Yokogawa EJX930A - Manual (Page 42)

<6. Explanation of Basic Items>
6-1
IM 01C25T02-01E
6. Explanation of Basic Items
6.1 Outline
This chapter describes the SENSOR transducer
block, the LCD transducer block, and the AI function
block and explains basic parameter settings.
Refer to Appendixes for other function blocks,
LM function, software download function, and
advanced diagnostics.
6.2 Setting and Changing
Parameters for the Whole
Process
IMPORTANT
Do not turn off the power immediately after
setting. When the parameters are saved to the
EEPROM, the redundant processing is executed
for an improvement of reliability. If the power
is turned off within 60 seconds after setting is
made, the modified parameters are not saved
and the settings may return to the original values.
Block mode
Many parameters require a change of the block
mode of the function block to O/S (Out of Service)
when their data is changed. To change the block
mode of the function block, its MODE_BLK needs
to be changed. The MODE_BLK is comprised of
the four sub-parameters below:
(1) Target (Target mode):
Sets the operating condition of the block.
(2) Actual (Actual mode):
Indicates the current operating condition.
(3) Permit (Permitted mode):
Indicates the operating condition that the
block is allowed to take.
(4) Normal (Normal mode):
Indicates the operating condition that the
block will usually take.
6.3 SENSOR Transducer Block
The SENSOR transducer block is in between the
sensor and the AI function blocks. It calculates
pressure/differential pressure, static pressure,
and capsule temperature from sensor signals.
Then it performs damping and range checks for
the measured values of these three variables and
sends signals to the AI function block.
6.3.1 Functional Block
Figure 6.1 presents the functional block of the
SENSOR transducer. The calculated values
of pressure/differential pressure, H-side static
pressure, L-side static pressure, and capsule
temperature are assigned to PRIMARY_VALUE,
SECONDARY_VALUE, TERTIARY_VALUE, CAP_
TEMP_VAL, AMP_TEMP_VAL, and FLG_TEMP_
VAL (option code: /DG1) respectively. Measured
values output to the AI function blocks are selected
by the Channel parameter of those blocks.
F0601.ai
PRIMARY_VALUE
(Channel1)
Sensor
signals
SECONDARY_VALUE
(Channel2)
TERTIARY_VALUE
(Channel3)
CAP_TEMP_VAL
(Channel4)
Pressure
/differential
pressure
calculation
Static
pressure
calculation
Damping
processing
Damping
processing
Range
check
Range
check
Range
check
Adjust-
ment
Adjust-
ment
Unit
Check
Unit
Check
H-side
static
pressure
L-side
static
pressure
Unit
Check
Capsule
temperature
calculation
AMP_TEMP_VAL
(Channel5)
Range
check
Unit
Check
Amplifier
temperature
calculation
Historical
records
Equipment
information
FLG_TEMP_VAL
(Channel6)
Range
check
Unit
Check
Flange
temperature
calculation
Figure 6.1 SENSOR Transducer Functional Block