LOG / LOGL

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. - Calculates the logarithm (base 10) of the input.

Inputs

IN : REAL/LREAL  Real value

Outputs

Q : REAL/LREAL   Result: logarithm (base 10) of IN

Remarks

In FFLD language, the operation is executed only if the input rung (EN) is TRUE. The output rung (ENO) keeps the same value as the input rung.

In IL"Instruction list" This is a low-level language and resembles assembly, the input must be loaded in the current result before calling the function.

ST Language

Q := LOG (IN);

FBD Language

FFLD Language

(* The function is executed only if EN is TRUE *)
(* ENO keeps 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
     LOG
     ST  Q    (* Q is: LOG (IN) *)

See also

ABS   TRUNC   POW   SQRT