Index: firmware/App/Monitors/Pressures.c
===================================================================
diff -u -rd595ea4a23b0b2371e31838c24990059653c1871 -r312045692a83bb40857b7ff055c454c5e05a60ea
--- firmware/App/Monitors/Pressures.c	(.../Pressures.c)	(revision d595ea4a23b0b2371e31838c24990059653c1871)
+++ firmware/App/Monitors/Pressures.c	(.../Pressures.c)	(revision 312045692a83bb40857b7ff055c454c5e05a60ea)
@@ -18,6 +18,7 @@
 #include "AirPump.h"
 #include "AlarmMgmtTD.h"
 //#include "BloodFlow.h"
+#include "DDInterface.h"
 #include "FpgaTD.h"
 #include "Messaging.h"
 //#include "ModeTreatment.h"
@@ -134,10 +135,11 @@
 static S32 currentVenousMinLimit;                                               ///< Minimum venous pressure limit (in mmHg).
 static BOOL pressureLimitsActive;                                               ///< Flag indicates whether arterial and venous pressure alarm limits are active.
 static U32 stabilizationStartTimeMs;                                            ///< Timestamp taken when pressure limit stabilization began (ms).
-static F32 longFilteredArterialPressure;                                        ///< Measured arterial pressure after long (10 s) filter.
-static OVERRIDE_F32_T shortFilteredArterialPressure;                            ///< Measured arterial pressure after short (1 s) filter.
-static F32 longFilteredVenousPressure;                                          ///< Measured venous pressure after long (10 s) filter.
-static OVERRIDE_F32_T shortFilteredVenousPressure;                              ///< Measured venous pressure after short (1 s) filter.
+static F32 longFilteredArterialPressure;                                        ///< Measured arterial pressure after long (10 s) filter (in mmHg).
+static OVERRIDE_F32_T shortFilteredArterialPressure;                            ///< Measured arterial pressure after short (1 s) filter (in mmHg).
+static F32 longFilteredVenousPressure;                                          ///< Measured venous pressure after long (10 s) filter (in mmHg).
+static OVERRIDE_F32_T shortFilteredVenousPressure;                              ///< Measured venous pressure after short (1 s) filter (in mmHg).
+static OVERRIDE_F32_T tmpPressure;                                              ///< Calculated trans-membrane pressure (in mmHg).
 static STABILIZATION_PERIODS_T pressureStabilizeTime;                           ///< Pressure stabilization time based on system events such as airpump, treatment param changes etc.,
 static BOOL resetFillExemptPeriod;                                              ///< Flag to reset the exempt period after defined time expire.
 static BOOL lowVenousPressureExemptCheck;                                       ///< low venous pressure exempt check flag based on the air trap valve status
@@ -224,6 +226,10 @@
     shortFilteredVenousPressure.ovData              = 0.0F;
     shortFilteredVenousPressure.ovInitData          = 0.0F;
     shortFilteredVenousPressure.override            = OVERRIDE_RESET;
+    tmpPressure.data                                = 0.0F;
+    tmpPressure.ovData                              = 0.0F;
+    tmpPressure.ovInitData                          = 0.0F;
+    tmpPressure.override                            = OVERRIDE_RESET;
 
     pressureDataPublicationTimerCounter             = DATA_PUBLISH_COUNTER_START_COUNT;
     pressureState                                   = PRESSURE_WAIT_FOR_POST_STATE;
@@ -526,6 +532,9 @@
     // Filter inline pressure readings
     filterInlinePressureReadings( fpgaArtPres, fpgaVenPres );
 
+    // Get latest dialysate pressure so we can calculate TMP
+    tmpPressure.data = getLongFilteredVenousPressure() - getDialysatePressure();
+
     // Handle pressure limits state machine
     execPressureLimits();
 
@@ -889,6 +898,18 @@
 
 /*********************************************************************//**
  * @brief
+ * The getTMPPressure function gets the calculated trans-membrane pressure.
+ * @details \b Inputs: tmpPressure
+ * @details \b Outputs: none
+ * @return the current calculated TMP (in mmHg).
+ *************************************************************************/
+F32 getTMPPressure( void )
+{
+    return getF32OverrideValue( &tmpPressure );
+}
+
+/*********************************************************************//**
+ * @brief
  * The filterInlinePressureReadings function adds a new arterial and venous
  * pressure sample to the filters.
  * @details \b Inputs: none
@@ -975,9 +996,9 @@
         data.h14MaxLimit          = currentVenousMaxLimit;
         data.h2LongFilterPres     = longFilteredArterialPressure;
         data.h14LongFilterPres    = longFilteredVenousPressure;
-        data.tmpPressure          = 0.0F;
-        data.tmpMinLimit          = 0.0F;
-        data.tmpMaxLimit          = 0.0F;
+        data.tmpPressure          = getTMPPressure();
+        data.tmpMinLimit          = -400.0F;  // TODO - use windowed min/max values based on user set params when implemented
+        data.tmpMaxLimit          = 100.0F;
 
         broadcastData( MSG_ID_TD_PRESSURE_DATA, COMM_BUFFER_OUT_CAN_TD_BROADCAST, (U08*)&data, sizeof( PRESSURE_DATA_T ) );
         pressureDataPublicationTimerCounter = 0;
Index: firmware/App/Monitors/Pressures.h
===================================================================
diff -u -rd595ea4a23b0b2371e31838c24990059653c1871 -r312045692a83bb40857b7ff055c454c5e05a60ea
--- firmware/App/Monitors/Pressures.h	(.../Pressures.h)	(revision d595ea4a23b0b2371e31838c24990059653c1871)
+++ firmware/App/Monitors/Pressures.h	(.../Pressures.h)	(revision 312045692a83bb40857b7ff055c454c5e05a60ea)
@@ -90,6 +90,7 @@
 F32 getLongFilteredArterialPressure( void );
 F32 getFilteredVenousPressure( void );
 F32 getLongFilteredVenousPressure( void );
+F32 getTMPPressure( void );
 
 BOOL testPressuresDataPublishIntervalOverride( MESSAGE_T *message );
 
Index: firmware/App/Services/DDInterface.c
===================================================================
diff -u -rd595ea4a23b0b2371e31838c24990059653c1871 -r312045692a83bb40857b7ff055c454c5e05a60ea
--- firmware/App/Services/DDInterface.c	(.../DDInterface.c)	(revision d595ea4a23b0b2371e31838c24990059653c1871)
+++ firmware/App/Services/DDInterface.c	(.../DDInterface.c)	(revision 312045692a83bb40857b7ff055c454c5e05a60ea)
@@ -326,7 +326,7 @@
         checkPersistentAlarm( alarmID, FALSE, 0.0, 0.0 );
     }
     else
-    {   // Alarm if not receiving DG fresh data message in timely manner
+    {   // Alarm if not receiving DD fresh data message in timely manner
         if ( TRUE == isDDCommunicating() )
         {
             checkPersistentAlarm( alarmID, TRUE, 0.0, 0.0 );