Valid is a read-only Boolean property that indicates if Data in the packet is in the format required for the FSP protocol and matches the values tranmitted to/from the remote FSP host. 

Valid contains True when the buffer used to process the packet is large enough to accomodate the DataLen for the packet, and when the calculated checksum for values received in Data match the checksum stored in the packet contents. 

The value in Valid is updated in the ReadPacket method.

ReadPacket 

Data 

DataLen