Manual
    <4.  Diagnostics>
4-11
IM 01C25T01-06EN
4.2.2.4  Operating Procedure
The basic ow of the ILBD operation is as follows.
1) Initial setting
2) Condition check
3) Start up
4) Perform the ILBD algorithm.
If an alarm is often generated or the process 
condition changed in the ILBD operation, do 
tuning to change the alarm setting, or to reset the 
reference values.
Fill out the information to the checklist, at the 
process shown in below gure. 
(Refer to the Appendix 1. ILBD Check List)
F0407.ai
NG
1, 2
7
3
4
5, 6
10
1-1) Alert Setting
• Enable an alert to be generated by 
Diag Out Option parameter.
1-2) Alarm Masking
• Select the alarm status to display on 
LCD or to give an alert by Diag 
Option parameter.
2-1) Check Stability of pressure
• Check the stability of Pres value.
2-2) Check Fluctuation Values
• Check whether the fluctuation values 
are available for ILBD.
3-1) Obtain Reference Values
• Obtain a reference fluctuation value of 
differential pressure/pressure and 
static pressure under normal condition.
3-2)
 Check Detection
 Capability
• Simulate the blockage detection 
operation with a three-valve 
manifold or stop valve.
Tuning
•  Change the threshold value by 
Limit parameter.
•  Change the sampling time by 
Diag Period parameter.
Reset Reference Values
•  Reset a reference fluctuation 
value of differential 
pressure/pressure according to 
process condition.
4) Perform ILBD algorithm
Refer to subsection 4.2.2.11
Refer to 
subsection 4.2.2.10
Process condition is 
changed by a 
comparison of the 
condition when the 
reference values were 
obtained.
Blockage Detection
Alarm is generated.
Refer to 
subsection 4.2.2.9
Spurious alarm detection.
Refer to subsection 4.2.2.8
Refer to subsection 4.2.2.7
Refer to subsection 4.2.2.6
Refer to subsection 4.2.2.6
Refer to subsection 4.2.2.5
Refer to subsection 4.2.2.5
1) Initial Setting
2) Condition 
 Check
3) Start up
Items on
Check sheet
OK
Figure 4.5  Flow Chart of ILBD Operation










