1、With anti-aspiration design, no aspiration when power on, higher safety. 2、Using standard industrial rail installation, one RS485 bus can be connected to 32 modules. 3、Strict quality control and quality assurance, high safety factor, can be used with peace of mind. 4、Small size, easy to carry and store, convenient to use and with good performance. 5、Using high-quality materials, strong and durable, has a long service life. 1 x Relay Module Item Type: Relay ModuleMaterial: PlasticModel: R4I4DWide Power Supply: DC9-24V power supplyCurrent: 10ABaud Rate: 1200-19200 (can be set)Wiring Instructions: GND--------ground (negative power supply)NO1----The first group of relays are normally openVCC-------9 to 24V (power positive)COM1---the common terminal of the first group of relays485A-------RS485 positiveNC1----The first group of relays are normally closed485B-------RS486 negativeNO2----The second group of relays are normally openIN1--------The first group of switch inputCOM2----The common terminal of the second group of relaysIN2--------The second group of switch inputNC2----The second group of relays are normally closedIN3--------The third group of switch inputNO3----The third group of relays are normally openIN4--------group 4 switch inputCOM3----The third group of relay common terminalNC---------Empty, not usedNC3-------The third group of relays are normally closedNO4-------The fourth group of relays are normally openCOM4------The fourth group of relay common terminalNC4-------The fourth group of relays are normally closed