Yokogawa EJX440A - Manual (Page 43)

<4. Diagnostics>
4-3
IM 01C25T01-01E
 Functional block diagram
The figure below shows the functional block diagram of ILBD.
EJX
Sensor
Process Value
calculation
Blockage degree
Alarm
Masking
Response Code
(Device Status)
Status group 8,9
Display on LCD
Contact Output
Digital Output
Sensor
signals
DO Config
Ratio fDP
Ratio fSPl
Ratio fSPh
BlkF
fDP
fSPl
fSPh
Diag Error
Add result of
blockage detection to status
Pres, Pres %
Engr Disp
SP, SP %
Snsr temp
Amp temp
Output 4-20mA
AO
Execution of
ILBD
Result of blockage detection
Blockage alarm
Blockage alarm
Diag Output
Option
Blockage alarm
Result of blockage detection
-------(6)
F0404.ai
-------(7)
-------(1)
-------(4)
-------(2)
-------(3)
-------(5)
Figure 4.2.1 Functional Block Diagram of ILBD
The following outputs are given for the ILBD results.
Table 4.2.1 List of Outputs for ILBD
OUTPUT
Parameter name
Parameters based on the fluctuation value and blockage degree.
[ Diag DPComp: Non-Compensation ]
:
[ Diag DPComp: Compensation ] :
Blockage degree characterized in comparison of high-pressure side and low-pressure
side pressure fluctuation value.
Average value of the sum of squares of differential pressure fluctuations.
Average value of the sum of squares of low-pressure side static pressure fluctuation.
Average value of the sum of squares of high-pressure side static pressure fluctuation.
When an impulse line blockage is detected, “More Status Avairable” is generated in
Response Code Device Status.
Response Code
Device Status
When an impulse line blockage is detected, the result of the blockage detection
(alarm status) is indicated.
When an impulse line blockage is detected, the results of the blockage detection
(alarm status) is indicated.
When impulse line blockage is detected, an alarm status is displayed on LCD.
When impulse line blockage is detected, an alarm status is output on 4 to 20mA.
When impulse line blockage is detected, an alarm status is output on Status output.
(option code:/ AL)
#
(1)
(3)
(4)
Status group 8,9
Diag Error
Ratio fDP
Ratio fSPl
Ratio fSPh
BlkF
(2)
= Ratio fDP
Ref fDP
fDP
s
DPAvg
Ref DPAvg
= Ratio fDP
Ref fDP
fDP
= Ratio fSPl
Ref fSPl
fSPl
= Ratio fSPh
Ref fSPh
fSPh
Remarks
(5)
(6)
(7)
Display on LCD
AO
Digital Output
fDP
fSPI
fSPh
F0405.ai