4-way network IO controller

  • 4 DI/DO, 2AI, 1 PT
  • Modbus TCP/RTU protocol
  • Support Master mode and Slave mode

Product overview

USR-IO424T-EWR is network IO product which supports 4-way input/output, 2-way analog quantity detection, 1-way temperature detection and Modbus RTU/TCP protocol. Take ‘Remote control’ as core function and have high usability. User can easily and quickly integrate USR-IO424T-EWR into own system to realize remote control which based on Ethernet and local control which based on LAN(WiFi) and RS485 .

Product features

  • Support 4-way Relay output.
  • Support 4-way input, default is dry contact.
  • Support 2-way analog input, default are voltage detection.
  • Support 1-way PT100 temperature input.
  • Support 8 conditional control command.
  • Support Web Server to configure IO424T-EWR.
  • Support various function code: 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x0F, 0x10.
  • Support socket to connect to remote server and TCP Client.
  • Support two work modes: Master mode and Slave mode. Master mode supports connecting to multiple Modbus RTU devices by RS485 cascading connection.
  • Adopt Modbus RTU protocol data processing. Support Modbus TCP/RTU protocol adaptation.
  • Support WAN/LAN interface.
  • Support connecting to USR Cloud.
  • Support FTP remote upgrade.
  • Support upgrading by RS485.
  • Support hardware watchdog.
  • Support various LED to indicate work status.
  • Support power supply over-current, over-voltage, anti-reverse connection protection.

4-way network io controller

Support USR Cloud function and can realize remote control directly after powering on
Be adaptive to Modbus TCP/RTU protocol
Support Master mode and Slave mode for user to choose

Basic function

  1. USR Cloud 
  2. Control equipment
  3. Ethernet Output interface
  4. Input interface
  5. Controlled terminal
  6. Local control terminal

Remote Control

After powering network IO controller, user can directly realize remote control by USR Cloud. Take lamp control as example:user can realize lamp control by PC or APP on mobile terminal, and user can also directly open/close lamp by local switch. Remote control can realize all weather and all-sided monitoring, save the cost of man power and material resources.

Modbus protocol adaptation

Can automatically identify Modbus RTU/TCP protocol in network side and respond data according to received protocol to realize response data as same format as received data.

Support Master mode and Slave mode for user to choose:

Default work mode of USR-IO424T is Slave mode and IO424T can be queried and controlled by Master device in Network side and RS485 side simultaneously in Salve mode. IO424T can also be configured into Master mode and Master mode supports connecting to multiple Modbus RTU devices by RS485 cascading connection. Master mode is suited to remote monitoring and control such as temperature and humidity monitoring of agricultural greenhouse.

Network IO series comparison table


Functional Diagram

  1. Full wired terminal installation and protection for lightning strike
  2. High current protection for power supply and interface
  3. RS485 anti-surge protection: 2KV
  4. Over-current protection for power supply

Hardware Protection

  1. Full wired terminal installation and protection for lightning strike
  2. High current protection for power supply and interface
  3. RS485 anti-surge protection: 2KV
  4. Over-current protection for power supply


  • When there is instantaneous high current in the circuit(such as power switch, etc.), it can ensure that the device hardware is not damaged.
  • Power supply interface ±4KV
  • Ethernet interface and serial port ±2KV


  • Prevent electrostatic damage equipment(Such as: dust electrostatic, electric arc, etc.)
  • Air ±15KV
  • Contact ±8KV


Well-designed hardware watchdog which can realize 24 hours stable operation.

Work mode

Master mode
In master mode, after IO424T receiving data, it will judge destination address firstly. If destination address is local address, IO424T will process data; if destination address isn’t local address, IO424T will forward data. In this mode, user can connect to multiple slave devices by RS485 cascading connection.

Slave mode
In this mode, IO424T can connect to master device or work as single device. In this mode, IO424T will analyse and process received data. If destination address is local address, IO424T will make a corresponding reaction; if destination address isn’t local address, IO424T will discard data.


