Input: power meter modbus unitid, also added value “unitid” in output JSON object. Read data in two parts: from address 3000, 120 registers and from address 21300, 40 registers one second later. Join all data and form an output JSON object in payload with these data: The Modbus protocol itself is declared as a ‘big-Endian’ protocol, as per the Modbus Application Protocol Specification, V1.1.b: Modbus uses a “big-Endian” representation for addresses and data items. This means that when a numerical quantity larger than a single byte is transmitted, the most significant byte is sent first.
May 10, 2013 · In this case I suggest you copy modbus.c to somewhere in your project directory, renaming it to something like "single_uart_modbus.c". Include this is your code instead of the original "mobus.c". Then in the copy, remove "UART1," from the line that's causing the first error, causing it to dfault to the one and only hardware serial port.