Siemens PROFIBUS PA SIPART PS2 Manual page 102

Operation
48. ZERO
49. OPEN
.
100
This function enables a preventive maintenance of the fitting, see also
chapter 4.5 "Diagnostics", page 103.
This monitoring function can be deactivated with the OFF setting
(factory setting).
Tolerance value for monitoring the bottom hard stop
With this value a limit value (in percent related to the total mechanical
distance) can be preset for the monitoring of the bottom hard stop. If
this tolerance value is exceeded or dropped below of, the fault
message output (optional) is activated.
This function detects when the bottom stop has changed by more than
the specified tolerance related to its initialization value. Monitoring
takes place when the valve is in tight closing bottom. Activation of the
tight closing bottom function (parameter "35.YCLS") is therefore a
prerequisite.
The fault message remains activated until either a subsequent
monitoring remains within the tolerance or a new initialization is
performed.
This monitoring function can be deactivated with the OFF setting
(factory setting). See also chapter 4.5 "Diagnostics", page 103.
Tolerance value for monitoring the top hard stop
With this value a limit value (in percent related to the total mechanical
distance) can be preset for the monitoring of the top hard stop. If this
tolerance value is exceeded or dropped below of, the fault message
output (optional) is activated.
This function detects when the top stop has changed by more then the
specified tolerance related to its initialization value. Monitoring takes
place when the valve is in tight closing top. Activation of the tight
closing top function (parameter "35.YCLS") is therefore a prerequisite.
The fault message remains activated until either a subsequent
monitoring remains within the tolerance or a new initialization is
performed.
This monitoring function can be deactivated with the OFF setting
(factory setting).
NOTE
But the monitors of the bottom and top hard stop do not only react to
valve errors. Adjustment of the position feedback is also detected as
an error if the tolerance values are exceeded as a result.
SIPART PS2 PA Manual
A5E00127926-03