Pour communiquer à travers le port Infrarouge d'un PPC, il y a deux possibilités :

- Utilisez le port infrarouge comme un port COM ou LPT -> fonctions s* de WinDev

- Utiliser le port infrarouge via le protocole IrDA (Infrared Data Association) -> fonctions SocketInfraRouge

 

1- Utilisation des fonctions s* sur le port InfraRouge :

Ce mode est à utiliser pour communiquer avec des périphériques qui ne proposent pas de communication IrDA, c'est en faite une "émulation" COM/LPT via IrDA.

Ce mode peut-être utiliser pour envoyer des informations sans attendre de réponse (télécommande par exemple).

Pas de difficulté majeure, mais quelques "pièges" à éviter:

- l'option "Recevoir tous les envois entrants" doit être décochée sur le PDA.

- Pour les fonctions s* utilisées après sOuvre, il faut utiliser le résultat de sOuvre et pas le nom du port

- Ambiguïté sur sFixeParametre pour le bit de stop.

 

2- Utilisation des fonctions SocketInfraRouge (IrDa) :

Ce mode est un standard de communication InfraRouge pour faciliter les échanges de données par infrarouge. Ce protocole effectue automatiquement les synchronisations de vitesse, de bits de données... Ce protocole permet également d'identifier les machines.

Pour communiquer via IrDA, il faut en plus préciser un service (option "Service" des sockets infra rouge de WDPPC), ce service correspond un peu au numéro de port pour le protocole TCP. Sans le service il est donc impossible de se connecter via IrDA. Le service utilisé implique le format de communication.

 

Liste des services IrDA standard :

 

* IAS (Information Access Service): A mandatory protocol defined by the IrDA to be used as a set along with IrLMP and IrLAP protocols. Each device maintains a mini-database of the services it provides, and their attributes. A required service attribute is the LSAP-SEL. Unlike TCP/IP where service ( well known ) port numbers are known in advance, each primary device must ask the secondary device what its port (LSAP-SEL) is for the service it want to connect to. IAS uses the Information Access Protocol (IAP) to resolve query's and responses between an IAS client and server. A secondary stack will generally contain an IAS server.

* IrLMP (Link Management Protocol): A mandatory protocol defined by the IrDA to be used as a set along with IrLAP and IR device PHY protocols. Provides fundamental discovery, multiplexing, and link control operations between stations. It supports multiplexing of multiple applications over a single IrLAP link. It also provides protocol and service discovery via the IAS (Information Access Service).

* IrLAP (Link Access Protocol): A mandatory protocol defined by the IrDA to be used as a set along with IrLMP and IR device PHY protocols. Provides a device to device connection for the reliable, ordered transfer of data; and device discovery procedures.

* PHY (Physical Signaling Layer): A mandatory protocol defined by the IrDA to be used as a set along with IrLAP and IrLMP protocols. PHY is managed by and contained in the physical IR device hardware. PHY does the following: Allows Bidirectional communication for a range of at least 1 meter. Allows data transmissions from 9600 bps to a maximum speed of up to 4Mbps. Data packets are protected using a CRC. CRC-16 is used for speeds up to 1.152Mbps and CRC-32 at 4Mbps.

* Tiny TP: Provides flow control on IrLMP connections with an optional Segmentation and Reassembly service.

* OBEX: Provides object exchange services similar to HTTP, but is more flexible, compact and efficient for embedded devices. It supports the basic need for devices to send arbitrary data objects to each other in a logically straight forward manner. OBEX consists of a model for representing objects and a protocol to support communication between devices.

* IrTranP : Provides image exchange protocol used in Digital Image capturing devices, i.e. digital cameras, etc.

* IrMC : Specifications on how mobile telephony and communication devices can exchange information. This includes phonebook, calendar, and message data. Also specifies how call control and real-time voice (RTCON) are handled.

* IrDA :IrCOMM ou IrCOMM: Provides COM (serial and parallel) port emulation for legacy COM applications, printing, and modem devices.

 

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