IM 01C25T02-01E
6-4
6. EXPLANATION OF BASIC ITEMS
Adjustment of static pressure signal:
The zero/span adjustment function can be used for
static signals, as in the case of pressure /differential
pressure signals. However, the zero-point adjustment
by the external screw function is not supported for
static pressure signal.
Automatic adjustment
The value of the static pressure exerted on the point
where adjustment is to be made is assigned to param-
eters (CAL_SP_POINT_LO, CAL_SP_POINT_HI).
After this assignment is set, the amount of adjustment
is calculated by the transmitter and automatically
updated. The procedure for adjusting the static pressure
signal is the same as that of pressure/differential
pressure signal.
Manual adjustment
From the exerted pressure and the output of the
transmitter, calculate the amount of zero/span adjust-
ment manually and assign the calculated value to
parameters (CAL_SP_DEVIATION_LO,
CAL_SP_DEVIATION_HI).
Selection of static pressure signal type:
EJX series differential pressure transmitters measure
the absolute static pressure. Based on the assumption
that atmospheric pressure is constant, these transmitters
can output signal equivalent to gauge pressure calcu-
lated by deducting the atmospheric pressure (fixed
value) from the measured absolute pressure. The type
of static pressure signal output to
SECONDARY_VALUE and TERTIARY_VALUE is
selected in SP_VALUE_TYPE. SP_VALUE_TYPE
allows selection of gauge pressure or absolute pressure.
When selecting gauge pressure, set the value of the
atmospheric pressure (fixed value) to ATM_PRESS.
The default value of ATM_PRESS is equal to the
value of standard atmospheric pressure (101.325 kPa).
6.3.5 Functions Relating to Capsule and
Amplifier Temperature
Reference to capsule and amplifier temperature
value:
In CAP_TEMP_VAL and AMP_TEMP_VAL, it is
possible to refer to the capsule and amplifier tempera-
ture value and status. The update period of this value is
about 1 sec. The temperature unit is selected by
XD_SCALE.unit of the AI block, in which
CAP_TEMP_VAL is selected. The status is normally
Good-Non Specific. However, in the case of sensor
failure or out of measurement range, it turns to Bad or
Uncertain. For specifics, refer to Table 8.9.
Determination of the range limit of capsule tem-
perature:
The range of capsule temperature is from –40 to
120 !C. When the measured capsule temperature
deviates from –50 to 130 !C range, set the status of
CAP_TEMP_VAL to Uncertain-Sensor Conversion not
Accurate. The status under normal conditions is Good-
Non Specific. Also, set the status of PRIMARY_
VALUE, SECONDARY_VALUE and TERTIARY_
VALUE TO Uncertain-Subnormal.
Determination of the range limit of amplifier
temperature:
The range of amplifier temperature is from –40 to
120!C. When the measured amplifier temperature
deviates from –50 to 95!C range, set the status of
AMP_TEMP_VAL to Uncertain-Sensor Conversion
not Accurate. The status under normal conditions is
Good-Non Specific.
6.3.6 BLOCK_ERR
BLOCK_ERR presents the cause of an error in the
block. The SENSOR transducer block checks the
following causes and sets the relevant bits.
BLOCK_ERR
T0601.EPS
Bit Error Cause
1
7
13
15
other
other
Out-of-Service
Pressure sensor failure,
Capsule temperature
sensor failure
Electronic circuit failure
MODE_BLK.Target is O/S
other
Differential pressure
adjusted by zero/span
adjustment out of
measurement range,
Static pressure adjusted by
zero/span adjustment out
of measurement range
6.3.7 XD_ERROR
XD_ERROR is a parameter that contains codes for the
most significant errors that can occur in the SENSOR
transducer block. The errors of XD_ERROR supported
by EJX and their causes are presented in the table
below. When multiple errors occur and their error
codes are different, the error with a larger code value is
stored first.
XD_ERROR
T0602.EPS
Bit Error Cause
22 I/O Failure An I/O failure has occurred.
15
Out of Service
Sensor TB is in O/S mode.
20
Electronics
Failure
An electronic component has failed.
18
Calibration
error
An error occurred during calibration or a
calibration error has been detected.
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