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Modicon Communication Driver Manual
484 PLC/J474 Modbus Communication Interface
The J474 Communication Interface allows for a computer or other intelligent devices to communicate
to a 484 PLC. The J474 may be connected to the Modbus or an RS232 device via a single 30-pin
connector. All user options such as baud rate, parity, and stop bits are selected by the wiring of this
connector.
The following tables include pin descriptions and selection options, for the J474 Modbus
Communication Interface.
Table 3 - Port Pinouts for the J474 Interface
Baud rate is selected by connecting pins 9, 11, 13 and 15 to signal ground at pin 7. The following
chart summarizes selection options, where YES = connect to pin 7 and NO = leave unconnected.
Table 4 - Baud Rate Selection for the J474 Interface