Start of work on Redundant Link. This first step modifies the exisitng link agent to allow it to be given an id (through the -link_id flag) and to send ivy messages of a different format (when -redlink is set). The messages are sent within the TELEMETRY_MESSAGE message as a ;sv (colon-seperated-value) which are listed to by the link_combiner.py agent.

conf/messages.xml

@@ -151,6 +151,7 @@
   </message>
 
   <message name="DOWNLINK_STATUS" id="23">
+    <field name="link_id" type="int8"/>
     <field name="run_time" type="uint32" unit="s"/>
     <field name="rx_bytes" type="uint32"/>
     <field name="rx_msgs" type="uint32"/>
@@ -2461,6 +2462,18 @@
     <field name="message" type="string"/>
   </message>
 
+   <message name="TELEMETRY_MESSAGE" id="34">
+    <field name="ac_id" type="string"/>
+    <field name="link_id" type="string" />
+    <field name="message" type="string" format=";sv"/>
+   </message>
+
+  <message name="DATALINK_MESSAGE" id="35">
+    <field name="ac_id" type="string"/>
+    <field name="link_id" type="string"/>
+    <field name="message" type="string" format=";sv"/>
+  </message>
+
   <message name="PLUMES" id="100">
     <field name="ids" type="string" format="csv"/>
     <field name="lats" type="string" format="csv"/>

sw/ground_segment/tmtc/link.ml

@@ -21,7 +21,7 @@
  *)
 
 (** Agent connecting a hardware modem, usually through USB/serial, with
-    the Ivy sowtware bus.
+    the Ivy software bus.
 *)
 
 open Latlong
@@ -40,7 +40,7 @@ type transport =
   | Pprz2  (* Paparazzi protocol, with timestamp, A/C id, message id and CRC *)
   | XBee  (* Maxstream protocol, API mode *)
 let transport_of_string = function
-"pprz" -> Pprz
+    "pprz" -> Pprz
   | "pprz2" -> Pprz2
   | "xbee" -> XBee
   | x -> invalid_arg (sprintf "transport_of_string: %s" x)
@@ -53,6 +53,9 @@ type ground_device = {
 (* We assume here a single modem is used *)
 let my_id = 0
 
+(* Here we set the default id of the link*)
+let link_id = ref 1
+
 (* enable broadcast messages by default *)
 let ac_info = ref true
 
@@ -70,7 +73,7 @@ let send_message_over_ivy = fun sender name vs ->
     match !add_timestamp with
         None -> None
       | Some start_time -> Some (Unix.gettimeofday () -. start_time) in
-  Tm_Pprz.message_send ?timestamp sender name vs
+  Tm_Pprz.message_send ?timestamp ~link_id:!link_id sender name vs
 
 
 (*********** Monitoring *************************************************)
@@ -146,7 +149,8 @@ let send_status_msg =
       status.last_rx_msg <- status.rx_msg;
       status.last_rx_byte <- status.rx_byte;
       status.ms_since_last_msg <- status.ms_since_last_msg + status_msg_period;
-      let vs = ["run_time", Pprz.Int t;
+      let vs = ["link_id", Pprz.Int !link_id;
+                "run_time", Pprz.Int t;
                 "rx_bytes_rate", Pprz.Float byte_rate;
                 "rx_msgs_rate", Pprz.Float msg_rate;
                 "rx_err", Pprz.Int status.rx_err;
@@ -453,6 +457,7 @@ let () =
       "-xbee_addr", Arg.Set_int XB.my_addr, (sprintf "<my_addr> (%d)" !XB.my_addr);
       "-xbee_retries", Arg.Set_int XB.my_addr, (sprintf "<nb retries> (%d)" !XB.nb_retries);
       "-xbee_868", Arg.Set Xbee.mode868, (sprintf "Enables the 868 protocol");
+      "-id", Arg.Set_int link_id, (sprintf "Sets the link id. This must be set if multiple links are to be used.")
     ] in
   Arg.parse options (fun _x -> ()) "Usage: ";
 

sw/lib/ocaml/pprz.ml

@@ -485,10 +485,10 @@ module type MESSAGES = sig
   val string_of_message : ?sep:string -> message -> values -> string
   (** [string_of_message ?sep msg values] Default [sep] is space *)
 
-  val message_send : ?timestamp:float -> string -> string -> values -> unit
-  (** [message_send sender msg_name values] *)
+  val message_send : ?timestamp:float -> ?link_id:int -> string -> string -> values -> unit
+  (** [message_send sender link_id msg_name values] *)
 
-  val message_bind : ?sender:string ->string -> (string -> values -> unit) -> Ivy.binding
+  val message_bind : ?sender:string -> string -> (string -> values -> unit) -> Ivy.binding
   (** [message_bind ?sender msg_name callback] *)
 
   val message_answerer : string -> string -> (string -> values -> values) -> Ivy.binding
@@ -609,8 +609,22 @@ module MessagesOfXml(Class:CLASS_Xml) = struct
     if n > 1000 then (** FIXME: to prevent Ivy bug on long message *)
       fprintf stderr "Discarding long ivy message (%d bytes)\n%!" n
     else
-      Ivy.send msg
-
+      match link_id with
+        None -> Ivy.send msg
+      | Some the_link_id -> begin
+        let index = ref 0 in
+        let modified_msg = String.copy msg in
+        let func = fun c -> 
+          match c with 
+            ' ' -> begin 
+            String.set modified_msg !index ';'; 
+            index := !index + 1
+            end
+          | x -> index := !index + 1; in
+        String.iter func modified_msg;
+        Ivy.send ( Printf.sprintf "redlink TELEMETRY_MESSAGE %s %i %s" sender the_link_id modified_msg);
+      end
+          
   let message_bind = fun ?sender msg_name cb ->
     match sender with
         None ->

sw/lib/ocaml/pprz.mli

@@ -162,7 +162,7 @@ module type MESSAGES = sig
   val string_of_message : ?sep:string -> message -> values -> string
   (** [string_of_message ?sep msg values] Default [sep] is space *)
 
-  val message_send : ?timestamp:float -> string -> string -> values -> unit
+  val message_send : ?timestamp:float -> ?link_id:int -> string -> string -> values -> unit
   (** [message_send sender msg_name values] *)
 
   val message_bind : ?sender:string ->string -> (string -> values -> unit) -> Ivy.binding

sw/tools/gen_messages.ml

@@ -242,7 +242,7 @@ module Gen_onboard = struct
             sprintf "({ union { uint64_t u; double f; } _f; _f.u = (uint64_t)(%s); Swap32IfBigEndian(_f.u); _f.f; })" !s
           | 4 ->
             sprintf "(%s)(*((uint8_t*)_payload+%d)|*((uint8_t*)_payload+%d+1)<<8|((uint32_t)*((uint8_t*)_payload+%d+2))<<16|((uint32_t)*((uint8_t*)_payload+%d+3))<<24)" pprz_type.Pprz.inttype o o o o
-          | _ -> failwith "unexpected size in Gen_messages.print_get_macros" in
+          | _ -> failwith "unexpected size in Gen_messages.print_get_macros. Possibly since a Telemetry message was defined with a field type of string." in
 
       (** To be an array or not to be an array: *)
       match _type with