TransCore SmartPass AI1611, System Manual

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SmartPass® Integrated Reader 2450 MHz (High Voltage) System Guide
410N Anti-Passback (Select Unique ID Code Criteria)
These commands instruct the reader to buffer and transmit ID codes according to the
following test: an ID is buffered if, in the time interval since the new ID was last
received, previously decoded IDs have changed value at least
N
+1 times or the
uniqueness timeout has occurred. IDs that do not pass the test are not buffered. The
factory default setting is command 4100, which selects a separation of one ID.
Table 9-9 Commands for Buffering and Transmitting ID Codes
Command Uniqueness Criteria
4100 Separation of 1 ID (factory default)
4101 Separation of 2 IDs
Each time the reader receives a tag ID, it compares the ID with the contents of a
comparison register. This register contains two items.
Comparison register items:
•
Item 1 Most recently acquired ID
•
Item 2 Second most recent ID (if different from item 1)
When the uniqueness filter is set to a separation of one ID, the newly acquired ID is
transmitted only if it is different from item 1. When the uniqueness filter is set to a
separation of two IDs, the newly acquired ID is transmitted only if it is different
from both items 1 and 2.
Note: A new ID can fail the filter test and not be transmitted; however, it is still
stored in the comparison register.
The uniqueness test has a 2-minute time limit. If an ID is buffered, it will not be
accepted again until it arrives at the reader more than 2 minutes from the previous
arrival, or until the receipt of one (one ID separation) or two (two ID separations)
other IDs resets uniqueness.
Reader message:
Done
43 Buffer All ID Codes
Command 43 buffers and transmits all acquired ID codes. It effectively cancels any
uniqueness criteria previously set by select unique ID code criteria command 410N.
Note: This command is for diagnostic purposes only.
After diagnostics are complete, reset the select unique ID code critieria using
command 410N.
Reader message:
Done
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