JULABO ME-26 Heating Circulators - Manual (Page 40)

Menu functions
40
9.5.4. Control parameters– XP-, TN-, TV- INTERNAL
In most cases the control parameters preset in the factory are adequate
for achieving an optimum temperature sequence.
The control parameters allow adjustment to special control processes..
Setting range: 0.1 ... 99.9
Proportional range >Xp<
The proportional range is the range below the setpoint in which the
control circuit reduces the heating capacity from 100% to 0 %
Setting range: 3 ...9999
Reset time >Tn< (Integral component)
Compensation of the remaining control deviation due to proportional
regulation. An insufficient reset time may cause instabilities. Excessive
reset times will result in unnecessary prolongation of compensation of the
control difference.
Setting range: 0 ... 999
Lead time >Tv< (Differential component)
The differential component reduces the transient time. An insufficient lead
time will prolong the time required for compensation of disturbance
effects and cause high overshooting during run-up. An excessive lead
time could cause instabilities (oscillations)
Optimization instructions for the PID control parameters
Optimum setting Control parameters XP-, TN-, TV- INTERNAL as well as
-EXTERNAL
The heat-up curve reveals possible faulty settings of the
control parameter.
Inappropriate settings may produce the following heat-up curves:
Xp too low Tv/Tn too low
Xp too high or Tv too high Tv/Tn too high or Xp too high