MOD / MODR / MODLR

FunctionA 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. - Calculation of modulo.

The modulo is calculated as follows:

Q = IN – Trunc(IN/BASE) * BASE

where Trunc(x) calculates the truncated (rounded toward zero) value of x.

• 
  

• If BASE = 0, then Q will return 0.
  If IN = 0, then Q will return 0.

Inputs	Function			Description
	MOD	MODR	MODLR
IN	DINT	REAL	LREAL	Input value
BASE	DINT	REAL	LREAL	Base of the modulo

Output	Function			Description	Range
	MOD	MODR	MODLR
Q	DINT	REAL	LREAL	Modulo result	(-BASE, BASE)

Examples

Remarks

The MOD family of functions can return negative numbers. By adding BASE to the result, the modulo value may be forced to a positive number if the range is required to be [0, BASE). An example of how to accomplish this in ST code follows.

q := MOD(x, base);
IF q < 0 THEN
   q := q + base;
END_IF;

In FFLD language, the input rung (EN) enables the operation, and the output rung keeps the state of the input rung. In IL"Instruction list" This is a low-level language and resembles assembly language, the first input must be loaded before the function call. The second input is the operand of the function.

ST Language

Q := MOD (IN, BASE);

FBD Language

FFLD Language

(* The comparison is executed only if EN is TRUE *)
(* ENO has the same value as EN *)

IL Language

Op1: LD"Ladder diagram" Ladder logic is a method of drawing electrical logic schematics. It is now a very popular graphical language for programming Programmable Logic Controllers (PLCs). It was originally invented to describe logic made from relays. The name is based on the observation that programs in this language resemble ladders, with two vertical "rails" and a series of horizontal "rungs" between them  IN
     MOD BASE
     ST  Q    (* Q is the rest of integer division: IN / BASE *)

See also

MIN   MAX   LIMIT   ODD