DeltaV SIS Advanced Function Blocks State Transition Diagram

Dirk Tuchel

Senior SIS Lead Engineer,

Haan

Analog Voter

Discrete Voter

CEM (Cause and Effect Matrix)

Step Sequencer

State Transition Diagram

all function blocks TÜV certified

SIS Advanced Function Blocks

2oo3 Voter

Cause and Effect Matrix

CEM – Cause and Effect FB

Typical BMS Sequence

Three Main Logic Parts to a BMS

States & Transitions

• When to move from one state to another

• What triggers / permits logic to transition between states

Outputs

• Valve positions defined for each state

Trips and Permissives

• Including which is active during each state

State

Transition

Diagram

Step

Sequencer

Cause &

Effect

State Transition Diagram

1

Tripped

2

Ready

Reset

3

Air On

Fan On FB

Fan Off FB

4

Prepare Purging

Start PB

5 Purging

Purge

Conditions FB

6 Prepare Ignition

Purge Time

Over

7

Ignition

Ignition

Conditions FB 8

Post Ignition

Safety Time Over

9

Burner On

Post Ignition Time Over

10 Close Valves

Stop PB

Stop PB Stop PB Stop PB Stop PB Stop PB

11 Open Vent

Valves

Close FB

Vent

Open FB

From

all States

Trip

STD Configuration

Realisation with State Transition Diagram FB

Transitions

States

STD Configuration

Realisation with State Transition Diagram FB

STD Configuration

Realisation with State Transition Diagram FB

STD FB

Timer

Transition

Inputs

BMS visualization

Engineering Operations Maintenance

Documentation

An Excel template is available to support such an approach and to document the functional requirements.

State Transition

Diagram

Outputs

Trips

Transitions