TransCore 1422E, Руководство пользователя

Страница: 60 / 102

AI1422E Reader
TransCore Proprietary 7-11
stored in the comparison register.
The uniqueness test’s time limit is set by Command !441. If an ID is buffered, it will not be
accepted again unless it arrives at the reader more than the programmed time interval from
the previous arrival or until the receipt of one or more other IDs reset the uniqueness.
Reader response:
Done
420N Select Valid ID Code Criteria
Command
!420N
directs the reader to validate an ID received only after it has been
obtained a specified number of times in sequence. Values for N are 0 through 3
(
Table 7 – 7 ). The factory setting is one acquisition (
N = 0
).
Table 7 – 7 Select Valid Code Commands and Frames
Command Valid Code Frames
4200 1 (Factory default)
4201 2
4202 3
4203 4
The validation procedure is executed before the unique ID test (Select Unique ID Code
Criteria
[!410N]
commands). IDs that do not pass the validation test are not reported.
For example, command
!4203
specifies that the same ID must be obtained from the RF
module 4 times in succession before it is considered for the uniqueness test. This feature is
useful in installations where RF reflections may cause a single tag to be read multiple times
or where an occasional ID might be read from fringe areas
440 Reset Uniqueness
Command
440
causes the ID filtering process set by Select Unique ID Code Criteria
(!410N)
to restart. It is used in conjunction with the Variable Timeout (
!44N
) commands.
This command provides a method to end all uniqueness timers.
44N Set Uniqueness Timeout
Places a time limit on the uniqueness criterion set by Select Unique ID Code Criteria
(
!410N
). The parameter N sets the number of minutes on the timeout clock. The factory
setting is two minutes (
N = 1
).
Command Timeout Clock
!441
2 minutes (factory setting)
!442
15 seconds
!443
30 seconds