E32.0.A3.6C-01 Manual for connection and operation of the JDS-211 page 15 of 16
Addendum B: Tips for using the JDS-211 as heating controller
1. Set point value „1.SP“
The temperature on which the controlling shall be done. Please set here the desired temperature.
2. Proportional band „1.Pb“
The proportional band defines how strongly the device reacts on divergence between the actual and the set
point temperature . If the divergence equals the proportional band, the heating power is 100%. For a diver-
gence of 0°C the heating power is 0%.
Example 1: „1.Sp“=200.0, „1.Pb“=50.0
actual temperature=150°C
!
divergence=50°C
!
heating power=100%
actual temperature=180°C
!
divergence=20°C
!
heating power =40%
Example 2: „1.Sp“=200.0, „1.Pb“=100.0
actual temperature =150°C
!
divergence=50°C
!
heating power =50%
actual temperature =180°C
!
divergence=20°C
!
heating power =20%
A small proportional proportion has the effect that the device reacts to a little divergence with a big change of
the heating power.
If the proportional action is too small, there will be a over-reaction. The control gets instable.
!! Attention : A too small proportional band can lead too big excess temperature!!
A big Proportional proportion has the effect, that the controller intervene weakly. The control gets inert.
Tips for identification of the proportional band „1.Pb“.
Please set the following values by the configuration of your device:
Set point value “1.SP“:
desired temperature
Proportional band “1.Pb“:
150.0
Integral time “1.Int“:
0 (off)
Derivative time “1.dEr“:
0 (off)
Cyclic time “1.CyC“:
2s (10s for inert control system)
Integral time „1.Int“ and derivative time „1.dEr“ are switched off. The device works as P-controller.
Start the control and wait until the temperature gets constant. This temperature , although much below the set point, has to be stable.
Now shorten the “1.Pb“ value, the divergence from the set point gets smaller. Go on with the scaling down until the temperature is not
stable any more, but oscillates continuously (about ±1°C). If the oscillation is too big re-raise the “1.Pb“ value a little bit.
Please consider the long settling time of some control systems you have to wait for.
Your “1.Pb“ value is the double of the value identified by that procedure.
3. Integral time „1.Int“
In chapter A.2 the device was a P-controller, who reacts only on divergences between actual and set point
temperature. Because there is no heating power at the divergence 0°, the actual temperature will always be
below the set point temperature. That changes with the configuration of the device as a PI-controller. The PI-
controller is additionally a integral controller, i.e. that it not only reacts on divergences, but considers also how
long this divergences have existed. The longer a divergence have existed, the bigger the heating power is. The
heating power changes while a divergence exists. Therefore even small divergences can be corrected in the
long run.
The strength of this effect is adjusted by the integral time „1.Int“. The device regulates the temperature quickly to
the set point temperature.
If “1.Int“ is too small, there will be a overshoot. The control gets instable and the temperature oscillates around
the set point.
!! Attention : A too small integral time “1.Int“ band can lead too big excess temperature!!
If 1.Int“ is too big, it may last very long until the device regulates the temperature to the set point.