Omron V600 Series User Manual page 78

Section 5
Communications
Polling
This section describes command processing when two Read/Write Heads are connected to one ID
Controller. For normal Auto Commands, the ID Controller does not return a response until the Data
Carrier approaches the specified Read/Write Head. This means that the communications path with the
host device remains in the Busy Status, and the host device cannot send commands to the ID Control-
ler's other Read/Write Head.
However, Polling Auto Commands enable the ID Controller to return a response when requested by the
host device. Thus, the Busy Status of the communications path to the host device is cleared and the
host device can send commands to the ID Controller's other Read/Write Head.
Host device
Polling Auto
Command
Head 1
Polling Auto
Command
Head 2
Subcommand
Polling head 1 check
Subcommand
Polling head 2 check
Subcommand
Polling head 1 check
RFID System
76
Operation Manual
ID Controller Data Carrier
Not approaching
Response
Head 1
Not approaching
Response
Head 2
Not approaching
Response
Not approaching Head 1
Not approaching
Response
Not approaching Head 2
Read or write
Data Carrier
processing
Head 1
Passing
Response
Head 1 processing
completed
1. A Polling Auto Command is sent to Head 1.
2. The ID Controller receives the command and
returns a response indicating that it has
received the command.
3. A Polling Auto Command is sent to Head 2.
4. The ID Controller receives the command and
returns a response indicating that it has
received the command.
5. The host device can check the status of
processing or end polling auto processing
using subcommands.
6. When a Data Carrier is not close to the
specified Read/Write Head, a "no Data Carrier"
response is returned in response to a check
subcommand.
7. When a Data Carrier passes by the Read/Write
Head, data is read or written.
8. Once processing has been completed, the ID
Controller sends a response to the host device
indicating that the processing indicated by the
check subcommand has been completed.