Providing various digital I/O functions, the ET-2255 module is an Ethernet I/O monitoring and control module. The module can be remotely controlled through a 10/100 M Ethernet network by using Modbus TCP/UDP protocol. Modbus has become a de facto standard communications protocol in industry and is now the most commonly available means of connecting industrial electronic devices. This makes the ET-2255 module perfect integration with the HMI, SCADA, PLC, and other software systems.

The ET-2255 provides 8 wet/dry contact digital input channels and 8 sink-type digital output channels. With 2 Ethernet ports, the ET-2255 allows a daisy chain connection which permits flexibility in locating devices, eases installation, and lowers infrastructure costs. It features optical isolation for 3000 Vrms of transient overvoltage protection but doesn’t provide channel-to-channel isolation. Each input channel can be used as a 32-bit counter and each output channel support configurable power-on and safe values. It can safely be used in applications where hazardous voltages are present. It features 8 kV ESD protection, 4 kV EFT protection, 3 kV surge, and 3000 VDC I/O isolation also provided to enrich the noise protection ability for the industrial environment.

The module can be used to create a DI to DO pair-connect through the Ethernet. After configuration, the ET-2255 module can poll the status of the local DI channels and then use the Modbus/TCP protocol to continuously write to the remote DO devices.

It is equipped with a removable terminal block connector for easy and robust wiring in industrial situations and features a powerful 32-bit ARM MCU to handle efficient network trafficking.

ET-2255 module supports MQTT protocol and can act as a message publisher and subscriber. After connecting to the server MQTT Broker, the I/O status of the module can be published in the form of a topic, and can also receive messages from the same subscription topics. In communication, when the ET-2255 module is disconnected from the broker, the module has a reconnection mechanism that can automatically reconnect with the broker. In addition, there is a Keep-Alive Interval mechanism to ensure that the connection with the Broker is always maintained.

The ET-2255 supports the standard SNMP V2c specification. Through this specification, ET-2200 can transmit module information and I/O information to SNMP network management equipment or software (SNMP Network Management Software) to help administrators monitor the status of ET-2200 in real time. If the Trap function is enabled, when the module I/O status changes or reboots, it can send a message to the manager to keep track of the channel status at any time.