CIRCUTOR CVM-NRG96 Series (Available until stocks) - Manual (Page 31)

CVM-NRG96
M9817250120-03-05A
31
MODBUS © Protocol
The CVM-NRG96 power analyzers communicate by using MODBUS© protocol,
described below:
In the MODBUS protocol the RTU (Remote terminal Unit) mode is used; each 8-bit
byte in a message contains two 4-bits hexadecimal characters.
The format for each byte in RTU mode
Code
8 bit binary, hexadecimal 0-9, A-F
2 hexadecimal characters contained in each 8-bit
field in the message.
Bits per byte 8 data bits
Field Check-Error CRC Type (Cyclical Redundancy Check)
Modbus functions used
Function 01
Reading the status of the relays
Function 03 and 04
Reading n Words (16 bits-2 bytes). Function used for
reading the electrical parameters that the CVM-NRG96 is
measuring. All electrical parameters are long with 32 bits,
because of this two Words are required to request each
parameter.
(4 bytes - XX XX XX XX)
Function 05
Writing a relay.