30
Mnemonic
Scrolling Display and description
Range
This section applies to control parameters
A.TUNE
AUTOTUNE
automatically tunes the control parameters to match the
process characteristics.
Off
On
Disable
Enable
PB
PROPORTIONAL BAND
sets an output which is proportional to the
size of the error signal. Units may be % or display units (default).
1 to 9999 display units
TI
INTEGRAL TIME
removes steady state control offsets by ramping the
output up or down in proportion to the amplitude and duration of the
error signal.
Off
to 9999 seconds
TD
DERIVATIVE TIME
determines how strongly the controller will react
to the rate of change of temperature. It is used to prevent overshoot
and undershoot and to restore the PV rapidly if there is a sudden
change in demand.
Off
to 9999 seconds
MR
MANUAL RESET
applies to a PD only controller i.e. the integral term
is turned off. Set this to a value of power output (from +100% heat, to
-100% cool which removes any steady state error between SP and PV.
-100 to 100%
R2G
RELATIVE COOL GAIN
adjusts the cooling proportional band relative
to the heating proportional band. Particularly necessary if the rate of
heating and rate of cooling are very different.
(Heat/Cool only
)
0.1 to 10.0
HYST.H
HEATING HYSTERESIS
Sets the difference in temperature units
between heating turning off and turning on when ON’OFF control is
used.
Only appears if channel 1(heating) control action is
0.1 to 200.0 display units
