US 12,405,589 B2
Programmable logic controller, sequence control system, and non-transitory computer readable medium
Kazuki Kurita, Nagoya (JP); and Yoshihiro Nagatomo, Nagoya (JP)
Assigned to MITSUBISHI ELECTRIC CORPORATION, Tokyo (JP)
Appl. No. 18/880,285
Filed by Mitsubishi Electric Corporation, Tokyo (JP)
PCT Filed Jul. 19, 2022, PCT No. PCT/JP2022/028025
§ 371(c)(1), (2) Date Dec. 31, 2024,
PCT Pub. No. WO2024/018515, PCT Pub. Date Jan. 25, 2024.
Prior Publication US 2025/0164958 A1, May 22, 2025
Int. Cl. G05B 19/05 (2006.01)
CPC G05B 19/05 (2013.01) [G05B 2219/13076 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A programmable logic controller for executing a sequence program, the sequence program including a first execution element defining a preceding action, a second execution element defining a subsequent action to be performed subsequently to the preceding action, and a transition condition element defining a transition condition for transition of an active state from the first execution element to the second execution element, the programmable logic controller comprising:
a flag data update receiver to receive an update of flag data indicating whether activation of the second execution element is permitted or prohibited;
an interrupt receiver to receive an interrupt instruction indicating a request for activating the second execution element independently of whether the transition condition is satisfied;
an interrupt preventer to refer to latest flag data when the interrupt receiver receives the interrupt instruction, and to maintain, when the flag data indicates that the activation of the second execution element is prohibited, an inactive state of the second execution element and output an interrupt invalidation error indicating that the interrupt instruction is invalidated; and
an executor to activate the second execution element when the interrupt receiver receives the interrupt instruction and the latest flag data indicates that the activation of the second execution element is permitted.