Description

The IS4320 is a chip that integrates a Modbus RTU Master stack. Your microcontroller communicates with it via I2C, sending simple commands that the chip translates into its appropriate Read Holding Registers, Write Single Register or Write Multiple Registers function codes. It automatically handles frame generation, timing, and CRC.

The result is stored in the chip’s internal memory, which can be retrieved over I2C.

The supported Function Codes are:

• 0x03 Read Holding Registers
• 0x06 Write Single Register
• 0x10 Write Multiple Registers

The IS4320 provides a ready-to-use Modbus stack solution, reducing development time and accelerating time-to-market, while fully complying with strict T1.5 and T3.5 Modbus protocol timing requirements.

How Does It Work?

The chip provides two interfaces:

• An I2C interface for your microcontroller, FPGA, Arduino, Raspberry Pi, etc.

➜ This is where your system reads/writes Modbus data.

• A UART output to connect your preferred RS485 (or RS232, RS422) transceiver.

➜ This is the fieldbus that connects to a Modbus slaves such as sensors, actuators, PLC, computers, or machines.

To use it, send the desired function code via I2C, then read the IS4320's internal memory to retrieve the result.