13
EN
COUNTIS E13 / E14 - 545 869 A - SOCOMEC
8.3. communication structure
The device communicates via a Modbus protocol which involves a dialogue in accordance with a master/slave
structure. The communication mode is the RTU (Remote Terminal Unit) mode with hexadecimal characters composed
of at least 8 bits.
Modbus frame structure (master -> slave question):
Slave address
Function code
Address
Number of words to be
read
CRC 16
1 byte
1 byte
2 bytes
2 bytes
2 bytes
To comply with the modbus protocol, the inter-character time must be ≤ 3 silences.
This means the time for 3 characters to be emitted so that the message is processed by the COUNTIS E13/E14.
In order to use the information correctly, you must use the modbus functions in accordance with the codes:
• 3: to read n words (maximum 128).
• 6: to write one word.
• 16: to write n words (maximum 128).
N.B.:
1 word <=> 2 bytes <=> 16 bits
2 words <=> 4 bytes <=> 32 bits
The broadcast communication is available for the log that stores the tariff.
8.4. communication tables
The communication tables and relevant notes are available online
on the COUNTIS E13/E14 documentation page at:
www.socomec.com/en/countis-e1x
