RFID Communications
6.4.13 ABxS Command 85H: Read All
DESCRIPTION
Command 85H reads data from all RFID
DISCUSSION
This command is used to read segments of data from contiguous areas of tag memory. It is capable of handling up to 1 kByte of data transferred to the host with one command. The timeout value is given in 1 ms increments and can have a value of 001EH to FFFEH (65,534 ms). When the timeout is set to 0, the controller will return a syntax error message 21H. The Read All consists of Tag Family ID and Reserved Byte, a start address and number of bytes, followed by a timeout value and the message terminator, FFFFH. If the read length exceeds the last tag address, the controller returns a syntax error message 21H. The data read from the tag is returned in the LSB of the register, and the MSB is always 00H. A special termination packet (AAH FFH) is sent after the timeout expires. The controller returns a response after the timeout expires. The command returns a response after the successful operation or when the timeout expires.
Field | Remarks |
Command | Command number in hex preceded by AAH |
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Tag Family | Tag Family ID - 00H = all tags |
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Reserved Byte | 00H |
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Start Address | Tag address where the read will start |
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Read Length | Number of tag addresses to be read |
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Timeout | Timeout value given in 1 ms units (001EH - FFFEH) |
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Message Terminator | FFFFH |
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73 | LRP2000 Passive Reader/Writer |