<7. HART Communication>
7-32
IM 01C25W05-01EN
■ Block Diagram
Response Code
(Device Status)
Status group 15,16
LCD display
Diag Error
4-20 mA DC
(Analog Output)
-------(6)
F0714.ai
DP, Pres 1, Pres2
Engr Disp, PV %
Temp1, Temp2,
Amp Temp
Ratio fDP
Ratio fP2
Ratio fP1
BlkF
fDP
fP2
fP1
Diag Applicable
-------(1)
-------(4)
-------(2)
-------(3)
-------(5)
EJX-DRS
Sensor
Process value
calculation
Fluctuation
calculation
Alarm Masking
Sensor
signals
Execution of
ILBD
Result of blockage detection
Blockage alarm
Blockage alarm
Result of blockage detection
Diag Output Option
Figure 7.3.2 Block Diagram of the ILBD Function
The following ILBD outputs (1) to (6) can be obtained.
Table 7.3.1 ILBD Outputs
#
(1) Ratio fDP
A value obtained by comparing the root mean square (RMS) of the differential pressure
fluctuation.
It is used for blockage detection.
Two types of output, which you can select with Diag DPComp (flow rate compensation flag),
are available.
[When Diag DPComp is set to Non-Compensation]
Ratio fDP = SQRT(fDP / Ref fDP)
[When Diag DPComp is set to Compensation]
Ratio fDP = SQRT(fDP / Ref fDP) × Ref DPAvg / DPAvg
Ratio fP2
A value obtained by comparing the root mean square (RMS) of the module 2 side pressure
fluctuation.
It is used for blockage detection.
Ratio fP2 = SQRT(fP2 / Ref fP2)
Ratio fP1
A value obtained by comparing the root mean square (RMS) of the module 1 side pressure
fluctuation.
It is used for blockage detection.
Ratio fP1 = SQRT(fP1 / Ref fP1)
BlkF
A value indicating the blockage level, which is characterized by comparing the module 1 side
pressure fluctuation and module 2 side pressure fluctuation.
It is used for blockage detection.
fDP
A value obtained by averaging the sum of squares of the differential pressure fluctuation.
fP2
A value obtained by averaging the sum of squares of the module 2 side pressure fluctuation.
fP1
A value obtained by averaging the sum of squares of the module 1 side pressure fluctuation.
Diag Applicable
After the reference value is acquired, detectable blockage and fluctuation error status is
displayed.
(2) Response code
Device status
When a blockage is detected, More Status Available is displayed under Response Code
Device Status.
(3) Status group 15, 16 When a blockage is detected, the blockage detection results (alarm information) are
displayed in Status group 15 and 16.
(4) Diag Error
When a blockage is detected, the blockage detection result is displayed in Diag Error.
(5) Display on LCD
When a blockage is detected, the blockage detection results (alarm information) are
displayed on the Integral indicator.
(6) Analog Output
When a blockage is detected, the blockage detection result is reflected in the 4 to 20 mA
analog output according to the settings.
