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Low-Cost Programmable Transmitters P5310, P5311 with LHP Communication
P5310, P5311
Low-Cost Programmable Transmitters
with LHP Communication
3.1 Application
Transmitters P5310 and P5311 are used for conversion of
a resistance or voltage temperature signal from a resistance
or thermocouple temperature sensor to a linearized current loop
output signal 4 to 20 mA. The transmitter type H1x is designed
for installation into an industrial sensor head type A or B
according to DIN 43729. Inputs and outputs of the transmitters
type P5310 are not galvanic-isolated, these types are suitable
for resistance temperature sensors and simple systems. The
transmitters type P5311 includes galvanic isolation of inputs
and outputs and are suitable for also in applications with many
measuring points and for thermocouples.
3.2 Description
Input signal, switched over according to the input configuration
are processed by an A/D transmitter and transformed into a
digital signal that is transferred to a micro-computer; according
to the preset configuration and after filtration of noise there
are calculated all measured variables. These values are then
used for calculation of the primary variable (temperature)
and according to selected range, the output current is also
calculated.
One resistance sensor (two-, three- or four-wire) can be
connected to the input. In case of a two-wire connection,
entering of a constant value of the loop resistance compensation
during configuration of the transmitter can compensate the
resistance of input leads. In other cases, the leads resistance
is compensated automatically.
A thermocouple can be also connected to the input. Temperature
of the thermocouple cold junction is compensated according
to configuration, either by the inner sensor of terminal block
temperature or by the entered constant temperature. The inner
sensor guarantees maximum accuracy and stability of cold
junction temperature measurement. If required, compensation
using an external sensor can be configured as well.
In addition to standard resistance sensors, there may be also
processed signals of potentiometer positions that are measured
in percents. One limit position is 0 % and the other is 100 %,
independently on the value of the total resistance. In case
there is necessary to measure position of the potentiometer
as a resistance, there may be used the configuration for
measurement of the resistance.
Output of the transmitter is analogue signal of the current loop
4 to 20 mA. The current output can be also used for testing
of the current loop and associated apparatus. Communication
is used mostly for configuration of the transmitter and is not
designed for distances over approx. 10 m. The transmitter can
be set up using a manual configurator LHPConf (HARTConf)
or a PC with the program LHPWinConf and HART modem
HARTMod (MH-02) or equivalent communication interface.
The transmitter communicates through an own protocol LHP
that is partially compatible with the protocol HART, uses the
same connection, however, communication is guaranteed
only for short distances and there are implemented only
few commands. This interface is designed for changes of
configuration. Continuous communication may influence
accuracy of measurement.
3. Product description
• One type of transmitter for all common resistance
and thermocouple sensors
• Linearized output signal 4 to 20 mA
• Accuracy from 0.1 % for ranges down to 1/5
of the basic range
• Span adjustability from 1 % to 100 %
of the basic range
• Galvanic isolation of input from output
1000 V AC (P5311)
• Adjustability by program LHPWinConf
and standard HART modem or by field
configurator LHPConf (HARTConf)
• High immunity against interference
(industrial environment)
• Intrinsically safe version
II 1GD
