BIFFI IMVS2000v2 - Page 33

Installation, Operation and Maintenance Manual
September 2019
MAN720_IMVS2000v2_IOM Rev. 6
Section 5: Working Principle
Working Principle
During the SOV TEST, the SOV A and the SOV B are briefly used for a short period of time to generate
a pressure drop inside the cylinder (detected by pressure sensor) without generating the actuator
movement.
The “SOV TEST Time” is automatically set by the IMVS2000v2.
The first SOV tested is always the SOV A.
If a problem is verified during the test on the SOV A, the test on the SOV B is executed anyway.
During the SOV TEST, the SOV A and the SOV B are briefly used for a short period of time to generate
a pressure drop inside the cylinder (detected by pressure sensor) without generating the actuator
movement.
The “SOV TEST Time” is automatically set by the IMVS2000v2.
The first SOV tested is always the SOV A.
If a problem is verified during the test on the SOV A, the test on the SOV B is executed anyway.
To perform the SOV A – SOV B TEST, the following commands must be successfully executed:
- Calibration
- Baseline Signature
There are two different types of “SOV A and SOV B Test”:
- Baseline SOV A – SOV B Test
- SOV A – SOV B Test
The “Baseline SOV A – SOV B Test” can be performed by using “Baseline PST” command.
“B. PST St.” describes the result of the last Baseline SOV A – SOV B Test.
“B. PST Date” and “B. PST Time” indicate the date and the time of the last Baseline SOV A – SOV B Test.
If the “Baseline SOV A – SOV B Test” command is received, but:
- “Cal. Status” ≠ “Passed” or
- “Base. S. St.” ≠ “Passed” or
- “Pr. S. 1-2” = “None” or
- “Al. PSA En.” = “No” or
- “Al. PSB En.” = “No”
Then:
- The command is not executed
- “B. PST St.” assumes the value “Conf. Err.”
- “B. PST Date” and “B. PST Time” assume the current date and time values
- The DO PST PASSED contact is opened
- The DO PST FAILED contact is closed
- The graph is not stored
If the “Baseline SOV A – SOV B Test” command is received, but:
- “Cal. Status” = “Passed” and “CAL Alarm” is active or
- “POS Alarm” is active or
- “HSP Alarm” is active or
- “LSP Alarm” is active or
- The start position is not valid
Then:
- The command is not executed
- “B. PST St.” assumes the value “Failed”
- “B. PST Date” and “B. PST Time” assume the current date and time values
- The PSA Alarm and PSB Alarm are activated
- The DO PST PASSED contact is opened
- The DO PST FAILED contact is closed
- The graph is not stored
If a “Baseline SOV A – SOV B Test” is executed, all previous “SOV A – SOV B TEST” are cleared.
The “SOV A – SOV B Test” can be executed only if the “Baseline SOV A – SOV B Test” is
successfully executed.
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