Application skills of programming rising and falling edge instructions of botu 1200/1500plc (bool array)

Portal PLC Falling edge and rising edge commands of , It is often used in control system programming . and SMART S7-200 Somewhat different , follow IEC-6113 The rising edge and falling edge function blocks provided by the standard , Need to be Edge memory bit address , The address of the edge memory bit can only be used once in the program at most , otherwise , This bit memory will be overwritten . Cause the program to run abnormally , The storage area of the edge storage bit must be located in DB( perhaps FB Static area ) Or bit storage . Self design of rising edge and falling edge commands , See the following blog post . Here we mainly talk about technical problems , How do we define intermediate variables in programming , When a large number of instructions are applied , How can we quickly define the middle address .

PLC Custom rising edge falling （ function ） Implementation along instructions _RXXW_Dor The blog of -CSDN Blog _ Rising edge function About rising and falling edges , We should use more general concepts to understand , The rising and falling edges are to capture the changing state of the signal , Perform a scan cycle when the edge occurs , Complete a function call . That is how to judge the problems of rising edge and falling edge , Let's draw a picture to illustrate , Using bit logic “ And ” Operation can realize the judgment of rising edge and falling edge , recycling Return（ Function returns the instruction ） Cooperate to complete the call and execute once .SCL Program realization （ Functional programming , The rising edge executes once FB） The falling edge function is realized （ It is suggested not to emphasize it as an instruction , It can be understood as a function , Such method ）. adopt 2 In fact, judgment can be realized by two adjacent discrete sequence signals . Self determination