STC (Signal Transistor) - Modular/Digital Input - Relay Output

I. Problem Requirements:
Based on STC8 and Modbus I/O extension or data acquisition, this project is geared towards industrial control design. It includes three inputs, three outputs, three ADCs, and one PWM.
II. Design Summary :
Based on STC8G and Modbus I/O extension or data acquisition, this project is geared towards industrial control.
III. Problem Analysis
Hints: Analyze and demonstrate the entire problem content .
IV. Overall Design Block Diagram
Hints: Overall design block diagram
: 1. Input: 40V-12V AC/DC power supply, rectified and regulated to obtain 12V/5V.
2. Digital input: 40V-12V DC/AC isolated input.
3. Output: Relay output.
4. ADC input: 0-5V input.
5. Communication method: TTL.
VI. Program Flowchart:
Modbus RTU reads data packets and writes them to registers, then operates on the underlying registers. VII.
Physical Demonstration VIII

. Precautions:

Modbus RTC communication baud rate
; Modbus RTC register description;
Note that the scan refresh time is fastest at 20ms.
Coil Register:
IX. Demonstration Video

: https://www.bilibili.com/video/BV1xA8PepEhN/?spm_id_from=333.1365.list.card_archive.click&vd_source=255998544fa920e134cee9717a40a58c
X. Attachment Content