Burkert 8619 Operating Instructions Manual page 116

PV: Choose the process input from the list displayed by the device. This value may be a measurement
input, the result of the function, the value entered by the user (PVC) or the value coming from a PLC (PVN).
See section 15.
SP TYPE: Choose between an internal setpoint value (choose "internal") or an external setpoint value
(choose "external"; then select the parameter used as the setpoint from the list in the "SP-PV" function
below).
SP: Choose the parameter used as the external setpoint for the function.
▶ Make sure SP and PV have the same units.
PV RANGE: Enter the minimum ("PVRange-") and maximum ("PVRange+") measurement values of the
process input.
REG TYPE: Choose a linear control mode (choose "linear") or non-linear control mode (choose "non-linear";
then enter under "Low" and "High" the 2 process input thresholds outside of which the "Drift" part is
deactivated).
Fig. 73: Example of non-linear control of the pH
CMD DIRECTION: Choose the control direction for the function (CMD1 or CMD2 respectively): ascending
(choose "Rise") or descending (choose "Fall").
Fig. 74: CMD DIRECTION graphs
116
pH
"High" value
Setpoint value
"Low" value
Fx / CMD
100%
0%
100%
English
"PI" function (D = 0)
"PID" function
"PI" function (D = 0)
Reagent
Rise
Fall
Output calculated by the function
Type 8619
Parameters menu