Time-delayed message transmitting method in process control system, transmits messages extracted from primary message queue according to determined transmission window size, for time period less than delay time period

摘要

The size of window to be used for data transmission is determined based on combination of upper and lower end of window with respective sequence number of both primary and secondary queues in which messages and unconfirmed messages are stored respectively. A message is extracted from primary queue based on determined window size and transmitted along with verification request for time period less than transmission delay time. The unconfirmed messages are then extracted from the secondary queue, and verification information is then received. The message to be communicated is stored in primary queue. The preset amount of unconfirmed messages are stored in secondary queue based on transmission circulation time delay of the communication connection. The size of window to be used for data transmission is determined in preset manner so that difference between sequence number of the both the queues is in inverse relation with amount of message stored in secondary queues. Independent claims are also included for the following: (a) Communication system; (b) Message communication method; (c) Process control system; (d) Application information communicating method