The Ebyte E831-RTU(8080T-485) is an industrial-grade 16-channel digital IO controller featuring RS485 communication with Modbus RTU protocol support, DC 8V-28V wide voltage operation, dry/wet contact digital acquisition, and relay output control designed for automated PLC expansion and SCADA systems.
| Parameter Name | E831-RTU(8080T-485) |
|---|---|
| Product Model | E831-RTU(8080T-485) |
| Acquisition Channel Count | 16 Channels (8 Digital Inputs / 8 Relay Digital Outputs) |
| Signal / Acquisition Type | Digital Input (Dry Contact / Wet Contact), Relay Output |
| Communication Interface | RS485 Serial Interface (Standard Modbus RTU Protocol) |
| Operating Voltage Range | DC 8V to 28V (12V or 24V recommended) |
| Operating Current | 56 mA at 12V (Standby), 86 mA at 12V (Operating) |
| Wiring & Interface Method | Crimping Method (1 x 12 x 5.08 mm pitch terminal block) |
| Product Dimensions (H x W x D) | 105 x 75 x 30 mm |
| Product Weight | 256 plus or minus 5 grams |
| Installation / Mounting | Standard DIN-rail / Wall-mount Industrial Casing |
| Hardware parameter | Index |
|---|---|
| Weight | 256g±5g |
| Interface method | Crimping method, 1*12*5.08mm |
| Operating Voltage | DC8V~28V, 12V or 24V is recommended, over 28V may damage the device |
| Operating current | 12V@ 56mAstand-by current,12V@ 86mA operating current |
| Communication Interface | RS485:1200~115200bps |
| 8 digital inputs | Dry contact,DI acquisition frequency1KHz |
| 8 digital outputs | Open collector,DO contact capacity:30V/50mA |
| Baud rate | Baud rate range 1200~115200bps,factory default 9600 |
| Operating temperature | -20℃~+70℃ |
| storage temperature | -40℃~+85℃ |
| Operating humidity | 5%~95% |
| Storage humidity | 1%~95% |













Practical Application Scenarios
1. Smart Factory Industrial Automation and PLC Distribute IO Expansion
In automated production lines, central PLCs often lack sufficient physical IO channels to collect sensor status signals across large manufacturing floors. Systems engineers deploy the E831-RTU(8080T-485) as a remote distributed IO expansion unit mounted on standard DIN rails near machinery. Using standard Modbus RTU commands over an RS485 bus, the controller collects digital inputs from photoelectric proximity switches and safety door interlocks while controlling local relay outputs, seamlessly expanding PLC capacity without costly field wiring.
2. Building Energy Management and HVAC Auxiliary Equipment Control
Commercial facility operators require real-time monitoring of HVAC dampers, exhaust fans, and lighting status. The E831-RTU(8080T-485) operates across DC 8V-28V supply voltage, making it directly compatible with standard 24V industrial power distribution cabinets. Integrated with Ebyte RS485-to-Ethernet serial servers or Wireless DTUs, the unit relays 16 channels of digital inputs and relay switching states directly to host SCADA software, enabling automated energy management and scheduled lighting control across multi-story buildings.
3. Industrial Security Monitoring and Access Control Telemetry
In security monitoring projects for remote substations and warehouses, tracking door contact sensors, PIR motion detectors, and fence intrusion alarms is essential. The E831-RTU(8080T-485) acquires dry contact and wet contact status from multiple alarm sensors across its 8 digital input channels. When paired with Ebyte 4G cellular DTU modules, alarm status changes trigger instant Modbus polling updates, activating physical strobe lights or siren relays locally while simultaneously transmitting event telemetry to off-site monitoring servers.
FAQ Section
1. What Modbus function codes does the E831-RTU(8080T-485) support for reading digital inputs and controlling relay outputs?
The E831-RTU(8080T-485) supports standard industrial Modbus RTU protocol commands. Developers can read the state of digital inputs using Function Code 02 (Read Discrete Inputs) or Function Code 01 (Read Coils / Inputs). To control or pulse relay outputs, host masters (such as PLCs, HMIs, or IPCs) send commands using Function Code 05 (Write Single Coil) or Function Code 0F (Write Multiple Coils).
2. How are baud rate, device slave address, and communication parameters configured on the E831-RTU(8080T-485)?
System parameters including device slave ID address, baud rate (typically 9600 bps up to 115200 bps), and parity settings can be configured using Ebyte official Modbus configuration software via the RS485 interface. Alternatively, users can modify specific holding registers directly by issuing Modbus RTU Function Code 06 (Write Single Register) commands when connected to host computers or PLC programming software.
3. What electrical protection features are integrated into the RS485 bus and power supply of the E831-RTU(8080T-485) for harsh industrial environments?
Designed for harsh electromagnetic environments, the E831-RTU(8080T-485) incorporates power reverse-polarity protection across its DC 8V-28V wide voltage input, preventing accidental hardware damage during installation. The RS485 communication line includes transient voltage suppression (TVS) diodes and ESD protection to guard against static discharges, ground potential differences, and surge interference on long-distance field buses.