Siemens SIPART Series Operating Instructions Manual page 181

9.4.3.2 Description of parameter b
b. DEVI - general control valve fault
Use this parameter to activate the general control valve fault test for dynamic monitoring of
the control valve response. The actual position course is compared with the expected
position course for this purpose. This comparison helps in drawing a conclusion about the
correct operational response of the control valve. Set the "On" parameter value to activate
the test. Sub-parameters are displayed. Sub-parameters are described below.
The current value is displayed in the "14 DEVI" diagnostics parameter. The positioner
triggers a fault message if the current value exceeds one of the three configurable limit
thresholds.
The factory setting is "OFF".
b1.TIM - time constant of the low-pass filter
Use this sub-parameter to define the attenuation effect of the low-pass filter. The unit is
seconds. This sub-parameter is set to "Auto" if the device is initialized automatically. The
"b1.TIM" time constant is determined from the initialization parameters such as "uP" and
"doWn" actuating times.
If the time constant is not adequate, the setting of "b1.TIM" can be changed manually. Set
the time constant in a range from "1" to "400". In this case:
● Setting "1" indicates too weak an attenuation.
● Setting "400" indicates too strong an attenuation.
The current value is displayed in the "14 DEVI" diagnostics parameter. The positioner
triggers a fault message if the current value exceeds one of the three configurable limit
thresholds.
The factory setting is "Auto".
b2.LIMIT - limit of the general control valve fault
Use this sub-parameter to set a base limit in percent. The base limit defines the magnitude
of the permissible deviation from the expected position course. The limit serves as a
reference variable for the fault message factors.
Set the base limit in a range from "0.1" to "100.0".
The factory setting is "1.0".
b3.FACT1 - factor 1
Use this sub-parameter to set the factor for the formation of limit threshold 1. Set the factor in
a range from "0.1" to "100.0". The limit threshold is the product of "b2.LIMIT" and
"b3.FACT1".
The threshold 1 fault message is displayed when the limit threshold 1 is exceeded. The
process to activate and display this fault message is described in the "XDIAG" parameter.
The factory setting is "5.0".
SIPART PS2 with and without HART
Operating Instructions, 10/2013, A5E00074631-11
Parameterizing/addressing
9.4 Description of parameters
179