Operation
Liquiline Control CDC90
86
Hauser
Outputting the manipulated variable of a controller
To output a controller manipulated variable via a relay, the relay is modulated. The relay is
energized (pulse, t
1
) and is then de-energized (interval, t
0
).
Function = Controller
Function
Options
Info
Source of data
Selection
• None
• Controller 1
• Controller 2
Factory setting
None
‣
Select the controller that should act as the
data source.
Operating mode
Selection
• PWM
• PFM
Factory setting
PWM
PWM=pulse width modulation
PFM=pulse frequency modulation
1.
PWM
(pulse width modulation):
The duty cycle is varied within a period
T
(T=t
1
+t
0
). The cycle duration remains
constant.
0
T
t
1
t
0
2T
3T
y = t / T
1
10 %
50 %
100 %
1 "High"
0 "Low"
t
52
Typical application: solenoid valve
2.
PFM
(pulse frequency modulation):
Here, pulses of a constant length (t
1
) are output and the interval between the pulses
varies (t
0
). At a maximum frequency, t
1
= t
0
.
1 "High"
0 "Low"
T
t
t
1
t
0
2T
y = f / f = T
/ T
max
min
100 %
50 %
20 %
3T
53
Typical application: dosing pump
Summary of Contents for Liquiline Control CDC90
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