Справочник Пользователя для Agrident Corporation ASR700
05.07.2007
Page 26 of 56
ASR700 Reader Operation
2.3.6 Connecting the reader to a control computer
Point-to-point connection
This structure is particularly suited to applications with just a few (or even a single) readers.
Each reader is connected to the control computer by its own interface. To reduce sensitivity to
interference and to increase the possible length of the line, the RS485 interface can also be
used instead of the RS232.
Each reader can be addressed by the control computer using suitable addresses (broadcast
addresses, individually assigned network or device addresses) and by its own interface (for ex-
ample, the COM port in PCs: Reader 1 = COM1, Reader 2 = COM2,…).
Single master bus system
This structure is particularly suited to applications with several readers (a maximum of 32 per
control computer interface).
An RS485 bus interface is used as interface and this networks multiple readers with the control
computer by a 2-wire bus. It allows a network to be set up at no great expense.
Each reader can be addressed by the control computer of the shared bus interface using the
individually assigned network or equipment address. This can be, for example, by an
RS232/RS485 converter at a COM port of a PC.
In order to organize access to the bus the control computer is declared sole master (single
master network). Each reader connected to the bus must have its own individual network ad-
dress.
Before installing a reader in a bus structure, the reader must be assigned as a yet unassigned
network address by point-to-point connection. Configuration of the network address is effected
using, for example, the ASR700 demo software.
control computer interface).
An RS485 bus interface is used as interface and this networks multiple readers with the control
computer by a 2-wire bus. It allows a network to be set up at no great expense.
Each reader can be addressed by the control computer of the shared bus interface using the
individually assigned network or equipment address. This can be, for example, by an
RS232/RS485 converter at a COM port of a PC.
In order to organize access to the bus the control computer is declared sole master (single
master network). Each reader connected to the bus must have its own individual network ad-
dress.
Before installing a reader in a bus structure, the reader must be assigned as a yet unassigned
network address by point-to-point connection. Configuration of the network address is effected
using, for example, the ASR700 demo software.
Control
Computer
Computer
Reader
Reader
Reader
Reader
Reader
Reader
Reader
Reader
Reader
Reader
Host