Diagnostic Value '21.P0 - Potentiometer Value Of Lower Endstop (0%)' / '22.P100 - Potentiometer Value Of Upper Endstop (100%) - Siemens SIPART PS2 Operating Instructions Manual

Alarm, error, and system messages
10.2 Diagnostics
10.2.4.19 Diagnostic value '21.P0 - Potentiometer value of lower endstop (0%)' / '22.P100 -
Potentiometer value of upper endstop (100%)'
Display range:
Requirement 1 -
read values
Purpose 1
Requirement 2 -
change values
Purpose 2:
218
• NO
• 0.0 ... 100.0
'NO': Changing the low or upper endstop is not possible in the cur-
rent state of the control valve. Initialize the positioner again.
The positioner is initialized.
Read values
You can use the P0 and P100 parameters to read the values for
the lower endstop (0%) and the upper endstop (100%) of the posi-
tion measurement as determined during the automatic initialization.
The values of manually approached end positions are applicable
for manual initialization.
• The positioner is initialized and in manual mode (MAN) or
automatic mode (AUT).
• The current position of the actuator is within the range -10 to
+10% of the lower endstop (P0).
• The current position of the actuator is within the range 90 to
110% of the upper endstop (P100).
Change values
You can use these two parameters to change the lower endstop
(P0) and the upper endstop (P100).
Since initialization is not usually carried out under process condi-
tions, the values for the lower endstop (P0) and the upper endstop
(P100) may change when the process is started. These changes
may result from temperature changes with the associated thermal
expansion of the material. If the Monitoring the lower endstop
'F.\\ZERO' (Page 188) and Monitoring the upper endstop
'G.\\OPEN' (Page 190) parameters are active, the thresholds set in
these two parameters can be exceeded as a result of thermal ex-
pansion. An error message is output in the display.
The process-dependent thermal expansion may represent the nor-
mal state in your application. You do not wish to receive an error
message as a result of this thermal expansion. Therefore reset the
'P0' and/or 'P100' parameters after the process-dependent thermal
expansion has had its complete effect on the control valve. The
procedure is described in the following.
SIPART PS2 with and without HART
Operating Instructions, 02/2016, A5E00074631-AB