Controller (Aw402); General Description; Controller's Parameters - ABB AW400 Series Instruction Manual

5.2 Controller (AW402)

The control strategies offered by the AW400 are:
• Standard PID Controller, with Feed Forward option
• Average Controller
These will be discussed in detail in the following paragraphs.

5.2.1 General description

The PID Controller of the AW400 is usable in the majority of process applications. In function of the difference
between the analytic measure (Process Variable, PV), and a Set-point (SP) value, it calculates an Output
(OUT), that is applied to a final control element (f.e. dosing pump) to restore actual process value to the set-
point demand. The output is calculated with the PID algorithm, which has Proportional, Integral and Derivative
actions. The effect these terms have on the calculated output is determined by the PID configuration.
The Controller can work in Automatic or Manual mode, pushing number 0 (zero). The Manual mode let the
user modify the output manually, whereby the PID calculated output is not used. The output is driven with
push-bottoms 1 (decrease) and 2 (increase). The Automatic mode is selected pushing button 5. The set-point
is modified with the push-bottoms 6 (decrease) and 7 (increase). The output signal to drive the control
element can be either a 4-20 mA analog signal or two contacts (increase-decrease). The user can choose to
control the final element according to the characteristics of the device used. The END key consents to change
the display to that of a different function.
5.2.2

Controller's Parameters

When the instrument is operating as a controller (AW402), the following menu become accessible:
Operation display
Process
Password
XXXXX
1,2,3....
Menu
Configuration
Entering the Controller Menu the accessible parameters are presented as per the following table:
1 - General Parameters (valid for all control strategies)
Description
4/20 mA / Contacts
Proportional Band
Time Reset or Integral action
36
Calibration
Controller
PID1
To enter
Controller Menu:
Symbol
-
PB
TR
Channel definition
Output Setting
Configuration
Selection of controller output as analog 4/20 mA
signal or Contact closure (See 5.2.2.5)
Numeric entry in % (Integer positive)
Default: 100 - Range: 2% – 500%
Numeric Entry in minutes per repetition
Alarms