Table of Contents

Single alarm memory

Block name

BD49_SINGLEALARMMEMORY

ST call

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

InputTypeDescription Default value
IN BOOLInput of the alarm signal False
ACK BOOLAcknowledge. If IN=TRUE and rising edge comes to ACK then ACKNOWLEDGED=TRUE (while keeping MEMORY=TRUE)False
RESETBOOLReset of the alarm memory and ACKNOWLEDGED output False

Outputs

Output TypeDescription
ACKNOWLEDGEDBOOLIndication that an alarm has been acked
MEMORY BOOLAlarm 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.