Filter
Top Products
Configuration
4/07 UDC2500 Universal Digital Controller Product Manual 35
3.4 Tuning Set Up Group
Introduction
Tuning consists of establishing the appropriate values for the tuning constants you are
using so that your controller responds correctly to changes in process variable and
setpoint. You can start with predetermined values but you will have to watch the system
to see how to modify them. The Accutune feature automatically selects Gain, Rate, and
Reset on demand.
ATTENTION
Because this group contains functions that have to do with security and lockout, we recommend
that you configure this group last, after all other configuration data has been loaded.
Function Prompts
Table 3-4 TUNING Group (Numeric Code 100) Function Prompts
Function Prompt
Lower Display
Selection or Range of Setting
Upper Display
English Numeric
Code
English Numeric
Code
Parameter
Definition
PB or GAIN 101
PB = 0.1 to 1000 %
Gain = 0.01 to
1000
PROPORTIONAL BAND (simplex) is the
percent of the range of the measured
variable for which a proportional controller
will produce a 100 % change in its output.
GAIN is the ratio of output change (%) over
the measured variable change (%) that
caused it.
G =
100%
PB%
where PB is the proportional band (in %)
If the PB is 20 %, then the Gain is 5. And, at
those settings, a 3 % change in the error
signal (SP-PV) will result in a 15 % change in
the controller's output due to proportional
action. If the Gain is 2, then the PB is 50 %.
Also defined as "HEAT" Gain on Duplex
models for variations of Heat/Cool
applications.
The selection of Proportional Band or Gain is
made in the CONTROL parameter group
under prompt PBorGAIN.
RATE T 102
0.00 to 10.00
minutes
0.08 or less = OFF
RATE action, in minutes, affects the
controller's output whenever the deviation is
changing; and affects it more when the
deviation is changing faster.