Samson 3274 - Priority Circuit (Version with Positioner); Direction of Action (Version with Positioner); Position Feedback Signal (Version with Positioner); Using the Positioner as a Position Transmitter

EB 8340 EN 3-5
Design and principle of operation
3.4 Priority circuit (version with
positioner)
Theactuatorstemmovestoadenedend
position after the terminals 82 and 83 in the
priority circuit are switched. After the con-
nection is interrupted, the actuator stem fol-
lows the control signal. The fail-safe action
has priority (in actuators with fail-safe ac-
tion).
3.5 Direction of action (version
with positioner)
Î SeeFig.3-2
Directionofaction:increasing/increasing
(>>)
The actuator stem moves towards the top end
position (stem retracts) as the input signal in-
creases.
Directionofaction:increasing/decreasing
(<>)
The actuator stem moves towards the lower
end position (stem extends) as the input sig-
nal increases.
100%
0%
4 20 m
A
12
4
20 m
A
100%
0%
< >>>
< >>>
Actuator stem
retracted
Actuator stem
extended
Split-range
operation
Input signal
Travel
Dead band
Fig.3-2: Characteristics
3.6 Position feedback signal
(version with positioner)
The position feedback signal issues the posi-
tion as a current or voltage signal propor-
tional to the actuator travel.
3.7 Using the positioner as a
position transmitter
The positioner can be used as a position
transmitter with three-step control.