Conditional control
Conditional control function supports user configuring the conditions to trigger IO changes. It can make using IO424T more flexibly and extend application scenario. User only needs to modify conditional control function register parameters, it will realize corresponding function. Conditional control function can provide convenience for project management.

Support configuring IO status hold
After restarting IO424T or powering on IO424T again, can choose holding the Relay output status or resetting to disconnect status.

Support upgrading firmware by FTP
Support upgrading firmware by FTP: can remotely upgrade firmware by Modbus commands.

EWR version supports Router function
EWR version supports multiple functions such as LAN control, Ethernet, WiFi, Web Server, etc.

Support analog acquisition and temperature acquisition
Analog acquisition adopts public reference ground method to connect, that’s to say it can convert to voltage detection; temperature acquisition can acquire temperature status by PT1003 line.

USR-IO424T supports USR Cloud

USR Cloud function

  • Industrial agreement: Modbus protocol devices can quickly access to USR Cloud
  • Historical data: curve and report forms.
  • Alarm push: E-mail.


Combine configuration software solution
Network IO controller can connect to devices that needs to be monitored by input interface, output interface and RS485 cascading connection. Then can choose local connection or USR Cloud remote monitoring, convert network data to serial data by VCOM software and transmit to configuration software to realize remote monitoring and control. Commonly be used in unmanned machine room, integrated management of hotel facilities, self-service supermarket, etc.

Temperature and humidity monitoring of agricultural greenhouse
User can connect IO424T to remote server to monitor and control greenhouse status such as: temperature and humidity, soil temperature and humidity, etc. This solution can realize starting or stopping by IO424T’s remote control function to realize automated management of smart agriculture.

Smart lamp control
User can connect to USR Cloud by USR-IO424T to realize remote street lamp monitoring and it is convenient to control in Cloud side and record the devices status. Whole solution can ensure overall rate of lighting of street lamp, help management and bring the benefit of environmental protection.

Smart hotel management
In smart hotel management project, user can connect USR-IO424T to TV, computer, refrigerator, air conditioner, door control system, etc. Then user can realize remote monitoring by mobile terminal. This solution is usually realized through local WiFi connection and it can also use USR Cloud to realize remote monitoring.

Self-service terminals solution
Based on remote monitoring function of USR-IO424T, user can connect output interface to multiple Relays and connect input interface to switching value, then connect USR-IO424T to Cloud platform to realize monitoring running condition of self-service terminals, adjusting supply chain at any time or handling failure timely.

Distribution box solution
Control AC contactor or breaker by USR-IO424T’s output Relays to realize remote control of powering on/off. USR-IO424T’s RS485 interface can connect to RS485 electricity meter to realize remote charging, remote control, etc.


Ethernet Interface
Wired WAN/LAN interface10/100M WAN/LAN interface
WiFi parameters
StandardSupport 802.11b/g/n
Antenna2.4G WiFi antenna
Range100 meters in open area
Hardware parameters
Data interface
Serial port: Support RS485.
Baud rate: 300bps~230400bps
Working voltage12V~36V
DI inputDry contact input, just needing to short-circuit DI and COM
DO outputAC 220V 10A
DC 28V 10A
Voltage acquisitionRange: 0V ~ 10V
Current acquisitionRange: 0mA ~ 20mA
Temperature detectionRange: -100℃ ~ 200 ℃
Working temperature -20℃ ~ +70℃
Storage temperature-40℃ ~ +85℃
Working humidity5%~95%
Storage humidity1%~95%
Software parameters
Work modeMaster mode, slave mode
Configuration commandModbus RTU
Network protocolModbus TCP, Modbus RTU
Application softwareSupport configuration software
Software function
Data transmission modeSupport TCP Client
EMC level
ESDIEC61000-4-2, Level 4
SurgeIEC61000-4-5, Level 3
Group pulseIEC61000-4-4, Level 3

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