Calculation Of Tag Traveling Speed - Omron V720S Series Operation Manual

Calculation of Tag Traveling Speed

The total number of characters is 33, i.e., 15 characters in the command part and 18 characters in the
response part. From this, the host communications time would be 33 * 11 bits /38400(bps) * 1000 =
9.5 (ms). The communications time would be14 ms for Fast Mode and 92.9 ms for Standard Mode.
TAT, therefore, would be 9.4 + 14 = 23.5 ms for Fast Mode and 9.4 + 92.9 = 102.4 ms for Standard
Mode.
7-2 Calculation of Tag Traveling Speed
Max. traveling speed =
Caution 1) As remedy for noise, the Reader/Writer is designed to retry using the internal
7-4
Note The provided TAT graph data shows an example in which the
V720S-BC5D4 Controller is used with the following communications
specifications for host communications: The data is continuously sent with
no space between characters, at a baud rate of 38,400 bps, in a data length
of 7 bits with 1 start bit, 2 stop bits and even parity.
When communicating with a Tag in motion, select Auto or Repeat for the
communications method.
The maximum speed at which the Tag can travel can be obtained easily, using
the formula below.
D (travel distance in communications area)
Calculate D from the communications area drawing between the Antenna and
the Tag or from the actual measurement.
Note The formula above is for communications with one Tag. Be sure to check the
traveling speed of multiple Tags in advance.
Direction of travel
software process when a communications error occurs between a Tag and
the Antenna. The time required for communications vary depending on the
noise condition of the environment in which the Reader/Writer is used. Be
sure to check the actual communications time using actual machines in
advance. The formula for communications time relates to cases where the
re-transmission process is not used.
2) The formula above is for communications with one Tag. If you need to
access multiple Tags while they are moving, be sure to experiment before
actual use. This cannot be checked by calculation. In access to multiple
Tags, the anti-collision algorism operates based on the theory of probability.
The communications time, therefore, may vary depending on how collisions
take place. It is strongly recommended that you allow for sufficient time for
communications.
T (communications time)
Communications
Section 7-2
x Safety factor (0.5)
area