Operating instructions

Parameterizing/addressing
10.4 Description of parameters
SIPART PS2 with and without HART communications
Operating Instructions, 09/2007, A5E00074631-07
147
10.4.2.10 Description of parameters 39
39.YCLS - Manipulated variable tight closing
This parameter is used to move the valve into its seat with the maximum force of the
actuator (permanent contact of the piezo valves). The tight closing function is activated on
one side or for both end positions. The parameter "39.YCLS" becomes effective if the
effective setpoint is below the parameter "40.YCDO" or above the parameter "41.YCUP".
See figure in
Description of parameters 37 (Page 145) and figure in Description of
parameters 13 through 33 (Page
144).
Note
Activated tight closing function
If the tight closing function is activated, then for parameter "49.
LIM" the monitoring of
regulation deviation is turned off in the appropriate overflow direction. Here, "YCDO: < 0 %"
and "YCUP: > 100 %" apply. This functionality is especially advantageous for valves with soft
seats. For a long-term monitoring of the end stop positions, we recommend activating the
parameters "F.
ZERO" and G. OPEN".
The factory setting is "no".
10.4.2.11 Description of parameters 40 and 41
40.YCDO - Lower value for tight closing
The factory setting is "0.5".
and
41.YCUP - Value for "tight closing above"
This parameter is used to set the value for "Tight closing below" and "Tight closing above".
Note
The value in the "40.YCDO" parameter must always be less than that in "41.YCUP". The
tight closing function has a fixed hysteresis of 1%. The parameters "40.YCDO" and
"41.YCUP" are relative to the mechanical stops. Both parameters are independent of the
values set in the "7.SDIR" and "38.YDIR" parameters.
The factory setting is "99.5".