Operate
6.2 Parameter description
SITRANS VP300 with or without HART
Operating Instructions, 03/2011, A5E01258666-03
115
Example:
Parameter "3.6.7.2 Time basis" (Page 115) was set to 8 hours. During the first 8 hours, the
valve position is continuously monitored by the positioner. The average value of the valve
position, which is determined within this 8 hour period, is stored as a reference value. This is
the reference position value. Another average is determined after another 8 hours. This is
the average position value. You can read the results of the calculations in the "3.4.14
Reference value of position" (Page 95) and "3.4.15 Average value of position" (Page 95)
parameters.
"3.6.7.1 Activation"
Factory setting:
Off
Setting options:
Off
On
Purpose:
Activation of calculation of average position value.
Description:
During the test, position and average reference value are always
compared at the end of a time interval. If the actual average position
value passes a threshold, the positioner initiates an error message.
Check whether the settings in the parameters "Time basis" and
"State" are correct and whether the "Thresholds" apply to your
application.
"3.6.7.2 Time basis"
Requirements:
Activation of the monitoring function.
"3.6.7.1 Activation" (Page 115)
Average reference value was determined.
Factory setting:
0.5 hours
Setting options:
0.5 hours
8 hours
5 days
60 days
Purpose:
Define time interval within which the reference position value and
the average position value are determined.
Description:
Following the start of the position reference calculation and the
expiry of the time interval, an average position value is created over
the defined time period and compared with the reference position
value. After that, the test is started again.
