first commit

2022-10-20 20:29:11 +08:00
commit 4d531f8044
3238 changed files with 1387862 additions and 0 deletions
--- a/src/Network/DDS/CMakeLists.txt
+++ b/src/Network/DDS/CMakeLists.txt
@@ -0,0 +1,34 @@
+include(FlightGearComponent)
+
+set(SOURCES
+        dds_ctrls.c
+        dds_gui.c
+        dds_fdm.c
+        dds_props.c
+	)
+
+set(HEADERS
+        dds_ctrls.h
+        dds_fdm.h
+        dds_gui.h
+        dds_props.h
+	)
+
+add_executable(fg_dds_log
+    WIN32
+    MACOSX_BUNDLE
+    fg_dds_log.cpp
+    ${SOURCES}
+)
+setup_fgfs_libraries(fg_dds_log)
+
+add_executable(fg_dds_prop
+    WIN32
+    MACOSX_BUNDLE
+    fg_dds_prop.cpp
+    ${SOURCES}
+)
+setup_fgfs_libraries(fg_dds_prop)
+
+
+flightgear_component(Network "${SOURCES}" "${HEADERS}")
--- a/src/Network/DDS/README
+++ b/src/Network/DDS/README
@@ -0,0 +1,12 @@
+
+Converting the OMG-IDL compatible interface definition files to C compatible
+header and code files can be done using the package provided by CycloneDDS,
+or any other OMG-IDL compatible IDL to C converter.
+
+java -classpath "/usr/lib/cmake/CycloneDDS/idlc/idlc-jar-with-dependencies.jar"\
+                org.eclipse.cyclonedds.compilers.Idlc dds_<type>.idl
+
+The .idl files as well as the genereated dds_ctrls, dds_fdm and dds_gui header
+and souce files in this dirctory are in the Public Domain, and come with no
+warranty.
+
--- a/src/Network/DDS/dds_ctrls.c
+++ b/src/Network/DDS/dds_ctrls.c
@@ -0,0 +1,88 @@
+/****************************************************************
+
+  Generated by Eclipse Cyclone DDS IDL to C Translator
+  File name: dds_ctrls.c
+  Source: dds_ctrls.idl
+  Cyclone DDS: V0.7.0
+
+*****************************************************************/
+#include "dds_ctrls.h"
+
+
+static const dds_key_descriptor_t FG_DDS_Ctrls_keys[1] =
+{
+  { "id", 0 }
+};
+
+static const uint32_t FG_DDS_Ctrls_ops [] =
+{
+  DDS_OP_ADR | DDS_OP_TYPE_2BY | DDS_OP_FLAG_SGN | DDS_OP_FLAG_KEY, offsetof (FG_DDS_Ctrls, id),
+  DDS_OP_ADR | DDS_OP_TYPE_2BY | DDS_OP_FLAG_SGN, offsetof (FG_DDS_Ctrls, version),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_Ctrls, aileron),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_Ctrls, elevator),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_Ctrls, rudder),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_Ctrls, aileron_trim),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_Ctrls, elevator_trim),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_Ctrls, rudder_trim),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_Ctrls, flaps),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_Ctrls, spoilers),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_Ctrls, speedbrake),
+  DDS_OP_ADR | DDS_OP_TYPE_BOO, offsetof (FG_DDS_Ctrls, flaps_power),
+  DDS_OP_ADR | DDS_OP_TYPE_BOO, offsetof (FG_DDS_Ctrls, flap_motor_ok),
+  DDS_OP_ADR | DDS_OP_TYPE_2BY, offsetof (FG_DDS_Ctrls, num_engines),
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_BOO, offsetof (FG_DDS_Ctrls, master_bat), 4,
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_BOO, offsetof (FG_DDS_Ctrls, master_alt), 4,
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_4BY, offsetof (FG_DDS_Ctrls, magnetos), 4,
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_4BY, offsetof (FG_DDS_Ctrls, starter_power), 4,
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_Ctrls, throttle), 4,
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_Ctrls, mixture), 4,
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_Ctrls, condition), 4,
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_4BY, offsetof (FG_DDS_Ctrls, fuel_pump_power), 4,
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_Ctrls, prop_advance), 4,
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_2BY, offsetof (FG_DDS_Ctrls, feed_tank_to), 4,
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_BOO, offsetof (FG_DDS_Ctrls, reverse), 4,
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_BOO, offsetof (FG_DDS_Ctrls, engine_ok), 4,
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_BOO, offsetof (FG_DDS_Ctrls, mag_left_ok), 4,
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_BOO, offsetof (FG_DDS_Ctrls, mag_right_ok), 4,
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_BOO, offsetof (FG_DDS_Ctrls, spark_plugs_ok), 4,
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_2BY, offsetof (FG_DDS_Ctrls, oil_press_status), 4,
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_BOO, offsetof (FG_DDS_Ctrls, fuel_pump_ok), 4,
+  DDS_OP_ADR | DDS_OP_TYPE_2BY, offsetof (FG_DDS_Ctrls, num_tanks),
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_2BY, offsetof (FG_DDS_Ctrls, fuel_selector), 8,
+  DDS_OP_ADR | DDS_OP_TYPE_BOO, offsetof (FG_DDS_Ctrls, cross_feed),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_Ctrls, brake_left),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_Ctrls, brake_right),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_Ctrls, copilot_brake_left),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_Ctrls, copilot_brake_right),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_Ctrls, brake_parking),
+  DDS_OP_ADR | DDS_OP_TYPE_BOO, offsetof (FG_DDS_Ctrls, gear_handle),
+  DDS_OP_ADR | DDS_OP_TYPE_BOO, offsetof (FG_DDS_Ctrls, master_avionics),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_Ctrls, comm_1),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_Ctrls, comm_2),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_Ctrls, nav_1),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_Ctrls, nav_2),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_Ctrls, wind_speed_kt),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_Ctrls, wind_dir_deg),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_Ctrls, turbulence_norm),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_Ctrls, temp_c),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_Ctrls, press_inhg),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_Ctrls, hground),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_Ctrls, magvar),
