Event driven programmer logic controller processor arrangement with buffered inputs and method of operation of the same
First Claim
1. A processor arrangement comprising:
- a programmer logic controller operating to a ladder diagram process comprising a sequence of instructional steps of a sequential process;
a number of event inputs connected to an interrupt buffer, in turn connected to a real time clock, for recording times of events of signals received on the event inputs and generating interrupts,a cyclical buffer comprising sequential storage locations for storing interrupts and their event times;
event retrieval means for inspecting each location of the cyclical buffer sequentially upon each new instructional step of the sequential process;
wherein the programmer logic controller is arranged to operate on any event inputs stored in the cyclical buffer which are affected by the new step of the sequential process before proceeding to the next step of the sequential process.
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Accused Products
Abstract
A processor arrangement is described having a programmer logic controller (PLC) operating to a ladder diagram process. A number of event inputs (11-15) are provided connected to an interrupt buffer (31), in turn connected to a real time clock (32), for recording times of events of signals received on the event inputs and generating interrupts. Sequential storage locations in a cyclical buffer (60) store interrupts and their event times, where events occurring within a predetermined incremental time window are stored, with their event times, in a storage location for that time window. Each location of the cyclical buffer is inspected in sequence upon each new step of the sequential process. The PLC is arranged to operate on any events stored in the buffer which are affected by the new step of the sequential process before proceeding to the next step of the sequential process.
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Citations
7 Claims
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1. A processor arrangement comprising:
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a programmer logic controller operating to a ladder diagram process comprising a sequence of instructional steps of a sequential process; a number of event inputs connected to an interrupt buffer, in turn connected to a real time clock, for recording times of events of signals received on the event inputs and generating interrupts, a cyclical buffer comprising sequential storage locations for storing interrupts and their event times; event retrieval means for inspecting each location of the cyclical buffer sequentially upon each new instructional step of the sequential process; wherein the programmer logic controller is arranged to operate on any event inputs stored in the cyclical buffer which are affected by the new step of the sequential process before proceeding to the next step of the sequential process. - View Dependent Claims (2)
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3. A method of operating a programmer logic controller operating to a ladder diagram process having a sequence of instructional steps of a sequential process, including instructions involving initiating of timers upon the occurrence of events;
- comprising the steps of;
receiving event signals at event inputs on the occurrence of events; recording times of the event signals received on the event inputs and generating interrupts on the occurrence of the events; storing in a cyclical buffer comprising sequential storage locations, interrupts and their event times; inspecting each location of the cyclical buffer sequentially upon each new instructional step of the sequential process, and operating on any events stored in the buffer which are affected by the new step of the sequential process before proceeding to the next step of the sequential process. - View Dependent Claims (4, 5, 6, 7)
- comprising the steps of;
Specification