Index: leahi_dialin/dd/dialysate_delivery.py
===================================================================
diff -u -r1f2bf6d939eb4033dbedb7d7005494cc12fccbc6 -re45b20cdc5d4c5dcff8cef530b173ca94cb2e422
--- leahi_dialin/dd/dialysate_delivery.py	(.../dialysate_delivery.py)	(revision 1f2bf6d939eb4033dbedb7d7005494cc12fccbc6)
+++ leahi_dialin/dd/dialysate_delivery.py	(.../dialysate_delivery.py)	(revision e45b20cdc5d4c5dcff8cef530b173ca94cb2e422)
@@ -30,6 +30,7 @@
 from .modules.pre_gen_dialysate import DDPreGenDialysate
 from .modules.rinse_pump import DDRinsePump
 from .modules.spent_chamber_fill import DDSpentChamberFill
+from .modules.substitution_pump import DDSubstitutionPump
 from .modules.drybicart import DDDryBicart
 from .modules.temperature_sensors import DDTemperatureSensors
 from .modules.dd_test_configs import DDTestConfig
@@ -43,7 +44,8 @@
 from ..common.constants import NO_RESET
 from ..common import dd_enum_repository
 from ..common.generic_defs import DataTypes
-from ..common.msg_defs import MsgIds, MsgFieldPositions
+from ..common.msg_defs import MsgFieldPositions
+from ..common.msg_ids import MsgIds
 from ..common.override_templates import cmd_generic_broadcast_interval_override, cmd_generic_override
 from ..protocols.CAN import CanMessage, CanMessenger, CanChannels
 from leahi_dialin.utils.abstract_classes import AbstractSubSystem
@@ -124,6 +126,7 @@
         self.concentrate_pumps = DDConcentratePumps(self.can_interface, self.logger)        #: The Concentrat Pumps module
         self.conductivity_sensors = DDConductivitySensors(self.can_interface, self.logger)  #: The Conductivity Sensors module
         self.dialysate_pumps = DDDialysatePumps(self.can_interface, self.logger)            #: The Dialysate Pumps module
+        self.drybicart = DDDryBicart(self.can_interface, self.logger)                       #: The Dry Bicarb module
         self.events = DDEvents(self.can_interface, self.logger)                             #: The Events module
         self.gen_dialysate = DDGenDialysate(self.can_interface, self.logger)                #: The Generate Dialysate module
         self.heaters = DDHeaters(self.can_interface, self.logger)                           #: The Heaters module
@@ -133,7 +136,7 @@
         self.pre_gen_dialysate = DDPreGenDialysate(self.can_interface, self.logger)         #: The Pre Generate Dialysate module
         self.rinse_pump = DDRinsePump(self.can_interface, self.logger)                      #: The Rinse Pump module
         self.spent_chamber_fill = DDSpentChamberFill(self.can_interface, self.logger)       #: The Spent Chamber module
-        self.drybicart = DDDryBicart(self.can_interface, self.logger)                       #: The Dry Bicarb module
+        self.substitution_pump = DDSubstitutionPump(self.can_interface, self.logger)        #: The Substitution Pump module
         self.temperature_sensors = DDTemperatureSensors(self.can_interface, self.logger)    #: The Temperature Sensors module
         self.test_configs = DDTestConfig(self.can_interface, self.logger)                   #: The Test Configs module
         self.ultrafiltration = DDUltrafiltration(self.can_interface, self.logger)           #: The Ultrafiltration module