+  DDS_OP_ADR | DDS_OP_TYPE_BOO, offsetof (FG_DDS_Ctrls, icing),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY, offsetof (FG_DDS_Ctrls, speedup),
+  DDS_OP_ADR | DDS_OP_TYPE_2BY, offsetof (FG_DDS_Ctrls, freeze),
+  DDS_OP_RTS
+};
+
+const dds_topic_descriptor_t FG_DDS_Ctrls_desc =
+{
+  sizeof (FG_DDS_Ctrls),
+  4u,
+  DDS_TOPIC_FIXED_KEY,
+  1u,
+  "FG::DDS_Ctrls",
+  FG_DDS_Ctrls_keys,
+  56,
+  FG_DDS_Ctrls_ops,
+  "<MetaData version=\"1.0.0\"><Module name=\"FG\"><Struct name=\"DDS_Ctrls\"><Member name=\"id\"><Short/></Member><Member name=\"version\"><Short/></Member><Member name=\"aileron\"><Float/></Member><Member name=\"elevator\"><Float/></Member><Member name=\"rudder\"><Float/></Member><Member name=\"aileron_trim\"><Float/></Member><Member name=\"elevator_trim\"><Float/></Member><Member name=\"rudder_trim\"><Float/></Member><Member name=\"flaps\"><Float/></Member><Member name=\"spoilers\"><Float/></Member><Member name=\"speedbrake\"><Float/></Member><Member name=\"flaps_power\"><Boolean/></Member><Member name=\"flap_motor_ok\"><Boolean/></Member><Member name=\"num_engines\"><UShort/></Member><Member name=\"master_bat\"><Array size=\"4\"><Boolean/></Array></Member><Member name=\"master_alt\"><Array size=\"4\"><Boolean/></Array></Member><Member name=\"magnetos\"><Array size=\"4\"><ULong/></Array></Member><Member name=\"starter_power\"><Array size=\"4\"><ULong/></Array></Member><Member name=\"throttle\"><Array size=\"4\"><Float/></Array></Member><Member name=\"mixture\"><Array size=\"4\"><Float/></Array></Member><Member name=\"condition\"><Array size=\"4\"><Float/></Array></Member><Member name=\"fuel_pump_power\"><Array size=\"4\"><ULong/></Array></Member><Member name=\"prop_advance\"><Array size=\"4\"><Float/></Array></Member><Member name=\"feed_tank_to\"><Array size=\"4\"><UShort/></Array></Member><Member name=\"reverse\"><Array size=\"4\"><Boolean/></Array></Member><Member name=\"engine_ok\"><Array size=\"4\"><Boolean/></Array></Member><Member name=\"mag_left_ok\"><Array size=\"4\"><Boolean/></Array></Member><Member name=\"mag_right_ok\"><Array size=\"4\"><Boolean/></Array></Member><Member name=\"spark_plugs_ok\"><Array size=\"4\"><Boolean/></Array></Member><Member name=\"oil_press_status\"><Array size=\"4\"><UShort/></Array></Member><Member name=\"fuel_pump_ok\"><Array size=\"4\"><Boolean/></Array></Member><Member name=\"num_tanks\"><UShort/></Member><Member name=\"fuel_selector\"><Array size=\"8\"><UShort/></Array></Member><Member name=\"cross_feed\"><Boolean/></Member><Member name=\"brake_left\"><Float/></Member><Member name=\"brake_right\"><Float/></Member><Member name=\"copilot_brake_left\"><Float/></Member><Member name=\"copilot_brake_right\"><Float/></Member><Member name=\"brake_parking\"><Float/></Member><Member name=\"gear_handle\"><Boolean/></Member><Member name=\"master_avionics\"><Boolean/></Member><Member name=\"comm_1\"><Float/></Member><Member name=\"comm_2\"><Float/></Member><Member name=\"nav_1\"><Float/></Member><Member name=\"nav_2\"><Float/></Member><Member name=\"wind_speed_kt\"><Float/></Member><Member name=\"wind_dir_deg\"><Float/></Member><Member name=\"turbulence_norm\"><Float/></Member><Member name=\"temp_c\"><Float/></Member><Member name=\"press_inhg\"><Float/></Member><Member name=\"hground\"><Float/></Member><Member name=\"magvar\"><Float/></Member><Member name=\"icing\"><Boolean/></Member><Member name=\"speedup\"><ULong/></Member><Member name=\"freeze\"><UShort/></Member></Struct></Module></MetaData>"
+};
--- a/src/Network/DDS/dds_ctrls.h
+++ b/src/Network/DDS/dds_ctrls.h
@@ -0,0 +1,96 @@
+/****************************************************************
+
+  Generated by Eclipse Cyclone DDS IDL to C Translator
+  File name: dds_ctrls.h
+  Source: dds_ctrls.idl
+  Cyclone DDS: V0.7.0
+
+*****************************************************************/
+
+#include "dds/ddsc/dds_public_impl.h"
+
+#ifndef _DDSL_DDS_CTRLS_H_
+#define _DDSL_DDS_CTRLS_H_
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define FG_DDS_CTRLS_VERSION 1
+#define FG_DDS_ENGINES 4
+#define FG_DDS_WHEELS 16
+#define FG_DDS_TANKS 8
+
+
+typedef struct FG_DDS_Ctrls
+{
+  int16_t id;
+  int16_t version;
+  float aileron;
+  float elevator;
+  float rudder;
+  float aileron_trim;
+  float elevator_trim;
+  float rudder_trim;
+  float flaps;
+  float spoilers;
+  float speedbrake;
+  bool flaps_power;
+  bool flap_motor_ok;
+  uint16_t num_engines;
+  bool master_bat[4];
+  bool master_alt[4];
+  uint32_t magnetos[4];
+  uint32_t starter_power[4];
+  float throttle[4];
+  float mixture[4];
+  float condition[4];
+  uint32_t fuel_pump_power[4];
+  float prop_advance[4];
+  uint16_t feed_tank_to[4];
+  bool reverse[4];
+  bool engine_ok[4];
+  bool mag_left_ok[4];
+  bool mag_right_ok[4];
+  bool spark_plugs_ok[4];
+  uint16_t oil_press_status[4];
+  bool fuel_pump_ok[4];
+  uint16_t num_tanks;
+  uint16_t fuel_selector[8];
+  bool cross_feed;
+  float brake_left;
+  float brake_right;
+  float copilot_brake_left;
+  float copilot_brake_right;
+  float brake_parking;
+  bool gear_handle;
+  bool master_avionics;
+  float comm_1;
+  float comm_2;
+  float nav_1;
+  float nav_2;
+  float wind_speed_kt;
+  float wind_dir_deg;
+  float turbulence_norm;
+  float temp_c;
+  float press_inhg;
+  float hground;
+  float magvar;
+  bool icing;
+  uint32_t speedup;
+  uint16_t freeze;
+} FG_DDS_Ctrls;
+
+extern const dds_topic_descriptor_t FG_DDS_Ctrls_desc;
+
+#define FG_DDS_Ctrls__alloc() \
+((FG_DDS_Ctrls*) dds_alloc (sizeof (FG_DDS_Ctrls)));
+
+#define FG_DDS_Ctrls_free(d,o) \
+dds_sample_free ((d), &FG_DDS_Ctrls_desc, (o))
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* _DDSL_DDS_CTRLS_H_ */
--- a/src/Network/DDS/dds_ctrls.idl
+++ b/src/Network/DDS/dds_ctrls.idl
@@ -0,0 +1,113 @@
+// format dfescription: https://www.omg.org/spec/IDL/4.2/PDF
+
+// Adapted from net_ctrls.hxx
+module FG
+{
+
+// defining it this way also generates accompanying #defines in the header file.
