Remote I/O system and synchronization method in the same

• Main Author: AMAGAI AKIHIRO
• Format: Patent
• Language: English
• Published: 05.02.2013
• Subjects: CALCULATING; COMPUTING; COUNTING; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRIC DIGITAL DATA PROCESSING; ELECTRICITY; MULTIPLEX COMMUNICATION; PHYSICS

The object of the present invention is to provide a synchronization method that enables more accurate synchronization on a clock included in each I/O node, in a node that forms a remote I/O system where a master node and I/O nodes communicate each other. The master node includes a clocking means 14 for indicating the current time; a beacon recognizing means for detecting a reception of a beacon that is sent from a wireless LAN access point 3; a time detecting means 12 for determining a time stamp indicating when the reception of the beacon is detected based on the time indicated by the clocking means 14; a master list generating means 13 for generating a master list that is a list of the time stamp; and a master list sending means for sending the master list to the I/O nodes 2 through the wireless LAN access point 3, and the beacon contains a TSF timer value for identifying the beacon, and the master list contains the TSF timer value of the beacon corresponding to the time stamp indicating the time of the clocking means 14.