Hello, we worked together with your system to develop cloud one-card system platform and now we are analyzing your communication protocol. We want to know the meaning of network symbol in the communication protocol about your access control, elevator, guard tour, consumption and water controller.

Hello, thank you for your support. Our network symbol is used to identify the command sequence number. The sequence number and the information code in the return value instruction indicate that this command is returned correctly, which prevents the occurrence of command return values and command content mismatches.

For example, send command A, before controller haven't response, send instructions, B controller A command receiving failure, B command returns success, then can according to the information in the return value to determine the controller code return instruction is sent instructions sent A or B.