Topic: DMD0080

NEXT - Index by Step

The Index by Step (NEXT) instruction marks the end of a For/Next loop.

Note: All of the looping instructions are 'power-rail' instructions. Even though the instructions are displayed in the left-most column of the ladder diagram (the power rail), they are created in the right-most column of the ladder logic diagram (the output column). Creating these instructions in Do-more Designer is a bit counter-intuitive because the first step is to position the edit cursor in the output column of the ladder logic diagram (the far right) instead of positioning it against the power rail (the far left).

Parameters:

There are no parameters for this instruction.

Status Display:

The NEXT instruction will show the current .TimeSlice value of the Program or Task when status is ON.

The  blue  triangle in the upper left corner indicates this is a Yielding instruction.

See Also:

• BREAK - Exit Loop

• CONTINUE - Skip to Loop End
   

• FOR - Index Loop

• NEXT - Index By Step
   

• REPEAT - Loop Until Condition is Non-Zero

• UNTIL - Repeat Until Condition is Non-Zero
   

• WEND - While End

• WHILE - Loop While Condition is Non-Zero

Rung Example:

The following simple example uses V100 as the loop index. It will be initialized to 4000 (From) on the first pass through the loop, and will increment by 1 (By Step) on each successive pass until it gets to 4009 (To).

 Each pass through the loop the comparison contact will compare the value in D[V100] - which is D4000, D4001, D4002 ... D4009 - to the value in D4010. If the value in D[V100] is greater than the current value in D4010, the value in D[V100] will be copied to D4010.