User manual

Toolbox 32 User Manual 1.47d www.cse-semaphore.com/mykingfisher

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Example - RS485

RS485 can be used on any CP-xx isolated serial port or PC-1 serial port 2.

• Configuration, Port List: Set Type to RS485 and set Baudrate to match the remote device (eg. 9600).

Set Pre Tx and Post Tx to 10 ms as illustrated below (note: Post Tx can be set to 1ms for fast response

RS485 devices).

• Configuration, Network List: Set Target RTU to the address of the RTU to communicate with and Port

# to the port number configured above. Note: a network link is not required if the RTU is not initiating

messages.

• Configure a communications block (eg. RX_DATA) in ladder logic to communicate with the target RTU.

Note 1: The length of the RS485 cable should be at least 1m.

Note 2: Each end of the RS485 cable should be terminated with a 120 ohm resistor. For short cable runs (<

5 m) a single terminating resistor of 60 ohms can be used at one end of the RS485 cable. Please see the

Kingfisher Hardware manual, CP-xx Serial Option Board wiring diagram for details.

Note 3: If problems persist, add a Pre TX delay to the remote device or decrease the baudrate (do not use

less than 4800 baud).