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. - Select one of the inputs - 8 inputs.
Inputs
SELECT : DINT Selection command
IN1 : ANY First input
IN2 : ANY Second input
... :
IN8 : ANY Last input
Outputs
Q : ANY IN1 or IN2 ... or IN8 depending on SELECT (see truth table)
Truth table
| SELECT | Q |
|---|---|
|
0 |
IN1 |
|
1 |
IN2 |
|
2 |
IN3 |
|
3 |
IN4 |
|
4 |
IN5 |
|
5 |
IN6 |
|
6 |
IN7 |
|
7 |
IN8 |
|
other |
0 |
Remarks
In FFLD language, the input rung (EN) enables the selection. The output rung keeps the
same state as the input rung. In IL"Instruction list"
This is a low-level language and resembles assembly language, the first parameter (selector) must be
loaded in the current result before calling the function. Other inputs are operands of the
function, separated by comas.
ST Language
Q := MUX8 (SELECT, IN1, IN2, IN3, IN4, IN5, IN6, IN7, IN8);
FBD Language
FFLD Language
(* the selection is performed only if EN is TRUE *)
(* ENO has the same value as EN *)
IL Language
Not available
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 SELECT
MUX8 IN1, IN2, IN3, IN4, IN5, IN6, IN7, IN8
ST Q
See also
