Index: firmware/App/Services/Messaging.c
===================================================================
diff -u -r4b270434e2fc3734e4b6b303822bbb8f96098616 -rff6b765b44991e46891475022fa819cf3af05156
--- firmware/App/Services/Messaging.c	(.../Messaging.c)	(revision 4b270434e2fc3734e4b6b303822bbb8f96098616)
+++ firmware/App/Services/Messaging.c	(.../Messaging.c)	(revision ff6b765b44991e46891475022fa819cf3af05156)
@@ -7,8 +7,8 @@
 *
 * @file    Messaging.c
 *
-* @author  (last)      Sameer Kalliadan Poyil
-* @date    (last)      24-Apr-2026
+* @author  (last)      Michael Garthwaite
+* @date    (last)      11-Jun-2026
 *
 * @author  (original)  Vinayakam Mani
 * @date    (original)  07-Aug-2024
@@ -38,6 +38,7 @@
 #include "Level.h"
 #include "Messaging.h"
 #include "MessagePayloads.h"
+#include "MixingControl.h"
 #include "ModeGenDialysate.h"
 #include "ModeGenPermeate.h"
 #include "ModeGenPermeateDefeatured.h"
@@ -122,6 +123,7 @@
     { MSG_ID_DD_TESTER_LOGIN_REQUEST,                                               &handleTesterLogInRequest },
     { MSG_ID_DD_SOFTWARE_RESET_REQUEST,                                             &handleDDSoftwareResetRequest },
     { MSG_ID_TD_OP_MODE_DATA,                                                       &handleSetTDOperationMode },
+    { MSG_ID_FFU_SIGNAL_DD_UPDATE_AVAILABLE,                                        &handleUpdateAvailable },
     { MSG_ID_DD_VALVE_PUBLISH_INTERVAL_OVERRIDE_REQUEST,                            &testValvesStatesPublishIntervalOverride },
     { MSG_ID_DD_VALVE_STATE_OVERRIDE_REQUEST,                                       &testValveStateOverride },
     { MSG_ID_DD_VALVE_SENSED_STATE_OVERRIDE_REQUEST,                                &testValveSensedStateOverride },
@@ -277,10 +279,10 @@
     { MSG_ID_FP_DEF_PRE_GEN_PUBLISH_INTERVAL_OVERRIDE_REQUEST,                      &testPreGenPermeateDefDataPublishIntervalOverride},
     { MSG_ID_FP_DEF_GEN_PUBLISH_INTERVAL_OVERRIDE_REQUEST,                          &testGenPermeateDefDataPublishIntervalOverride},
     { MSG_ID_FP_DEF_STATUS_REQUEST,                                                 &testGetFPDefeaturedStatus },
-    { MSG_ID_DD_BICARB_MIX_VOL_CONTROL_KP_GAIN_COEFF_OVERRIDE_REQUEST,              &testDryBiCartBicarbMixVolControlKiGainOverride },
-    { MSG_ID_DD_BICARB_MIX_VOL_CONTROL_KI_GAIN_COEFF_OVERRIDE_REQUEST,              &testDryBiCartAcidMixVolControlKpGainOverride },
-    { MSG_ID_DD_ACID_MIX_VOL_CONTROL_KP_GAIN_COEFF_OVERRIDE_REQUEST,                &testDryBiCartAcidMixVolControlKpGainOverride },
-    { MSG_ID_DD_ACID_MIX_VOL_CONTROL_KI_GAIN_COEFF_OVERRIDE_REQUEST,                &testDryBiCartAcidMixVolControlKiGainOverride },
+    { MSG_ID_DD_BICARB_MIX_VOL_CONTROL_KP_GAIN_COEFF_OVERRIDE_REQUEST,              &testMixingControlBicarbVolControlKiGainOverride },
+    { MSG_ID_DD_BICARB_MIX_VOL_CONTROL_KI_GAIN_COEFF_OVERRIDE_REQUEST,              &testMixingControlBicarbVolControlKpGainOverride },
+    { MSG_ID_DD_ACID_MIX_VOL_CONTROL_KP_GAIN_COEFF_OVERRIDE_REQUEST,                &testMixingControlAcidVolControlKpGainOverride },
+    { MSG_ID_DD_ACID_MIX_VOL_CONTROL_KI_GAIN_COEFF_OVERRIDE_REQUEST,                &testMixingControlAcidVolControlKiGainOverride },
     { MSG_ID_DD_BICART_UPPER_PRESSURE_OVERRIDE_REQUEST,                             &testDryBiCartUpperCartPressureOverride },
     { MSG_ID_DD_BICART_LOWER_PRESSURE_OVERRIDE_REQUEST,                             &testDryBiCartLowerCartPressureOverride } ,
     { MSG_ID_FP_SET_OPERATION_SUB_MODE_REQUEST,                                     &testSetFPOperationSubMode },
@@ -291,6 +293,10 @@
     { MSG_ID_DD_TEMPERATURE_SENSOR_FILTERED_TEMP_OVERRIDE_REQUEST,                  &testDDTemperatureSensorFilteredReadingsOverride },
     { MSG_ID_FP_SET_RECOVERY_VALVES_REQUEST,                                        &testIOFPSetValveRecoveryConfig },
     { MSG_ID_DD_SUBSTITUTION_PUMP_START_STOP_OVERRIDE_REQUEST,                      &testSubstitutionPumpStartStopOverride },
+    { MSG_ID_DD_SUBSTITUTION_PUMP_BROADCAST_INTERVAL_OVERRIDE_REQUEST,              &testSubstitutionPumpDataPublishIntervalOverride },
+    { MSG_ID_DD_SUBSTITUTION_PUMP_TARGET_RATE_OVERRIDE_REQUEST,                     &testSubstitutionPumpTargetRateOverride },
+    { MSG_ID_DD_CONDUCTIVITY_SENSOR_CAL_REQUEST,                                    &testHandleConductivitySensorCalRequest },
+    { MSG_ID_FP_CONDUCTIVITY_SENSOR_CAL_REQUEST,                                    &testHandleConductivitySensorCalRequest },
 };
 
