User`s guide

Appendix A - Logic Application Examples
Basic PLC Ladder Logic
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Example 5 - Basic PLC ladder logic
Free Form Logic- Boolean Expressions - Example 5
Rather than using individual logic function blocks, a boolean expression may be entered directly using the Free Form Logic
block which accepts up to 8 inputs. This can save function blocks. The inputs may come from other blocks with discrete
outputs, DI’s, or digital signal tags. The example below is a direct entry of the Example 4 boolean expression, with the ouput
connected to two DO’s. The Free Form Logic popup dialog box is also shown indicating format for expression entry. Note that
Input H is unused. You may use multiple levels of parenthesis to generate the boolean expression. There is no limit to the
number of these blocks. This implementation uses 10 function blocks, saving 2 blocks vs. Example 4.