FT-10 Fill Technical Manual, Rev. 2.21, July 2020
Page 79 of 131
10.
M
ODBUS
RTU
FT-10 FILL controller has a Modbus RTU interface over RS485 / 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;
10.1 Modbus RTU Data Structure
After programming RS485 / 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 (Page 30). Functions
code ‘0x03’ (Read Holding Registers) and ‘0x10’ (Preset Multiple Regs) 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 RS-485 / RS 232C parameter settings as defined on Page 29.
Please find Modbus information in the web site of http://www.modbus.org
Modbus RTU Command Table;
Address
R/W
Word
Command
Definition
40001
R
2
Actual weight (Net if the indication is in Net)
40003
R
1
Status
D0
0
– System Ready
1
– System Busy
D1
0
– Error ( D13-D15 ) 1 – Data ok
D2
0
– Weight Stable
1
– Weight unstable
D3
0
– Gross Mode
1
– Net mode
D4
Not used
D5
0 - No process error
1
– Process error (ref. to 40113)
D6
–
D11
Not used
D12
0
– Out of zero range 1 – Weight is in zero range
D13
D14
D15
Error Code
Dec
Description
0
No Errors
1
ADC out of range
2
ADC over range
3
ADC under range
4
System error
5
In programming mode
6
Low/High voltage det.
40004
R
2
Tare weight
40006
R
2
Gross weight
40008
R
1
Status
Motion, Net mode, Data ok, (image of register 40003)
