RFID Communications
6.5.16 ABxF Command 88H: Tag Search All
DESCRIPTION
Command 88H searches for tags within range of the antenna.
DISCUSSION
This command activates the controller to look for tags within range of the antenna. As soon as the controller finds a tag, it returns a command echo to the host. The timeout value is given in 1 msec increments and can have a value of 1EH to FFFEH (65,534 ms). If no tag is present, it returns an error message. See Section 6.6 for information on the error messages.
Field | Content |
Header | 0202H |
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Command Size | Packet length in bytes excluding the header, command size, checksum, and terminator bytes. |
| 0005H for this command |
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Command | 88H |
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Family ID | Tag Family ID - 00H = all tags |
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Reserved | Ignored byte, set to 00H |
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Timeout | |
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Checksum | Optional checksum |
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Terminator | <ETX> |
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Example
Checks for the presence of an RFID tag within range of the antenna. A timeout of 2 seconds (07D0H = 2000 x 1 msec increments) is set for the completion of the Tag Search All. In this example, a tag is found.
Command from Host
Field | Content |
Header | 0202H |
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Command Size | 0005H |
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Command Code | 88H |
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Family ID | 00H |
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Reserved | 00H |
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Timeout | 07D0H |
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Checksum | 99H |
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Terminator | 03H |
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Response from Controller
Field | Content |
Header | 0202H |
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Response Size | 0003H |
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Command Echo | 88H |
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Number of Tags | 01H |
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Status Byte | 08H |
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Checksum | 73H |
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Terminators | 03H |
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LRP2000 Passive Reader/Writer | 112 |