MODBUS RTC industrial control board/data access design idea:

all MODBUS industrial control boards on the market only support coil input and output as IO expansion,

and there is no one that can do data access records. 

Just before there was a project that required the register data to be written to the SD card,

and the data monitored by the industrial control board should also be saved to the SD card. 

SD card data can be read or written through industrial control boards such as PLC, man-machine touch screen, etc. 

Similarly, SD card data can also be read or written via a card reader connected to a computer.

Usage scenario:

Example 1 monitors the number of times a host starts and stops on a certain day, saves it on the SD card, and facilitates future viewing. 

Example 2 Set the water level of a pump to 5 water levels,

write the data to the SD card through the computer PC,

and then read the data on the card by the industrial control board...

1. The power supply on the board adopts 24V voltage, which is 90% compatible with the voltage of industrial control boards such as PLC on the market.

2. Adopt RS485 communication and support MODBUS RTU protocol.

3. There are 10 relay coil outputs, which can be used as PLC control IO output, touch screen coil output, etc...

4. Coil, SD detection, data communication all have LED status indicator, the working status is clear at a glance.