MODBUS RTU messages are a simple 16-bit CRC (Cyclic-Redundant Checksum). The simplicity of these messages is to ensure reliability. Due to this simplicity, the basic 16-bit MODBUS RTU register structure can be used to pack in floating point, tables, ASCII text, queues, and other unrelated data.
Under Modbus RTU, all communications will be controlled by the Modbus functions. The Modbus protocol will determine the function, address, size, and offset register for the message. The command interface data will be within the data portion of the message and will define the command to our instrument.
