YOKOGAWA DPharp EJXC40A, Руководство пользователя

Страница: 91 / 150

<7. HART Communication>
7-38
IM 01C25W05-01EN
7.3.2.2.4 Operating Procedure
The basic ILBD operating procedure is provided below.
1) Initial setup
2) Condition confirmation
3) Startup
4) ILBD execution
If alarms occur frequently or if the process conditions change during ILBD execution, change the alarm trigger
conditions or reacquire the reference data.
In addition, when using the ILBD, record the settings and verifications made in each step in the ILBD check list
of appendix 1.
F0717.ai
NG
1, 2
7
3
4
5, 6
10
1-1) Set alerts
• Set how to handle the 4-20 mA analog output when a
blockage is detected (using the Diag Out Option parameter).
2-1) Check the pressure value
• Check that the Pres value is stable.
2-2) Check the pressure fluctuation parameter
• Check whether the pressure fluctuation value can be applied
to ILBD.
1-2) Alarm masking
• Set the alarm to indicate through communication or on the
LCD (using the Diag Option parameter).
3-1) Acquire reference values
• Acquire fluctuation data under steady state operation to use
it as a reference.
3-2) Check detection capability
• Perform blockage detection simulation test
using valves.
Tuning
• Change the threshold.
• Change the sampling time.
Reset reference values
• Reacquire the differential
pressure/pressure value according
to the process conditions.
4) Execute ILBD
See subsection
7.3.2.2.11.
See subsection
7.3.2.2.10.
Process conditions have
changed greatly as
compared to those when
the reference values were
acquired.
See subsection 7.3.2.2.9.
Erroneous alarms occur frequently.
See subsection 7.3.2.2.8.
See subsection 7.3.2.2.7.
See subsection 7.3.2.2.6.
See subsection 7.3.2.2.6.
See subsection 7.3.2.2.5.
See subsection 7.3.2.2.5.
1) Initial setting
2) Condition
check
3) Start up
Items on
checklist
OK
Blockage detection alarm is generated.
Figure 7.3.5 ILBD Operation Flowchart