+
+const short DDS_CTRLS_VERSION = 1;
+
+const short DDS_ENGINES = 4;
+const short DDS_WHEELS = 16;
+const short DDS_TANKS = 8;
+
+struct DDS_Ctrls
+{
+    short id;			// DDS id
+    short version;		// packet version
+
+    // Aero controls
+    // net_ctrl.hxx defines doubles but flouts do have enough precission
+    float aileron;		// -1 ... 1
+    float elevator;		// -1 ... 1
+    float rudder;		// -1 ... 1
+    float aileron_trim;		// -1 ... 1
+    float elevator_trim;	// -1 ... 1
+    float rudder_trim;		// -1 ... 1
+    float flaps;		//  0 ... 1
+    float spoilers;
+    float speedbrake;
+
+    // Aero control faults
+    boolean flaps_power;	// true = power available
+    boolean flap_motor_ok;
+
+    // Engine controls
+    unsigned short num_engines;	// number of valid engines
+    boolean master_bat[DDS_ENGINES];
+    boolean master_alt[DDS_ENGINES];
+    unsigned long magnetos[DDS_ENGINES];
+    unsigned long starter_power[DDS_ENGINES];	// true = starter power
+    float throttle[DDS_ENGINES];		//  0 ... 1
+    float mixture[DDS_ENGINES];			//  0 ... 1
+    float condition[DDS_ENGINES];		//  0 ... 1
+    unsigned long fuel_pump_power[DDS_ENGINES];	// true = on
+    float prop_advance[DDS_ENGINES];		//  0 ... 1
+    unsigned short feed_tank_to[4];
+    boolean reverse[4];
+
+
+    // Engine faults
+    boolean engine_ok[DDS_ENGINES];
+    boolean mag_left_ok[DDS_ENGINES];
+    boolean mag_right_ok[DDS_ENGINES];
+    boolean spark_plugs_ok[DDS_ENGINES];	// false = fouled plugs
+    unsigned short oil_press_status[DDS_ENGINES];// 0 = normal, 1 = low, 2 = full fail
+    boolean fuel_pump_ok[DDS_ENGINES];
+
+    // Fuel management
+    unsigned short num_tanks;			// number of valid tanks
+    unsigned short fuel_selector[DDS_TANKS];	// false = off, true = on
+//  unsigned short xfer_pump[5];		// specifies transfer from array
+						// value tank to tank specified
+						// by int value
+    boolean cross_feed;				// false = off, true = on
+
+    // Brake controls
+    float brake_left;
+    float brake_right;
+    float copilot_brake_left;
+    float copilot_brake_right;
+    float brake_parking;
+
+    // Landing Gear
+    boolean gear_handle;	// true=gear handle down; false= gear handle up
+
+    // Switches
+    boolean master_avionics;
+
+    // nav and Comm
+    float comm_1;
+    float comm_2;
+    float nav_1;
+    float nav_2;
+
+    // wind and turbulance
+    float wind_speed_kt;
+    float wind_dir_deg;
+    float turbulence_norm;
+
+    // temp and pressure
+    float temp_c;
+    float press_inhg;
+
+    // other information about environment
+    float hground;			// ground elevation (meters)
+    float magvar;			// local magnetic variation in degs.
+
+    // hazards
+    boolean icing;			// icing status could me much
+					// more complex but I'm
+					// starting simple here.
+
+    // simulation control
+    unsigned long speedup;		// integer speedup multiplier
+    unsigned short freeze;		// 0=normal
+					// 0x01=master
+					// 0x02=position
+					// 0x04=fuel
+};
+#pragma keylist DDS_Ctrls id
+
+}; // module FG
--- a/src/Network/DDS/dds_fdm.c
+++ b/src/Network/DDS/dds_fdm.c
@@ -0,0 +1,96 @@
+/****************************************************************
+
+  Generated by Eclipse Cyclone DDS IDL to C Translator
+  File name: dds_fdm.c
+  Source: dds_fdm.idl
+  Cyclone DDS: V0.7.0
+
+*****************************************************************/
+#include "dds_fdm.h"
+
+
+static const dds_key_descriptor_t FG_DDS_FDM_keys[1] =
+{
+  { "id", 0 }
+};
+
+static const uint32_t FG_DDS_FDM_ops [] =
+{
+  DDS_OP_ADR | DDS_OP_TYPE_2BY | DDS_OP_FLAG_SGN | DDS_OP_FLAG_KEY, offsetof (FG_DDS_FDM, id),
+  DDS_OP_ADR | DDS_OP_TYPE_2BY | DDS_OP_FLAG_SGN, offsetof (FG_DDS_FDM, version),
+  DDS_OP_ADR | DDS_OP_TYPE_8BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, longitude),
+  DDS_OP_ADR | DDS_OP_TYPE_8BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, latitude),
+  DDS_OP_ADR | DDS_OP_TYPE_8BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, altitude),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, agl),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, phi),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, theta),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, psi),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, alpha),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, beta),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, phidot),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, thetadot),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, psidot),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, vcas),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, climb_rate),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, v_north),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, v_east),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, v_down),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, v_body_u),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, v_body_v),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, v_body_w),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, A_X_pilot),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, A_Y_pilot),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, A_Z_pilot),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, stall_warning),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, slip_deg),
+  DDS_OP_ADR | DDS_OP_TYPE_2BY, offsetof (FG_DDS_FDM, num_engines),
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_2BY, offsetof (FG_DDS_FDM, eng_state), 4,
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, rpm), 4,
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, fuel_flow), 4,
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, fuel_px), 4,
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, egt), 4,
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, cht), 4,
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, mp_osi), 4,
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, tit), 4,
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, oil_temp), 4,
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, oil_px), 4,
+  DDS_OP_ADR | DDS_OP_TYPE_2BY, offsetof (FG_DDS_FDM, num_tanks),
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, fuel_quantity), 8,
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_BOO, offsetof (FG_DDS_FDM, tank_selected), 8,
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, capacity_m3), 8,
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, unusable_m3), 8,
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, density_kgpm3), 8,
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, level_m3), 8,
+  DDS_OP_ADR | DDS_OP_TYPE_2BY, offsetof (FG_DDS_FDM, num_wheels),
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_2BY, offsetof (FG_DDS_FDM, wow), 16,
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, gear_pos), 16,
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, gear_steer), 16,
