PROSAGA码农传奇-PLC/vPLC-PLC梯形逻辑 - 使用两个电位计的有问题的序列

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    希望这就是你的意思。我把它写成一个“工作”的伪代码。
在现实生活中，这段代码不是最好的，因为从那时起你有2个以上的泵应该是复杂的，但是这个非常详细。
还缺少紧急开关（如果他必须手动停止泵，则可以按下某个按钮）。
更好的是使用一些function_blocks和方法......
  
  
    宣言：
  
   <pre>
 <code>
 VAR
//INPUT
levelTank1 AT %I* : INT; //potentiometer 1
levelTank2 AT %I* : INT; //potentiometer 2

pump1Malfunction    AT %I*  : BOOL; //TRUE=pump has no malfunction || FALSE=malfunction
pump2Malfunction    AT %I*  : BOOL;

//OUTPUT
pump1Operation      AT %Q*  : BOOL; //TRUE=pump should run
pump2Operation      AT %Q*  : BOOL;

lastPumpInOperation : BYTE := 1;

nState  : UINT  := 0;
END_VAR

</code>
 </pre>
  
    在某处你应该定义最小和最大级别，我把它作为一个常量值：
  
   <pre>
 <code>
 VAR CONSTANT
tank1Hmax : INT := 32000;
tank1Hmin : INT := 5000;
tank2Hmax : INT := 25000;
tank2Hmin : INT := 2000;
END_VAR

</code>
 </pre>
  
    注意：模拟输入通常是INT值，因此最大值。等于32767
  
  
    而现在该计划：
  
   <pre>
 <code>
 CASE nState OF
0: //wait till tank 1 is filled and make sure tank2 is not overcharged
 IF (levelTank1 >= tank1Hmax) AND NOT (levelTank2 >= tank2Hmax) THEN
 nState := 1;
 END_IF

1: //start one pump
    //first check worst case - both pumps are broken
    IF NOT pump1Malfunction AND NOT pump2Malfunction THEN
        nState := 100;  //emergency 
    //last time pump1 was used, and now pump 2 should start when it has no malfunction
    ELSIF lastPumpInOperation = 1 AND pump2Malfunction THEN 
        pump2Operation := TRUE;
        lastPumpInOperation := 2;
        nState := 2;
    //last time pump2 was used, and now pump 1 should start when it has no malfunction
    ELSIF lastPumpInOperation = 2 AND pump1Malfunction THEN
        pump1Operation := TRUE;
        pump2Operation := FALSE;
        lastPumpInOperation := 1;
        nState := 2;
    //now we have to define what happens when one pump is in malfunction
    ELSIF NOT pump1Malfunction THEN
        pump2Operation := TRUE;
        pump1Operation := FALSE;
        lastPumpInOperation := 2;
        nState := 2;
    ELSIF NOT pump2Malfunction THEN
        pump1Operation := TRUE;
        lastPumpInOperation := 1;
        nState := 2;
    END_IF

2: //pump operation till tank1 is "empty", tank2 is "full" or pump failure occurs
 IF (levelTank1 <= tank1Hmin) OR (levelTank2 >= tank2Hmax) THEN
 nState := 3; //stop pumps
 ELSIF (pump1Operation AND NOT pump1Malfunction) THEN //pump has gone in malfunction during operation
 nState := 1; //go back to step2 to start another pump
 ELSIF (pump2Operation AND NOT pump2Malfunction) THEN
 nState := 1;
 END_IF

3:  //stop pumps
    pump1Operation := FALSE;
    pump2Operation := FALSE;
    nState := 0;

100:    //emergency
        //do what you can do - close the valve to tank1 or run as fast as you can
        pump1Operation := FALSE;
        pump2Operation := FALSE;

IF (pump1Malfunction OR pump2Malfunction) THEN
            nState := 0;
        END_IF 
END_CASE

</code>
 </pre>
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