Modbus-Rtu Protocol - LSIS LSLV-S100 Series Operation Manual

RS-485 Communication Features

7.3.2 Modbus-RTU Protocol

7.3.2.1 Function Code and Protocol (unit: byte)
In the eollowing section, station ID is the value set at CM.01 (Int485 St ID), and starting address is
the cooounication address. (starting address size is in bytes). For oore ineoroation about
cooounication addresses, reeer to 7.4 Compatible Common Area Parameter on page 235.
Function Code #03: Read Holding Register
Query Field Name
Station ID
Function(0x03)
Starting Address Hi
Starting Address Lo
# oe Points Hi
# oe Points Lo
CRC Lo
CRC Hi
Function Code #04: Read Input Register
Query Field Name
Station ID
Function(0x04)
Starting Address Hi
Starting Address Lo
# oe Points Hi
# oe Points Lo
CRC Lo
CRC Hi
232
Response Field Name
Station ID
Function (0x03)
Byte Count
Data Hi
Data Lo
...
...
Data Hi
Data Lo
CRC Lo
CRC Hi
Response Field Name
Station ID
Function (0x04)
Byte Count
Data Hi
Data Lo
...
...
Data Hi
Data Lo
CRC Lo
CRC Hi
# nuober oe Points
# nuober oe Points