plc il - 18.9
Program File 2: |
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Operand |
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Comment |
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START: |
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CAL |
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3 |
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(* Jump to program file 3 *) |
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Program File 3: |
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Comment |
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TEST: |
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LD |
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%I:000 |
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(* Load the word from input card 000 *) |
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BCD_TO_INT |
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(* Convert the BCD value to an integer *) |
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ST |
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%N7:0 |
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(* Store the value in N7:0 *) |
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GT |
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100 |
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(* Check for the stored value (N7:0) > 100 *) |
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JMPC |
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ON |
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(* If true jump to ON *) |
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CAL |
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RES(C5:0) |
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(* Reset the timer *) |
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ON: |
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LD |
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2 |
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(* Load a value of 2 - for the preset *) |
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ST |
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%C5:0.PR |
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(* Store 2 in the preset value *) |
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CAL |
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TON(C5:0) |
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(* Update the timer *) |
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LD |
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%C5:0.DN |
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(* Get the timer done condition bit *) |
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ST |
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%O:001/00 |
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(* Set the output bit *) |
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RET |
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(* Return from the subroutine *) |
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Figure 18.7 An Example of an IL Program
18.4SUMMARY
•Ladder logic can be converted to IL programs, but IL programs cannot always be converted to ladder logic.
•IL programs use a stack to delay operations indicated by parentheses.
plc il - 18.10
• The Allen Bradley version is similar, but not identical to the IEC 61131 version of IL.
18.5PRACTICE PROBLEMS
18.6PRACTICE PROBLEM SOLUTIONS
18.7ASSIGNMENT PROBLEMS
1.Explain the operation of the stack.
2.Convert the following ladder logic to IL programs.
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A |
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C |
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X |
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B |
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C |
D |
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Y |
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B |
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C |
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LD 001 |
LD 001 |
LD NOT 001 |
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AND 002 |
AND 002 |
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OR 003 |
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LD 004 |
LD 004 |
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LD 002 |
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AND 005 |
OR 007 |
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OR 004 |
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OR LD |
AND 005 |
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AND LD |
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OR 007 |
OR LD |
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LD 005 |
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LD 003 |
LD 003 |
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OR 007 |
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OR NOT 006 |
OR NOT 006 |
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AND 006 |
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AND LD |
AND LD |
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OR LD |
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OR NOT 008 |
3. Write the ladder diagram programs that correspond to the following Boolean programs. |
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OUT 204 |
OUT 204 |
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AND 009 |
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OUT 206 |
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AND NOT 010 |
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OUT 201 |