Any troubleshooting ideas

1. The computer has multiple COM ports, and the selected port is incorrect.

2. The device address is wrong, or there are devices with duplicate addresses (all factory defaults are 1).

3. Baud rate, check mode, data bit, stop bit error.

4. Host polling interval and waiting response time are too short, both need to be set above 200ms.

5. 485 bus is disconnected, or A and B lines are connected in reverse.

6. Too many devices or too long wiring, power supply should be provided nearby, 485 enhancer should be added, and 120Ω terminal resistance should be added.

7. USB to 485 driver is not installed or damaged.

8. Equipment is damaged.

Note: To ensure the accuracy of the equipment, please clean the lower surface of the measuring area of the equipment regularly to keep it clean and free of dust or other foreign matter.