Omron V680 Series - Page 279

Data Characteristics
Section 11
Section 11
Appendices
277
RFID System
User's Manual
(Modbus TCP)
 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) 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:
Maximum speed =
D (Distance traveled in communications field)
T (Communications time)
Y
X
Y
X
D
Movement
direction
Communications field
50
100
150
200
Y
-250 -200 -150 -100 -50 0 50 100 150 200 X
170mm
Maximum speed =
D (Distance traveled in communications field)
T (Communications time)
=
170(mm)
267.8(ms)
= 38.1 m/min