Siemens SITRANS PCS 7 Function Manual page 210

SIPART PS2 HART
7.1 SipPS2HA
"Actuator active" information
● With PosReached.Value = 0, the following applies:
With PosDiClose < MV < PosDiOpen, the control valve is detected as active and bit 24 is
set in Status1.
● The following applies to PosReached.Value = 1: Status1.Bit 24 = 0
This status can be used to indicate a customized symbol in the process image, for example, and
is saved in the status word (see Status word section in Description of SipPS2HA (Page 191)).
General function "MV difference"
The manipulated variable difference is sent to the ER output and is calculated with the following
formula:
ER = MV - Rbk
If ER is within the dead band, ER = 0 is set and the manipulated variable is considered reached.
Manipulated variable difference generation and dead band
The manipulated variable difference is formed by the effective manipulated variable MV and the
position feedback Rbk, and sent to the ER output. A dead band can be set at the PosDeadBand
input:
● PosDeadBand = 0 Dead band is disabled
● PosDeadBand ≠ 0 Dead band is enabled
Limit monitoring of manipulated variable and control error
This block provides the standard "Limit monitoring of the setpoint, manipulated variable and
control error" function that is described in the APL Online Help.
Monitoring is disabled in the following situations:
● The auxiliary valve is closed
● The control valve is in the neutral position
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SITRANS Library for PCS 7
Function Manual, 05/2019, A5E35351976-11