Index: firmware/App/Services/SystemCommMessages.c
===================================================================
diff -u -rb8f298547eb578000b3ff3cf55732fda7a689ce0 -r72bca5d2e489fa253f3bdfdb254261a32c7a0c19
--- firmware/App/Services/SystemCommMessages.c	(.../SystemCommMessages.c)	(revision b8f298547eb578000b3ff3cf55732fda7a689ce0)
+++ firmware/App/Services/SystemCommMessages.c	(.../SystemCommMessages.c)	(revision 72bca5d2e489fa253f3bdfdb254261a32c7a0c19)
@@ -4312,4 +4312,60 @@
     sendTestAckResponseMsg( (MSG_ID_T)message->hdr.msgID, result );
 }
 
+#ifndef _RELEASE_
+/*********************************************************************//**
+ * @brief
+ * The handleTestDGNelsonDisinfectSupport function handles a request
+ * to set the Nelson disinfect support mode.
+ * @details Inputs: none
+ * @details Outputs: message handled
+ * @param message a pointer to the message to handle
+ * @return none
+ *************************************************************************/
+void handleTestDGNelsonDisinfectSupport( MESSAGE_T *message )
+{
+    TEST_OVERRIDE_PAYLOAD_T payload;
+    BOOL result = FALSE;
+
+    // verify payload length
+    if ( sizeof( TEST_OVERRIDE_PAYLOAD_T ) == message->hdr.payloadLen )
+    {
+        memcpy( &payload, message->payload, sizeof( TEST_OVERRIDE_PAYLOAD_T ) );
+
+        NELSON_SUPPORT_T nelson = (NELSON_SUPPORT_T)payload.state.u32;
+
+        switch( nelson )
+        {
+            case NELSON_INOCULATE:
+                setNelsonSupportMode( nelson );
+                requestNewOperationMode( DG_MODE_HEAT );
+                break;
+
+            case NELSON_HEAT_DISINFECT:
+                setNelsonSupportMode( nelson );
+                requestNewOperationMode( DG_MODE_HEAT );
+                break;
+
+            case NELSON_POS_CONTROL_CHEM_DISINFECT:
+                setNelsonSupportMode( nelson );
+                requestNewOperationMode( DG_MODE_CHEM );
+                break;
+
+            case NELSON_CHEM_DISINFECT:
+                setNelsonSupportMode( nelson );
+                requestNewOperationMode( DG_MODE_CHEM );
+                break;
+
+            case NELSON_DRAIN_SAMPLES:
+                setNelsonSupportMode( nelson );
+                requestNewOperationMode( DG_MODE_HEAT );
+                break;
+        }
+    }
+
+    // respond to request
+    sendTestAckResponseMsg( (MSG_ID_T)message->hdr.msgID, result );
+}
+#endif
+
 /**@}*/