CIRCUTOR CBS8 (Available until stocks) - Manual (Page 36)

----- Relay Station CBS-8 -------- --- Page No. 35
10.3.- MODBUS © Protocol
The CBS-8 system analyzer can communicate via MODBUS ©
protocol, as described below.
The MODBUS © protocol uses RTU mode (Remote terminal Unit). Each
8-bit byte in a message contains two hexadecimal 4 bit characters.
The format for each byte in RTU mode is:
* Code : 8- bit binary , hexadecimal 0-9, A-F
2 hexadecimal characters in each 8
bit field of the message.
* Bits per byte : 8 data bits
* Field CHECK- ERROR : CRC (Cyclical Redundancy Check).
MODBUS FUNCTIONS USED IN THE CBS-8:
FUNCTION 03h and 04h Reading n Words (16 bits - 2 bytes). The reading
function used by all of the CBS-8 parameters.
FUNCTION 06h Writing one WORD (16 bits - 2 bytes) in one
position in the memory.
FUNCTION 10h Writing n WORDS (16 bits - 2 bytes) in
consecutive positions in the memory.