Contrec 515 BR03, Operation Manual

Page: 40 / 110

Operation
30 515 BR03 - 15 August 2021
Tuning the Control Loop
The Process Controller has a special control mode, within the Parameters
section of calibration, to assist in tuning the control loop. This mode
provides a concise list of key parameters and allows for immediate
feedback. The basic principle in tuning the loop is to gradually adjust the
Proportional Band (P-BAND) and the Integral Time (I-TIME) and observe
the response to a step change in the setpoint.
The tune menu provides for this by allowing the P-BAND and I-TIME to be
programmed and then a Process Flow (P-FLOW) setpoint value to be
entered. The next items in the menu are the actual live process variable and
the deviation from the target value, so that the response of the system to a
setpoint change can be observed. Unless the menu is quit the program will
step back to start of the tuning menu so that new values of P-BAND and
I-TIME can be entered and the effect of a step change in the setpoint be
monitored.
As the idle position for any On-Off control valve in a batching system is
“closed”, a special option in the Batch Mode parameter, RELEASE, allows
the valve to be opened from within calibration. For more information, refer
to
Release Mode on page 32.