FB_BA_PIDControlSequence

PID sequence controller as part of a sequence.

On receipt of the enable bEn = TRUE, the higher-level control block FB_BA_SequenceLinkBase is informed that the sequence controller is ready for operation for sequence control.

The data exchange between the sequence controllers FB_BA_SeqCtrl and the control block FB_BA_SequenceLinkBase takes place via the structure stSeqLink.

	The input variable bHold on the function block FB_BA_SeqCtrl has no function!

Output value fPresentValue

The function block determines the resulting value at the output fPresentValue depending on the enables bEn and stSequenceLink.bEnSeqLink, the control direction eActionPgm / eActionRm and the sequence number nActvSeqCtrl / nMyNum.

bEn	stSequenceLink.bEnSeqLink	eActionPgm/eActionRm	nActvSeqCtrl/nMyNum	fPresentValue
TRUE	FALSE	E_BA_Action.eReverse		fMaxOutputPgm / fMaxOutputRm
TRUE	FALSE	E_BA_Action.eDirect		fMinOutputPgm / fMinOutputRm
FALSE	FALSE			0
TRUE	TRUE	E_BA_Action.eReverse	nActvSeqCtrl > nMyNum	fMinOutputPgm / fMinOutputRm
TRUE	TRUE	E_BA_Action.eReverse	nActvSeqCtrl < nMyNum	fMaxOutputPgm / fMaxOutputRm
TRUE	TRUE	E_BA_Action.eDirect	nActvSeqCtrl < nMyNum	fMinOutputPgm / fMinOutputRm
TRUE	TRUE	E_BA_Action.eDirect	nActvSeqCtrl > nMyNum	fMaxOutputPgm / fMaxOutputRm
TRUE	TRUE		nActvSeqCtrl = nMyNum	FB_BA_Loop.fPresentValue

Error detection

The error messages listed below are detected by FB_BA_SeqCtrl.

The x in the text messages stands for a numerical specification of a sequence controller.

The error messages are output in the TwinCAT 3 development environment in the "Error list" window. This can be activated under the menu item View.

The error texts are output via the properties ErrorParamMaxSeqCtrl and ErrorSeqNumMultiple.

	Global parameter Tc3_BA2.BA_Param.nMaxSeqCtrl < 1 This message is the only one that disables sequence control.

German	English
Globaler Parameter Tc3_BA2.BA_Param.nMaxSeqCtrl < 1	Global parameter Tc3_BA2.BA_Param.nMaxSeqCtrl < 1
Sequenznummer nMyNum = x mehrfach vergeben	Sequence number nMyNum = x assigned multiple times

Inheritance hierarchy

FB_BA_Base

FB_BA_BasePublisher

FB_BA_Object

FB_BA_Loop

Syntax

FUNCTION_BLOCK FB_BA_SeqCtrl EXTENDS FB_BA_Loop
VAR_INPUT
  nMyNum            : UDINT;
END_VAR
VAR_OUTPUT
  fE                : REAL;
  bSeqActv          : BOOL;
  nActvSeqCtrl      : UDINT;
  bIsActvSeqCtrl    : BOOL;
  bErr              : BOOL;
END_VAR
VAR_IN_OUT
  stSeqLink         : ST_BA_SeqLink;
END_VAR

Inputs

Name	Type	Description
nMyNum	UDINT	My number in the sequence. This number may only be present once in a sequence control. An internal limitation only allows values from 1 - XBA_Param.nMaxSeqCtrl.

Name

Type

Description

nMyNum

UDINT

My number in the sequence. This number may only be present once in a sequence control.

An internal limitation only allows values from 1 - XBA_Param.nMaxSeqCtrl.

Outputs

Name	Type	Description
fE	REAL	Displays the control deviation of the sequence controller. This depends on the control direction of the sequence controller. E_BA_Action.eDirect -> fE = fX-fW E_BA_Action.eReverse -> fE = fW-fX
bSeqActv	BOOL	The sequence controller is implemented in the control sequence.
nActvSeqCtrl	UDINT	Number of the active sequence controller.
bIsActvSeqCtrl	BOOL	Indicates that the sequence controller is the active one in the sequence control. The property IsActvSeqCtrl also displays this message.
bErr	BOOL	Indicates that an error has been detected. More detailed information is shown in the properties ErrorParamMaxSeqCtrl and SeqNumMultiple. Further explanations on error analysis can be found at Error detection.

/ Inputs Outputs

Name	Type	Description
stSeqLink	ST_BA_SeqLink	Data and command structure between the individual sequence controllers FB_BA_SeqCtrl and the function block FB_BA_SequenceLinkBase.

Properties

Name	Type	Access	Description
ActvSeqCtrl	UDINT	Get	The property shows the number of the active sequence controller.
ErrorParamMaxSeqCtrl	T_MaxString	Get	The property displays the following text in case of error: "Global parameter Tc3_BA2.BA_Param.nMaxSeqCtrl < 1", see BA_Param.nMaxSeqCtrl. The global parameter must be adjusted in any case, because due to the wrong parameterization the sequence stops.
SeqNumMultiple	T_MaxString	Get	The property displays the following text in case of error: "Sequence number nMyNum = x assigned multiple times". A check of the displayed sequence number is necessary because it has been assigned several times in the sequence.
IsActvSeqCtrl	BOOL	Get	The sequence controller is the active one in the sequence control.

Requirements

Development environment	Required PLC library
TwinCAT from v3.1.4024.56	Tc3_BA2 from v5.4.2.0