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The TRP-C68 AIO support Modbus/RTU protocol, The serial communication data format is
Start bit: 1,
Data bit: 8,
Parity check: None,
Stop bit: 1,
Baud-rate: 1200bps~115200bps.
6-1. Modbus Syntax
Command Format :ID
(HEX)+
FC
(HEX)+
SU
(HEX)+
DA
(HEX) or
RC
(HEX)+
CRC16
(HEX),
Response Format : ID
(HEX)+
FC
(HEX)+
SU
(HEX)+
DA
(HEX) or
RC
(HEX)+
CRC16
(HEX),
Error Format: ID
(HEX)+
FC
(HEX)+
CRC16
(HEX).
ID
: RS485 Device Address (HEX)…..1~247 1Byte,
FC:
Function Code (HEX)…1 Byte,
SU:
Sub Function (HEX)…..1 Byte,
DA
:
Data Format….No Limit,
RC:
Reserved code…No Limit,
CRC:
Cyclic Redundancy Check…2 Byte.
*Error Response: If CRC IS mismatches error the response is empty!
7. Modbus/RTU Command List