 /// Calculation for number of entries in the incoming message function handler look-up table.
@@ -770,7 +776,45 @@
     return result;
 }
 
+/*********************************************************************//**
+ * @brief
+ * The resetMicroControllerUnit function resets the MCU.
+ * @details \b Inputs: none
+ * @details \b Outputs: none
+ * @return none
+ *************************************************************************/
+void resetMicroControllerUnit( void )
+{
+    setSystemREG1_SYSECR( (0x2) << 14 );  // Reset processor
+}
 
+/*********************************************************************//**
+ * @brief
+ * The handleUpdateAvailable function handles a request from the
+ * Firmware FPGA Updater (FFU) to reset the TD firmware processor.
+ * @note If reset is successful, this function will not return.
+ * @details \b Inputs: none
+ * @details \b Outputs: TD processor soft reset if request is valid
+ * @param message Pointer to the reset request message
+ * @return FALSE if reset command rejected
+ *************************************************************************/
+BOOL handleUpdateAvailable( MESSAGE_T *message )
+{
+    BOOL result = FALSE;
+
+    // Verify payload length
+    if ( 0 == message->hdr.payloadLen )
+    {   // S/w reset of processor
+        result = TRUE;                        // Reset will prevent this from getting transmitted though
+        requestNewOperationMode( DD_MODE_UPDT );
+    }
+
+    sendAckResponseMsg( (MSG_ID_T)message->hdr.msgID, COMM_BUFFER_OUT_CAN_DD_2_UI, result );
+
+    return result;
+}
+
+
 /*************************************************************************
  *                       TEST SUPPORT FUNCTIONS
  *************************************************************************/
@@ -906,7 +950,7 @@
     if ( 0 == message->hdr.payloadLen )
     {   // S/w reset of processor
         result = TRUE;                        // Reset will prevent this from getting transmitted though
-        setSystemREG1_SYSECR( (0x2) << 14 );  // Reset processor
+        resetMicroControllerUnit();
     }
 
     return result;