Read Registers (Function Code 0X03 & 0X04); Write Single Holding Register (Function Code 0X06) - Liebert OpenComms Installation & User Manual

RTU Framing Examples
READ REGISTERS (FUNCTION CODE 0X03 &
0X04)
Query: for reading holding /input registers (requested by a client)
Server Function
Addres Code
s
(0x3/0x4)
1 byte 1 byte
Response: for reading holding/input registers (response by the server)
Server Function
Addres Code
s
(0x3/0x4)
1 byte 1 byte
WRITE SINGLE HOLDING REGISTER
(FUNCTION CODE 0X06)
Query: for writing a single holding register (requested by a client)
Server Function
Addres Code
s (0x06)
1 byte 1 byte
Response: for writing a holding registers (response by the server)
Server Function
Addres Code
s (0x06)
1 byte 1 byte
36
Index of
starting register
2 bytes
Byte Data from registers
Count
1 2*m bytes (= Byte Count)
bytes
Index of the
register
2 bytes
Index of the
register
2 bytes
Number of
registers to be read
2 bytes
16 bit value to
be written
2 bytes
16 bit value
been written
2 bytes
NIC Setup and Testing
16 bit
CRC
2
bytes
16 bit
CRC
2 bytes
16 bit CRC
2 bytes
16 bit CRC
2 bytes