User Guide

Table Of Contents

Command Syntax

Siemens Building Technologies, Inc. 3-23

Use

Adaptive control technology is a closed loop control application,

which automatically adjusts the field panel operating parameters to

compensate for changes that continuously occur during the normal

building control process. With adaptive control technology, tuning

and retuning are not required.

Either the ADAPTM or ADAPTS control statement can be

implemented as a one-line replacement for an existing LOOP

statement in PPCL.

ADAPTS is a general purpose single input, single output controller

for both linear and non-linear processes. Example applications are

mixed air temperature, static pressure, return airflow, and humidity

control.

To be able to control, adaptive control requires that the loop be:

• Controllable–this means that the sensor is in the right range and

the output is sufficient to bring the process variable to setpoint.

• Open-loop Stable–this means that the process can achieve a

steady state for every position of the final output device. (All AHU

loops are open-loop stable.)

• Direct or Reverse Acting–this means the process is either

always direct or always reverse acting. That is, the process does

not change its action (direction or sign) within the control range.

• Modulating–this refers to the loop’s output device, such as a

cooling coil with a modulating water valve. For example, DX

cooling or step controlled electric heat, cannot be controlled by

the ADAPTM or ADAPTS statements in PPCL.

• Not Excessive in Dead Time–this means that the total delay in

the sensor and actuator signals should not exceed two times the

time constant of the process.

NOTE: The Soft Controller does not support adaptive control

technology.