iDTRONIC BLUEBOX Panel Reader LF, Руководство пользователя

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BLUEBOX Panel Reader Page 8 of 36
3 Operating Features
In ‘continuous’ mode the BLUEBOX is characterized by the coexistence of 2
‘parallel’ and asynchronous activities: the transponder identification and the
communication with the ‘host’ system. The ‘continuous’ identification activity
interacts with the communication activity through a buffer that contains the code
of the last identified transponder or the 0 code that indicates the absence of a
transponder. Due to synchronization and filtering reasons, the buffer is handled
by a parameter defined as ‘hold time’ ( to be set in the range of 0 … 99 seconds,
default value 1 second) and allows to extend ‘artificially’ the presence of the
transponder after it leaves the antenna’s influence area; this behavior is
observable looking at the ‘ANT’ LED status that is ‘on’ indicating the presence of
a transponder. Through the command ‘data request’ it is possible to get the data
contained in the buffer.
The BLUEBOX handles also a 31 elements FIFO queue which is combined with
a ‘filter time’ parameter (to be set in a range of 0 … 99 sec onds, default value 1
second) that prevents the queue saturation in case of a transponder ‘continuous’
presence. When a transponder is identified, the BLUEBOX compares it to the
previous read transponder. If the transponder is different (it is defined as ‘new’),
its code will be inserted in the queue and the filter time will be started. Otherwise
(the transponder is the same of the previous read one), the
BLUEBOX verifies
if the filter time is expired. In this case (the filter time is expired), the
transpo
nder is defined as ‘new’ and will be processed as described above,
otherwise only the filter time will be rearmed. Through the command ‘queue
data request’ and the relative ‘ack’, it is possible to get the data contained in the
queue and unload it.
In ‘continuous’ mode the BLUEBOX can be configured to obtain the behavior of
a ‘spontaneous’ reader that will send a message on the USB Virtual COM line.
This feature is enabled (on) / disabled (off) by the solder jumper W2 or using a
flag in the general configuration of the reader. It can be also configured to obtain
the behavior of an HID Keyboard that will send a message as keyboard
emulation. This feature is enabled (on) / disabled (off) by the solder jumper W3
or using a flag in the general configuration of the reader.
• If configured and available an host can receive the ‘spontaneous’ message
through the USB Virtual COM line. The ‘spontaneous’ message is sent only
once and no ACK/NAK reply message is implemented, see the protocol
manual for details.
• If configur ed and available an host can receive the ‘spontaneous’ message
through the USB HID Keyboard line. The ‘spontaneous’ message is sent
only once.