Firmware Manual

Chapter 7—Multi-PID Application
PowerXL DG1 Series Adjustable Frequency Drives MN040004EN—March 2014 www.eaton.com 75
Chapter 7—Multi-PID Application
Introduction
The Multi-PID Application is designed to be used with up to
2 PID Control applications determined by the use of a digital
input; it is typically used with pumps and fans to maintain a
desired set-point. With PID, the frequency converter is given
a set reference from a keypad, analog inputs, or fieldbus
data-in. It also uses an analog probe that measures flow,
temperature, and pressure in the system referred to as
feedback. The frequency converter takes the feedback signal
and compares it to the set point. From there based off the
Gain, Integral time, and Derivative time, it corrects the speed
of the motor to meet the set point value and maintain it; no
additional components. Drive controlwise it provides the
ability to have 2 control and reference locations with 8 digital
inputs, 2 analog inputs, 3 relay outputs, 1 digital output, and
2 analog outputs that are programmable. Motor control is
customizable to frequency or speed control, and the V/Hz
curve can be programmable. Drive/Motor protection
selections can be programmable to defined actions. Below
is a list of additional features available in addition to the
Standard and Multi-Pump and Fan Application features that
are available in the Multi-PID Application.
Select the Multi-PID Application in menu P21.1.2.
Multi-PID Application includes all the functions in Multi-Pump
and Fan Application, and Additional functions:
●
The Second PID control
I/O Controls
●
“Terminal To Function” (TTF) Programming
The design behind the programming of the digital inputs in
the DG1 drive is to use “Terminal To Function”
programming, which is composed of multiple functions that
get assigned a digital input to that function. The parameters
in the drive are set up with specific functions and by defining
the digital input and slot in some cases, depending on which
options are available. For use of the drives control board
inputs, they will be referred to as DigIN:1 through DigIN:8.
When additional option cards are used, they will be defined
as DigIN:X:IOY:Z. The X indicates the slot that the card is
being installed in, which will be either A or B. The IOY
determines the type of card it is, which would be IO1 or IO5.
The Z indicates which input is being used on that available
option card.
●
“Function To Terminal” (FTT) Programming
The design behind the programming of the relay outputs
and digital output in the DG1 drive is to use “Function To
Terminal” programming. It is composed of a terminal, be it a
relay output or a digital output, that is assigned a parameter.
Within that parameter, it has different functions that can be set.
The parameters of the Multi-PID Application are explained
on Page 130 of this manual, “Description of Parameters.”
The explanations are arranged according to the parameter
number.
Figure 34. PID Controller Flowchart