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

Switch-on delay

Block name

BD12_SWITCHONDELAY

ST call

PROGRAM BD12_TEST
VAR 
  IN1,OUT1: BOOL;
 FB: LIB.CORE.V1_1.BD12_SWITCHONDELAY;
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. The falling edge of IN is not delayed, it appears on the output immediately. 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	False
RESET	BOOL	Resets the TRES	False
IGNORESTARTEDGE	BOOL	If TRUE the block is not initialised after start	False
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 usage of this block is very versatile, in fact, this is one of the most used blocks at all. It is used for time insensivity of binary alarms, for sequential switching of cascade members, or for time delays at AHU starting sequence.

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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