AbsB

AbsB (FB)

FUNCTION_BLOCK AbsB

Short description

Anti-blocking protection for a binary signal

Representation

Interfaces

Inputs

Name	Data type	Value range	Initial value	Function
xFb	BOOL			Operating message

Outputs

Name	Data type	Value range	Initial value	Function
xOut	BOOL			Enable - output
xAbsOn	BOOL			Indicator - anti-blocking process
dtAbsLastOn	DATE_AND_TIME			Start date/time of the last anti-blocking process

Setpoints / Parameters

Name	Data type	Value range	Initial value	Function
tMinFbTime	TIME		T#30s	Minimum operating duration
tTime	TIME		120s	Duration of the anti-blocking process
eDay	eDoW		eDow.Monday	Weekday of the anti-blocking process
todStartTime	TOD		08:00:00	Start time of the anti-blocking process

Function description

General

This function block is used to monitor the operating message xFb for activity. The monitoring period always covers 168 hours (= 1 week). The operating message xFb is active if it is continuously active at least once during the monitoring period for the minimum operating duration tMinFbTime The anti-blocking process is thus prevented and the monitoring period restarts. If no operating message is available, the request/enable can alternatively be connected. If no activity was recorded during the monitoring period, the anti-blocking process (enable - output xOut = TRUE ) is triggered with the duration tTime on the weekday eDay at the time todStartTime triggered. At the same time the monitoring period restarts. The initial triggering of the anti-blocking process may be delayed depending on the relevant settings ( weekday eDay and todStartTime )

Example

Monitoring period ended on Tuesday morning, anti-blocking process triggered only on the following Monday. At the output dtAbsLastOn the start date and start time of the last anti-blocking process are available.

##### Prerequisite for using the AbsB function block

The use of the TimeRead2 function block is required for correct operation.

Enable - output xOut

xFb	Anti-blocking process	xOut	Notes
X	FALSE	FALSE	Anti-blocking process not active
X	TRUE	TRUE	Anti-blocking process active

Legend: X = any

Indicator - anti-blocking process xAbsOn

xFb	Anti-blocking process	xAbsOn	Notes
X	FALSE	FALSE	Anti-blocking process not active
X	TRUE	TRUE	Anti-blocking process active

Legend: X = any

Setpoint / parameter eDay

The anti-blocking function can be globally disabled by setting eDay = eDow.Inactive

Setpoint / parameter tTime

The anti-blocking function can be globally disabled by setting tTime = 0s can be globally disabled.

CODESYS

InOut:

Scope	Name	Type	Initial
Input	xFb	BOOL
Input Const	tMinFbTime	TIME	TIME#30s0ms
Input Const	tTime	TIME	TIME#2m0s0ms
Input Const	eDay	eDoW	eDow.Monday
Input Const	todStartTime	TOD	TIME_OF_DAY#8:0
Output	xOut	BOOL
Output	xAbsOn	BOOL
Output	dtAbsLastOn	DT