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, gear_compression), 16,
+  DDS_OP_ADR | DDS_OP_TYPE_8BY, offsetof (FG_DDS_FDM, cur_time),
+  DDS_OP_ADR | DDS_OP_TYPE_8BY, offsetof (FG_DDS_FDM, warp),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, visibility),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, elevator),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, elevator_trim_tab),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, left_flap),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, right_flap),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, left_aileron),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, right_aileron),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, rudder),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, nose_wheel),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, speedbrake),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_FDM, spoilers),
+  DDS_OP_RTS
+};
+
+const dds_topic_descriptor_t FG_DDS_FDM_desc =
+{
+  sizeof (FG_DDS_FDM),
+  8u,
+  DDS_TOPIC_FIXED_KEY,
+  1u,
+  "FG::DDS_FDM",
+  FG_DDS_FDM_keys,
+  64,
+  FG_DDS_FDM_ops,
+  "<MetaData version=\"1.0.0\"><Module name=\"FG\"><Struct name=\"DDS_FDM\"><Member name=\"id\"><Short/></Member><Member name=\"version\"><Short/></Member><Member name=\"longitude\"><Double/></Member><Member name=\"latitude\"><Double/></Member><Member name=\"altitude\"><Double/></Member><Member name=\"agl\"><Float/></Member><Member name=\"phi\"><Float/></Member><Member name=\"theta\"><Float/></Member><Member name=\"psi\"><Float/></Member><Member name=\"alpha\"><Float/></Member><Member name=\"beta\"><Float/></Member><Member name=\"phidot\"><Float/></Member><Member name=\"thetadot\"><Float/></Member><Member name=\"psidot\"><Float/></Member><Member name=\"vcas\"><Float/></Member><Member name=\"climb_rate\"><Float/></Member><Member name=\"v_north\"><Float/></Member><Member name=\"v_east\"><Float/></Member><Member name=\"v_down\"><Float/></Member><Member name=\"v_body_u\"><Float/></Member><Member name=\"v_body_v\"><Float/></Member><Member name=\"v_body_w\"><Float/></Member><Member name=\"A_X_pilot\"><Float/></Member><Member name=\"A_Y_pilot\"><Float/></Member><Member name=\"A_Z_pilot\"><Float/></Member><Member name=\"stall_warning\"><Float/></Member><Member name=\"slip_deg\"><Float/></Member><Member name=\"num_engines\"><UShort/></Member><Member name=\"eng_state\"><Array size=\"4\"><UShort/></Array></Member><Member name=\"rpm\"><Array size=\"4\"><Float/></Array></Member><Member name=\"fuel_flow\"><Array size=\"4\"><Float/></Array></Member><Member name=\"fuel_px\"><Array size=\"4\"><Float/></Array></Member><Member name=\"egt\"><Array size=\"4\"><Float/></Array></Member><Member name=\"cht\"><Array size=\"4\"><Float/></Array></Member><Member name=\"mp_osi\"><Array size=\"4\"><Float/></Array></Member><Member name=\"tit\"><Array size=\"4\"><Float/></Array></Member><Member name=\"oil_temp\"><Array size=\"4\"><Float/></Array></Member><Member name=\"oil_px\"><Array size=\"4\"><Float/></Array></Member><Member name=\"num_tanks\"><UShort/></Member><Member name=\"fuel_quantity\"><Array size=\"8\"><Float/></Array></Member><Member name=\"tank_selected\"><Array size=\"8\"><Boolean/></Array></Member><Member name=\"capacity_m3\"><Array size=\"8\"><Float/></Array></Member><Member name=\"unusable_m3\"><Array size=\"8\"><Float/></Array></Member><Member name=\"density_kgpm3\"><Array size=\"8\"><Float/></Array></Member><Member name=\"level_m3\"><Array size=\"8\"><Float/></Array></Member><Member name=\"num_wheels\"><UShort/></Member><Member name=\"wow\"><Array size=\"16\"><UShort/></Array></Member><Member name=\"gear_pos\"><Array size=\"16\"><Float/></Array></Member><Member name=\"gear_steer\"><Array size=\"16\"><Float/></Array></Member><Member name=\"gear_compression\"><Array size=\"16\"><Float/></Array></Member><Member name=\"cur_time\"><ULongLong/></Member><Member name=\"warp\"><ULongLong/></Member><Member name=\"visibility\"><Float/></Member><Member name=\"elevator\"><Float/></Member><Member name=\"elevator_trim_tab\"><Float/></Member><Member name=\"left_flap\"><Float/></Member><Member name=\"right_flap\"><Float/></Member><Member name=\"left_aileron\"><Float/></Member><Member name=\"right_aileron\"><Float/></Member><Member name=\"rudder\"><Float/></Member><Member name=\"nose_wheel\"><Float/></Member><Member name=\"speedbrake\"><Float/></Member><Member name=\"spoilers\"><Float/></Member></Struct></Module></MetaData>"
+};
--- a/src/Network/DDS/dds_fdm.h
+++ b/src/Network/DDS/dds_fdm.h
@@ -0,0 +1,104 @@
+/****************************************************************
+
+  Generated by Eclipse Cyclone DDS IDL to C Translator
+  File name: dds_fdm.h
+  Source: dds_fdm.idl
+  Cyclone DDS: V0.7.0
+
+*****************************************************************/
+
+#include "dds/ddsc/dds_public_impl.h"
+
+#ifndef _DDSL_DDS_FDM_H_
+#define _DDSL_DDS_FDM_H_
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define FG_DDS_FDM_VERSION 1
+#define FG_DDS_ENGINES 4
+#define FG_DDS_WHEELS 16
+#define FG_DDS_TANKS 8
+
+
+typedef struct FG_DDS_FDM
+{
+  int16_t id;
+  int16_t version;
+  double longitude;
+  double latitude;
+  double altitude;
+  float agl;
+  float phi;
+  float theta;
+  float psi;
+  float alpha;
+  float beta;
+  float phidot;
+  float thetadot;
+  float psidot;
+  float vcas;
+  float climb_rate;
+  float v_north;
+  float v_east;
+  float v_down;
+  float v_body_u;
+  float v_body_v;
+  float v_body_w;
+  float A_X_pilot;
+  float A_Y_pilot;
+  float A_Z_pilot;
+  float stall_warning;
+  float slip_deg;
+  uint16_t num_engines;
+  uint16_t eng_state[4];
+  float rpm[4];
+  float fuel_flow[4];
+  float fuel_px[4];
+  float egt[4];
+  float cht[4];
+  float mp_osi[4];
+  float tit[4];
+  float oil_temp[4];
+  float oil_px[4];
+  uint16_t num_tanks;
+  float fuel_quantity[8];
+  bool tank_selected[8];
+  float capacity_m3[8];
+  float unusable_m3[8];
+  float density_kgpm3[8];
+  float level_m3[8];
+  uint16_t num_wheels;
+  uint16_t wow[16];
+  float gear_pos[16];
+  float gear_steer[16];
+  float gear_compression[16];
+  uint64_t cur_time;
+  uint64_t warp;
+  float visibility;
+  float elevator;
+  float elevator_trim_tab;
+  float left_flap;
+  float right_flap;
+  float left_aileron;
+  float right_aileron;
+  float rudder;
+  float nose_wheel;
+  float speedbrake;
+  float spoilers;
+} FG_DDS_FDM;
+
+extern const dds_topic_descriptor_t FG_DDS_FDM_desc;
+
+#define FG_DDS_FDM__alloc() \
+((FG_DDS_FDM*) dds_alloc (sizeof (FG_DDS_FDM)));
+
+#define FG_DDS_FDM_free(d,o) \
+dds_sample_free ((d), &FG_DDS_FDM_desc, (o))
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* _DDSL_DDS_FDM_H_ */
--- a/src/Network/DDS/dds_fdm.idl
+++ b/src/Network/DDS/dds_fdm.idl
@@ -0,0 +1,106 @@
+// format dfescription: https://www.omg.org/spec/IDL/4.2/PDF
+
+// Adapted from net_fdm.hxx
+module FG
+{
+
+// defining it this way also generates accompanying #defines in the header file.
