Index: firmware/App/Services/MessagePayloads.h
===================================================================
diff -u -rc6f3b01d1b0a5e3fdf480a7ee205ca349e10d6d2 -r8dad6fab1c33602ad94908fd31b8b15153a9eb6e
--- firmware/App/Services/MessagePayloads.h	(.../MessagePayloads.h)	(revision c6f3b01d1b0a5e3fdf480a7ee205ca349e10d6d2)
+++ firmware/App/Services/MessagePayloads.h	(.../MessagePayloads.h)	(revision 8dad6fab1c33602ad94908fd31b8b15153a9eb6e)
@@ -22,20 +22,28 @@
 
 #pragma pack(push,1)
 
+/**
+ *  @addtogroup SystemCommMessages
+ *  @{
+ */
+
+/// Payload record structure for an off button confirmation message from the UI.
 typedef struct
 {
-    U08 confirmed;                              // 1 = confirmed, 0 = rejected/timed out
+    U08 confirmed;                              ///< 1 = confirmed, 0 = rejected/timed out
 } OFF_BUTTON_MESSAGE_FROM_UI_PAYLOAD_T;
 
+/// Payload record structure for an alarm status message.
 typedef struct
 {
-    U32 alarmState;                             // 0 = no alarms, 1 = low priority, 2 = medium priority, 3 = high priority
-    U32 alarmTop;                               // ID of top active alarm
-    U32 escalatesIn;                            // seconds
-    U32 silenceExpiresIn;                       // seconds
-    U16 alarmsFlags;                            // bit flags: 1 = true, 0 = false for each bit
+    U32 alarmState;                             ///< Alarm state: 0 = no alarms, 1 = low priority, 2 = medium priority, 3 = high priority
+    U32 alarmTop;                               ///< ID of top active alarm
+    U32 escalatesIn;                            ///< Top active alarm escalates in this many seconds
+    U32 silenceExpiresIn;                       ///< Silencing of alarms expires in this many seconds
+    U16 alarmsFlags;                            ///< bit flags: 1 = true, 0 = false for each bit flag
 } ALARM_COMP_STATUS_PAYLOAD_T;
 
+/// Payload record structure for an HD versions message.
 typedef struct
 {
     U08 major;
@@ -48,19 +56,22 @@
     U08 fpgaLab;
 } HD_VERSIONS_T;
 
+/// Payload record structure for a linear calibration message.
 typedef struct
 {
     F32 gain;
     F32 offset;
 } LINEAR_F32_CAL_PAYLOAD_T;
 
+/// Payload record structure for an accelerometer calibration message.
 typedef struct
 {
     F32 xOffset;
     F32 yOffset;
     F32 zOffset;
 } ACCEL_CAL_PAYLOAD_T;
 
+/// Payload record structure for a peristaltic pump data message.
 typedef struct
 {
     U32 setPoint;
@@ -72,6 +83,7 @@
     F32 pwmDC;
 } PERISTALTIC_PUMP_STATUS_PAYLOAD_T;
 
+/// Payload record structure for the pressure & occlusions data message.
 typedef struct
 {
     F32 arterialPressure;
@@ -81,20 +93,23 @@
     F32 doPumpOcclusion;
 } PRESSURE_OCCLUSION_DATA_T;
 
+/// Payload record structure for a treatment time status message.
 typedef struct
 {
     U32 treatmentTimePrescribedinSec;
     U32 treatmentTimeElapsedinSec;
     U32 treatmentTimeRemaininginSec;
 } TREATMENT_TIME_DATA_T;
 
+/// Payload record structure for a treatment state message.
 typedef struct
 {
     U32 treatmentSubMode;
     U32 uFState;
     U32 salineBolusState;
 } TREATMENT_STATE_DATA_T;
 
+/// Payload record structure for a load cell data message.
 typedef struct
 {
     F32 res1PrimaryLoadCell;
@@ -103,19 +118,22 @@
     F32 res2BackupLoadCell;
 } LOAD_CELL_READINGS_PAYLOAD_T;
 
+/// Payload record structure for an RO pump data message.
 typedef struct
 {
     U32 setPtPSI;
     F32 measFlowRateMlMin;
     F32 setPWM;
 } DG_RO_PUMP_DATA_PAYLOAD_T;
 
+/// Payload record structure for a drain pump data message.
 typedef struct
 {
     U32 setPtRPM;
     F32 setPWM;
 } DG_DRAIN_PUMP_DATA_PAYLOAD_T;
 
+/// Payload record structure for a DG pressures data message.
 typedef struct
 {
     F32 roInPSI;
@@ -124,19 +142,22 @@
     F32 drainOutPSI;
 } DG_PRESSURES_DATA_PAYLOAD_T;
 
+/// Payload record structure for a reservoirs data message.
 typedef struct
 {
     U32 resID;
     U32 setFillToVolumeMl;
     U32 setDrainToVolumeMl;
 } DG_RESERVOIRS_DATA_PAYLOAD_T;
 
+/// Payload record structure for an ultrafiltration volume change confirmation message.
 typedef struct
 {
     F32 volume_mL;
     U32 adjustType;
 } UF_SETTINGS_CHANGE_CONFIRMATION_PAYLOAD_T;
 
+/// Payload record structure for DG temperature sensors data message.
 typedef struct
 {
     F32 TPi;
@@ -153,13 +174,16 @@
     F32 HtrTrimInternal;
 } DG_TEMPERATURES_T;
 
+/// Payload record structure for a pump set point override message.
 typedef struct
 {
     BOOL reset;
     S32 setPt;
     U32 ctrlMode;
 } OVERRIDE_PUMP_SET_PT_PAYLOAD_T;
 
+/**@}*/
+
 #pragma pack(pop)
 
 #endif