Omron V680S-HMD64-EIP User Manual page 275

 Mutual Interference of RF Tags
If you use more than one RF Tag, separate them by at least the interval shown below to prevent
malfunctions due to mutual interference.
If the distance between the RF tags is too short, read / write distance will be reduced.
 V680S-HMD63-EIP Reader/Writer
 V680S-HMD64-EIP Reader/Writer
 V680S-HMD66-EIP Reader/Writer
60 mm min.
90 mm min.
120 mm min.
60 mm min.
90 mm min.
120 mm min.
Section 11
Appendices
RFID System
273
User's Manual
(EtherNet/IP TM )