stackint

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Function Block A function block groups an algorithm and a set of private data. It has inputs and outputs. - Manages a stack of DINT integers.

Inputs

Input	Data Type	Description
PUSH	BOOL	Command: When changing from FALSE to TRUE, the value of IN is pushed on the stack.
POP	BOOL	Pop command: When changing from FALSE to TRUE, deletes the top of the stack.
R1	BOOL	Reset New start of the microprocessor. command: If TRUE, the stack is emptied and its size is set to N.
IN	DINT	Value to be pushed on a rising pulse When the step gets activated, the action is activated for a single execution, and possibly once again when the step is deactivated. of PUSH.
N	DINT	Maximum stack size. Cannot exceed 128.

Outputs

Output	Data Type	Description
EMPTY	BOOL	TRUE if the stack is empty.
OFLO	BOOL	TRUE if the stack is full.
OUT	DINT	Value at the top of the stack.

Remarks

Push and pop operations are performed on rising pulse of PUSH and POP inputs.
The specified size (N) is taken into account only when the R1 (reset) input is TRUE.

FBD Language Example

FFLD Language Example

In the FFLD language, the input rung is the PUSH command.
- The output rung is the EMPTY output.

IL Language Example

(* MyStack is a declared instance of STACKINT function A function calculates a result according to the current value of its inputs. 
A function has no internal data and is not linked to declared instances. block *)
Op1: CAL MyStack (PUSH, POP, R1, IN, N)
     FFLD MyStack.EMPTY
     ST EMPTY
     FFLD MyStack.OFLO
     ST OFLO
     FFLD MyStack.OUT
     ST OUT

ST Language Example

(* MyStack is a declared instance of STACKINT function block *)
MyStack (PUSH, POP, R1, IN, N);
EMPTY := MyStack.EMPTY;
OFLO := MyStack.OFLO;
OUT := MyStack.OUT;