FB_BA_FIFO04

FB_BA_FIFO04 1:

The function block FB_BA_FIFO04 enables sequential control of up to four units, with automatic switching of the switch-on sequence based on operating hours.
The function block is available in two versions: for a sequence of four or eight units.
Units with fewer operating hours take precedence in the sequence over units with more operating hours.

A rising edge at bChg forces a sequence change. The units with the fewest operating hours are set to the top of the FIFO and thus given priority for switching on.
In the sequence only units are entered, which are enabled at inputs bEn01..bEn04. nNum indicates the number of requested units.
The operating hours of the units are entered at inputs nActvTi01 to nActvTi04. If all these inputs are set to a constant value of zero, the sequence change is controlled cyclically, depending on bChg.
The first unit is removed from the FIFO, the other units are advanced, and the first unit is appended at the end of the FIFO again. As a result is an alternating sequence of units.

FB_BA_FIFO04 2: Inputs

VAR_INPUT
  bEn           : BOOL;
  nNum          : UDINT;
  bChg          : BOOL;
  bEn01         : BOOL;
  bEn02         : BOOL;
  bEn03         : BOOL;
  bEn04         : BOOL;
  nActvTi01     : UDINT;
  nActvTi02     : UDINT;
  nActvTi03     : UDINT;
  nActvTi04     : UDINT;
END_VAR

Name

Type

Description

bEn

BOOL

Function block enable

nNum

UDINT

Number of aggregates

bChg

BOOL

Force sequence change

bEn01...bEn04

BOOL

Enable aggregate 1...enable aggregate 4.

nActvTi01...nActvTi04

UDINT

Operating hours aggregate 1...operating hours aggregate 4.

FB_BA_FIFO04 3: Outputs

VAR_OUTPUT
  bQ01        : BOOL;
  bQ02        : BOOL;
  bQ03        : BOOL;
  bQ04        : BOOL;
  nNextOn     : UDINT;
  nNextOff    : UDINT;
  aFIFO       : ARRAY [1..4] OF UDINT;
  nNumOfEn    : UDINT;
END_VAR

Name

Type

Description

bQ01...bQ04

BOOL

Switches aggregate 1...4.

nNextOn

UDINT

Number of the aggregate that is switched on next.

nNextOff

UDINT

Number of the aggregate which will be switched off next.

aFIFO

ARRAY OF UDINT

FIFO buffer as a field.

nNumOfEn

UDINT

Number of devices, depending on the individual enable states.

Requirements

Development environment

Required PLC library

TwinCAT from v3.1.4024.22

Tc3_BA2 from v5.2.5.0