User Manual

LOGO! functions

4.4 Special functions list - SF

LOGO!

158 Manual, 06/2014, A5E33039675

Functional description

A 0 to 1 transition at input Trg sets output Q.

If output Q = 0, and input Trg is set hi at least for the duration of T

, LOGO! enables the

permanent lighting function and sets output Q accordingly.

LOGO! triggers the off-delay T when input Trg returns to 0 before T

has expired.

Output Q is reset when T

= T.

You can output an off-warning signal prior to the expiration of the off-delay time (T - T

) that

resets Q for the duration of the prewarning time period T

. A subsequent signal at Trg

always resets T and the output Q.

If the block is retentive, LOGO! resets output Q and the expired time to the values before a

power failure; if the block is not retentive, LOGO! resets output Q and the expired time to

defaults after a power failure.

Setting the Par parameter

Note the defaults specified in the topic "Time response (Page 128)".

Note

T, T

and T

must all have the same timebase.

View in programming mode (example):

View in parameter assignment mode (example):