The 4-way Modbus relay module is equipped with a mature and stable 8-bit MCU and RS232 level communication chip.Using the standard MODBUS RTU format RS232 communication protocol, it can realize 4-channel input signal detection and 4-channel relay output, which can be used for digital quantity detection or power control occasions.Communication protocol: support standard Modbus RTU protocol.Communication interface: Support RS232/TTL UART interface.Communication baud rate: 4800/9600/19200, default 9600bps, support power-down save.1. Onboard mature and stable 8bit MCU and MAX3232 level conversion chip;2. Communication protocol: support standard Modbus RTU protocol;3. Communication interface: support RS232/TTL UART interface;4. Communication baud rate: 4800/9600/19200, default 9600bps, support power-down save;5. Optocoupler input signal range: DC3.3-24V (this input cannot be used for relay control);6. Output signal: relay switch signal, supports manual, flash-off, flash-off mode, the delay base of flash-off/flash-off is 0.1S, and the maximum flash-off/flash-off time can be set to 0xFFFF*0.1S=6553.5 S;7. Device address: range 1-255, default 255, support power-down save;8. The baud rate, input signal, relay status, and device address can be read using software/commands;9. On-board 4-way 5V, 10A/250V AC 10A/30V DC relays, which can be pulled in 100,000 times continuously, with diode bleed protection and short response time;10. Onboard relay switch indicator light11. Supply voltage: DC7-24VSize: 93 x 87mmMaterial: PCBcolour: greenPackage Contents:1 x 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.