User Manual

CM2N8894E / 10.1999 Siemens Building Technologies
4/4 Landis & Staefa Division
In the VISONIK BPS, the control functions can roughly be distinguished as follows:
−
Functions implemented in the BPS
−
Procedures loaded into the BPS via the plant operating program
The following table provides a list of functions. These include the above controllers,
supplemented by further basic elements for control tasks:
Element Functions Notes
Controller block
(RGB)
Modulating controller:
−
Fixed setpoint
−
P-algorithm
−
PI/PID algorithm
The setpoint can be controlled; see
elements and procedures below.
Adaptive
controller
(STR)
Same as RGB plus:
−
Self-adaptation
Sequence
controller (SEQ)
Same as RGB plus:
−
Sequences, 2 or more
−
Cascade
Each sequence has its own RGB.
Reference controller + sequences
Positioning
(POS)
Converts input variable x to
output variable y in a specific
range
−
For setpoint shifts
For several positioning sequences
on
one
controller output
Minimum value
(MIN)
Supplies the smallest value
from one or several variables
Maximum value
(MAX)
Supplies the greatest value
from one or several variables
For example for defining the min. ZL
portion for damper control
Hysteresis
(HYS)
ON/OFF switching function
with selectable switching
difference
Results in 2-position controller output
PTM1.2Y250T-M Positioning module 3-position Results in 3-position controller output
Procedures are predefined and tested COLBAS subroutines for specific functions or
applications. The table below contains the procedures for control tasks:
Procedure Function Notes
CASCREG Room supply air cascade Based only on RGB
COMPENSATION Room temperature
compensation
Summer or winter, based on outside
temperatures
DAMPREG
+ ENTHALPY
Control of circulating air
dampers following temperature
or enthalpy comparison
h;x control strategy
SCALE Setpoint shift Summer compensation, flow
temperature in dependence of
outside temperature, etc.
SEQREG Sequence controller For limit value control
In addition to this function sheet, the following documents contain further information on
the VISONIK BPS control functions:
Document no. Title
CM2Z8567E VISONIK
Point Types and Parameters (expert documentation)
CM2T8567E VISONIK System Basics (expert documentation)
CM2Z8387E COLBAS Language Description
UXPS0703E VISOTOOL 4.0 Procedure Library (on request)
Overview of
control functions
Functions
Procedures
Further documentation

1999 Siemens Building Technologies Ltd.