
+
+from .constants import RESET, NO_RESET
+from ..common.msg_defs import MsgIds, MsgFieldPositions
+from ..protocols.CAN import DenaliMessage, DenaliChannels
+from ..utils.base import AbstractSubSystem, publish, DialinEnum
+from ..utils.checks import check_broadcast_interval_override_ms
+from ..utils.conversions import integer_to_bytearray, float_to_bytearray
+
+
+class DialysateFlowSensor(AbstractSubSystem):
+    """
+    Dialysate Generation (DG) interface for dialysate flow sensor related commands.
+    """
+
+    def __init__(self, can_interface, logger: Logger):
+        """
+
+        @param can_interface: Denali CAN Messenger object
+        """
+
+        super().__init__()
+
+        self.can_interface = can_interface
+        self.logger = logger
+        # The flow rate of the sensor L/min
+        self.flow_rate = 0.0
+
+
+        if self.can_interface is not None:
+            channel_id = DenaliChannels.dg_sync_broadcast_ch_id
+            msg_id = MsgIds.MSG_ID_DG_DIALYSATE_FLOW_METER_DATA.value
+            self.can_interface.register_receiving_publication_function(channel_id, msg_id,
+                                                                       self._handler_flow_sensor_sync)
+
+    def get_flow_rate(self):
+        """
+        Gets a flow value from the sensor
+
+        @param: flow sensor: (int) sensor index
+        @return: The dialysate flow rate L/min of a flow sensor
+        """
+        return self.flow_rate
+
+    @publish(['sensor'])
+    def _handler_flow_sensor_sync(self, message):
+        """
+        Handles published flow sensor message.
+
+        @param message:  published flow sensor message
+        @return: none
+        """
+        flow = struct.unpack('f', bytearray(
+            message['message'][MsgFieldPositions.START_POS_FIELD_1:MsgFieldPositions.END_POS_FIELD_1]))
+
+        self.flow_value = flow
+
+    def cmd_flow_sensor_value_override(self, rate: float, reset: int = NO_RESET) -> int:
+        """
+        Constructs and sends the flow sensor value override command
+        Constraints:
+            Must be logged into DG.
+
+        @param rate: float the sensor flow rate to be set
+        @param reset: (int) 1 to reset a previous override, 0 to override
+        @return 1 if successful, zero otherwise
+        """
+        reset_value = integer_to_bytearray(reset)
+        vlu = float_to_bytearray(rate)
+        payload = reset_value + vlu
+
+        message = DenaliMessage.build_message(channel_id=DenaliChannels.dialin_to_dg_ch_id,
+                                              message_id=MsgIds.MSG_ID_DIALYSATE_MEASURED_FLOW_OVERRIDE.value,
+                                              payload=payload)
+        # Send message
+        received_message = self.can_interface.send(message)
+
+        # If there is content...
+        if received_message is not None:
+            # response payload is OK or not OK
+            return received_message['message'][DenaliMessage.PAYLOAD_START_INDEX]
+        else:
+            self.logger.debug("Dialysate flow sensor value override Timeout!!!")
+            return False
+
+    def cmd_flow_sensor_data_broadcast_interval_override(self, ms: int, reset: int = NO_RESET) -> int:
+        """
+        Constructs and sends the flow sensor data publish interval command.
+        Constraints:
+            Must be logged into DG.
+            Given interval must be non-zero and a multiple of the DG priority task interval (10 ms).
+
+        @param ms: (int) interval (in ms) to override with
+        @param reset: (int) 1 to reset a previous override, 0 to override
+        @return: 1 if successful, zero otherwise
+        """
+        if not check_broadcast_interval_override_ms(ms):
+            return False
+
+        rst = integer_to_bytearray(reset)
+        mis = integer_to_bytearray(ms)
+        payload = rst + mis
+
+        msg_id = MsgIds.MSG_ID_DIALYSATE_FLOW_SEND_INTERVAL_OVERRIDE.value
+        message = DenaliMessage.build_message(channel_id=DenaliChannels.dialin_to_dg_ch_id, message_id=msg_id,
+                                              payload=payload)
+
+        self.logger.debug("Overriding dialysate flow sensor broadcast interval")
+
+        # Send message
+        received_message = self.can_interface.send(message)
+
+        # If there is content...
+        if received_message is not None:
+            # self.logger.debug(received_message)
+            if reset == RESET:
+                str_res = "reset back to normal"
+            else:
+                str_res = str(mis)
+            self.logger.debug(
+                "Dialysate flow sensor data broadcast interval overridden to " + str_res + " ms: " +
+                str(received_message['message'][DenaliMessage.PAYLOAD_START_INDEX]))
+            # response payload is OK or not OK
+            return received_message['message'][DenaliMessage.PAYLOAD_START_INDEX]
+        else:
+            self.logger.debug("Timeout!!!!")
+            return False