Implementation

AN2319

4/8

2

Implementation

The body of a loop (see Example 1) is used by a reader to detect and identify RFID tags.

This loop starts by switching the reader RF output OFF and then back ON again. This safely

resets any tags in the field and puts them in a READY state.

By issuing the INITIATE() command, the tag enters ACTIVE (SR176) or INVENTORY

(SRIxx) mode.

A non-zero response to the INITIATE() command indicates the presence of a tag and

enables the reader to obtain the ChipID.

This ChipID is used as a link to the tag for the following SELECT() command.

After a successful SELECT() command, the tag is ready for read / write operations.

Once the value of the UID is known, the application can easily determine and set the

important parameters for communication with the particular tag using the switch()

statement shown in Example 1: high-level mnemonic source code.

In certain applications and when using certain tags, it is necessary to identify the tag

product type. In this case, it is recommended to first read the tag UID value (which contains

the product type value) as shown in Example 2: low-level mnemonic source code.