Polling Auto Mode - Omron V720S Series Operation Manual

Communications Method

5-8-2-4 Polling Auto Mode

If an Auto command is used when a single host controls more than one Reader/Writer, the commu-
nications path between the host and one of the Reader/Writers to which the command is sent be-
comes busy, disabling the host to control other Reader/Writers. On the other hand, when a Polling
Auto command is sent instead, the Reader/Writer returns a response according to the request from
the host. The communications line with the host will not remain busy, allowing the host to send a
command to other Reader/Writers. During the execution of the Polling Auto command, commands
other than the Polling subcommand, Reset and Stop commands are not executed. The following
flowchart shows the case where the Polling Auto Command is sent to 2 Reader/Writers.
(Host)
Polling Auto
Command
Node 1
Polling Auto
Command
Node 2
Polling
subcommand
Referring to Node 1
Polling
subcommand
Referring to Node 2
Polling
subcommand
Referring to Node 1
(Reader/Writer)
Response
Response
Node 2
Response
Node 1
Yet to enter.
Response
Node 2
Yet to enter
Communications
processing
Passing in front of Node
Node 1
1's antenna
Response
Communications
processing by Node 1 is
complete.
(Tag)
(1) The host sends the Polling Auto
(2) Immediately after command reception,
Yet to enter
(3) The host sends the Polling Auto
Yet to enter
(4) Immediately after command reception,
(5) The host inquires after the progress of
Yet to enter
Tag
(6) The Node 1 communicates with a Tag
(7) Node 1 returns a response indicating
Section 5-8
Command to the Node 1
Reader/Writer.
Node 1 returns a response indicating
the acceptance of the command.
Command to Node 2.
Node 2 returns a response indicating
acceptance of the command.
the communications processing or
stops the Polling Auto processing
using the Polling sub command. When
the communications processing is not
yet complete, the Reader/Writer
returns a response indicating
unfinished processing in reply to the
inquiry of the Polling sub command.
entering the communications area.
the results of communications with the
Tag in reply to the Polling
subcommand.
5-59