As a standard feature, the positioner comes with a binary input used to signalize process infor-
mation over the F
OUNDATION™ fieldbus network.
The extended EXPERTplus diagnostics are integrated into the positioner. They provide informa-
tion on the positioner and generate diagnostic and status messages, which allow faults to be
pinpointed quickly.
2.1 Application type
Two application types for the valve are available: Control valve and Open/Close (on/off)
valve. The manual mode (MAN) and the automatic mode (AUTO) can be selected with
both application types.
Depending on the application type that has been selected, the positioner behaves differently in
the automatic mode (AUTO) :
Control over F
OUNDATION™ fieldbus is performed over the AO Function Block (control valve)
and over the DO1 Function Block (on/off valve). The application type can be set in the Resource
Block over the SELECT_DO_1 parameter or at the positioner using Code 49 - h0.
Control valve Open/Close valve
AUTO
The positioner follows the reference variable
continuously.
The valve position (current position) appears in
% on the display.
Discrete analysis of the reference variable.
The valve position (current position) in %
and O/C (Open/Close) appear in alter-
nating sequence on the display.
MAN
The positioner follows the reference variable entered over local operation.
Note:
–
Depending on the application type, certain diagnostic functions cannot be performed or
analyzed. Refer to EB 8389 EN on EXPERTplus valve diagnostics.
–
In manual mode, an on/off valve can be moved past 100 % of the nominal range (with
the closed position for ATO) or below 0 % of the nominal range (with the closed position
for ATC).
8 KH 8384-5 EN
Principle of operation
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