ero electronic ELK Manuel Utilisateur page 37

Mnemonic
The following parameters set up the control characteristics
PB PROPORTIONAL BAND sets an output which is proportional to the
size of the error signal. Units may be % or 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.
TD DERIVATIVE TIME determines how strongly the controller will react to
the rate of change in the process value. It is used to prevent overshoot
and undershoot and to restore the PV rapidly if there is a sudden
change in demand.
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.
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)
HYST.H HEATING HYSTERESIS sets the difference in PV units between output
1 turning off and turning on.
Only shown if channel 1 control action is On/Off.
Part number HA028438. Issue 3.0.
Scrolling Display and description
Oct-05
Range
1 to 9999 display units
Default 20
Off to 9999 seconds
Default 360
Off to 9999 seconds
Default 60 for PID control
Default 0 for valve
position control
-100 to 100%
Default 0
0.1 to 10.0
Default 1.0
0.1 to 200.0 display units
Default 1.0
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