ST_BA_SeqLink / ST_BA_SeqLinkData

Structure of the data and command exchange between the control function block FB_BA_SeqLink and the sequence controllers FB_BA_SeqCtrl.

This structure has to be created once per sequence control:

stSeqLink : ST_BA_SeqLink;

Within this structure, a further field structure is declared automatically, through which the sequence link function block and the individual sequence controllers exchange all relevant data. Each sequence controller writes its data into the field element corresponding to its ordinal number (entry at input usiMyNum at the sequence controller function block). It is always the complete structure with all field elements that is linked to the function blocks.

The structures have the following setup:

TYPE ST_BA_SeqLink :
STRUCT
  arrSeqLinkData : ARRAY[1..cMaxSeqCtrl] OF ST_BA_SeqLinkData;
  bSeqActv       : BOOL;
  usiCurSeq      : USINT;
  byDummy        : ARRAY[1..2] OF BYTE; 
END_STRUCT
END_TYPE

bSeqActv: the sequence control is enabled and active.

usiCurSeq: from FB_BA_SeqLink: specification of current sequence controllers

byDummy: unused filling variables for creating a 4-byte configuration. This configuration is important, if this structure part of a data exchange between controllers has a different architecture (ARM/I486).

TYPE ST_BA_SeqLinkData:
STRUCT
  lrY         : LREAL;
  lrYMin      : LREAL;
  lrYMax      : LREAL;
  lrW         : LREAL;
  bActn       : BOOL;
  bOp         : BOOL;
  bPresence   : BOOL;
  bErrDouble  : BOOL;
  usiCurSeq   : USINT;
  byDummy     : ARRAY[1..3] OF BYTE;
END_STRUCT
END_TYPE

lrY: from FB_BA_SeqCtrl: transfer of current control value

lrYMin: from FB_BA_SeqCtrl: transfer of minimum control value

lrYMax: from FB_BA_SeqCtrl: transfer of maximum control value

lrW: from FB_BA_SeqCtrl: transfer of current setpoint

bActn: from FB_BA_SeqCtrl: transfer of inverse control direction (bActn = FALSE: heating mode - bActn = TRUE: cooling mode).

bOp: from FB_BA_SeqCtrl: sequence controller is enabled, i.e. its input bEn is set to TRUE.

bPresence: from FB_BA_SeqCtrl: check bit, see below.

bErrDouble: from FB_BA_SeqCtrl: error during number verification: there are at least 2 sequence controllers of the same ordinal number usiMyNum.

usiCurSeq: from FB_BA_SeqLink: specification of current sequence controllers

byDummy: unused filling variables for creating a 4-byte configuration. This configuration is important, if this structure part of a data exchange between controllers has a different architecture (ARM/I486).