PIOS RFID API Guidelines 

Definition

There are several guidelines for the Peripheral Input/Output Services (PIOS) Radio Frequency Identification (RFID) API, part of the SAP NetWeaver Mobile Client API. Each guideline is defined.

Use

These guidelines are intended for all developers working on the SAP NetWeaver Developer Studio in a mobile application with RFID peripheral requirements. It helps the developer get the most out of the PIOS architecture. The developer accesses these features, provided by PIOS, through the SAP NetWeaver Mobile Client API.

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Tag Configuration File

The RFID API programs read and/or write tag types that have been predefined in the tag configuration file. The tags can be edited, added to, or removed from the file using the tag configuration manager, part of the RFID API.

The RFID reader can work (read, write, and so on) only on those tag types defined in the tag configuration file and supported by the hardware. Supported tag types depend on the RFID reader make and model.

Tags that are not defined in the tag configuration file are ignored by the API, even if they are supported by the RFID reader.

List Tag Types Method

This method returns all the tag types that have been configured in the API. An array of tag types is returned. The configured tag types are returned in an array. This method must be called before an identify by tag type is called, this assures using a valid tag type when calling the identify.

Tag Configuration Manager

To receive a list of all the configured tag types for a specific RFID reader, use the listTagTypes method. To edit the list by adding or removing a tag type, or to edit a particular tag type. use the TagConfigurationManager class.

Identify Method

To obtain a list of all tags that are defined in the API within the RFID reader's range, use the identify method without parameters. To obtain a list of all in-range tags for a specific tag type, pass the tag type as a parameter to the identify method.

Read and Write Operations

The API can read data from or write data to one tag at any given time. The tag you want to access must be in the RFID reader's range. To do this, call the identify method before starting either the read or the write operation. This guarantees the use of a valid (in range) tag.

Tag Structure Awareness

An RFID tag can be divided in several areas. These areas can be one the following:

●         Reserved - This data is written by the tag manufacturer. The data in this area can be used internally by the tag.

●         Read only - A portion of the data that is both written and locked, or is written in a single-use tag. The information in this area is accessible but cannot be changed.

●         Writable - This area can be written and read using the API.

It is important to be aware of the different areas and to avoid trying to write to reserved or read-only areas. Otherwise an exception occurs.

Writing without Exceptions

SAP recommends that you use this procedure to write to a tag without raising an exception:

       1.      Identify the tags in the RFID reader's range, either with a tag type as a parameter or without a tag type, depending on what needs to be done.

A list of available tags is returned.

       2.      Select the tag to be written to from the list and obtain its tag type.

       3.      Use the tag type writable areas for the tag to determine what section or sections of the tag can be written to.

By doing this, you avoid exceptions occurring.