Siemens SIPART Series - 9.4.2.4 Description of parameters 10 and 11; 9.4.2.5 Description of parameters 12

Parameterizing/addressing
9.4 Description of parameters
SIPART PS2 with and without HART
Operating Instructions, 10/2013, A5E00074631-11
163
9.4.2.4
Description of parameters 10 and 11
10.TSUP - Setpoint ramp OPEN
and
11.TSDO - Setpoint ramp CLOSED
The setpoint ramp is effective in automatic mode and limits the speed of change of the
effective setpoint. When switching from manual to automatic mode, the setpoint ramp is
used to adjust the effective setpoint to the setpoint occupied by the positioner.
This smooth switching from manual to automatic mode prevents pressure excess in long
pipelines.
The parameter value "TSUP = Auto" means the slower of the two actuating times determined
during initialization is used for the setpoint ramp. Parameter value "TSDO" then has no
effect.
The factory setting is "0".
9.4.2.5
Description of parameters 12
12.SFCT - Setpoint function
This parameter is used to linearize nonlinear valve characteristics. For linear valve
characteristics, arbitrary flow characteristics are formed.
See figure in Description of parameters 13 through 33 (Page 164).
Seven valve characteristics are stored in the positioner and are selected using the "SFCT"
parameter:
Valve characteristics
Set with parameter value
Linear
Lin
Equal percentage
1:25
1-25
Equal percentage
1:33
1-33
Equal percentage
1:50
1-50
Inverse equal percentage
25:1
n1-25
Inverse equal percentage
33:1
n1-33
Inverse equal percentage
50:1
n1-50
Freely adjustable
FrEE
The factory setting is "Lin".