US 12,278,661 B2
Industrial wireless communication system
Tomohiko Aki, Tsukubamirai (JP); and Norimasa Ozaki, Tsukubamirai (JP)
Assigned to SMC CORPORATION, Chiyoda-ku (JP)
Appl. No. 18/261,232
Filed by SMC CORPORATION, Chiyoda-ku (JP)
PCT Filed Aug. 20, 2021, PCT No. PCT/JP2021/030506
§ 371(c)(1), (2) Date Jul. 12, 2023,
PCT Pub. No. WO2022/158015, PCT Pub. Date Jul. 28, 2022.
Claims priority of application No. 2021-009661 (JP), filed on Jan. 25, 2021.
Prior Publication US 2024/0072842 A1, Feb. 29, 2024
Int. Cl. H04B 1/7143 (2011.01); H04W 56/00 (2009.01)
CPC H04B 1/7143 (2013.01) [H04W 56/00 (2013.01)] 17 Claims
OG exemplary drawing
 
1. An industrial wireless communication system, comprising:
a computer configured to carry out a monitoring control of industrial equipment;
a base wireless device connected by a field bus to the computer; and
a plurality of remote wireless devices provided in each of a plurality of apparatuses that make up the industrial equipment, and configured to perform wireless communications with the base wireless device,
wherein the base wireless device and the remote wireless devices, which are configured to be synchronously connected, switch a hopping frequency at a predetermined hopping period to thereby carry out transmission and reception of data;
the base wireless device includes a synchronous connection transmitter which, in a case that a synchronous connection with any of the remote wireless devices is not established, is configured to carry out a transmission process, by broadcasting, of transmitting a synchronous connection signal for a purpose of synchronous connection with the remote wireless devices only at a single essentially synchronous connection period that is an integer multiple of the predetermined hopping period;
the synchronous connection transmitter, by sequentially switching communication frequencies for synchronization, which are frequencies used for synchronous communication, transmits the synchronous connection signal at the plurality of communication frequencies for synchronization within the predetermined hopping period; and
the remote wireless devices each include a synchronous connection receiver which, in a case that a synchronous connection with the base wireless device is not established, is configured to carry out a process of waiting for reception of the synchronous connection signal at the plurality of communication frequencies for synchronization, and by sequentially switching the communication frequencies for synchronization at a switching period that is longer than the predetermined hopping period, and is shorter than a period that is two times the predetermined hopping period.