Monitoring The Number Of Total Strokes; Monitoring The Number Of Changes In Direction; Monitoring The Lower Endstop And 7 Monitoring The Upper Endstop; Monitoring Deadband - Siemens SIPART PS2 Operating Instructions Manual

12.3.4.4

4 Monitoring the number of total strokes

The diagnostics value "1 STRKS" is constantly compared with the thresholds that are
determined from the "L1.LIMIT" to "L4.FACT3" parameters. If the thresholds are exceeded, the
fault message output or the alarm outputs respond depending on the mode of the extended
diagnostics. These two functions can be deactivated using the parameter setting "OFF" for
"L. STRK".
12.3.4.5

5 Monitoring the number of changes in direction

The diagnostics value "2 CHDIR" is constantly compared with the thresholds that are
determined from the "O1.LIMIT" to "O4.FACT3" parameters. If the thresholds are exceeded,
the fault message output or the alarm outputs respond depending on the mode of the extended
diagnostics. These two functions can be deactivated using the parameter setting "OFF" for
"O. DCHG".
12.3.4.6

6 Monitoring the lower endstop and 7 Monitoring the upper endstop

If the parameter "F. ZERO" is set to "ON", monitoring of the lower endstop is activated. This
function can be used to detect the errors in the valve seat. An overshot limit indicates the
possibility of deposits or foreign bodies in the valve seat. An undershot limit indicates probable
wear and tear of the valve seat or flow restrictor. Even a mechanical misalignment of the
position feedback can trigger this fault message.
Monitoring is always carried out whenever the valve is in the "tight closing/fast closing Down"
position. The current position is compared with the position that was determined as the lower
endstop at the time of initialization. Requirement: ' 36.YCLS' Tight closing/fast closing with
manipulated variable (Page 150) Parameter is set to one of the following values: 'do', 'uP do',
'Fd', 'Fu Fd'.
Example: A value of 3% is set. The position is normally adopted for "tight closing/fast closing
Down". A fault is reported if a value > 3% or < -3% is determined instead.
The fault message remains activated until either a subsequent monitoring remains within the
tolerance or a re-initialization process is executed. Even the deactivation of monitoring ("F.
ZERO"=OFF) may trigger an error message.
This monitoring function does not deliver any utilizable results if the endstops were not
determined automatically at the time of initialization, but the limits were set manually (manual
initialization, "5.INITM").
Similar diagnostics is carried out for the upper endstop. The "G. OPEN" parameter is used to
set the limit for this. Requirement: ' 36.YCLS' Tight closing/fast closing with manipulated
variable (Page 150) Parameter is set to one of the following values: 'uP', 'uP do', 'Fu', 'Fu Fd',
'uP Fd', 'Fu do
12.3.4.7

8 Monitoring deadband

If the deadband increases disproportionately when adjusting it automatically ("DEBA"=Auto
parameter), it indicates an error in the system (e.g. severely increased packing gland friction,
play in the position displacement sensor, leakage). A limit can therefore be entered for this
value ("E1.LEVL3", threshold for deadband monitoring). An error message output is activated
when this value is exceeded.
SIPART PS2 with PROFIBUS PA
Operating Instructions, 05/2019, A5E00127926-AC
Diagnostics and troubleshooting
12.3 Online diagnostics
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