+
+const short DDS_FDM_VERSION = 1;
+
+// same as defined in net_ctrls.hxx
+// this is different from net_fdm.hxx
+const short DDS_ENGINES = 4;
+const short DDS_WHEELS = 16;
+const short DDS_TANKS = 8;
+
+struct DDS_FDM
+{
+    short id;		// DDS id
+    short version;	// packet version
+
+    // Positions
+    double longitude;	// geodetic (radians)
+    double latitude;	// geodetic (radians)
+    double altitude;	// above sea level (meters)
+    float agl;		// above ground level (meters)
+    float phi;		// roll (radians)
+    float theta;	// pitch (radians)
+    float psi;		// yaw or true heading (radians)
+    float alpha;	// angle of attack (radians)
+    float beta;		// side slip angle (radians)
+
+    // Velocities
+    float phidot;	// roll rate (radians/sec)
+    float thetadot;	// pitch rate (radians/sec)
+    float psidot;	// yaw rate (radians/sec)
+    float vcas;		// calibrated airspeed
+    float climb_rate;	// feet per second
+    float v_north;	// north velocity in local/body frame, fps
+    float v_east;	// east velocity in local/body frame, fps
+    float v_down;	// down/vertical velocity in local/body frame, fps
+    float v_body_u;	// ECEF velocity in body frame
+    float v_body_v;	// ECEF velocity in body frame
+    float v_body_w;	// ECEF velocity in body frame
+
+    // Accelerations
+    float A_X_pilot;	// X accel in body frame ft/sec^2
+    float A_Y_pilot;	// Y accel in body frame ft/sec^2
+    float A_Z_pilot;	// Z accel in body frame ft/sec^2
+
+    // Stall
+    float stall_warning;// 0.0 - 1.0 indicating the amount of stall
+    float slip_deg;	// slip ball deflection
+
+    // Pressure
+ 
+    // Engine status
+    unsigned short num_engines;		// Number of valid engines
+    unsigned short eng_state[DDS_ENGINES];// Engine state (off, cranking, running)
+    float rpm[DDS_ENGINES];		// Engine RPM rev/min
+    float fuel_flow[DDS_ENGINES];	// Fuel flow gallons/hr
+    float fuel_px[DDS_ENGINES];		// Fuel pressure psi
+    float egt[DDS_ENGINES];		// Exhuast gas temp deg F
+    float cht[DDS_ENGINES];		// Cylinder head temp deg F
+    float mp_osi[DDS_ENGINES];		// Manifold pressure
+    float tit[DDS_ENGINES];		// Turbine Inlet Temperature
+    float oil_temp[DDS_ENGINES];	// Oil temp deg F
+    float oil_px[DDS_ENGINES];		// Oil pressure psi
+
+    // Consumables
+    unsigned short num_tanks;		// Max number of fuel tanks
+    float fuel_quantity[DDS_TANKS];	// used by GPSsmooth and possibly others
+    boolean tank_selected[DDS_TANKS]; // selected, capacity, usable, density and level required for multiple-pc setups to work
+    float capacity_m3[DDS_TANKS];
+    float unusable_m3[DDS_TANKS];
+    float density_kgpm3[DDS_TANKS];
+    float level_m3[DDS_TANKS];
+
+
+    // Gear status
+    unsigned short num_wheels;
+    unsigned short wow[DDS_WHEELS];
+    float gear_pos[DDS_WHEELS];
+    float gear_steer[DDS_WHEELS];
+    float gear_compression[DDS_WHEELS];
+
+    // Environment
+    unsigned long long cur_time;// current unix time, 64-bit
+    unsigned long long warp;	// offset in seconds to unix time
+    float visibility;		// visibility in meters (for env. effects)
+
+    // Control surface positions (normalized values)
+    float elevator;
+    float elevator_trim_tab;
+    float left_flap;
+    float right_flap;
+    float left_aileron;
+    float right_aileron;
+    float rudder;
+    float nose_wheel;
+    float speedbrake;
+    float spoilers;
+};
+#pragma keylist DDS_FDM id
+
+}; // module FG
--- a/src/Network/DDS/dds_fwd.hxx
+++ b/src/Network/DDS/dds_fwd.hxx
@@ -0,0 +1,10 @@
+// dds_fwd.hxx
+//
+// This file is in the Public Domain, and comes with no warranty.
+
+#pragma once
+
+#include "dds_gui.h"
+#include "dds_fdm.h"
+#include "dds_ctrls.h"
+#include "dds_props.h"
--- a/src/Network/DDS/dds_gui.c
+++ b/src/Network/DDS/dds_gui.c
@@ -0,0 +1,55 @@
+/****************************************************************
+
+  Generated by Eclipse Cyclone DDS IDL to C Translator
+  File name: dds_gui.c
+  Source: dds_gui.idl
+  Cyclone DDS: V0.7.0
+
+*****************************************************************/
+#include "dds_gui.h"
+
+
+static const dds_key_descriptor_t FG_DDS_GUI_keys[1] =
+{
+  { "id", 0 }
+};
+
+static const uint32_t FG_DDS_GUI_ops [] =
+{
+  DDS_OP_ADR | DDS_OP_TYPE_2BY | DDS_OP_FLAG_SGN | DDS_OP_FLAG_KEY, offsetof (FG_DDS_GUI, id),
+  DDS_OP_ADR | DDS_OP_TYPE_2BY | DDS_OP_FLAG_SGN, offsetof (FG_DDS_GUI, version),
+  DDS_OP_ADR | DDS_OP_TYPE_8BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_GUI, longitude),
+  DDS_OP_ADR | DDS_OP_TYPE_8BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_GUI, latitude),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_GUI, altitude),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_GUI, agl),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_GUI, phi),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_GUI, theta),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_GUI, psi),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_GUI, vcas),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_GUI, climb_rate),
+  DDS_OP_ADR | DDS_OP_TYPE_2BY, offsetof (FG_DDS_GUI, num_tanks),
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_GUI, fuel_quantity), 8,
+  DDS_OP_ADR | DDS_OP_TYPE_8BY, offsetof (FG_DDS_GUI, cur_time),
+  DDS_OP_ADR | DDS_OP_TYPE_8BY, offsetof (FG_DDS_GUI, warp),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_GUI, ground_elev),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_GUI, tuned_freq),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_GUI, nav_radial),
+  DDS_OP_ADR | DDS_OP_TYPE_BOO, offsetof (FG_DDS_GUI, in_range),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_GUI, dist_nm),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_GUI, course_deviation_deg),
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP, offsetof (FG_DDS_GUI, gs_deviation_deg),
+  DDS_OP_RTS
+};
+
+const dds_topic_descriptor_t FG_DDS_GUI_desc =
+{
+  sizeof (FG_DDS_GUI),
+  8u,
+  DDS_TOPIC_FIXED_KEY,
+  1u,
+  "FG::DDS_GUI",
+  FG_DDS_GUI_keys,
+  23,
+  FG_DDS_GUI_ops,
+  "<MetaData version=\"1.0.0\"><Module name=\"FG\"><Struct name=\"DDS_GUI\"><Member name=\"id\"><Short/></Member><Member name=\"version\"><Short/></Member><Member name=\"longitude\"><Double/></Member><Member name=\"latitude\"><Double/></Member><Member name=\"altitude\"><Float/></Member><Member name=\"agl\"><Float/></Member><Member name=\"phi\"><Float/></Member><Member name=\"theta\"><Float/></Member><Member name=\"psi\"><Float/></Member><Member name=\"vcas\"><Float/></Member><Member name=\"climb_rate\"><Float/></Member><Member name=\"num_tanks\"><UShort/></Member><Member name=\"fuel_quantity\"><Array size=\"8\"><Float/></Array></Member><Member name=\"cur_time\"><ULongLong/></Member><Member name=\"warp\"><ULongLong/></Member><Member name=\"ground_elev\"><Float/></Member><Member name=\"tuned_freq\"><Float/></Member><Member name=\"nav_radial\"><Float/></Member><Member name=\"in_range\"><Boolean/></Member><Member name=\"dist_nm\"><Float/></Member><Member name=\"course_deviation_deg\"><Float/></Member><Member name=\"gs_deviation_deg\"><Float/></Member></Struct></Module></MetaData>"
+};
--- a/src/Network/DDS/dds_gui.h
+++ b/src/Network/DDS/dds_gui.h
@@ -0,0 +1,61 @@
+/****************************************************************
+
+  Generated by Eclipse Cyclone DDS IDL to C Translator
+  File name: dds_gui.h
+  Source: dds_gui.idl
+  Cyclone DDS: V0.7.0
+
+*****************************************************************/
+
+#include "dds/ddsc/dds_public_impl.h"
+
+#ifndef _DDSL_DDS_GUI_H_
+#define _DDSL_DDS_GUI_H_
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define FG_DDS_GUI_VERSION 1
+#define FG_DDS_TANKS 8
+
+
+typedef struct FG_DDS_GUI
+{
+  int16_t id;
+  int16_t version;
+  double longitude;
+  double latitude;
+  float altitude;
+  float agl;
+  float phi;
+  float theta;
+  float psi;
+  float vcas;
+  float climb_rate;
+  uint16_t num_tanks;
+  float fuel_quantity[8];
+  uint64_t cur_time;
+  uint64_t warp;
+  float ground_elev;
+  float tuned_freq;
+  float nav_radial;
+  bool in_range;
+  float dist_nm;
+  float course_deviation_deg;
+  float gs_deviation_deg;
+} FG_DDS_GUI;
+
+extern const dds_topic_descriptor_t FG_DDS_GUI_desc;
+
+#define FG_DDS_GUI__alloc() \
+((FG_DDS_GUI*) dds_alloc (sizeof (FG_DDS_GUI)));
+
+#define FG_DDS_GUI_free(d,o) \
+dds_sample_free ((d), &FG_DDS_GUI_desc, (o))
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* _DDSL_DDS_GUI_H_ */
--- a/src/Network/DDS/dds_gui.idl
+++ b/src/Network/DDS/dds_gui.idl
@@ -0,0 +1,55 @@
+// format dfescription: https://www.omg.org/spec/IDL/4.2/PDF
+
+// Taken from net_gui.hxx
+
+module FG
+{
+
+// defining it this way also generates accompanying #defines in the header file.
