Burkert Type 8793 - Manual (Page 98)

98
Start-Up
25.5. P.TUNE – Self-optimization of the process
controller
This function can be used to automatically parameterize the PID controller integrated in the process controller.
In doing so, the parameters for the P, I and D-contribution of the PID controller are automatically determined and
transferred to the corresponding menus of (
KP, TN, TV). This is where they can be viewed and changed.
Explanation.of.the.PID.controller:
The control system of Type 8793 has an integrated PID process controller. Any process variable, such as flow rate,
temperature, pressure, etc., can be controlled by connecting an appropriate sensor.
To obtain good control behavior, the structure and parameterization of the PID controller must be adjusted to the
properties of the process (controlled section).
This task requires control experience as well as measuring instruments and is time-consuming. The P.TUNE function
can be used to automatically parameterize the PID controller integrated in the process controller.
Basic information for setting the process controller can be found in Chapters "40. Properties of PID Con-
trollers" and "41. Adjustment rules for PID Controllers".
25.5.1. The mode of operation of P.TUNE
The P.TUNE function automatically identifies the process. To do this, the process is activated with a defined
disturbance variable. Typical process characteristics are derived from the response signal and the structure and
parameters of the process controller are determined on the basis of the process characteristics.
When using P.TUNE self-optimization, optimum results are obtained under the following conditions:
• Stable or stationary conditions concerning the process actual value PV when starting P.TUNE.
• Execution of P.TUNE in the operating point or within the operating range of the process control.
25.5.2. Preparatory measure for execution of P.TUNE
The measures described below are not compulsory conditions for execution of the function P.TUNE.
However, they will increase the quality of the result.
The P.TUNE function can be run in the MANUAL or AUTOMATIC operating state.
When P.TUNE is complete, the control system is in the operating state which was set previously.
English
Type 8792, 8793