User's Manual

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5.4.12 Inventory-Single (50-01)
This function can be used to make a single inventory round. The reader then returns a list of tags that are in its
field. With some interfaces the data length for transmission is limited, so if the return packet would be too large, it
is separated into more packets. Therefore two counters are transmitted; one that indicates how many tags were
found and one that indicates how many tag ids are transmitted in this packet.
The reader can send more additional information then only the tag id. Therefore the structure TagInfo is used. This
structure has a variable length that is dependent of the information sent from the reader. The type of additional
information is dependent of the used reader. This information and the specific identifier can be found in the
documentation of the used reader.
The first byte of the structure indicates the length of the whole structure. After this the tag id is sent. This is
splitted in a start byte, a length indicator and the id itself. After that additional information can be added by the
reader. In the example below, the RSSI value of the tag is added.
Length-of-TagInfo
1 Byte
StartByte-Tag ID 1 Byte 0x01
ID-Length 1 Byte
ID Length
StartByte-RSSI
1 Byte
0x02
RSSI 2 Byte
Parameters: None
Return Values: RFE_RET_VALUE status, unsigned char idCount, unsigned char packetIdCount, TagInfo tags
[packetIdCount]
Status Values: RFE_SUCCESS, RFE_ERR_ON_EXEC_OP, RFE_ERR_WRONG_PARAM_COUNT,
RFE_ERR_WRONG_PARAM