Communications Method
Section 5-8
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5-8 Communications
Method
The operation sequence, e.g., how communications with a Tag will take place and when a response
will be returned, varies depending on the specification made for a command. For communications,
settings for access and mode should be made according to the state of Tags n the communications
area of the Antenna and their operation after the Tags receive commands.
5-8-1 Access Settings
There are the following four access settings according to the number of Tags in the communications
area and their states.
5-8-1-1 Single Access
In single access, a single Tag can exist in the communications area. The presence of two or more
Tags in the communications area causes a communications error.
5-8-1-2 FIFO Access
In FIFO (first-in, first-out) access, communications with Tags entering the communications area one
after another are carried out in sequence. Once communications with Tags are completed, access
to them is prohibited. Consequently, even if Tags with which communications are already completed
exist in the communications area, a newly entering Tag can be accessed. Simultaneous entering of
two or more Tags causes a communications error. Once an access-prohibited Tag leaves the com-
munications area, access to the Tag is enabled again.
