1. Onboard mature and stable 8bit MCU and MAX485 level conversion chip2. Communication protocol: support standard Modbus RTu protocol3. Communication interface: support RS485/TTL UART interface4. Communication baud rate: 4800/9600/19200, default 9600bps, support power-off save5. Optocoupler input signal range: DC3.3-30V (this input cannot be used for relay control)6. Output signal: relay switch signal, support manual, flash off, flash off mode, flash off/flashThe base of the delay time is 0.1, and the maximum flash time can be set as0XFFFF *.1s=65535*0.1S=6553.5S7. Device address: range 1-255, default 255 supports power-off save8.There are 4 onboard 5V, 10A/250VAC10A/30VDC relays, which can be activated continuously for 100,000 times, with diode effusion protection, and short response time.9. On-board relay switch indicator10.Power supply voltage: DC7-24V, support DC socket/5.08mm terminal power supply, with input anti-reverse protectionColour:BlueMaterial:plasticSize:93x87mmPackage Contents:1* Modbus Rtu 4CH Relay ModuleOnly the above package content, other products are not included.Note: Light shooting 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.