NEW BRUNSWICK SCIENTIFIC BioFlo 415, Manual To Operations

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New Brunswick Scientific User’s Guide
Figure 18: Cascade Screen
11.2 Controlling DO by Cascade
Example: Cascading DO to Agitation, GasFlo and O2 (2).
In the example below, errors in DO are corrected by increasing agitation, gas flow, and
oxygen concentration:
2. Use this
T
dropdown menu
to select the
“Cascade-From”
loop.
3. Use the first
T
dropdown menu
to select the first
“Cascade-To” loop.
4. Set the Start
Setpoint, At DO
Start Output%, End
Setpoint and At DO
End Output%
values one by one
by pressing the edit
box, entering the
desired value on the
touchpad and
pressing the OK
button.
5. Press the Enable
button to select
YES.
(1)
DO
is the source of
the cascade.
Agit
is the loop
being influenced by
the cascade.
Start Setpoint
is the value the system will set the loop
setpoint to when the
DO Start Out%
is reached. This
value is typically close to, or at, the normal operating
setpoint.
@DO Start Out%
is the DO output %
value at which the user wants the cascade
to begin. When this output value is
reached, the loop’s setpoint will be the
value of the start setpoint. In this
example, when the DO output is -100.0,
the setpoint will be 250.
End Setpoint
is the maximum loop setpoint value the
user defines, once the
@DO End Out%
is reached.
Typically this value is the maximum allowable value the
process can handle. In this example, when the
DO End
Out%
reaches 25, the agitation will have increased to
1000 rpm.