18 EB 8359-1 EN
Operating the positioner
6.1.1 Determining and
changing the operating
direction
For an increasing input signal (reference
variable), the signal pressure p
st
can either
be increasing (direct action <<) or decreas-
ing (reverse action <>).
Similarly, as the reference variable decreas-
es, the signal pressure can either decrease
(direct action <<) or increase (reverse action
<>).
On the apper plate, the operating direction
is indicated by symbols (direct <<, reverse
<>). Depending on the position of the ap-
per plate, the adjusted operating direction
and the associated symbol is visible.
If the required operating direction does not
correspond to the visible symbol or if the op-
erating direction is to be changed, proceed
as follows:
1. Unscrew both screws on the cover plate
and lift off the nozzle block along with
the cover plate.
2. Reinstall the nozzle block turned by 180°
together with the cover plate and refas-
ten.
Make sure that the nozzle block and apper
plate are correctly located above or below
the feeler pin as shown in Fig.10.
If the operating direction is to be changed
after the initially determined arrangement of
positioner and actuator, note that the posi-
tioner must be mounted in a different loca-
tion and the nozzle block must be turned.
Make sure the location of the lever (1) and
the plate (20), "lever located at top of plate"
or "lever located at bottom of plate" is cor-
rect (Fig.5 to Fig.8).