+
+const short DDS_GUI_VERSION = 1;
+
+// same as defined in net_ctrls.hxx
+// this is different from net_gui.hxx
+const short DDS_TANKS = 8;
+
+struct DDS_GUI
+{
+    short id;
+    short version;
+
+    // Positions
+    double longitude;	// geodetic (radians)
+    double latitude;	// geodetic (radians)
+
+    float altitude;	// above sea level (meters)
+    float agl;		// above ground level (meters)
+    float phi;		// roll (radians)
+    float theta;	// pitch (radians)
+    float psi;		// yaw or true heading (radians)
+
+    // Velocities
+    float vcas;
+    float climb_rate;	// feet per second
+
+    // Consumables
+    unsigned short num_tanks;	// Max number of fuel tanks
+    float fuel_quantity[DDS_TANKS];
+
+    // Environment
+    unsigned long long cur_time;// current unix time
+    unsigned long long warp;		// offset in seconds to unix time
+    float ground_elev;		// ground elev (meters)
+
+    // Approach
+    float tuned_freq;		// currently tuned frequency
+    float nav_radial;		// target nav radial
+    boolean in_range;		// tuned navaid is in range?
+    float dist_nm;		// distance to tuned navaid in nautical miles
+    float course_deviation_deg;	// degrees off target course
+    float gs_deviation_deg;	// degrees off target glide slope
+};
+#pragma keylist DDS_GUI id
+
+}; // module FG
+
--- a/src/Network/DDS/dds_props.c
+++ b/src/Network/DDS/dds_props.c
@@ -0,0 +1,47 @@
+/****************************************************************
+
+  Generated by Eclipse Cyclone DDS IDL to C Translator
+  File name: dds_props.c
+  Source: dds_props.idl
+  Cyclone DDS: V0.7.0
+
+*****************************************************************/
+#include "dds_props.h"
+
+
+static const dds_key_descriptor_t FG_DDS_prop_keys[1] =
+{
+  { "id", 0 }
+};
+
+static const uint32_t FG_DDS_prop_ops [] =
+{
+  DDS_OP_ADR | DDS_OP_TYPE_4BY | DDS_OP_FLAG_SGN | DDS_OP_FLAG_KEY, offsetof (FG_DDS_prop, id),
+  DDS_OP_ADR | DDS_OP_TYPE_1BY, offsetof (FG_DDS_prop, version),
+  DDS_OP_ADR | DDS_OP_TYPE_BOO, offsetof (FG_DDS_prop, mode),
+  DDS_OP_ADR | DDS_OP_TYPE_UNI | DDS_OP_SUBTYPE_4BY | DDS_OP_FLAG_SGN, offsetof (FG_DDS_prop, val._d), 9u, (31u << 16) + 4u,
+  DDS_OP_JEQ | DDS_OP_TYPE_BOO | 0, FG_DDS_BOOL, offsetof (FG_DDS_prop, val._u.Bool),
+  DDS_OP_JEQ | DDS_OP_TYPE_4BY | DDS_OP_FLAG_SGN | 0, FG_DDS_NONE, offsetof (FG_DDS_prop, val._u.Int32),
+  DDS_OP_JEQ | DDS_OP_TYPE_4BY | DDS_OP_FLAG_SGN | 0, FG_DDS_INT, offsetof (FG_DDS_prop, val._u.Int32),
+  DDS_OP_JEQ | DDS_OP_TYPE_8BY | DDS_OP_FLAG_SGN | 0, FG_DDS_LONG, offsetof (FG_DDS_prop, val._u.Int64),
+  DDS_OP_JEQ | DDS_OP_TYPE_4BY | DDS_OP_FLAG_FP | 0, FG_DDS_FLOAT, offsetof (FG_DDS_prop, val._u.Float32),
+  DDS_OP_JEQ | DDS_OP_TYPE_8BY | DDS_OP_FLAG_FP | 0, FG_DDS_DOUBLE, offsetof (FG_DDS_prop, val._u.Float64),
+  DDS_OP_JEQ | DDS_OP_TYPE_STR | 0, FG_DDS_ALIAS, offsetof (FG_DDS_prop, val._u.String),
+  DDS_OP_JEQ | DDS_OP_TYPE_STR | 0, FG_DDS_STRING, offsetof (FG_DDS_prop, val._u.String),
+  DDS_OP_JEQ | DDS_OP_TYPE_STR | 0, FG_DDS_UNSPECIFIED, offsetof (FG_DDS_prop, val._u.String),
+  DDS_OP_ADR | DDS_OP_TYPE_ARR | DDS_OP_SUBTYPE_1BY, offsetof (FG_DDS_prop, guid), 16,
+  DDS_OP_RTS
+};
+
+const dds_topic_descriptor_t FG_DDS_prop_desc =
+{
+  sizeof (FG_DDS_prop),
+  8u,
+  DDS_TOPIC_FIXED_KEY | DDS_TOPIC_NO_OPTIMIZE | DDS_TOPIC_CONTAINS_UNION,
+  1u,
+  "FG::DDS_prop",
+  FG_DDS_prop_keys,
+  15,
+  FG_DDS_prop_ops,
+  "<MetaData version=\"1.0.0\"><Module name=\"FG\"><Enum name=\"propType\"><Element name=\"DDS_NONE\" value=\"0\"/><Element name=\"DDS_ALIAS\" value=\"1\"/><Element name=\"DDS_BOOL\" value=\"2\"/><Element name=\"DDS_INT\" value=\"3\"/><Element name=\"DDS_LONG\" value=\"4\"/><Element name=\"DDS_FLOAT\" value=\"5\"/><Element name=\"DDS_DOUBLE\" value=\"6\"/><Element name=\"DDS_STRING\" value=\"7\"/><Element name=\"DDS_UNSPECIFIED\" value=\"8\"/></Enum><Union name=\"propValue\"><SwitchType><Type name=\"propType\"/></SwitchType><Case name=\"Bool\"><Boolean/><Label value=\"DDS_BOOL\"/></Case><Case name=\"Int32\"><Long/><Label value=\"DDS_NONE\"/><Label value=\"DDS_INT\"/></Case><Case name=\"Int64\"><LongLong/><Label value=\"DDS_LONG\"/></Case><Case name=\"Float32\"><Float/><Label value=\"DDS_FLOAT\"/></Case><Case name=\"Float64\"><Double/><Label value=\"DDS_DOUBLE\"/></Case><Case name=\"String\"><String/><Label value=\"DDS_ALIAS\"/><Label value=\"DDS_STRING\"/><Label value=\"DDS_UNSPECIFIED\"/></Case></Union><Struct name=\"DDS_prop\"><Member name=\"id\"><Long/></Member><Member name=\"version\"><Octet/></Member><Member name=\"mode\"><Boolean/></Member><Member name=\"val\"><Type name=\"propValue\"/></Member><Member name=\"guid\"><Array size=\"16\"><Octet/></Array></Member></Struct></Module></MetaData>"
