[SEQ_REV] Reverse sequence linker

Function block SEQ_REV helps interconnect CTR function blocks in a programmable sequence, i.e., each controller can be assigned to a sequence based on the related input value.

SEQ_REV helps interconnect CTR function blocks in a programmable sequence, i.e., each controller can be assigned to a sequence based on the related input value. The reverse acting function block is used for heating or humidification.

Functioning

SEQ_REV sequentially interconnects CTR function blocks. The sequence is configured via inputs [SeqNr1]...[SeqNr8].

Multiple CTR controllers are interconnected in a sequence (based on load, modulating sequence) for temperature control, humidity control, and eventually other types of control.

Some controllers are responsible for heating or humidification, the others for cooling or dehumidification. Each controller can command a specific plant element, e.g. radiator, heating coil, fan, etc.

In the control program, the CTR controllers for heating or humidification, and those for cooling or dehumidification are grouped to improve understanding and increase flexibility.

  • The sequence for the CTR controllers is determined by a value.
  • To connect SEQ_DIR to SEQ_REV, specific inputs and outputs are reserved.

The following function blocks are used for cooling and heating sequences:

  • Cooling: SEQ_DIR (Direct Sequence Linker)
  • Heating: SEQ_REV (Reverse Sequence Linker)

SEQ_DIR and SEQ_REV are connected via [SeqCnctIn] and [SeqCnctOut].

Pins

Input

Description

Data type

Default value
Value range

SeqNr1…SeqNr8

Sequence number 1…Sequence number 8

Sequence number input value

Integer

0

0…8

ToHi1…ToHi8

To higher neighbor element 1…To higher neighbor element 8

Structure

-

ToHi1…ToHi8
> CtlMod

Control mode

Integer

1: Inactive

1: Inactive - Pin is not interconnected.
2: Active - CTR is active.
3: Off - CTR is switched off.
4: On - CTR is switched on.

ToHi1…ToHi8
> Crdn

Sequence coordination

CTR coordination signal.

Integer

1: Nil

1: Nil - Not connected (Default value).
2: Link - Connected in a sequence.
3: Low - Low controller output.
4: ErrLow - Error in sequence coordination.
5: Act - Controller active.
6: High - High controller output.

ToHi1…ToHi8
> Ctkn

Control token

Controller enabled.

Integer

1: Nil

1: Nil - Not connected (Default value).
2: Link - Connected in a sequence.
3: Low - Low controller output.
4: ErrLow - Error in sequence coordination.
5: Act - Controller active.
6: High - High controller output.

ToHi1…ToHi8
> IsInt

Is integrator

Information on the integrating action of the CTR element.

Boolean

0

0 - CTR element is not integrating.
1 - CTR element is integrating.

ToHi1…ToHi8
> DeltaE

Covered error

Covered control error of the proportional part.

Real

0.0

ToLo1…ToLo8

To lower neighbor element 1…To lower neighbor element 8

Structure

-

ToLo1…ToLo8
> CtlMod

Control mode

Integer

1: Inactive

1: Inactive - Pin is not interconnected.
2: Active - CTR is active.
3: Off - CTR is switched off.
4: On - CTR is switched on.

ToLo1…ToLo8
> Crdn

Sequence coordination

CTR coordination signal.

Integer

1: Nil

1: Nil - Not connected (Default value).
2: Link - Connected in a sequence.
3: Low - Low controller output.
4: ErrLow - Error in sequence coordination.
5: Act - Controller active.
6: High - High controller output.

ToLo1…ToLo8
> Ctkn

Control token

Controller enabled.

Integer

1: Nil

1: Nil - Not connected (Default value).
2: Link - Connected in a sequence.
3: Low - Low controller output.
4: ErrLow - Error in sequence coordination.
5: Act - Controller active.
6: High - High controller output.

ToLo1…ToLo8
> IsInt

Is integrator

Information on the integrating action of the CTR element.

Boolean

0

0 - CTR element is not integrating.
1 - CTR element is integrating.

ToLo1…ToLo8
> DeltaE

Covered error

Covered control error of the proportional part.

Real

0.0

SeqCnctIn

Sequence connection input

Structure

-

SeqCnctIn
> CtlMod

Control mode

Integer

1: Inactive

1: Inactive - Pin is not interconnected.
2: Active - CTR is active.
3: Off - CTR is switched off.
4: On - CTR is switched on.

SeqCnctIn
> Crdn

Sequence coordination

CTR coordination signal.

Integer

1: Nil

1: Nil - Not connected (Default value).
2: Link - Connected in a sequence.
3: Low - Low controller output.
4: ErrLow - Error in sequence coordination.
5: Act - Controller active.
6: High - High controller output.

SeqCnctIn
> Ctkn

Control token

Controller enabled.

Integer

1: Nil

1: Nil - Not connected (Default value).
2: Link - Connected in a sequence.
3: Low - Low controller output.
4: ErrLow - Error in sequence coordination.
5: Act - Controller active.
6: High - High controller output.

