Documentation

Switch-On/Off Delay (BD14)

Block name

BD14_SWITCHONOFFDELAY

ST call

PROGRAM BD14_TEST
VAR
IN1,OUT1: BOOL;
FB: LIB.CORE.V1_1.BD14_SWITCHONOFFDELAY;
END_VAR
FB(IN:=IN1);
OUT1:=FB.OUT;
END_PROGRAM

Library

LIB\CORE

Version

V1.1

Description

The delay block transforms the input signal IN so that each rising edge is delayed by TON and each falling edge is delayed by TOFF. The TRES parameter gives time remaining to the end of delay. The TRES value can be reset by a rising edge on the RESET input.

Inputs

Input Type Description Default value
IN BOOL Input value True
RESET BOOL Resets the TRES. False
IGNORESTARTEDGE BOOL If TRUE the block is not initialised after start. False
TOFF TIME Falling edge delay (30 s by default). 30s
TON TIME Rising edge delay (30 s by default). 30s

Outputs

Output Type Description
OUT BOOL Output signal
TRES TIME Time remaining to the end of delay

Application example

The block is used to smoothe the binary signal, it is actually a digital filter. The most frequent usage is in cascade controllers to delay the activation of a next cascade stage together with delayed switch-off to make the system more stable.

 

 

Older versions

 

Version V1.0 is flagged as BROKEN. It contained an error of IGNORESTARTEDGE input. Valu on this input during firt cycle of program was not reflecter even if the function block was set correctly.