LS Industrial Systems LGRF-H, Руководство пользователя

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3.3.3 RS 422 Multi Drop Connection
RS 422 connection method supports a single connection between PLC and LGRF-H
Reader as well as Multi Drop connection. LGRF-H Reader enables to use max. 16 Readers by
Multi Drop connection.
[Fig. 3.3.3.1] describes the example that 16 Readers are connected to the Host (PC or PLC).
In this case, it is required to check if the Host supports RS-422 communication. If general PC is
used as a Host, RS422/232 Converter should be added for connection as PC has only RS232
Connector. (RS 232 Port of LGRF-H Reader shall be used only for 1:1 connection.)
[Fig. 3.3.3.2] shows Multi Drop connection between Reader and Reader. In this case, as
shown on [Table 3.3.3.1], it is required to bind RX among RX and TX among TX to add them to
Reader. But in case of Host (PLC) connection, TX and RX shall be twisted each other for
connection.
[Fig. 3.3.3.1] Example of connection of 16 Readers