User Manual

ManualsBrandsSiemens ManualsBuilding automationBPS communication Function sheet

Siemens Building Technologies CM2N8895en / 26.02.01

Landis & Staefa Division 1/4

VISONIK

BPS plant control

Function sheet

The VISONIK BPS plant control coordinates and implements all the control

functions of the building services systems assigned according to the plant

operating program created by engineering.

This document describes the elements and principle of operation of plant control.

Control functions in building services systems such as HVAC plants are carried out

chiefly as the result of certain events. The latter can be triggered by very varied

influences either inside or outside the plant. The following are some typical examples:

Influence Event

control function

Time 07:00 is reached:

Change ventilation from night to day operation.

Heating requirement Maximum heat output reached at Boiler 1:

Turn on Boiler 2.

Outside temperature Temperature falls below the frost protection limit:

Trigger the frost protection functions.

Degree of pollution The pressure difference between the two sides of the filter

is too high:

Output maintenance alarm “Replace filter mat”.

Operating hour Twin pump “A” reaches the operating hour limit:

Switch to twin pump “B”.

Plant elements Fan contactor is defective / No “ON” feedback message:

Switch off plant.

Energy requirement External heat surplus in the “south” plant part while there

is a heating demand in the “north” plant part:

Carry out energy-optimized demand switchovers.

Room occupancy Spontaneous evening event in the assembly hall:

Set the plant setpoint manually to day operation.

The VISONIK BPS implements the control functions using its basic and processing

functions, and according to the conditions for the participating elements set down by

engineering.

Use

Examples of control

functions

Implementation

Summary of content (4 pages)

PAGE 1
8 895 VISONIK® BPS plant control Function sheet The VISONIK BPS plant control coordinates and implements all the control functions of the building services systems assigned according to the plant operating program created by engineering. This document describes the elements and principle of operation of plant control. Use Examples of control functions Control functions in building services systems such as HVAC plants are carried out chiefly as the result of certain events.
PAGE 2
Plant control elements $060 $030 $040 $050 Damper Heating valves Pump Fan DDC program Operating state table PLTn Plant commands Explanations (illustration) Remote TSP Manual Fault VISONIK BPS Plant elements Electrical and mechanical part The following illustration shows the plant control elements in the electrical and mechanical plant and in the VISONIK BPS.
PAGE 3
Definition of the plant functions Set plant states Before the control of a building services system can be programmed, all the states a plant must assume have to be defined in a first step. The outcome of these considerations gives the list of set plant states. These could be the following for the example previously shown: • • • • Plant element operating states Plant OFF. Day operation (controlled to comfort temperature). Night operation (controlled to reduced temperature).
PAGE 4
Plant task The plant tasks created are loaded and started when the VISONIK BPS is commissioned. The following illustration is a simplified schematic presentation of how the plant tasks are processed in the DDC program using the example given above. TSKn Initialization 8895Z03en Block diagram Control Loop PLTn CONTROL PSTA DISPATCH DSPn Remote Local Manual Fault DSPn .