Alarm memory
- Block name
- ST call
- Library
- Version
- Description
- Inputs
- Outputs
- Function
- Application example

Alarm memory

Block name

BD50_ALARM_MEMORY

ST call

PROGRAM TEST_BD50
  VAR
 BOOL1, BOOL2, BOOL3, BOOL4, BOOL5, BOOL6:BOOL;   
   FB : LIB.CORE.V1_0.BD50_ALARM_MEMORY;
   END_VAR
  FB.IN[1] := BOOL3;
  FB.IN[2] := BOOL4;  
    FB(ACK:=BOOL1,RESET:=BOOL2);
    BOOL5 := FB.OUT[1];
     BOOL6 := FB.OUT[2];
END_PROGRAM

Library

LIB\CORE

Version

V1.0

Description

The block is an alarm memory, with up to 16 alarms.

Inputs

Input	Type	Description	Default value
IN	MULTIIOBOOL	Inputs of the alarm signals as an array	[False,…,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
IN0,IN1,..,IN15	BOOL	Inputs of the alarm signals

Outputs

Output	Type	Description
OUT	MULTIIOBOOL	Alarm output signals as an array.
ACKNOWLEDGED	MULTIIOBOOL	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)
OUT0,OUT1,..,OUT15	BOOL	Alarm output signals. OUT is in TRUE until an alarm has been reset.

Function

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 RESET input, but may be acknowledged by a rising edge brought to the ACK input. Note that in ST, the indeces are 1…16 rather than 0…15.

alrstatus values:

alrstatus=256 - at least one alarm is active.
alrstatus=512 - at least one alarm has been acknowledged
alrstatus=1024 - memory = true, alarm was active but has not been reset.

The alrstatus value may be addition of more of these states.

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