Omron V680 Series User Manual page 279

 Travel Speed Calculations
When you communicate with a moving RF Tag, set the communications option to Auto.
The maximum speed for communicating with the RF Tag can be calculated simply using the following
formula.
D (Distance traveled in communications field)
Maximum speed =
D (Distance traveled in communications field) is calculated from the actual measurement or the
communications field between the Reader/Writer and RF Tag.
In order to ensure a margin, it is preferable that the communication time is calculated at twice.
 Calculation Example
The following example is for reading 128 bytes with the V680S-D2KF68, and V680S-HMD66-ETN.
From the above chart,
Distance traveled in communications field = 170 mm when Y (communications range) is 50 mm
Communications time T = 267.8 ms (calculated from the communications time , i.e., 2 times × (0.9 × 128 bytes +
18.7))
Therefore, the maximum speed of the Tag is as follows:
D (Distance traveled in communications field)
Maximum speed =
T (Communications time)
Y
Communications field
Movement
D
direction
Y
200
150
100
50
-250 -200 -150 -100 -50 0 50
170mm
T (Communications time)
X
Y
X
100 150 200 X
170(mm)
=
267.8(ms)
= 38.1 m/min
Section 11
Appendices
RFID System
277
User's Manual
(Modbus TCP)