+};
--- a/src/Network/DDS/dds_props.h
+++ b/src/Network/DDS/dds_props.h
@@ -0,0 +1,79 @@
+/****************************************************************
+
+  Generated by Eclipse Cyclone DDS IDL to C Translator
+  File name: dds_props.h
+  Source: dds_props.idl
+  Cyclone DDS: V0.7.0
+
+*****************************************************************/
+
+#include "dds/ddsc/dds_public_impl.h"
+
+#ifndef _DDSL_DDS_PROPS_H_
+#define _DDSL_DDS_PROPS_H_
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define FG_DDS_PROP_VERSION 0
+#define FG_DDS_PROP_REQUEST -1
+#define FG_DDS_MODE_READ (0)
+#define FG_DDS_MODE_WRITE (1)
+typedef enum FG_propType
+{
+  FG_DDS_NONE,
+  FG_DDS_ALIAS,
+  FG_DDS_BOOL,
+  FG_DDS_INT,
+  FG_DDS_LONG,
+  FG_DDS_FLOAT,
+  FG_DDS_DOUBLE,
+  FG_DDS_STRING,
+  FG_DDS_UNSPECIFIED
+} FG_propType;
+
+#define FG_propType__alloc() \
+((FG_propType*) dds_alloc (sizeof (FG_propType)));
+
+
+typedef struct FG_propValue
+{
+  FG_propType _d;
+  union
+  {
+    bool Bool;
+    int32_t Int32;
+    int64_t Int64;
+    float Float32;
+    double Float64;
+    char * String;
+  } _u;
+} FG_propValue;
+
+#define FG_propValue__alloc() \
+((FG_propValue*) dds_alloc (sizeof (FG_propValue)));
+
+
+typedef struct FG_DDS_prop
+{
+  int32_t id;
+  uint8_t version;
+  bool mode;
+  FG_propValue val;
+  uint8_t guid[16];
+} FG_DDS_prop;
+
+extern const dds_topic_descriptor_t FG_DDS_prop_desc;
+
+#define FG_DDS_prop__alloc() \
+((FG_DDS_prop*) dds_alloc (sizeof (FG_DDS_prop)));
+
+#define FG_DDS_prop_free(d,o) \
+dds_sample_free ((d), &FG_DDS_prop_desc, (o))
+
+#ifdef __cplusplus
+}
+#endif
+#endif /* _DDSL_DDS_PROPS_H_ */
--- a/src/Network/DDS/dds_props.idl
+++ b/src/Network/DDS/dds_props.idl
@@ -0,0 +1,90 @@
+// format dfescription: https://www.omg.org/spec/IDL/4.2/PDF
+
+// Adapted from net_fdm.hxx
+module FG
+{
+
+// defining it this way also generates accompanying #defines in the header file.
+const octet DDS_PROP_VERSION = 0;
+const short DDS_PROP_REQUEST = -1;
+const boolean DDS_MODE_READ = 0;
+const boolean DDS_MODE_WRITE = 1;
+
+enum propType
+{
+    DDS_NONE,	// The node hasn't been assigned a value yet
+    DDS_ALIAS,	// The node "points" to another node
+    DDS_BOOL,
+    DDS_INT,	// 32-bit integer
+    DDS_LONG,	// 64-bit integer
+    DDS_FLOAT,	// 32-bit floating point number
+    DDS_DOUBLE,	// 64-bit floating point number
+    DDS_STRING,	// UTF-8 string
+    DDS_UNSPECIFIED // Resolves to STRING
+};
+
+union propValue switch ( propType )
+{
+    case DDS_BOOL:
+        boolean Bool;
+
+    case DDS_NONE:
+    case DDS_INT:
+        long Int32;
+
+    case DDS_LONG:
+        long long Int64;
+
+    case DDS_FLOAT:
+        float Float32;
+
+    case DDS_DOUBLE:
+        double Float64;
+
+    case DDS_ALIAS:
+    case DDS_STRING:
+    case DDS_UNSPECIFIED:
+        string String;
+};
+
+// Initial property request sequence
+// for properties where the id is not yet known:
+// 1. Set id to FG_DDS_PROP_REQUEST
+// 2. Set version to FG_DDS_PROP_VERSION
+// 3. Set mode to FG_DDS_MODE_READ
+// 4. set guid to the 16-byte participants GUID
+// 5. Set val type to FG_DDS_STRING
+// 6. Set val String to the propery path
+// 7. Send the package.
+//
+// 8. Wait for an answer
+//    * Check whether guid matches the participants GUID.
+//    * The index of the requested propery path is stored in the id variable
+//      which should be used by successive request as the id for that property.
+//    * The val union holds the value of the propery.
+//
+// Successive property request sequence:
+// 1. Make sure id is to the id of the requested property
+// 2. Make sure version is to FG_DDS_PROP_VERSION
+// 3. Set mode to FG_DDS_MODE_READ or FG_DDS_MODE_WRITE
+// 3a. Optionally set the val union to match the property to overwrite.
+// 4. Send the package.
+//
+// 5. Wait for an answer
+//    * Check whether id matches the requested property id.
+//    * The val union holds the value of the propery.
+struct DDS_prop
+{
+    long id;		// 32-bit property index and DDS id.
+    octet version;	// 8-bit sample-type version number.
+
+    boolean mode;	// FG_DDS_MODE_READ or FG_DDS_MODE_WRITE
+    propValue val;	// property value or path.
+
+    // A sequence could be used here but unfortunatelly it's initializer
+    // already is 10-bytes in size.
