User's Manual
Table Of Contents
- IMPORTANT NOTICES
- RELEASE NOTES
- INTRODUCTION
- QUICK START
- UNDERSTANDING RFID READER
- COMMUNICATION INTERFACE
- SETTING UP A WPAN CONNECTION
- SCANNING UHF RFID TAG
- DEFINING OUTPUT FORMAT
- ALTERNATE MODE
- SPECIFICATIONS
- FIRMWARE UPGRADE
- ASCII TABLE
- SCAN CODE
- STATUS CODE
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Chapter 4
SCANNING UHF RFID
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4.6 ADVANCED SETTINGS
4.6.1 APPLICATIONS IN MULTIPLE TAGS ENVIRONMENT
In an energizing RF field, Tags implement a slot counter into which a random value
involving the Q-parameter is loaded and Readers use the slot counter to regulate the
probability of a Tag responding to commands of the Inventory operation.
In practical applications, the ability of the Reader to read multiple Tags is affected by the
Q value. Greater Q value allows the Reader to identify and collect information from more
Tags; however, the reading distance will thus be decreased, and vice versa. The Q value
should be set to zero in the case of a single Tag field. For the multiple Tags field, Q
should be increased depending on the amount of Tags. A valid Q value can take any
integer between 0 to 15.
Command:
#@rf_q?\r
Purpose Get the Current Q Value
Response OK,[m]\r
[m]: Q value
Valid integer value ranging from 0 to 15 (default=0 for 1861; default=4 for 1862)
ERR,[code]\r
#@rf_q=[m]\r
Purpose Set New Q Value
Request [m]: The number of slots (Q) for the inventory round.
Response OK\r
ERR,[code]\r