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plc il - 18.3<br />

LD I:000/0<br />

AND( I:000/1<br />

OR( I:000/2<br />

ANDN I:000/3<br />

)<br />

)<br />

I:000/0<br />

I:000/1<br />

(<br />

AND I:000/0<br />

I:000/2<br />

(<br />

OR I:000/1<br />

(<br />

AND I:000/0<br />

result_1<br />

(<br />

OR I:000/1<br />

(<br />

AND I:000/0<br />

result_2<br />

(<br />

AND I:000/0<br />

result_3<br />

Given:<br />

I:000/0 = 1<br />

I:000/1 = 0<br />

I:000/2 = 1<br />

I:000/3 = 0<br />

1<br />

0<br />

(<br />

AND 1<br />

1<br />

(<br />

OR 0<br />

(<br />

AND 1<br />

1<br />

(<br />

OR 0<br />

(<br />

AND 1<br />

1<br />

(<br />

AND 1<br />

1<br />

AND 1<br />

1<br />

Given:<br />

I:000/0 = 0<br />

I:000/1 = 1<br />

I:000/2 = 0<br />

I:000/3 = 1<br />

0<br />

1<br />

(<br />

AND 0<br />

0<br />

(<br />

OR 1<br />

(<br />

AND 0<br />

0<br />

(<br />

OR 1<br />

(<br />

AND 0<br />

0<br />

(<br />

AND 1<br />

0<br />

AND 1<br />

0<br />

Figure 18.2<br />

Using a Stack for Instruction Lists<br />

A list of operations is given in Figure 18.3. The modifiers are;<br />

N - negates an input or output<br />

( - nests an operation <strong>and</strong> puts it on a stack to be pulled off by ’)’<br />

C - forces a check for the currently evaluated results at the top of the stack<br />

These operators can use multiple data types, as indicated in the data types column.<br />

This list should be supported by all vendors, but additional functions can be called using<br />

the CAL function.

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