7�2�- Modbus Protocol; 7�2�1�- Reading Example : Funtion 0X04; 7�2�2�- Writing Example : Funtion 0X05 - Circutor CVM-E3-MINI-ITF Instruction Manual

CVM-E3-MINI
7.2.- MODBUS PROTOCOL
In the Modbus protocol, the CVM-E3-MINI device uses the RTU (Remote Terminal Unit) mode.
The Modbus functions implemented in the device are as follows:
Function 0x03 and 0x04. Reading integer registers.
Function 0x05. Writing a relay.
Function 0x10. Writing multiple registers.
7�2�1�- READING EXAMPLE : Funtion 0x04�
Question: Instantaneous value of the phase voltage of L1
Address: 0A, Peripheral number: 10 in decimals.
Function: 04, Read function.
Initial Register: 0000, register on which the reading will start.
No� of registers: 0002, number of registers read.
CRC: 70B0, CRC Character.
Response:
Address
0A
Address: 0A, Responding peripheral number: 10 in decimals.
Function: 04, Read function.
No� of bytes: 04, No. of bytes received.
Register: 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 : Funtion 0x05�
Question: Deleting maximum and minimum values.
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.
Instruction Manual
Address Function
register
0A 04
No� of
Function
Bytes
04 04
Address Function
Register
0A 05
Initial No� of
CRC
registers
0000 0002 70B0
Register Register
No� 1 No� 2
0000 084D
Initial
Value CRC
0834 FF00 CEEF
CRC
8621
83