# Modbus TCP/IP Server Module (IS4350-M1) Ready-to-use Modbus TCP/IP server module with RJ45 for any microcontroller with I2C. 65,500 Holding Registers, no stack needed. - **Seller:** [INACKS](https://lectronz.com/stores/inacks), Terrassa, Barcelona, Spain - **Price:** €20.00 (EUR, before shipping and taxes) - **Availability:** Coming soon - **Categories:** Robotics, Sensors, Home automation - **Product page:** https://lectronz.com/products/modbus-tcp-ip-server-module-is4350-m1 ## Links - [Documentation](https://inacks.com/wp-content/uploads/IS4350-M1-User-Manual-I2C-Modbus-TCP-Server-Module-with-RJ45-ISDOC155.pdf) ## Images ![Modbus TCP/IP Server Module (IS4350-M1)](https://lectronz-images.b-cdn.net/lectronz/active_storage/representations/proxy/eyJfcmFpbHMiOnsiZGF0YSI6NzM4MDEsInB1ciI6ImJsb2JfaWQifX0=--49187c4cd869d5edf4a288b47426d4e7cfd1aa56/eyJfcmFpbHMiOnsiZGF0YSI6eyJmb3JtYXQiOiJqcGciLCJyZXNpemVfdG9fbGltaXQiOls5NjAsNjQwXSwic2F2ZXIiOnsic3RyaXAiOnRydWV9fSwicHVyIjoidmFyaWF0aW9uIn19--970c165836a83091725a1a0fd4f37ce9408da1bf/IS4350-M1%20Modbus%20TCP%20Server%20Module+RJ45%20(3).jpg) ![Modbus TCP/IP Server Module (IS4350-M1)](https://lectronz-images.b-cdn.net/lectronz/active_storage/representations/proxy/eyJfcmFpbHMiOnsiZGF0YSI6NzM4MDUsInB1ciI6ImJsb2JfaWQifX0=--38aadeda475d4c1bc526d825d2a906e2921fdee1/eyJfcmFpbHMiOnsiZGF0YSI6eyJmb3JtYXQiOiJqcGciLCJyZXNpemVfdG9fbGltaXQiOls5NjAsNjQwXSwic2F2ZXIiOnsic3RyaXAiOnRydWV9fSwicHVyIjoidmFyaWF0aW9uIn19--970c165836a83091725a1a0fd4f37ce9408da1bf/IS4350-M1%20Modbus%20TCP%20Server%20Module+RJ45%20(1).jpg) ![Modbus TCP/IP Server Module (IS4350-M1)](https://lectronz-images.b-cdn.net/lectronz/active_storage/representations/proxy/eyJfcmFpbHMiOnsiZGF0YSI6NzM4MDksInB1ciI6ImJsb2JfaWQifX0=--36d74c32e8c68d84b4946aba6f1a2f8e27f12a90/eyJfcmFpbHMiOnsiZGF0YSI6eyJmb3JtYXQiOiJqcGciLCJyZXNpemVfdG9fbGltaXQiOls5NjAsNjQwXSwic2F2ZXIiOnsic3RyaXAiOnRydWV9fSwicHVyIjoidmFyaWF0aW9uIn19--970c165836a83091725a1a0fd4f37ce9408da1bf/IS4350-M1%20Modbus%20TCP%20Server%20Module+RJ45%20(2).jpg) ## Description ## Description ## The **IS4350-M1** is a ready-to-use Ethernet module that turns any microcontroller with an I2C port into a **Modbus TCP/IP server**. It integrates the **IS4350 I2C Modbus TCP/IP Server IC**, the **LAN8742A 10/100 Ethernet PHY**, the Ethernet magnetics, ESD protection and an **RJ45 connector with status LEDs** on a single, pre-designed and tested board. Designing an Ethernet interface from scratch means dealing with the PHY, its reference clock, strap configuration, impedance-controlled RMII and MDI routing, magnetics and line termination. The IS4350-M1 already contains all of this. Your design only needs to provide **3.3 V, two I2C lines and a few configuration pins**. --- ## How it Works? ## The IS4350-M1 exposes **65,500 Holding Registers** that work as a shared memory: - Your **microcontroller** reads and writes them over **I2C** (Arduino, STM32, ESP32, Raspberry Pi, FPGA, etc.). - Any **Modbus client** on the network (PLC, SCADA, HMI or PC) reads and writes them over **Ethernet**. Your firmware writes measurements for the client to read, and reads the set-points and commands the client writes. From your microcontroller's point of view, the module behaves like an **I2C memory with 16-bit addresses and 16-bit registers**. ➡️ **No Ethernet driver, TCP/IP stack or Modbus library required.** --- ## Key Features ## **Modbus** - Function codes: **03** Read Holding Registers, **06** Write Single Register, **16** Write Multiple Registers - 65,500 Holding Registers - Port 502, IP by **DHCP or static** (default: DHCP) **Ethernet** - Onboard LAN8742A PHY, **10/100 Mbps** auto-negotiation - RJ45 with link/activity and speed LEDs **I2C** - Speeds: **100 kHz, 400 kHz and 1 MHz** (selected with the SPD pin) - Addresses: **24, 25 or 26** (selected with the ADR pin), so up to 3 modules can share one bus **Safety** - **Fail-safe power-up**: the server only goes online when your firmware tells it to - Optional **I2C watchdog** (I2C-WDT): the server stops if your microcontroller stops refreshing it - Optional **I2C CRC protection** (I2C-CRC) - **INT output** pin that signals every Modbus write, so you don't have to poll - **DFT pin** to restore the default network configuration - Firmware can be updated with security patches through the provisioning UART **Mechanical** - 20 × 62 mm, **36 castellated pads on a 2.54 mm pitch** - Solder it onto your PCB as an SMD part, or fit pin headers for breadboard prototyping - Single **3.3 V** supply --- ## Getting Started ## 1. Connect 3V3, GND, SCL, SDA, SPD and ADR. That's the minimum. 2. Connect the RJ45 to your network. 3. Write your initial data to the Holding Registers. 4. Write `1` to **GO_ONLINE** to start the Modbus server. 5. Read the assigned IP address from the IP registers and connect your Modbus client. The user manual, Arduino example, KiCad symbol and footprint, and STEP 3D model are available at [IS4350-M1 Manual](https://inacks.com/wp-content/uploads/IS4350-M1-User-Manual-I2C-Modbus-TCP-Server-Module-with-RJ45-ISDOC155.pdf). The full IS4350 datasheet is at [IS4350-L64 Datasheet](https://inacks.com/wp-content/uploads/IS4350-Datasheet-I2C-Modbus-TCP-Server-ISDOC139.pdf). --- ## Questions? ## 💬 Contact us anytime for support or customization. --- *This company and the products provided herein are developed independently and are not affiliated with, endorsed by, or associated with any official protocol or standardization entity. All trademarks, names, and references to specific protocols remain the property of their respective owners.* ## Shipping policy We ship all products from Barcelona via UPS within 1–2 business days. A tracking number is provided. Transit time is typically less than one week worldwide (excluding handling time).