Modbus TCP/IP Server Chip – IS4350

The IS4350 is a chip that integrates a Modbus TCP/IP Slave stack. It features an internal memory of 500 Holding Registers, accessible by both a microcontroller (via I2C) and a Modbus Master device (e.g., PLC, computer, etc.).

The goal of the IS4350 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 RMII to connect your preferred Ethnernet PHY transceiver. ➜ This is the fieldbus that connects to a PLC, computer, or machine.

The internal memory is composed of 504 registers: – 500 Holding Registers for user data. – 4 Configuration Registers for communication settings.

You can use the IS4350 in two main modes:

• As a Sensor → your microcontroller writes data to the chip via I2C.
• As an Actuator → your microcontroller reads data from the chip via I2C.
• As an Advanced Device → your microcontroller reads and writes data to and from the chip via I2C.

➡️ 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