Alicat VC Series Volumetric Flow Controller User Manual
Page 12
12
Control Setup Mode
The Control Setup Mode is accessed by pressing the center button above “Control Setup” on the Select
Menu display (Fig.7) This mode allows the user to set up most parameters commonly associated with
PID control. Alicat Scientific flow controllers allow the user to select how the set-point is to be conveyed
to the controller, what that set-point is if control is local, and what the Proportional and Differential terms
of the PID control loop will be. The UP and DOWN buttons for adjusting variables can be held down for
higher speed adjustment or pressed repeatedly for fine adjustment.
Input – Alicat Scientific Flow Controllers normally ship defaulted to analog control as indicated in Figure
8. To change how the set-point will be conveyed to the controller push the button in the upper right hand
corner just above the dynamic label “Input” until the arrow is directly in front of the desired option. The
controller will ignore any set-point except that of the selected input and it will remember which input is
selected even if the power is disconnected.
Analog refers to a remote analog set-point applied to Pin 4 of the Mini-DIN connector as described
in the installation section of this manual. To determine what type of analog set-point your controller
was ordered with, refer to the Calibration Data Sheet that was included with your controller. 0-5 Vdc
is standard unless ordered otherwise. Note that if nothing is connected to Pin 4, and the controller is
set for analog control, the set-point will float.
CAUTION!
N
ever
leave
a
C
oNtroller
with
aNy
NoN
-
zero
set
-
poiNt
if
No
pressure
is
available
to
make
flow
. t
he
CoNtroller
will
apply
full
power
to
the
valve
iN
aN
attempt
to
reaCh
the
set
-
poiNt
. w
heN
there
is
No
flow
,
this
CaN
make
the
valve
very
hot!
Serial refers to a remote digital RS-232 set-point applied via a serial connection to a computer or
PLC as described in the Installation and RS-232 sections of this manual.
CAUTION! N
ever
leave
a
C
oNtroller
with
aNy
NoN
-
zero
set
-
poiNt
if
No
pressure
is
available
to
make
flow
. t
he
CoNtroller
will
apply
full
power
to
the
valve
iN
aN
attempt
to
reaCh
the
set
-
poiNt
. w
heN
there
is
No
flow
,
this
CaN
make
the
valve
very
hot!
Local refers to a set-point applied directly at the controller. For more information on changing the set-
point locally refer to the heading “Select” below. Local input must be selected prior to attempting to
change the set-point locally.
CAUTION! N
ever
leave
a
C
oNtroller
with
aNy
NoN
-
zero
set
-
poiNt
if
No
pressure
is
available
to
make
flow
. t
he
CoNtroller
will
apply
full
power
to
the
valve
iN
aN
attempt
to
reaCh
the
set
-
poiNt
. w
heN
there
is
No
flow
,
this
CaN
make
the
valve
very
hot!
Select Loop Input
>P 200 >Mass >Analog
D 500 Volume Serial
AUT0on
Press Local
Set 0.00
Control
Up Down Setup
Figure 8. MC Series Control Setup Display