Siemens SITRANS PCS 7 Function Manual page 201

The signal status of the FbkCloseOut and FbkOpenOut outputs is fetched and sent from the
worst signal status from the RbkOut output and the corresponding feedback signal inputs
FbkClose and FbkOpen.
The signal status of the manipulated variable output MV always corresponds to the signal status
of the input parameter MV_Ext or MV_Int, depending on how the setpoint is specified. If the
internal manipulated variable MV_Int is used, the signal status 16#80 is always output.
The signal status of manipulated variable difference ER is fetched and sent from the worst
signal status of the two outputs RbkOut and MV.
The worst signal status ST_Worst for the block is formed from the following parameters:
● FbkOpenOut.ST
● FbkCloseOut.ST
● FbkAuxVOpenOut.ST
● FbkAuxVCloseOut.ST
● RbkOut.ST
● LocalLi.ST
Forcing operating modes
This block provides the standard "Forcing operating modes" function that is described in the
APL Online Help.
Note
If the block is operated with a auxiliary valve, the OpenForce and CloseForce commands
also affect the auxiliary valve.
The high range limit (MV_HiLim) and the low range limit (MV_LoLim) are output at MV
for OpenForce and CloseForce respectively.
With CloseForce, the auxiliary valve is closed, thereby triggering the neutral position of the
control valve regardless of the MV output.
A configured ramp limit has no effect.
Feedback monitoring
This block provides the standard "Feedback monitoring" function that is described in the APL
Online Help.
Digital feedback signals for the "Open" and "Closed" positions are formed from the position
feedback:
● Feedback for "Open" position: Rbk ≥ PosDiOpen
● Feedback for "Closed" position: Rbk ≤ PosDiClose
SITRANS Library for PCS 7
Function Manual, 05/2019, A5E35351976-11
SIPART PS2 HART
7.1 SipPS2HA
201