30-Ch Ethernet Relay Module, Modbus RTU/Modbus Protocol, PoE Port Communication, With Isolation And Protection Circuits, Industrial Grade Rail-Mount Case. The Modbus POE ETH Relay 30CH is very easy to use. Due to its fast communication, stability, reliability, and , it is an ideal choice for industrial control equipments and/or applications with high communication requirements. Features flash-on, flash-off function, by passing argument to the , it is possible to turn on the relay for a while and then close it automatically. Supports DC 7-36V wide range power input and PoE power supply. Supports relay control through MQTT protocol, comes with Alibaba Cloud MQTT application demo. Onboard Optocoupler isolation, prevent the relay from being interfered by high-voltage circuit. Adopts dedicated relay driver chip, with built-in flyback diode protection, for stronger and more stable driving ability. Note:Due to different production batches, there are differences in appearance, which does not affect the use. Colour:Black Material:Plastic Package Contents: 1 x Ethernet Relay Module Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.