Parker 10G-11-0015 Series, Product Manual

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Modbus Communication
12-1
AC10 Inverter
Chapter 12
Modbus Communication
12.1 General
Modbus is a serial and asynchronous communication protocol. Modbus protocol is a general
language applied to PLC and other controlling units. This protocol has defined an information
structure which can be identified and used by a controlling unit regardless of whatever network
they are transmitted.
You can read reference books or ask for the details of MODBUS from manufactures.
Modbus protocol does not require a special interface while a typical physical interface is
RS485.
12.2 Modbus Protocol
12.2.1 Transmission mode
Format
ASCII mode
Start Address Function Data LRC check End
:
(0X3A)
Inverter
Address
Function
Code
Data
Length
Data
1 …
… Data
N High-order
byte of LRC
Low-or
der
byte of
LRC
Return
(0X0D) Line
Feed
(0X0A)
RTU mode
Start Address Function Data CRC check End
T1-T2-T3-T4
Inverter
Address
Function
Code
N data Low-order
byte of CRC
High-order
byte of CRC
T1-T2-T3-T4
12.2.2 ASCII Mode
In ASCII mode, one Byte (hexadecimal format) is expressed by two ASCII characters.
For example, 31H (hexadecimal data) includes two ASCII characters’3(33H)’,’1(31H)’.
Common characters, ASCII characters are shown in the following table:
Characters ‘0’ ‘1’ ‘2’ ‘3’ ‘4’ ‘5’ ‘6’ ‘7’
ASCII Code 30H 31H 32H 33H 34H 35H 36H 37H
Characters ‘8’ ‘9’ ‘A’ ‘B’ ‘C’ ‘D’ ‘E’ ‘F’
ASCII Code 38H 39H 41H 42H 43H 44H 45H 46H
12.2.3 RTU Mode
In RTU mode, one Byte is expressed by hexadecimal format. For example, 31H is delivered to
data packet.
12.3 Baud rate
Setting range: 1200, 2400, 4800, 9600, 19200, 38400, 57600
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