User Manual

Siemens Building Technologies CM2N8893en / 02.2000

Landis & Staefa Division 1/2

893

VISONIK

DDC

Function sheet

DDC stands for "Direct Digital Control". In building automation and control, this

term normally is used in connection with an automation station. DDC automation

stations in brief DDC stations have a digital computer. This computer directly

implements the control functions for the assigned building services system via

the connected inputs and outputs.

The following illustration shows a simple building services system which is controlled by

means of a DDC station of the VISONIK system:

BLN

BPS

I/Os

8893Z01

The primary elements relative to DDC are:

Element Explanation

BPS Building Process Station: DDC station of the VISONIK system

I/Os Inputs and outputs from and to the building services system. Connected to

the BPS via I/O modules.

BLN Building Level Network: Connects the individual DDC stations with each

other and with the superposed management station via the VISONIK Data

and Communication Server (DCS). This is done for communication,

operation, and data security purposes.

Use

Example

Explanations

(

illustration

)

PAGE 1
8 893 VISONIK® DDC Function sheet DDC stands for "Direct Digital Control". In building automation and control, this term normally is used in connection with an automation station. DDC automation stations in brief DDC stations have a digital computer. This computer directly implements the control functions for the assigned building services system via the connected inputs and outputs.
PAGE 2
DDC stations: description Properties DDC stations similar to the VISONIK BPS normally are located in areas with a high concentration of information points of the building services system. They have the following properties: Properties Explanation Digital process data processing The signals from the building services system that are digitised by the I/O modules are acquired and processed. Where appropriate, signals such as switching and positioning commands are issued to the system.