JERGUSON Intelligent Displacer Level Transmitter

JERGUSON Intelligent Displacer Level Transmitter
Instruction manual IP2020
JERGUSON Intelligent Displacer
Level Transmitter
Installation, operation and
maintenance instructions
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CONTENTS
Page
1.0
1.1
1.2
1.3
1.4
OVERVIEW
Use
Basic operation
Calibration
Take care !
5
5
5
5
2.0
2.1
2.2
2.3
2.4
2.5
2.6
UNPACKING & INSTALLATION (Mechanical)
Unpacking
Mounting arrangements
Level Transmitter assembly
Transmitter range
Mounting on the vessel
Securing the LVDT cap
7
7
7
9
9
11
3.0
3.1
3.2
3.3
3.4
3.5
3.6
3.7
3.8
ELECTRICAL CONNECTION
Power Supply
Cable type and length
Cable gland
Connection
Safety Barriers
Lightning protection
Multi-drop installations
Final checks
4.0
4.1
4.2
4.3
COMMISSIONING
In-Situ commissioning
Local calibration adjustments at operating conditions
Zero, Span and Re-ranging
Damping
Customisation Using a SMART communicator
Adjustments to accommodate changes in process operating conditions
16
16
16
17
17
18
5.0
5.1
5.2
5.3
FAULT-FINDING
No output
Incorrect output
Display Module - Error messages
20
20
21
6.0
6.1
6.2
MAINTENANCE
Routine Maintenance
Spares
22
22
7.0
7.1
7.2
7.3
CK1 HANDHELD SMART COMMUNICATOR
Calibration adjustments at operating conditions
Further customisation using the SMART communicator
Adjustments to accomdate changes in process conditions using a SMART HHC
23
24
25
13
13
14
14
14
14
15
15
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APPENDICES
A
B
C
D
D1.0
D.2.0.
D.3.0.
D.4.0.
D.5.0.
D.6.0.
D.7.0.
D.8.0.
D.9.0.
D.10.0.
D.11.0.
D.12.0.
D.13.0.
D.14.0.
D.15.0.
D.16.0.
D17.0 .
D.18.0.
E
Model code information
Bolting torque details
Bench calibration
Handheld Communicator CK*
HHC Assembly
Notes
Requirements for SMART operation
How to connect the SMART communicator
HHC - Operation
Intrinsically safe SMART communicator
How to drive az Psion based SMART communicator
Introduction and FUNCTION menu
Keyboard Functions
Parameter List
Parameter Descriptions
Using the Non-linear profile facility
Safe, working, offline, default Registers
Error messages on the HHC
Current loop checks and trimming
Multidrop or Bus Operation
Unknown Instrument
SMART Interface - Compatibility
Block diagram / flowchart
26
27
28
31
31
31
33
33
34
34
35
39
42
43
45
57
63
68
71
73
76
77
78
FIGURES
Fig I
Fig II
Fig III
Fig IV
Fig V
Fig VI
Fig VII
Fig VIII
Main Components
Pressure tube assembly
Level transmitter components
Supporting the displacer element before mounting the head assembly
Securing the LVDT cap
Transmitter head with cover removed
Load .v. Voltage
Temperature graphs
Fig D1
Fig DII
Fig DIII
Fig DIV
Fig DV
Fig DVI
Fig DVII
Fig EI
CK*HHC assembly
Loop Diagram
PSION HHC menu str ucture
Linear vessel or sump
6
6
8
8
10
12
13
19
30
32
38 & 40
58
Memory Locations in Smart Communicator
Off Line memory transfers
Block diagram / Flowchart
3
64
66
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The Displacement Level Transmitter
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1.0.
OVERVIEW
1.1
Use: The Displacer Level Transmitter type will transmit a 4 – 20mA signal proportional to
liquid level or interface position over a simple 2 wire 24v dc power loop. The instrument is installed either
directly on the top of the vessel or in an external chamber, valved to the main vessel, such that the displacer
element is immersed in the liquid.
DT Series may be installed in a hazardous area. There are two designs of DT Series; one I.S. for
use in a suitable I.S. circuit, and one Flameproof/Explosionproof, suitable for connection to suitable stopper
glands and conduit. Always refer to the installation requirements stated on the enclosed certificates for
specific installation instructions. DT Series may, of course, be used in a non-hazardous area, where any local
wiring requirements apply.
