The Ebyte ME31-AXAX4040 is an industrial DIN-rail network I/O module featuring 4-way dry contact digital inputs and 4-way relay outputs that supports Modbus TCP and Modbus RTU protocols while functioning as an automated Modbus gateway to dynamically cross-route serial and Ethernet traffic.
| Specification Key | Technical Data Details |
|---|---|
| Product Model | ME31-AXAX4040 |
| Digital Input (DI) | 4 Channels (Dry Contact Input Detection) |
| Digital Output (DO) | 4 Channels (Mechanical Relay Output) |
| Supported Protocols | Modbus TCP and Modbus RTU standards |
| Gateway Functionality | Simple Modbus Gateway (Auto-forwards non-native Modbus addresses) |
| Installation Mode | Standard 35mm DIN-Rail Mounting |
| Product Size | 121 x 72 x 34 mm |
| Product Weight | 143 to 153 g |
| Name | Parameter |
|---|---|
| Nominal Voltage | DC 8~28V |
| Power indicator | Blue LED indication |
| Communication Interface | RJ45, RS485 |
| Baud rate | 9600bps (customizable) |
| Protocol | Modbus TCP, Modbus RTU |
| Device address | The default value is 1 and can be changed |
| Number of DI | 4 |
| DI Input type | Default passive switch input |
| Input instructions | Green LED indicates |
| Number of DO | 4 |
| DO output type | Single pole single throw type |
| DO output mode | Level output, Pulse output, Follow-up mode |
| Relay contact capacity | DC30V/7A、AC250V/7A |
| Product weight | 148g ± 5g |
| Product size | 121mm * 72mm * 34mm(Length*width*height) |
| Working temperature and humidity | -40 ~ + 105℃, 5% ~ 95%RH(No condensation) |
| Storage temperature and humidity | -40 ~ + 85℃, 5% ~ 95%RH(No condensation) |
| Installation method | Rail installation |

Practical Application Scenarios
1. Remote Pump and Valve Control in Water Treatment Facilities
In modern water management networks, engineers deploy the ME31-AXAX4040 inside localized power distribution boxes to handle remote fluid dynamics. The 4-way dry connection digital inputs monitor real-time physical states from float switches and fault indicators. Concurrently, the 4-way relay outputs connect directly to industrial contactors, allowing remote SCADA host systems to trigger or shut down heavy water pumps and motorized valves via Modbus TCP without delay.
2. Substation Environmental Control and Security Integration
Power distribution substations require automated environmental feedback loops to maintain grid safety. The module acts as an edge node that interfaces with physical infrastructure using a standard DIN-rail mount. The 4 DI channels register immediate dry contact alarm signals from localized smoke detectors and door access limit switches. When an alert condition triggers, the central controller commands the 4 DO channels over the Ethernet interface to instantly activate ventilation fans or auxiliary security warning sirens.
3. Factory Legacy Fieldbus-to-Ethernet System Migration
During industrial upgrades, plant system integrators frequently need to bridge older RS485 machinery with modern localized IT infrastructure. By utilizing this network module as a hardware bridge, technicians can connect serial sensors to the RS485 terminal. Leveraging its simple Modbus gateway feature, the internal processor intercepts polling frames, detects non-local slave addresses, and automatically shifts instructions across the serial/gateway network boundary to achieve seamless cross-protocol polling.
FAQ Section
1. What type of physical connections do the Digital Input channels expect on this module?
The 4 DI channels on the ME31-AXAX4040 are specifically engineered for dry contact detection. This means they are designed to interface with potential-free mechanical switches, limit switches, or clean relay contacts. They do not require external voltage injection to register a logic state change, shielding the internal microcontroller from field-level electrical transients.
2. How does the simple Modbus gateway mechanism route commands with non-local addresses?
When the module is connected to both a serial network and an Ethernet backbone, its protocol stack monitors the destination slave IDs. If the device receives a Modbus command containing an address that does not match its own local node configuration, the gateway logic automatically packs and passes those instructions out through the alternative communication interface to maintain open inter-device telemetry.
3. Are the relay outputs on the module suitable for directly switching high-power AC loads?
The 4 DO channels consist of integrated mechanical relays designed for standard industrial logic routing and small-signal switching. For high-power AC inductive loads, such as large industrial motors, high-wattage heating elements, or heavy-duty solenoids, it is essential to route the relay output to drive an external AC contactor or solid-state relay to prevent contact welding and inductive noise feedback.














