Working process of reverse isolation device in secondary safety and secondary protection system of photovoltaic power station. Reverse isolation device is used to transmit data from safety zone III to safety zone I/II, and it is the only data transmission mode from safety zone III to safety zone I/II. The reverse isolation equipment centrally receives the data sent from the security zone III to the security zone I/II, performs signature verification, content filtering, validity check and other processing, and then forwards it to the receiving program inside the security zone I/II. The specific process is as follows:

1. The data sender in the whole area III first signs the data to be sent, and then sends it to the reverse isolation equipment.

2. After receiving the data, the reverse isolation device performs signature verification, and performs content filtering, validity check and other processing on the data.