Switch-on/off delay
- Block name
- ST call
- Library
- Version
- Description
- Inputs
- Outputs
- Application example
- Older versions

Switch-on/off delay

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 longer than TON is delayed by TON and each falling edge longer than TOFF 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.

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