GXPacket component calls this method when the checksum is counted.

GXPacket component includes a header, and a data field, of a data packet used in communication. It also includes the methods for modifying those fields. In addition, every packet can be set to have unique settings. For example, a certain single packet can be set to wait a shorter time in sending, than other packets sent by the system. Also, for example, the resend count can vary from packet to another.