If you can't confirm the problem, you can eliminate it by sending and receiving it yourself. 1. Your serial network device communicates directly with the computer. See if it is normal according to the baud rate related settings you know, so as to confirm whether there is any problem with the settings of your serial networking device.

2. Disconnect your device from the serial server, then short-circuit RXD and TXD of ttl serial port of our serial server, and send and receive data through the network to see if the data is normal and confirm that our serial server works normally.

3. Disconnect your device from the serial server, then short-circuit your device serial port, and check whether the data is normal through computer self-receipt, so as to confirm that the hardware from your computer to the serial port works normally.