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Alarm, error, and system messages
10.2 Diagnostics
10.2.3.19
Diagnostics parameters '21.P0' Potentiometer value of bottom end stop / '22.P100'
Potentiometer value of top end stop
Display range:
Requirement 1 -
read values
Purpose 1
Requirement 2 -
change values
Purpose 2:
216
• NO
• 0.0 ... 100.0
"NO": Changing the low or upper endstop is not possible in the
current 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 (zero point 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
(zero point P0) and the upper endstop (P100).
Since initialization is not usually carried out under process condi-
tions, the values for the lower endstop (zero point P0) and the up-
per endstop (P100) may change when the process is started.
These changes may result from temperature changes with the as-
sociated thermal expansion of the material. If the "F.ZERO" or
"G.OPEN" parameters are active, the thresholds set in these two
parameters can be exceeded as a result of thermal expansion. 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 ther-
mal 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, 09/2014, A5E00074631-12
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