Samson 5857 - Annex A: Travel Settings; Travel Adjustment Modes

16-6 EB 5857 EN
Annex A (conguration instructions)
16.5 Travel
16.5.1 Limited travel range
The Limited travel rangeparameterdeterminesin%howfartheactuatorstemcanmoveat
the maximum. The travel determined during initialization acts as the reference.
Settings\Actuator\Travel
Function WE Adjustment range
Limited travel range 100.0% 30.0to100.0%
16.5.2 Travel adjustment
Travel adjustment can be made to be absolute or relative. The way the travel adjustment is
made affects the control behavior.
− Absolute travel adjustment:
The absolute travel adjustment causes the actuator stem to move to the travel position de-
termined by the input signal. To achieve this, an automatic zero calibration is performed
after every start-up to obtain a reference value for the zero point. The position feedback
indicates the position of the actuator stem.
− Relative travel adjustment
The relative travel adjustment causes the change in input signal to be reproduced by the
position of the actuator stem. The actuator stem extends or retracts from the current actu-
ator stem position corresponding to the change in signal. After starting up the actuator, a
zero calibration is not performed. The stem position is unknown on reconnection after
powerfailure.Theinputsignalisassignedinthiscaseasthestartvalue.12Visissued
as the position feedback signal. When, during operation, the actuator stem reaches the
travelstopfor"stemextends"and,atthesametime,theinputsignalis0%,thestempo-
sition is recognized as a result.
Settings\Actuator\Travel
Function WE Adjustment range
Limited travel range 100.0% 30.0to100.0%
In closed-loop operation, the positioner must be operated with absolute travel adjustment
(default setting).
Tip