User Manual
    <Appendix 8. Advanced Diagnostics>
A8-12
IM 01C25T02-01E
3) Set “Calculation” to DIAG_MODE so as to start 
blockage detection operation.
4) Check that an alarm of “High Side Blocking” is 
generated after the time that consists of DIAG_
PERIOD and DIAG_COUNT passed.
5) Check also the operation of the analog alert if 
an analog alert is set.
6) Open the valve completely and check that there 
are no alarms.
  Simulation of Low-pressure-side 
Blockage
1) Close the low-pressure-side valve.
2) Conrm the value of PRIMARY_VALUE is 
stable. If unstable, open valve a little.
3) Set “Calculation” to DIAG_MODE so as to start 
blockage detection operation.
4) Check that an alarm of “Low Side Blocking” is 
generated after the time that consists of DIAG_
PERIOD and DIAG_COUNT passed.
5) Check also the operation of the analog alert if 
an analog alert is set.
6) Open the valve completely and check that there 
are no alarms.
  Simulation of Both-pressure-side 
Blockage
1) Close the both-pressure-side valves.
2) Conrm the value of PRIMARY_VALUE is 
stable. If unstable, open valve a little.
3) Set “Calculation” to DIAG_MODE so as to start 
blockage detection operation.
4) Check that an alarm of “B Blocking” is 
generated after the time that consists of DIAG_
PERIOD and DIAG_COUNT passed.
5) Check also the operation of the analog alert if 
an analog alert is set.
6) Open the valves completely and check that 
there are no alarms.
A8.2.9  Start ILBD Operation
If process condition and capability to detect a 
blockage are conrmed, the ILBD operation can be 
started according to the following procedure.
1) Check the value of sampling period
  (DIAG_PERIOD).
2) Check the number of times that detect the 
blockage consecutively in order to give an 
alarm (DIAG_COUNT). The default value at the 
shipment is set to 3 times.
3) Set “Calculation” status to DIAG_MODE.
  If the reference value has not yet been 
obtained, set “Reference” to DIAG_MODE. 
After obtained the reference values, the ILBD 
starts automatically. At the same time, DIAG_
MODE changes automatically from “Reference” 
to “Calculation”.
A8.2.10  Tuning
When the pressure uctuation amplitude in uids is 
not sufciently large or an alarm is often generated 
according to the process condition, tune up by 
changing the threshold for the blockage detection 
(DIAG_LIM) or the sampling period (DIAG_
PERIOD) to enhance the accuracy of the blockage 
detection.
The ILBD operation must be stopped to tune up. 
Set “Stop” to DIAG_MODE.
A8.2.10.1 Threshold Value
The gure below shows the image of tuning effect 
with a monochrome bar.
FA0809.ai
0 1 3
Threshold (lower side) Threshold (upper side)
1) DIAG_LIM [2]
2) DIAG_LIM [4]
3) DIAG_LIM [6]
1) DIAG_LIM [1]
2) DIAG_LIM [3]
3) DIAG_LIM [5]
(a)  The tuning image of the threshold values for
  1) RATIO_FDP Sqrt
    (VALUE_FDP/REFERENCE_FDP),
  2) RATIO_FSPL Sqrt
    (VALUE_FSPL/REFERENCE_FSPL),
  3) RATIO_FSPH Sqrt
    (VALUE_FSPH/REFERENCE_FSPH)
(b)  The tuning image of the threshold values for 
  4) Sqrt (VALUE_BLKF/REFERENCE_BLKF)
0-1 1
Threshold (lower side) Threshold (upper side)
4) DIAG_LIM [8] 4) DIAG_LIM [7]
Figure A8.7  Tuning Image of Threshold Value










