Timing extension method of PLC (programmable logic controller) timer

Abstract

The invention discloses a timing extension method of a PLC (programmable logic controller) timer. The method comprises the following steps: (A) constructing a timing module and a counting module by software programming, wherein the timing module and the counting module can be combined to form an extended timer; (B) setting M seconds as the timing time of the timing module, setting N as the counting number of the counting module, and setting M*N seconds as the extended timing time; (C) starting the timing module to start timing, stopping the timing module when the time arrives at M seconds, and reducing 1 from the counting number of the counting module; and (D) determining whether the counting number of the counting module is zero, if no, executing the step (C) and step (D) repeatedly; and otherwise, finishing and stopping the timing operation when the extended timing time is over. The method can greatly prolong the timing time by using software programming to extend the timer, and can reduce the number of hardware, thereby saving much capital.

Description

technical field [0001] The invention relates to a PLC timer, in particular to a timing extension method of a PLC timer. Background technique [0002] In the production of modern society, the application of PLC is more and more extensive, and there are more and more occasions to use it. The number of timers supported by different CPU modules in the PLC ranges from 32 to 512, and the longest timing time of the timer in the PLC is 9 990 s, which is about two hours. In most cases, the number of timers and the timing time are sufficient, but in practical applications, sometimes the number of timers is not enough or the timing time is too long, which exceeds the timing range of the timer, which obviously cannot meet the needs of production , the number of timers and timing time must be extended. Contents of the invention [0003] In order to overcome the above disadvantages, the present invention provides a timing extension method of a PLC timer that uses software programming ...

AI Technical Summary

Problems solved by technology

In most cases, the number of timers and the timing time are sufficient, but in practical applications, sometimes the number of timers is not enough or the timing time is too long, which exceeds the timing range of the timer, which obviously cannot meet the needs of production , the number of timers and timing time must be extended

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