+    octet guid[16];
+};
+#pragma keylist DDS_prop id
+
+}; // module FG
--- a/src/Network/DDS/fg_dds_log.cpp
+++ b/src/Network/DDS/fg_dds_log.cpp
@@ -0,0 +1,170 @@
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include <map>
+
+#include <simgear/io/SGDataDistributionService.hxx>
+
+#include "dds_fwd.hxx"
+
+/* An array of one message(aka sample in dds terms) will be used. */
+#define MAX_SAMPLES 1
+
+#ifndef _WIN32
+# include <termios.h>
+
+void set_mode(int want_key)
+{
+    static struct termios tios_old, tios_new;
+    if (!want_key) {
+        tcsetattr(STDIN_FILENO, TCSANOW, &tios_old);
+        return;
+    }
+
+    tcgetattr(STDIN_FILENO, &tios_old);
+    tios_new = tios_old;
+    tios_new.c_lflag &= ~(ICANON | ECHO);
+    tcsetattr(STDIN_FILENO, TCSANOW, &tios_new);
+}
+
+int get_key()
+{
+    int c = 0;
+    struct timeval tv;
+    fd_set fs;
+    tv.tv_usec = tv.tv_sec = 0;
+
+    FD_ZERO(&fs);
+    FD_SET(STDIN_FILENO, &fs);
+    select(STDIN_FILENO + 1, &fs, 0, 0, &tv);
+
+    if (FD_ISSET(STDIN_FILENO, &fs)) {
+        c = getchar();
+    }
+    return c;
+}
+#else
+# include <conio.h>
+
+int get_key()
+{
+   if (kbhit()) {
+      return getch();
+   }
+   return 0;
+}
+
+void set_mode(int want_key)
+{
+}
+#endif
+
+int main()
+{
+  std::map<std::string, SG_DDS_Topic*> topics;
+  SG_DDS participant;
+
+  FG_DDS_GUI gui;
+  topics["gui"] = new SG_DDS_Topic(gui, &FG_DDS_GUI_desc);
+  participant.add(topics["gui"], SG_IO_IN);
+
+  FG_DDS_FDM fdm;
+  topics["fdm"] = new SG_DDS_Topic(fdm, &FG_DDS_FDM_desc);
+  participant.add(topics["fdm"], SG_IO_IN);
+
+  FG_DDS_Ctrls ctrls;
+  topics["ctrls"] = new SG_DDS_Topic(ctrls, &FG_DDS_Ctrls_desc);
+  participant.add(topics["ctrls"], SG_IO_IN);
+
+  FG_DDS_prop prop;
+  topics["prop"] = new SG_DDS_Topic(prop, &FG_DDS_prop_desc);
+  participant.add(topics["prop"], SG_IO_IN);
+
+  set_mode(1);
+  while(participant.wait(0.1f))
+  {
+    if (topics["gui"]->read()) {
+      printf("=== [fg_dds_log] Received : ");
+      printf("GUI Message:\n");
+      printf(" version: %i\n", gui.version);
+      printf(" tuned_freq: %lf\n", gui.longitude);
+      printf(" nav_radial: %lf\n", gui.latitude);
+      printf("    dist_nm: %lf\n", gui.altitude);
+    }
+
+    if (topics["fdm"]->read()) {
+      printf("=== [fg_dds_log] Received : ");
+      printf("FDM Message:\n");
+      printf(" version: %i\n", fdm.version);
+      printf("  longitude: %lf\n", fdm.longitude);
+      printf("   latitude: %lf\n", fdm.latitude);
+      printf("   altitude: %lf\n", fdm.altitude);
+    }
+
+    if (topics["ctrls"]->read()) {
+      printf("=== [fg_dds_log] Received : ");
+      printf("Ctrls Message:\n");
+      printf(" version: %i\n", ctrls.version);
+      printf("    aileron: %lf\n", ctrls.aileron);
+      printf("   elevator: %lf\n", ctrls.elevator);
+      printf("     rudder: %lf\n", ctrls.rudder);
+    }
+
+    if (topics["prop"]->read() &&
+         prop.version == FG_DDS_PROP_VERSION )
+    {
+      printf("=== [fg_dds_log] Received : ");
+      printf("Prop Message:\n");
+      printf(" version: %i\n", prop.version);
+      printf(" mode: %s\n", prop.mode ? "write" : "read");
+      printf("   id: %i\n", prop.id);
+      if (prop.id == FG_DDS_PROP_REQUEST) {
+        printf(" path: %s\n", prop.val._u.String);
+        printf("GUID: ");
+        for(int i=0; i<16; ++i)
+          printf("%X ", prop.guid[i]);
+        printf("\n");
+      }
+      else
+      {
+        switch(prop.val._d)
+        {
+        case FG_DDS_BOOL:
+          printf("       type: bool");
+          printf("      value: %i\n", prop.val._u.Bool);
+          break;
+        case FG_DDS_INT:
+          printf("       type: int");
+          printf("      value: %i\n", prop.val._u.Int32);
+          break;
+        case FG_DDS_LONG:
+          printf("       type: long");
+          printf("      value: %li\n", prop.val._u.Int64);
+          break;
+        case FG_DDS_FLOAT:
+          printf("       type: float");
+          printf("      value: %f\n", prop.val._u.Float32);
+          break;
+        case FG_DDS_DOUBLE:
+          printf("       type: double");
+          printf("      value: %lf\n", prop.val._u.Float64);
+          break;
+        case FG_DDS_STRING:
+          printf("       type: string");
+          printf("      value: %s\n", prop.val._u.String);
+          break;
+        default:
+          break;
+        }
+      }
+    }
+
+    fflush(stdout);
+
+    if (get_key()) break;
+  }
+  set_mode(0);
+
+  return EXIT_SUCCESS;
+}
--- a/src/Network/DDS/fg_dds_prop.cpp
+++ b/src/Network/DDS/fg_dds_prop.cpp
@@ -0,0 +1,99 @@
+#include <cstdio>
+#include <cstring>
+#include <cstdlib>
+
+#include <simgear/io/SGDataDistributionService.hxx>
+
+#include "dds_props.h"
+
+/* An array of one message(aka sample in dds terms) will be used. */
+#define MAX_SAMPLES 1
+
+int main()
+{
+  SG_DDS participant;
+
+  FG_DDS_prop prop;
+  SG_DDS_Topic *topic = new SG_DDS_Topic(prop, &FG_DDS_prop_desc);
+
+  participant.add(topic, SG_IO_BI);
+
+  dds_guid_t guid = topic->get_guid();
+  memcpy(prop.guid, guid.v, 16);
+  printf("GUID: ");
+  for(int i=0; i<16; ++i)
+    printf("%X ", prop.guid[i]);
+  printf("\n");
+
+  char path[256];
+  printf("\nType 'q' to quit\n");
+  do
+  {
+    printf("Property path or id: ");
+    int len = scanf("%255s", path);
+    if (len == EOF) continue;
+
+    if (*path == 'q') break;
+
+    char *end;
+    int id = strtol(path, &end, 10);
+
+    prop.id = (end == path) ? FG_DDS_PROP_REQUEST : id;
+    prop.version = FG_DDS_PROP_VERSION;
+    prop.mode = FG_DDS_MODE_READ;
+    prop.val._d = FG_DDS_STRING;
+    prop.val._u.String = path;
+
+    topic->write();
+
+    participant.wait();
+    if (topic->read() &&
+         prop.version == FG_DDS_PROP_VERSION &&
+         prop.id != FG_DDS_PROP_REQUEST)
+    {
+      printf("\nReceived:\n");
+      switch(prop.val._d)
+      {
+      case FG_DDS_NONE:
+        printf("       type: none");
+        break;
+      case FG_DDS_ALIAS:
+        printf("       type: alias");
+        printf("      value: %s\n", prop.val._u.String);
+        break;
+      case FG_DDS_BOOL:
+        printf("       type: bool");
+        printf("      value: %i\n", prop.val._u.Bool);
+        break;
+      case FG_DDS_INT:
+        printf("       type: int");
+        printf("      value: %i\n", prop.val._u.Int32);
+        break;
+      case FG_DDS_LONG:
+        printf("       type: long");
+        printf("      value: %li\n", prop.val._u.Int64);
+        break;
+      case FG_DDS_FLOAT:
+        printf("       type: float");
+        printf("      value: %f\n", prop.val._u.Float32);
+        break;
+      case FG_DDS_DOUBLE:
+        printf("       type: double");
+        printf("      value: %lf\n", prop.val._u.Float64);
+        break;
+      case FG_DDS_STRING:
+        printf("       type: string");
+        printf("      value: %s\n", prop.val._u.String);
+        break;
+      case FG_DDS_UNSPECIFIED:
+        printf("       type: unspecified");
+        printf("      value: %s\n", prop.val._u.String);
+        break;
+      default:
+        break;
+      }
+    }
+  } while(true);
+
+  return EXIT_SUCCESS;
+}