Yokogawa EJX115A - Manual (Page 34)

<6. Explanation of Basic Items>
6-1
IM 01C25T04-01EN
6. Explanation of Basic Items
6.1 Outline
This chapter describes brief explanation of the
SENSOR transducer block, the LCD transducer
block, the AI function block, and the Totalizer
function block.
Actual mode
Many parameters require a change of the mode
of the function block to O/S (Out of Service) when
their data is changed. To change the mode of the
function block, its Target Mode (TARGET_MODE)
needs to be changed. The Actual Mode (MODE_
BLK) is comprised of the three sub-parameters
below:
(1) Actual (Actual mode):
Indicates the current operating condition.
(2) Permit (Permitted mode):
Indicates the operating condition that the block
is allowed to take.
(3) Normal (Normal mode):
Indicates the operating condition that the block
will usually take.
6.2 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.
6.2.1 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,
STATIC_PRESSURE_HIGH_VALUE, STATIC_
PRESSURE_LOW_VALUE, TEMPERATURE_
VALUE and, AMP_TEMP_VAL respectively.
Measured values output to the AI function blocks or
Totalizer function block are selected by the Channel
parameter of those blocks.
Pressure
Raw Value
Pressure
Value
Scale
In
Scale
Out
Primary
Value
Calculate Value Analog
Input 1
Analog
Input 2
Analog
Input 3
Totlizer
Static Pressure High Side Value
Static Pressure Low Side Value
Capsule Temperature
Amplifier Temperature
Pressure
Raw Value Unit Pressure Value Unit Primary Value Unit
Calculate Value Unit
Static Pressure Unit
Temperature Unit
Linear
User defined
(table)
Square root
Characterization
Type
Low Flow Cut Off
Simulation
Simulation
Value
Enable
Calculate
Coefficient
Channel
Sensor
signals
Disable
F0601.ai
Figure 6.1 SENSOR Transducer Functional Block