FT-111(D) Panel Weighing Indicator, Technical Manual, Rev.1.0.0, May 2019
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97
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10.2 Modbus RTU and TCP/IP
IMPORTANT NOTE: Modbus RTU and Modbus TCP interfaces require Modbus SD card at the SD2 card slot
on the rear of the instrument.
FT-111 controller supports a Modbus RTU interface over RS485, RS422 or RS232C serial port. This interface can be
programmable to High-Low or Low-
High for different type of PLC’s. You can find below the difference of these data formats
and some companies using these formats. Two types are available as;
Please find Modbus information in the web site of http://www.modbus.org
Modbus RTU Data Structure
After programming RS485, RS422 or RS232C serial port for Modbus RTU, it can be used as a Modbus RTU slave on
Modbus RTU network. The Modbus slave address is defined in the RS-485 address (
). Functions code ‘0x03’
(Read Holding Registers), ‘0x06’ (Single Write Register), ‘0x17’ (Read/Write Multiple Registers) and ‘0x10’ (Preset Multiple
Registers) are supported.
Modbus RTU High-Low:
In two-word registers, the data is stored to the registers in big-endian format. Least significant
word is stored to the highest register address; and most significant word is stored to the lowest register address.
Modbus RTU Low-High:
In two-word registers, the data is stored to the registers in little-endian format. Least significant
word is stored to the lowest register address; and most significant word is stored to the highest register address.
Parameter’s set-up:
Set the RS 485 / RS 232C Data Format
: Modbus
RTU
High-Low
or
Modbus
RTU
Low-High
RS-485 Data Length & Parity
: 8 none 1, 8 odd 1 or 8 even 1
RS-485 Address
: 01 to 31
Make the RS485 / RS422 / RS232C parameter settings as defined on
Modbus TCP Data Structure
If the instrument is programmed for Modbus TCP/IP, it can be used as a Modbus TCP/IP slave on Ethernet communication
network. Functions code ‘0x03’ (Read Holding Registers), ‘0x06’ (Single Write Register), ‘0x17’ (Read/Write Multiple
Registers) and ‘0x10’ (Preset Multiple Registers) are supported.
Modbus TCP/IP High-Low:
In two-word registers, the data is stored to the registers in big-endian format. Least significant
word is stored to the highest register address; and most significant word is stored to the lowest register address.
Modbus TCP/IP Low-High:
In two-word registers, the data is stored to the registers in little-endian format. Least significant
word is stored to the lowest register address; and most significant word is stored to the highest register address.
Parameter’s set-up:
Set Ethernet Data Format : Modbus
TCP/IP
High-Low
or Modbus
TCP/IP
Low-High
Ethernet Address
: 01 to 255
Make the Ethernet parameter settings as defined on sub-block
15-.