1.2
Basic operation : The displacer, which is normally partially-immersed in the process fluid, is suspended
from an extension spring. The effective weight on this spring changes as the level of the process liquid rises
and falls on the displacer. This is predictable and depends upon the density of the liquid and the diameter of
the displacer. In turn the extension of the suspension spring will change as the weight suspended from it
changes. The core of an LVDT (Linear Variable Differential Transformer) is attached to the moving parts
suspended from the spring, and moves up and down in the pressure tube of the transmitter enclosure. An
LVDT is positioned on the pressure tube in the enclosure. The positional changes of the core in relation to
the LVDT will cause electrical changes which are interpreted by the transmitter electronics as changes of
liquid level.
1.3
Calibration : Each DT Series is factory calibrated to give optimum performance in the application conditions
advised at the time of order. Provided these conditions have not changed, the instrument will give accurate
readings of level at operating pressure, temperature and SG. Refer to sections 4 & 5 for details of recalibration if this is necessary.
1.4
Take care ! : The DT Series is an instrument, and should be handled with due care and attention at all times.
Mounting flanges can be heavy and difficult to handle. It is particularly important that the DT Series is not
damaged when installing on the vessel or chamber, and that the Installation instructions in section 2 are
carefully followed.
Thank you for choosing a Displacement level transmitter – correct installation and use will result in
many years of trouble free operation.
PLEASE NOW READ THE RELEVANT SECTIONS OF THIS MANUAL.
Footnote :- In this manual the following terms are used which refer to trademarks from other manufacturers:
HART: is the protocol adopted for the DT Series SMART Communications.
HART is a registered trademark of the HART Communications Foundation and is a mnemonic For
Highway Addressable Remote Transducer.
PSION: is the trade mark of PSION plc who manufacture the PSION ORGANISER
Hand held computer. The SMART program is stored in a DATAPAK which is also a
trademark of PSION plc, and is an accessory for the Model LZ Organiser
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Fig I : DT Series - main components
100mm Standard version
321mm H.T. version
Fig II :
Pressure tube assembly
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2.0
2.1
UNPACKING & INSTALLATION
Unpacking
The unit is supplied in three parts, usually in two packages. The larger package contains the control head and
spring/rod assembly. A second package contains the displacement element. Any mounting flange or
chamber will be packaged separately. Refer to Fig I.
After unpacking the control head check that the model code / Tag Number is the one expected for this
application (refer to Appendix A for model code explanation). Note that the head, the spring assembly and
the displacer element are a matched set. Components must not be mixed and matched between transmitters.
Each will be marked with the unique transmitter Final Assembly Number for identification.
If there are any queries, please refer to your local Agent , quoting the transmitter
Final Assembly Number and our order reference.
2.2
Mounting arrangements
2.2.1
External Chamber Mounting Transmitters.
If a chamber has been supplied, unpack and remove any packing or tie strings. Ensure that the chamber is
completely clean and fit to the mating vessel connections. The chamber should be mounted within 1.5 deg. to
the vertical, and the top flange should be checked with a spirit level to see it is horizontal.
Sometimes, when the DT Series is used on a chamber, there is not enough space above the upper liquid level
for its moving parts. In these situations an extension in the form of a stand pipe will have been supplied, and
this should now be fitted to the chamber using a suitable gasket or seal, ensuring once again that the top
flange is horizontal.
2.2.2.
Direct Mounting Transmitters.
2.2.2.1
Stilling tubes.
If there is a high degree of agitation in the vessel, such that the displacer element could be caused to swing or
bounce, then a stilling tube should be installed in the vessel. Ensure that the stilling tube has an internal
diameter large enough to allow free movement of the displacer element, and that a vent hole is drilled at the
top to prevent air-locks. The tube must be installed vertically so that the displacer element does not touch the
tube at any point.
2.2.2.2
Stand Off
Sometimes, when the DT Series is used on a vessel, there is not enough space above the upper liquid level for
its moving parts. In these situations an extension in the form of a stand pipe will have been supplied, and this
should now be fitted to the vessel using a suitable gasket or seal, ensuring that the top flange is horizontal.
2.3
Level transmitter assembly.
IMPORTANT NOTES.
It is strongly recommended that two people work together at this stage, particularly when installing
the instrument on the vessel.
Take great care not to bend the rod at any stage of installation. A bent rod will prevent your
DT Series from working.
Do not slacken any of the lock nuts on the rod assembly; these have all be present for your
application.
When unpacked, the enclosure will be free to rotate on the pressure tube assembly. This is to allow correct
orientation of the enclosure, conduit entry and display (if fitted) after installation. High pressure transmitters
will have been supplied with the head factory fitted and secured in the mounting flange. If a flange is
supplied separately, you should now screw the head into the mounting flange using a suitable thread sealant,
using the hexagon to tighten and effect the pressure seal. The thread is 1” NPT taper.
