Modbus TCP/IP is a serial communications protocol published by Schneider Electric for use with its programmable logic controllers (PLCs). Simple and robust, it has since become a de facto standard communication protocol.

Modbus RTU is an open, serial (RS-232 or RS-485) protocol derived from the Master/Slave architecture. It is a widely accepted protocol due to its ease of use and reliability. Modbus RTU is widely used within Industrial Automation Systems (IAS). This wide acceptance is due in large part to MODBUS RTU’s ease of use.

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.

Modbus RTU is supported in the following products:

HI 6300 and HI 6310 Weight Processors

HI 6500 and HI 6510 Weight Processors

HI 6600 Series Modular Sensor System