Documentation

PROGRAM TEST_BD49
	VAR
	BOOL1, BOOL2, BOOL3:BOOL;   
	FB : LIB.CORE.V1_0.BD49_SINGLEALARMMEMORY;
	END_VAR

	FB(IN:=BOOL1, RESET:=BOOL2);
	BOOL3 := FB.MEMORY;
END_PROGRAM

Library

LIB\CORE

Version

V1.0

Description

This block is dedicated to deal with alarm states. The alarm signal is at the IN input. A rising edge on the IN input sets MEMORY to TRUE (alarm memory). The alarm can be reset by a rising edge at the RESET input. If IN=FALSE at the reset time, then MEMORY goes to FALSE. If the alarm is active (IN=TRUE), it can not be reset by the RESETinput, but may be acknowledged by a rising edge brought to the ACK input.

Inputs

Input	Type	Description	Default value
IN	BOOL	Input of the alarm signal	False
ACK	BOOL	Acknowledge. If IN=TRUE and rising edge comes to ACK then ACKNOWLEDGED=TRUE (while keeping MEMORY=TRUE)	False
RESET	BOOL	Reset of the alarm memory and ACKNOWLEDGED output	False

Outputs

Output	Type	Description
ACKNOWLEDGED	BOOL	Indication that an alarm has been acked
MEMORY	BOOL	Alarm memory
ALRSTATUS	INT	Status of the alarm block (bit 8 indicates IN=TRUE, bit 9 indicates ACKNOWLEDGED=TRUE, bit 10 indicates MEMORY=TRUE)

Application example

This alarm is activated by the b1 input. It is not acknowledged (input ACK is not connected), so it can only be reset after b1 is FALSE again.

Documentation

Single Alarm Memory (BD49)

Block name

ST call