Modbus TCP/IP Client Chip – IS4360

The IS4360 is a chip that integrates a Modbus TCP/IP 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 goal of the IS4360 is to eliminate the engineering effort typically required to implement and validate Modbus TCP/IP communication. It offers a reliable, ready-to-use solution that helps reduce development time and speed up your time-to-market (TTM).

How it Works?

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.

➡️ Just read/write the registers you need — no protocol stack required.

Default Chip Settings

Default Modbus Settings:

• Modbus Slave ID: 1
• IP: DHCP

Default I2C Settings:

• I2C Slave Address: 0x11 (fixed)
• I2C Speed: 100 kHz, 400 kHz, 1 MHz