OBID i-scan
®
System-Manual
ID ISC.LR200
FEIG ELECTRONIC GmbH
Page 149 of 174
H90692-16e-ID-B.doc
8. Protocols for Buffered Read Mode
8.1. The Buffered Read Mode Procedure
By using the “BRM” the Reader itself reads data from every Transponder which is inside the antenna
field. This mode must be enabled in the
3.10. CFG10: General System Parameters
configuration block
and configured in the
3.11. CFG11: Buffered Read Mode
configuration block.
The sampled Transponder data sets are stored in a FIFO organized data buffer inside the Reader. The
buffered read mode runs offline from any host commands and is immediately started after power up or
a
5.3. [0x63] CPU Reset
command.
Only two commands are necessary to read out sampled Transponder data sets. The figure below
illustrates the Buffered Read Mode procedure:
Host
→
Reader
[0x21]
Read Buffer
Command to the Reader
to read data
Ø
typ. 6 ms
Host
←
Reader:
Status e.g. = 0x92
No Valid Data
there are no data sets inside the data buffer
Ù
.
Ù
.
Ù
.
Ù
.
Host
→
Reader
[0x21]
Read Buffer
Command to the Reader
to read data
Ø
typ. 6 ms
Host
←
Reader:
Status e.g. = OK
and n Data Sets
there are data sets inside the data buffer and
n data sets are transferred to the host
Ù
.
Ù
.
Ù
.
Host
→
Reader
[0x32]
Clear Data Buffer
Command to the Reader
to clear the read data sets
Ø
typ. 6 ms
Host
←
Reader
Status e.g. = OK
the n read out data sets are
cleared from the data buffer
Ø
:
Host waits for an answer from the Reader
Ù
:
Host is able to do other jobs e.g. to communicate with other Readers
Additional information about the capacity of the data buffer can be determined with the
8.4. [0x31]
Read Data Buffer Info
command.
Note:
•
If the RF power is switched off with a
5.7. [0x6A] RF ON/OFF
command and the Reader
synchronization is used an incoming synchronization pulse is handled directly through the
Reader to the synchronization output.
