Simple Logic Driver

This driver takes another driver's flag, string and integer variables and applies simple logic functions (that you create) to those variables. The result is stored in this driver's flag and not flag variables for you to use in any way you want. There are commands to cause the results to be calculated but you do not need to run these commands. The logical expressions will get evaluated whenever any of the variables happen to be changed either by a system macro, by a driver variable getting updated (volume was raised manually for example or temperature fell by one degree).

Configuration

During configuration you select which other driver variables to use for logic operations. These can be set to any driver's variables such as a temperature set point number. Then you can write a logic expression that represents your logical function. Use 'X1' in place of the first integer input variable 'X2' for the second integer input variable and so on. Use F1 for the first flag variable, 'F2' for the second flag variable and so on. Use S1 for the first string variable, 'S2' for the second string variable and so on. You can not use any other variables in expressions at this time other than F1 through F50, S1 through S50 and X1 through X50.

For example: Logic Expression 1 might hold the logical expression "F1 AND (X1 < 80) AND (S1 EQ "ON"). This will result in a true flag when F1 is true AND when X1 is less than 80 AND when S1 is a string with value "ON". ie. It will perform a clipping function if flag F1 is true and no clipping if F1 is false. When the resulting flag variable becomes true, the event Result True Event 1 will fire. Note that it will not continue to fire the event. The event will only fire once.

Available Math Expressions

For logical testing of flag variables you can use these comparison operators: AND, OR, NOT

And for testing whether two variables are equal, use the EQ operator.

For Integer comparisons, you can use any of the following operators: EQ, >=, <=, >, <

For Integer operations, you can do +, -, /, * and you can use ABS() to take the absolute value of any integer equation, quantity or variable. eg. ABS(X1) will give the absolute value of the variable, X1. YOU MUST USE SURROUNDING PARENTHESES. ABS X1 will not work. ABS(X2-X1) is valid.

Dynamic Naming

In Version 1.02 and above, you can name your logic equations for easy reference while programming your System File. Name only the Logic Equations you are using and make the names short but meaningful.

Result Flags

These are result variables that hold the results of the logical expression evaluations.

Result Not Flags

These are the logical opposite of the Result Flags and are true when the corresponding Result Flag is false.

Commands

Evaluate Logical Expression

Call this function to directly execute a logical expression by index. This may help you test your logical expressions. You do not need to use this function to make this driver work.

Set Logical Expression

Call this function to manually set your logical expression function at run time. This is advanced system function and should be used with caution.

Store Logical Expression

Call this function to manually set your logical expression function at run time from a pre-configured source variable from another driver. This is advanced system function and should be used with caution.