A：

1: Connects the controller and the PTZ camera to observe whether are they funcitoning normally? (To crosscheck one/both of them are faulty)

2: Check the TX and RX 422/485 cable sequence

3: TX and RX enters Setting > Serial Port > Select the correct Serial Port Type (422/485)

4: TX amd RX enter Setting > Serial Port > Select the correct Baud setting (same as Baud of controller and PTZ camera, commonly it is 9600)