September 2019
Installation, Operation and Maintenance Manual
MAN720_IMVS2000v2_IOM Rev. 6
MAN720_IMVS2000v2_IOM Rev. 6
Section 5: Working Principle
Working Principle
5.2.8.1
Digital Input FST Graphs
The IMVS2000v2 stores the graphs of the Opening FST and Closing FST generated through the
Digital Inputs (SOV A CONTROL and SOV B CONTROL).
If the parameter “M. FST Alr En” (see 6 for details) is set to “Yes” the data of the Digital Input FSTs are
compared with the Baseline ones for diagnostic.
If the parameter “M. FST Alr En.” is set to “No” the Digital Input FST is only stored as a graph and not
used for diagnostic (Travel Time, Break Time and Break Pressure are not measured and stored).
For using Digital Input FSTs for diagnostic and obtaining consistent results it is recommended to:
-
to open and close the actuator when pressures and position are stable
-
for the Opening FST wait for the Opening Maximum Time before Closing (*)
-
for the Closing FST wait for the Closing Maximum Time before Opening (*)
(*):
the graph could have less than 351 samples.
The Digital Input FST Graphs can be stored only if Baseline Signature is already successfully performed.
5.2.8.2
External Source FST Graphs
The IMVS2000v2 can store the graphs of the FST generated by external sources
(i.e. SOVs not controlled by the IMVS2000v2).
The FST is memorized only if the position changes at least 1% in a time equal to the Opening Break
Time (for the Opening FST) or the Closing Break Time (for the closing FST).
If the position is greater than 50% the IMVS2000v2 can detect Closing FST generated by External
Sources otherwise it can detect Opening FST.
The External Source FST is only stored as graph and never compared with the Baseline Signature (no
alarms can be generated). Time, Break Time and Break Pressure are not measured and stored.
The External Source FST Graphs can be stored only if Baseline Signature is already successfully performed.
5.2.8.3
External Source PST Graphs
When the PST Graph stored is a SOV Test, the source is saved as “External Contro."
The Baseline SOV Test is always placed at position 1.
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Summary of Contents for IMVS2000v2
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