IDEC SmartAXIS FT9Z-1A01, User Manual

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11: M
ODBUS
C
OMMUNICATION
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ANUAL
FT9Y-B1378
Modbus Slave Communication
Modbus slave communication can be configured by selecting Modbus RTU Slave for port 2 and port 3 in the WindLDR Function
Area Settings. When a Modbus slave receives a request from the Modbus master, the Modbus slave reads or writes data according
to the request. The request is processed at the END processing of the user program.
Modbus slaves do not reply to the Modbus master for the broadcast requests.
Modbus Slave Communication Specifications
*1: When timeout occurs, the SmartAXIS discards the received data and waits for the first frame of the next valid communication.
*2: For communication at 19200bps or higher, the timeout between characters needs to be a minimum of 0.75ms.
*3: For communication at 19200bps or higher, the timeout between frames needs to be a minimum of 1.75ms.
Item Description
Baud Rate (bps) 9600, 19200, 38400, 57600, 115200
Data Bits 8 bits (fixed)
Stop bits 1, 2 bits
Parity Odd, even, none
Slave Number
Constant 1 to 247
Data register The value in D8027 (port 2) or D8028 (port 3) is used
Timeout between Characters
*1
1.5 characters minimum
*2
Timeout between Frames
*1
3.5 characters minimum
*3