SMAR LD291, Инструкция по эксплуатации и техническому обслуживанию

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Configuration
3.3
Configuration Features
By means of the HART

Configurator, the LD291 firmware allows the following configuration features to
be accessed:

Transmitter Identification and Manufacturing Data;

Primary Variable Trim – Pressure;

Primary Variable Trim – Current;

Transmitter Adjustment to the Working Range;

Engineering Unit Selection;

Linearization Table;

Device Configuration;

Equipment Maintenance.
The operations, which take place between the configurator and the transmitter do not interrupt the
Pressure measurement, and do not disturb the output signal. The configurator can be connected on the
same pair of wires as the 4-20 mA signal, up to 2 km away from the transmitter.
Manufacturing Data and Identification
The following information about the
LD291 manufacturing and identification data is available:
TAG -
8 character alphanumeric field for identification of the transmitter;
DESCRIPTOR
-
16 character alphanumeric field for additional identification of the transmitter. May be
used to identify service or location;
DATE - The date may be used to identify a relevant date as the last calibration, the next calibration or
the installation. The date is presented in the form of bytes where DD = [1,..31], MM = [1..12], AA =
[0,..255], where the effective year is calculated by [Year = 1900 + AA];
MESSAGE
- 32 character alphanumeric field for any other information, such as: the name of the person
who made the last calibration, some special care to be taken, or if a ladder is needed for accessing;
INTEGRAL METER – Installed, Inert, Special, Unknown and None;
SENSOR FLUID* - Silicone, Inert, Special, Unknown and None;
SENSOR ISOLATING DIAPHRAGM* - 316 SST, Hastelloy C, Monel, Tantalum and Special;
SENSOR TYPE* - It shows the sensor type;
SENSOR RANGE* - It shows the sensor range in engineering units chosen by user. See Configuration
Unit.
NOTE
Items marked with asterisk cannot be changed. They are read directly from the sensor memory.
Primary Variable Trim - Pressure
Pressure, defined as a Primary Variable, is determined from the sensor readout by means of a
conversion method. This method uses parameters obtained during the fabrication process. They
depend on the electric and mechanical characteristics of the sensor, and on the temperature change to
which the sensor is submitted. These parameters are recorded in the sensor's EEPROM memory.
When the sensor is connected to the transmitter, such information is made available to the transmitter's
microprocessor, which sets a relationship between the sensor signal and the measured pressure.
Sometimes, the pressure shown on the transmitter's display is different from the applied pressure. This
may be due to several reasons, among which the following can be mentioned: