Parker ACR Series Programmer's Manual

Also see for ACR8020: Hardware manual

Contents

Parker ACR Series Programmer's Manual Manual pdf 19 page image

Parker HannifinProgram FlowCode is executed sequentially, following the order in which it iswritten. But based on some input, you can shift code executionelsewhere in a program using conditional statements. Usingconditional statements, you can create code that tests for specificconditions and repeats code statements.The conditional statement provides a logical test—a truthstatement—allowing decisions based on whether the conditions aremet. In the code, you create an expression and test whether theresult is true.You can divide conditional statements into two sub-categories,selection and repetition.NOTE: Each level (or nest) uses 4 bytes of memory. For more onmemory use, see How Much Memory?SelectionThe selection structure controls the direction of program flow. Thinkof it as a branch in your program. When the conditions are met, theprogram moves to a different block of code. AcroBASIC providesthe following conditional statements:• IF/THEN• IF/ELSE/ENDIF• GOSUB• GOTOIF/THENPrograms need to run code based on specific conditions. TheIF/THEN statement lets a program test for a specific condition andrespond accordingly.The IF portion sets of the condition to test; if the condition provestrue, the THEN portion of the statement executes. If instead thecondition proves false, the THEN statement is ignored and programexecution moves on to the next statement.NOTE: Enclose the condition being tested in parentheses.Though the IF/THEN statement provides a single-line test, it canexecute multiple statements when the condition proves true. All thestatements must appear on a single line and be separated by aspace, colon, and another space.Programming Basics 19