Index: firmware/App/Modes/OperationModes.c
===================================================================
diff -u -r4d7d40a27130dc813d653f044cbb856b1b7d8481 -r0bf1c0824844ed4c227eef0323238daedf505dc7
--- firmware/App/Modes/OperationModes.c	(.../OperationModes.c)	(revision 4d7d40a27130dc813d653f044cbb856b1b7d8481)
+++ firmware/App/Modes/OperationModes.c	(.../OperationModes.c)	(revision 0bf1c0824844ed4c227eef0323238daedf505dc7)
@@ -17,9 +17,6 @@
 
 #include "gio.h"
 
-#include "SystemCommMessages.h"
-#include "TaskGeneral.h"
-#include "OperationModes.h"
 #include "ModeChemicalDisinfect.h"
 #include "ModeDrain.h"
 #include "ModeFault.h"
@@ -31,6 +28,9 @@
 #include "ModeService.h"
 #include "ModeSolo.h"
 #include "ModeStandby.h"
+#include "OperationModes.h"
+#include "SystemCommMessages.h"
+#include "TaskGeneral.h"
 
 /**
  *  @addtogroup DGOperationModes
@@ -39,18 +39,17 @@
 
 // ********** private definitions **********
 
-#define BROADCAST_DG_OP_MODE_INTERVAL   ( MS_PER_SECOND / TASK_GENERAL_INTERVAL )   ///< interval (ms/task time) at which the op mode is published on the CAN bus.
+#define BROADCAST_DG_OP_MODE_INTERVAL   ( MS_PER_SECOND / TASK_GENERAL_INTERVAL )   ///< interval (ms/task time) at which the operation mode is published on the CAN bus.
 
 // ********** private data **********
 
-static volatile BOOL modeRequest[NUM_OF_DG_MODES - 1];                              ///< Array of mode request flags.
+static volatile BOOL modeRequest[ NUM_OF_DG_MODES - 1 ];                            ///< Array of mode request flags.
 static DG_OP_MODE_T currentMode = DG_MODE_INIT;                                     ///< The currently active mode.
 static U32 currentSubMode = 0;                                                      ///< The currently active state of the active mode.
-static U32 broadcastModeIntervalCtr = 11;                                           ///< Interval counter used to determine when to broadcase operation mode.  Initialize to 11 to stagger broadcast.
-static U32 dgOpModePublicationTimerCounter = 0;                                    ///< Timer counter for DG operation mode publication
+static U32 broadcastModeIntervalCtr = 11;                                           ///< Interval counter used to determine when to broadcast operation mode.  Initialize to 11 to stagger broadcast.
 
 /// This matrix determines legal transitions from one mode to another.
-static const DG_OP_MODE_T MODE_TRANSITION_TABLE[NUM_OF_DG_MODES - 1][NUM_OF_DG_MODES - 1] =
+static const DG_OP_MODE_T MODE_TRANSITION_TABLE[ NUM_OF_DG_MODES - 1 ][ NUM_OF_DG_MODES - 1 ] =
 {
 // from     to->           FAULT        SERVICE         INIT         STANBY       STBY-SOLO      RE-CIRC       FILL          DRAIN         FLUSH         HEAT DIS     CHEM DIS
         /* FAUL     */{ DG_MODE_FAUL, DG_MODE_SERV, DG_MODE_NLEG, DG_MODE_NLEG, DG_MODE_NLEG, DG_MODE_NLEG, DG_MODE_NLEG, DG_MODE_NLEG, DG_MODE_NLEG, DG_MODE_NLEG, DG_MODE_NLEG },
@@ -107,9 +106,6 @@
     initFlushMode();
     initHeatDisinfectMode();
     initChemicalDisinfectMode();
-
-    // initialize broadcast timer counter
-    dgOpModePublicationTimerCounter = 0;
 }
 
 /*********************************************************************//**
@@ -125,7 +121,7 @@
 
     // any new mode requests?
     newMode = arbitrateModeRequest();   // will return current mode if no pending requests
-    newMode = MODE_TRANSITION_TABLE[currentMode][newMode];
+    newMode = MODE_TRANSITION_TABLE[ currentMode ][ newMode ];
 
