OBID
i-
scan
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Application-Note
ID ISC.LR(M)200
FEIG ELECTRONIC GmbH
Page 5 of 27
N11200-0e-ID-B.doc
2. Synchronizing RFID Long Range Readers using the digital in-/outputs
In this context synchronization means that the magnetic field of the RFID Reader antennas are
alternately turned on while all other antenna outputs on the readers are turned off.
This is implemented for readers with antennas using the digital in- and outputs by having the
reader firmware itself turning on only one antenna of several readers. During this time the other
readers turn off the HF field of the respective antennas.
Fig. 1: Sequence of communication between the readers
Communication takes place through the digital inputs IN1 and outputs OUT1. The Master starts by
sending a pulse to the next reader as soon as it has finished communicating with the transponder.
The latter passes the signal to the next reader after finishing its read cycle. The last reader then
passes the signal back to the Master.
MASTER
SLAVE 1
SLAVE 2
IN 1
IN 1
IN 1
OUT 1
OUT 1
OUT 1