Bürkert 8619 multiCELL WM AC, Operating Instructions Manual

Page: 102 / 194

PV: Choose the process input from the list displayed by the device. This value may be a measurement input, the
result of the function or a value sent by a PLC (PVN). See section 8.16.
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.
PV RANGE : Enter the minimum ("PVRange-") and maximum ("") 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).
pH
"High" value
Reagent
"Low" value
Setpoint value
"PID" function
"PI" function (D = 0)
"PI" function (D = 0)
Fig. 67 : 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").
0%
100%
100%
Fx / CMD
Output calculated by the function
Rise
Fall
Fig. 68 : CMD DIRECTION graphs
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Adjustmentandcommissioning
Type 8619
English