7�2�- MODBUS PROTOCOL
In the Modbus protocol, the
CVM-C11
device uses the RTU (Remote Terminal Unit) mode.
The Modbus functions implemented in the device are as follows:
Function 0x03 and 0x04
: Reading integer logs.
Function 0x05
: Writing a relay.
Function 0x10:
Writing multiple logs.
7�2�1�- READING EXAMPLE: FUNCTION 0x04�
Question:
Instantaneous value of the phase voltage of L1
Address
Function
Initial
Register
No� of
Registers
CRC
0A
04
0000
0002
70B0
Address: 0A
, Peripheral number: 10 in decimals.
Function: 04
, Read function.
Initial Register: 0000
, on which the reading will start.
No� of Registers: 0002
, number of registers read.
CRC: 70B0
, CRC Character.
Response:
Address
Function
No� of Bytes Register No� 1
Register
No� 2
CRC
0A
04
04
0000
084D
8621
Address: 0A
, Responding peripheral number: 10 in decimals.
Function: 04
, Read function.
No� of bytes: 04
, No. of bytes received.
Registers: 0000084D
, value of the phase voltage of L1: VL1 x 10 : 212.5V
CRC: 8621
, CRC Character.
Note:
Every Modbus frame has a maximum limit of 20 variables (40 logs).
7�2�2�- WRITING EXAMPLE: FUNCTION 0x05�
Question:
Deleting maximum and minimum values.
Address
Function
Initial
Register
Value
CRC
0A
05
0834
FF00
CEEF
Address: 0A
, Peripheral number: 10 in decimal.
Function: 05
, Read function.
Initial Register: 0834
, Register of the parameter for deleting maximum and minimum values.
Value: FF00
, we indicate that we want to delete the maximum and minimum values.
CRC: CEEF
, CRC character.
75
Instruction Manual
CVM-C11
