Agrident Corporation ASR500 Manuale Utente
05.07.2007
Page 27 of 59
ASR500 Reader Operation
'Get_Single_ID' to reader 1, reply from reader 1, 'Get_Single_ID' to reader 2, reply from reader
2, and so on.
2, and so on.
3.2 Operating in slave continuous mode (Cfg_mode register 0x01)
In slave continuous mode the read function or the RF field is continuously activated. It autono-
mously detects a transponder, which is present and sends the transponder data to an internal
ring buffer memory (two IDs in size). Repeated addition of the same ID entry to the buffer can
be blocked with the aid of the configurable 'Delay time'. Every time an ID is added to the buffer
the 'Delay time' is restarted. The contents of the buffer can be read out (output of the oldest ID)
by the control computer with the command 'Get_Last_ID'. The response comes after max. 120
ms. If the buffer memory is empty a blank ID message will be transmitted. Repetition of the
command is a way of emptying the buffer.
Interrogation by 'Get_Single_ID' starts a new read cycle.
After a request with 'Get_Single_ID', if a transponder is detected within the configured time-out
period, the ID will be transmitted (a blank ID in the case of failure to pick up a transponder).
Note: In the case of a bus set-up using RS485 connection, data collision is possible on the bus
if several readers are addressed simultaneously with 'Get_Single_ID' or 'Get_Last_ID'.
Possible applications
Point-to-point connection with RS232/RS485: only one reader is connected by computer serial
interface.
Bus system with RS485: several readers are connected to a computer, configured with different
network addresses and are interrogated in sequence by the computer; for example,
'Get_Last_ID' to reader 1, reply from reader 1, 'Get_Last_ID' to reader 2, reply from reader 2,
and so on.
mously detects a transponder, which is present and sends the transponder data to an internal
ring buffer memory (two IDs in size). Repeated addition of the same ID entry to the buffer can
be blocked with the aid of the configurable 'Delay time'. Every time an ID is added to the buffer
the 'Delay time' is restarted. The contents of the buffer can be read out (output of the oldest ID)
by the control computer with the command 'Get_Last_ID'. The response comes after max. 120
ms. If the buffer memory is empty a blank ID message will be transmitted. Repetition of the
command is a way of emptying the buffer.
Interrogation by 'Get_Single_ID' starts a new read cycle.
After a request with 'Get_Single_ID', if a transponder is detected within the configured time-out
period, the ID will be transmitted (a blank ID in the case of failure to pick up a transponder).
Note: In the case of a bus set-up using RS485 connection, data collision is possible on the bus
if several readers are addressed simultaneously with 'Get_Single_ID' or 'Get_Last_ID'.
Possible applications
Point-to-point connection with RS232/RS485: only one reader is connected by computer serial
interface.
Bus system with RS485: several readers are connected to a computer, configured with different
network addresses and are interrogated in sequence by the computer; for example,
'Get_Last_ID' to reader 1, reply from reader 1, 'Get_Last_ID' to reader 2, reply from reader 2,
and so on.
PC
"Get Last ID"
ASR400
Buffer 3 IDs
Maximum 3 Ids in buffer
Oldest ID is transmitted
"ID-Message"