beautypg.com

Moniteur 50 Series SMART Positioners User Manual

Page 79

background image

Operation

4-17

Positioner SIPART PS2/SIPART PS2 PA
C79000-G7476-C150–01

Dead zone of the controller

when DEBA = AUto the dead zone is constantly adapted to the require-
ments of the control loop in automatic mode. If control oscillation is de-
tected the dead band is increased step by step. Reverse adaptation is
achieved using a time criterion.

In other discrete settings the permanent value for the dead zone is
used.

Start of manipulated variable limiting (see Fig. 4-8)

and

End of manipulated variable limiting (see Fig. 4-8)

With parameters 31.YA and 32.YE the mechanical travel (from stop to
stop) is limited to the set values. In this way the mechanical correcting
range of the actuator can be limited to the active flow and integral satu-
ration of the leading controller can be avoided.

Normalization of manipulated variable (see Fig. 4-8)

Limiting the manipulated variable (by YA and YE) produces two diffe-
rent scales (MPOS and FLOW) for the display and the position feed-
back via the current output.

The MPOS scale shows the mechanical position (0 to 100 %) between
the hard stops of initialization. This is not affected by parameters YA
and YE. Parameters YA and YE are displayed in MPOS scale.

The FLOW scale is the normalization (0 to 100 %) to the range bet-
ween YA and YE. The setpoint w (0 to 100 %) always refers to this
range. This results in a display and position feedback Jy that are pro-
portional to the flow (even if valve characteristic curves are used).

In order to calculate the system deviation the setpoint is also displayed
in the relevant scale.

30.DEBA

31.YA

32.YE

33.YNRM