
EB 7500 EN
15
Design and principle of operation
Circuit version 1
for fixed
set point and slave con-
trol
P/PI
P
PI
PID
PD
R
w
Z
y
A
y
A
y
H
y
A
y
H
y
H
x
S
S
S
y
A
w
Z
R
w
ext
w
int
w
w
x
w
ext
x
y
Circuit version 2
for
slave
control
S
P/PI
P
PI
PID
PD
R
w
Z
y
A
y
A
y
H
y
A
y
H
y
H
x
S
S
y
A
w
Z
R
x
y
w
ext
w
x
Circuit version 9
for
ratio
control
P/PI
P
PI
PID
PD
Z
a
y
A
y
H
y
A
y
H
y
H
e
S
S
y
A
w
Z
R
e
a
w
ext
x
x
y
Fig. 7:
Circuits of Type 3421 Compact Controller
Pneumatic
connection
Self-seal push-on
fitting
Supply air Z
Venting
Pneumatic adjuster
End connection
Manual/automatic
switch
y
Manipulated
variable
x
Controlled variable
w
Set point
w
ext
External set point
w
int
Internal set point
R
Feedback
yA Output pressure
yH
Manual output
S
Switching pressure
a
Output pressure
e
Input pressure
Содержание Series 420
Страница 37: ...EB 7500 EN 37 ...
Страница 38: ...38 EB 7500 EN ...
Страница 39: ...EB 7500 EN 39 ...