SeqCnctIn
> IsInt

Is integrator

Information on the integrating action of the CTR element.

Boolean

0

0 - CTR element is not integrating.
1 - CTR element is integrating.

SeqCnctIn
> DeltaE

Covered error

Covered control error of the proportional part.

Real

0.0

 

Output

Description

Data type

Default value
Value range

FmHi1…FmHi8

From higher neighbor element 1…From higher neighbor element 8

Structure

-

FmHi1…FmHi8
> CtlMod

Control mode

Integer

1: Inactive

1: Inactive - Pin is not interconnected.
2: Active - CTR is active.
3: Off - CTR is switched off.
4: On - CTR is switched on.

FmHi1…FmHi8
> Crdn

Sequence coordination

CTR coordination signal.

Integer

1: Nil

1: Nil - Not connected (Default value).
2: Link - Connected in a sequence.
3: Low - Low controller output.
4: ErrLow - Error in sequence coordination.
5: Act - Controller active.
6: High - High controller output.

FmHi1…FmHi8
> Ctkn

Control token

Controller enabled.

Integer

1: Nil

1: Nil - Not connected (Default value).
2: Link - Connected in a sequence.
3: Low - Low controller output.
4: ErrLow - Error in sequence coordination.
5: Act - Controller active.
6: High - High controller output.

FmHi1…FmHi8
> IsInt

Is integrator

Information on the integrating action of the CTR element.

Boolean

0

0 - CTR element is not integrating.
1 - CTR element is integrating.

FmHi1…FmHi8
> DeltaE

Covered error

Covered control error of the proportional part.

Real

0.0

FmLo1…FmLo8

From lower neighbor element 1…From lower neighbor element 8

Structure

-

FmLo1…FmLo8
> CtlMod

Control mode

Integer

1: Inactive

1: Inactive - Pin is not interconnected.
2: Active - CTR is active.
3: Off - CTR is switched off.
4: On - CTR is switched on.

FmLo1…FmLo8
> Crdn

Sequence coordination

CTR coordination signal.

Integer

1: Nil

1: Nil - Not connected (Default value).
2: Link - Connected in a sequence.
3: Low - Low controller output.
4: ErrLow - Error in sequence coordination.
5: Act - Controller active.
6: High - High controller output.

FmLo1…FmLo8
> Ctkn

Control token

Controller enabled.

Integer

1: Nil

1: Nil - Not connected (Default value).
2: Link - Connected in a sequence.
3: Low - Low controller output.
4: ErrLow - Error in sequence coordination.
5: Act - Controller active.
6: High - High controller output.

FmLo1…FmLo8
> IsInt

Is integrator

Information on the integrating action of the CTR element.

Boolean

0

0 - CTR element is not integrating.
1 - CTR element is integrating.

FmLo1…FmLo8
> DeltaE

Covered error

Covered control error of the proportional part.

Real

0.0

ErrSta

Error state

Integer

1: No error

1…3

1: No error
2: Multiple sequence number
3: Connected, no sequence number

ErrSeqNr

Error sequence number

Integer

1

1…9

1: ---
2: 1
3: 2
4: 3
5: 4
6: 5
7: 6
8: 7
9: 8

SeqCnctOut

Sequence connection output

Structure

-

SeqCnctOut
> CtlMod

Control mode

Integer

1: Inactive

1: Inactive - Pin is not interconnected.
2: Active - CTR is active.
3: Off - CTR is switched off.
4: On - CTR is switched on.

SeqCnctOut
> Crdn

Sequence coordination

CTR coordination signal.

Integer

1: Nil

1: Nil - Not connected (Default value).
2: Link - Connected in a sequence.
3: Low - Low controller output.
4: ErrLow - Error in sequence coordination.
5: Act - Controller active.
6: High - High controller output.

SeqCnctOut
> Ctkn

Control token

Controller enabled.

Integer

1: Nil

1: Nil - Not connected (Default value).
2: Link - Connected in a sequence.
3: Low - Low controller output.
4: ErrLow - Error in sequence coordination.
5: Act - Controller active.
6: High - High controller output.

SeqCnctOut
> IsInt

Is integrator

Information on the integrating action of the CTR element.

Boolean

0

0 - CTR element is not integrating.
1 - CTR element is integrating.

SeqCnctOut
> DeltaE

Covered error

Covered control error of the proportional part.

Real

0.0

Application

SEQ_REV is used to interconnect CTR function blocks to heating or humidification.

Troubleshooting

The following errors may occur related to SEQ_REV:

  • SeqNr > 0 and is used multiple times.
  • SeqNr > 0 and the related inputs are not connected or the structural elements have default values.
  • SeqNr = 0 and the corresponding inputs are connected.

In the event of error, output [ErrSta] is set to the corresponding vlaue and the function block stops the processing response. All controllers are commanded to stop control.

info

The new sequence numbers are valid immediately and do not require a restart.