The Ebyte M31 Series offers a comprehensive line of industrial-grade distributed remote I/O host and expansion modules that support Modbus TCP and Modbus RTU protocols over RJ45 and RS485 interfaces, providing a highly scalable and flexible solution for automated data acquisition and control systems. Built for harsh environments, the M31 series ensures stable 24/7 operation in industrial automation applications.
| Feature | Specification |
| Operating Voltage | DC 9~36V |
| Operating Temperature | -40°C to +85°C (-40°F to 185°F) |
| Operating Humidity | 5% ~ 95% RH (Non-condensing) |
| Installation Method | Standard DIN-Rail & Positioning Hole Mounting |
| Communication Protocols | Standard Modbus TCP & Modbus RTU |
| Interfaces | RJ45 (Network) & RS485 (Serial) |
| Isolation Protection | Built-in power supply isolation |
| Relay Contact Capacity | 5A 30VDC / 5A 250VAC (DO output) |
Developer Resources
1. M31-A/X Series Manual & Modbus Register Address Map(PDF)
2. M31-G Series Manual(PDF)
3. M31 Series Upgrade Notes(PDF)
4. M31 Series Configuration tool(PDF)
5. Ebyte Company Profile(PDF)
Product Selection Guide
Important Note: The M31-G series models are expansion modules and CANNOT work independently. They must be connected to an M31 Host module (e.g., M31-AAAX4440G) to function via Modbus TCP.
| Model | Module Type | Communication Interfaces | Digital Input (DI) | Digital Output (DO) | Analog Input (AI) | Analog Output (AO) |
|---|---|---|---|---|---|---|
| M31-XXXA0008G | Host Module | RJ45 + RS485 | 0 | 0 | 0 | 8 |
| M31-XGXX0800G | Host Module | RJ45 + RS485 | 0 | 0 | 8(Differential) | 0 |
| M31-XFXX0800G | Host Module | RJ45 + RS485 | 0 | 0 | 8 | 0 |
| M31-AAAX4440G | Host Module | RJ45 + RS485 | 4 | 4 | 4 | 0 |
| M31-XXAX0080G | Host Module | RJ45 + RS485 | 0 | 0 | 8 | 0 |
| M31-AXXX8000G | Host Module | RJ45 + RS485 | 8 | 0 | 0 | 0 |
| M31-AXAX8080G | Host Module | RJ45 + RS485 | 8 | 0 | 8 | 0 |
| M31-AXAX4040G | Host Module | RJ45 + RS485 | 4 | 0 | 4 | 0 |
| M31-XAXA0404G | Host Module | RJ45 + RS485 | 0 | 4 | 0 | 4 |
| M31-XAXX0800G | Host Module | RJ45 + RS485 | 0 | 8 | 0 | 0 |
| M31-XXAX00A0G | Host Module | RJ45 + RS485 | 0 | 0 | 10 | 0 |
| M31-AXXXA000G | Host Module | RJ45 + RS485 | 10 | 0 | 0 | 0 |
| M31-GAAAX4440 | Expansion Module | RS485 | 4 | 4 | 4 | 0 |
| M31-GAXXX8000 | Expansion Module | RS485 | 8 | 0 | 0 | 0 |
| M31-GXXAX0080 | Expansion Module | RS485 | 0 | 0 | 8 | 0 |
| M31-GAXAX4040 | Expansion Module | RS485 | 4 | 0 | 4 | 0 |
| M31-GAXXXA000 | Expansion Module | RS485 | 10 | 0 | 0 | 0 |
| M31-GXXAX00A0 | Expansion Module | RS485 | 0 | 0 | 10 | 0 |
| M31-GAXAX8080 | Expansion Module | RS485 | 8 | 0 | 8 | 0 |
| M31-GXAXX0800 | Expansion Module | RS485 | 0 | 8 | 0 | 0 |
| M31-GXXXA0008 | Expansion Module | RS485 | 0 | 0 | 0 | 8 |
| M31-GXAXA0404 | Expansion Module | RS485 | 0 | 4 | 0 | 4 |
| M31-GXFXX0800 | Expansion Module | RS485 | 0 | 0 | 8 | 0 |
| M31-GXGXX0800 | Expansion Module | RS485 | 0 | 0 | 8 | 0 |
Key Features & Advantages
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Massive Expandability: Adopts a distributed architecture. A single host can connect to up to 16 I/O expansion modules, saving costs and meeting complex on-site demands without replacing the main unit.
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Multi-Client Access: Supports up to 5 Modbus TCP clients accessing simultaneously, ensuring data synchronization across multiple control centers or HMIs.
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Smart Status Diagnostics: Built-in real-time monitoring of the I/O module communication status for quick troubleshooting.
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High-Precision Acquisition: Supports differential analog input with 16-bit resolution and accuracy within 1‰, backed by power supply isolation for extreme reliability.
Industrial Installation & Wiring
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Mounting: Supports standard 35mm DIN-Rail and positioning hole installation, perfect for industrial control cabinets.
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Wiring: Clearly defined terminals for RS485, RJ45, DI (NPN/PNP active input, 12-24V), DO (Relay max 5A), and AI/AO. (Tip: Insert a wiring diagram image from Chapter 2.2 of the manual here for maximum clarity).
Practical Application Scenarios
1. Automated Factory Data Acquisition
The M31 series acts as the primary bridge between analog sensors (such as pressure, temperature, and flow meters) and industrial PLCs or SCADA systems. By converting local sensor signals into standard Modbus TCP packets over Ethernet, it enables facility-wide data transparency, allowing operators to monitor equipment health in real-time across decentralized production lines.
2. Intelligent Building Energy Management
Building management systems utilize M31 I/O modules to integrate HVAC, lighting, and power meters into a unified network. With the support for both RS485 and RJ45, these modules facilitate the aggregation of energy usage data from multiple floors into a central server, enabling fine-grained control and optimization of building operational costs.
3. Remote Infrastructure Monitoring (Smart Water/Gas)
In remote monitoring stations for water distribution or gas networks, the M31 series provides a scalable way to monitor critical infrastructure status. Its support for Modbus RTU ensures compatibility with legacy serial-based field equipment, while the Ethernet interface provides the necessary throughput for high-frequency status updates to regional control centers.
FAQ Section
1. Does the M31 series support concurrent Modbus TCP and RTU operation?
Yes, the M31 series is engineered to support both protocols, allowing users to leverage the speed and ubiquity of Modbus TCP for centralized server communication while maintaining compatibility with serial-based Modbus RTU field devices via the integrated RS485 interface.
2. How does the host module handle network failure or communication interruption?
The M31 series includes built-in safeguards and robust communication timeouts. In the event of a network loss, the module can be configured to enter a safe state (Fail-Safe), ensuring that critical outputs remain in a pre-defined condition to protect physical assets.
3. Can I mix different I/O expansion modules on the same network?
Absolutely. The M31 architecture is designed for high scalability. You can daisy-chain or network multiple host and expansion modules according to your specific I/O requirements, creating a fully customized data acquisition network that grows alongside your industrial application.
