Using Siemens PLC timer - Solutions - Huaqiang electronic network

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The user uses the CPU of the CPU315-2DP to implement a very complicated process control. The time requirement is very strict. There are many time series. For example, the A point signal is 1 and the timer 1 is triggered. The timing is 5 seconds. After the time is up, the output level is Give point B, trigger timer 2, delay 3 seconds, collect the value of C sensor, trigger timer 3, and calculate every 10 seconds (there is a formula), etc. There are many segments in this process, each segment It's not the same, the number of timers used is different, the user program is compiled, but it has not been completed, because the timer is not enough, more than 256 timers can be provided by plc, so there are those complaints above. . To sum up, users complain that the number of timers that Siemens plc can provide is too small to be enough to meet the needs of users (finally understood). After listening to the user's question, the user has calmed down a lot, and my heart has a bottom. First of all, I didn't give the user a direct answer, but first concerned about the difficulty of the user debugging program. I just said: "Is it too inconvenient to debug the program?" My voice just fell, and the user's words turned on again. The complaint is inconvenient, the debugging is inconvenient, the timer is out of order, and the conditions depend on each other too much. In short, there is no easy to use place, and it is almost tortured to death. After listening to the user's words, remind yourself, don't sprinkle salt on the user's "wound", or prescribe the prescription, first look at the disease, and then talk about it. Not enough to use IEC timer (SFB3-SFB5), as long as the CPU capacity is sufficient, the number is not limited, obviously the user does not know this information, otherwise he will not complain that the timer is not enough, if the IEC timer is used Programming, it is estimated that half of the user's program is a timer program, so I did not tell him first, so as not to lead to a lot of words, the user is not easy. What prescription has it given to the user? The formula is very simple: one timer, one addition instruction (MW0=MW0+1). How to use: Because all the timers used by the user are in seconds, then T1 is set to a 1 second timer. After the program runs, the timer is started, and then MW0=MW0+1 is executed after the timing time expires. MW0 is incremented by 1 every 1 second, so that by judging the value of MW0, the corresponding time (seconds) is obtained, and it can be determined how many seconds have elapsed, for example, MW0=10, which is 10 seconds, when MW0 The value can be cleared after the maximum timing value has been reached. This is a good way to meet the needs of users, solve the problem, and the program structure is relatively clear, not easy to mess.