Omron V680S-HMD64-EIP User Manual page 99

The FIFO Repeat detects the RF tag in the sequence of "1. RF tag detection processing" and executes
read/write with the RF tag detected in the sequence of "2. communication processing".
<Without ID code check>
When using FIFO Repeat (Without ID code check), please do not put the next RF tag B in the
communication area until communication with the detected RF tag is completed. (See the figure below) *
Host device Reader/Writer
Host device Reader/Writer
Reader/Writer RF Tag
RF Tag operation
Since RF tag B does not exist in the communication
area, communication processing with RF tag B is
never executed.
* When using FIFO Repeat (Without ID code check), the ID code of the RF tag is not checked. Therefore communication time will
be shorter than FIFO Repeat (With ID code check). However, if the next RF tag enters the communication area during "2.
communication processing" with the detected RF tag, there is a possibility of reading / writing the next RF tag.
<With ID code check>
When FIFO Repeat (With ID code check) is used, even if the next RF tag enters the communication
area before communication with the detected RF tag is completed, it can read / write without any
problem I will. *
Host device Reader/Writer
Host device Reader/Writer
Reader/Writer RF Tag
RF Tag operation
FIFO Repeat (With ID code check)
Even if the next RF tag B enters the communication
area during communication processing with the RF
tag A, it will not read / write to the next RF tag B.
* When using FIFO Repeat (With ID code check), the ID code of the RF tag is checked. Even if the next RF tag enters the
communication area during "2. communication processing" with the detected RF tag, there is no possibility of reading / writing
the next RF tag. However, compared with "Without ID code check", communication time will be longer.
"ID code" is a unique ID previously stored in each RF tag. By performing ID code check, even if an RF tag with another
ID code enters the communication area during communication processing, it does not communicate with that RF tag.
Refer to RF Tag Communications Time (for Reference Only) in Section 11 Appendices for details of Communications Time.
p.248
Repeat communications
Response
Communications processing
Waiting for RF Tag Waiting for RF Tag
1 2 3
RF Tag A
Repeat communications
Response
Communications processing
Waiting for RF Tag
1 2 3 1
RF Tag A
RF Tag B
Response
Waiting for RF Tag
1 2 3
1: RF tag detection processing
RF Tag B
2: Communication processing
3: RF tag operation stop processing
After RF tag B is detected, communication
processing with RF tag B is executed.
Response
Waiting for RF Tag
2 3
1: RF tag detection processing
2: Communication processing
3: RF tag operation stop processing
After RF tag B is detected, communication
processing with RF tag B is executed.
Section 6
Functions
Processing completed.
Processing completed.
RFID System
97
User's Manual
(EtherNet/IP TM )