     // is requested new mode valid and legal at this time?
     if ( newMode >= DG_MODE_NLEG )
@@ -194,7 +190,7 @@
             currentMode = DG_MODE_FAUL;
             currentSubMode = 0;
             break;
-    }   // end switch
+    }
 
     // publish op mode on interval
     broadcastOperationMode();
Index: firmware/App/Services/SystemComm.c
===================================================================
diff -u -r32d22b41c0297166bf2c89e59c968d69828d5025 -r0bf1c0824844ed4c227eef0323238daedf505dc7
--- firmware/App/Services/SystemComm.c	(.../SystemComm.c)	(revision 32d22b41c0297166bf2c89e59c968d69828d5025)
+++ firmware/App/Services/SystemComm.c	(.../SystemComm.c)	(revision 0bf1c0824844ed4c227eef0323238daedf505dc7)
@@ -1148,6 +1148,10 @@
                 handleDGSoftwareResetRequest( message );
                 break;
 
+            case MSG_ID_DG_OPERATION_MODE_REQUEST:
+                handleDGOperationModeRequest( message );
+                break;
+
             case MSG_ID_CONCENTRATE_PUMP_TARGET_SPEED_OVERRIDE:
                 handleSetConcentratePumpTargetSpeed( message );
                 break;
Index: firmware/App/Services/SystemCommMessages.c
===================================================================
diff -u -r32d22b41c0297166bf2c89e59c968d69828d5025 -r0bf1c0824844ed4c227eef0323238daedf505dc7
--- firmware/App/Services/SystemCommMessages.c	(.../SystemCommMessages.c)	(revision 32d22b41c0297166bf2c89e59c968d69828d5025)
+++ firmware/App/Services/SystemCommMessages.c	(.../SystemCommMessages.c)	(revision 0bf1c0824844ed4c227eef0323238daedf505dc7)
@@ -1900,6 +1900,35 @@
 
 /*********************************************************************//**
  * @brief
+ * The handleDGOperationModeRequest function handles a request to change
+ * DG operation mode.
+ * @details Inputs: none
+ * @details Outputs: message handled
+ * @param message a pointer to the message to handle
+ * @return none
+ *************************************************************************/
+void handleDGOperationModeRequest( MESSAGE_T *message )
+{
+    BOOL result = FALSE;
+    DG_OP_MODE_T mode;
+
+    // verify payload length
+    if ( sizeof( DG_OP_MODE_T ) == message->hdr.payloadLen )
+    {
+        if ( TRUE == isTestingActivated() )
+        {
+            memcpy( &mode, message->payload, sizeof( DG_OP_MODE_T ) );
+            requestNewOperationMode( mode );
+            result = mode < DG_MODE_NLEG;
+        }
+    }
+
+    // respond to request
+    sendTestAckResponseMsg( (MSG_ID_T)message->hdr.msgID, result );
+}
+
+/*********************************************************************//**
+ * @brief
  * The handleSetConcentratePumpTargetSpeed function handles a request to
  * override a concentrate pump's target speed value.
  * @details Inputs: none
Index: firmware/App/Services/SystemCommMessages.h
===================================================================
diff -u -r32d22b41c0297166bf2c89e59c968d69828d5025 -r0bf1c0824844ed4c227eef0323238daedf505dc7
--- firmware/App/Services/SystemCommMessages.h	(.../SystemCommMessages.h)	(revision 32d22b41c0297166bf2c89e59c968d69828d5025)
+++ firmware/App/Services/SystemCommMessages.h	(.../SystemCommMessages.h)	(revision 0bf1c0824844ed4c227eef0323238daedf505dc7)
@@ -200,6 +200,9 @@
 // MSG_ID_DG_SOFTWARE_RESET_REQUEST
 void handleDGSoftwareResetRequest( MESSAGE_T *message);
 
+// MSG_ID_DG_OPERATION_MODE_REQUEST
+void handleDGOperationModeRequest( MESSAGE_T *message);
+
 // MSG_ID_CONCENTRATE_PUMP_TARGET_SPEED_OVERRIDE
 void handleSetConcentratePumpTargetSpeed( MESSAGE_T *message );