I ground the positive (+) output terminal of PWR-01 series. Can you provide details on the isolation of its external control signals?

The COM terminal (A GND) of the J1 connector is connected to its negative output terminal.
If the COM terminal (A GND) is grounded when the positive terminal of the output is grounded, the output will be short-circuited, possibly causing burnout of the external control circuit.
To prevent this, it is recommended to isolate the outputs.