Provided by standard library.

The function block Timer On Delay implements a turn-on delay.

TON(IN, PT, Q, ET) means:

IN and PT are input variables of the BOOL and TIME types respectively. Q and ET are output variables of the BOOL and TIME types respectively. If IN is FALSE, Q is FALSE and ET is 0.

As soon as IN becomes TRUE, the time will begin to be counted in milliseconds in ET until its value is equal to PT. It will then remain constant.

Q is TRUE when IN is TRUE and ET is equal to PT. Otherwise it is FALSE.

Thus, Q has a rising edge when the time indicated in PT in milliseconds has run out.

Graphic display of TON behavior over time:

Example in Function Block Diagram

Example in Structured Text

TONInst(IN := VarBOOL1, PT:= T#5s);