Evoqua WALLACE & TIERNAN MFC, Инструкция по эксплуатации, Страница: 90 / 268

90
WT.050.580.000.DE.IM.0714
Functions
MFC
4.
The following parameters must be set for this operating mode in
menu (2):
• Band
• Change
• Xsh
• Tconst
• Tvar
Band This parameter describes the range within which the compound-
loop-control setpoint 1 can be adjusted by the setpoint trim.
The Band corresponds to the measuring range in percent. The
compound-loop-control setpoint may, therefore, move within the
range of set Band or setpoint2 - Band.
Example:
Measuring range = 2.0 mg/l free chlorine
Setpoint 2
= 1.00 mg/l
Setpoint range = 20 %
The setpoint range of 20 % defined here corresponds to the
measuring range, (i.e. 20 % of 2.00 mg/l = 0.40 mg/l). Therefore,
the setpoint may move in the range of 0.60 to 1.40 mg/l.
If the setpoint trim function records a value outside this Band, the
maximum or minimum value of the Band is entered (in this
example: 0.60 mg/l and 1.40 mg/l).
Change This parameter describes the modification factor, by which the
compound-loop-control setpoint 1 should change in the event of a
control deviation. The value corresponds to the control deviation in
percent.
Example:
Measured value
= 0.60 mg/l free chlorine
Setpoint = 1.00 mg/l
Change = 50 %
Error = 0.40 mg/l
The setpoint is increased by 0.20 mg/l, which reflect 50 % of the
error.
Xsh This parameter describes a neutral range for the measured value
of module2 and is indicated in percent on the measuring range end
value. If the measured value in module2 is within this range around
the setpoint, the setpoint trim function is inactive. If the measured
value of module2 is outside this neutral range, the setpoint trim
function is active and optimises the setpoint of module1.