Next, fit the spring and rod assembly to the head. Make sure that the core, rod, and anti-friction sleeve are
free from any dirt or pieces of packing material. Remove any seal from the bottom of the pressure tube
assembly and gently pass the core into the pressure tube assembly. Carefully feed the rod into the tube,
avoiding the step reduction in diameter of the internal bore of the tube. (See Fig II).
Once inserted, check that the rod moves freely in the pressure tube, then screw the top of the upper spring
carrier onto the thread at the foot of the pressure tube. Assemble finger tight, then lock in position by
tightening the 3mm grub screw using a 1.5mm hexagonal key. (See Fig III)
The head assembly is now complete and no other adjustments need be made at this stage.
Your transmitter has already been factory calibrated for use at the operating conditions stated at the
time of order. Decide now if you wish to bench check the calibration of your transmitter at 20C, in which
case refer to Appendix C or if you want to mount your transmitter on the vessel and check calibration at
operating conditions, in which case please read on.
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LOCKING
TA B S
SPLIT PIN
Fig III : Level transmitter components
Fig IV : Supporting the displacer element
before mounting the head assembly.
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2.4
Checking the position of the transmitter range. (normal liquid application, not interface applications)
Before you mount the transmitter assembly into the vessel you may wish to check that the displacer element is
hanging at the correct level below the transmitter head.
Attach the chain at the top of the displacer element (See Fig.III) to the end of the spring rod using the split
pin provided. Locate the split pin in the third link down from the rod so that you have two unused links free
at the top. (Do not remove these free links or fully bend the pin legs at this time as you may need to remove
or re-position the displacer again later).
With the displacer element hanging in free air at 20C and the spring extended by the weight of the displacer,
measure the distance from the sealing face of the mounting flange to the bottom of the displacer, which is
called the “free hanging distance”. Include the thickness of any seals or gaskets.
This is the approximate distance below the sealing face of the flange which is factory calibrated to give a
4mA output from the transmitter in a normal level application, unless you requested otherwise at the time of
order. You can re-range later if you require – see Section 4.0. For interface applications it is not possible to
check the 4mA point without the upper liquid present.
Check that this dimension is correct to your requirements, ±5mm, particularly if you are mounting the
transmitter on a chamber. In this case, the dimension should be equal to the dimension from the chamber
mounting flange sealing face to the centre line of the bottom process connection bore, or around 30mm from
the bottom of the chamber for a side/bottom connection chamber.
There is some mechanical adjustment possible of the position of the displacer element below the top flange :
+/- 25mm. If the error is within this band, locate the small length (typically 5 links) of chain on which the
displacer element is suspended and adjust the number of links to correct the error. Do not cut any surplus
links from the chain. If the error is greater than ±25mm, refer to Magne-Sonic for assistance.
2.5
Mounting the transmitter on the vessel or chamber.
If you attached the displacer to the head as above, it is best to now disconnect the displacer from the rod,
leaving the chain attached to the displacer. Ensure that the chain is securely fixed to the displacer, checking
that the locknut is tight.
Lower the displacer into the vessel and slip the 5mm diameter support rod through the lowest link of the
chain so that the weight of the displacer is taken by the rod and the vessel mounting flange. See Fig.IV.
Remember that the enclosure is still free to rotate on the pressure tube at this stage.
Ensure a suitable gasket or seal is fitted to the mating flange and, holding the head vertical, attach the bottom
of the rod to the chain coupling. Bend the split pin legs to effect a permanent fixing. Taking the weight of
the displacer by hand, carefully withdraw the support rod and allow the displacer element to extend the
spring, lowering the element into the vessel. Do not allow the displacer weight to fall freely and damage the
spring.
Check that the displacer element does not foul on any part of the chamber or vessel.
Locate the transmitter flange on the mating flange so that the cable entry and display (if fitted) are facing the
way you require.
Fit the flange bolts and tighten to the recommended torque (see Appendix B) to achieve a pressure seal.
Check that the pressure tube is sufficiently tightened into the top flange, using the hexagons on the pressure
tube.
Rotate the enclosure to the exact position required and strike the tabs of the locking tab washer (see Fig.III)
under the enclosure base onto the hexagon flats of the pressure tube to prevent further rotation of the
enclosure on the pressure tube.
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Fig V : Securing the LVDT cap
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2.6
Securing the LVDT cap
The LVDT cap inside the enclosure leaves the factory free to rotate on the LVDT so that movement in
transit and during installation is not transmitted to the LVDT. The LVDT cap must now be secured in
position. (See Fig. V).
If the cover is in place, locate and unscrew the cover locking grub screw and unscrew the cover from the
base.
Locate and tighten the LVDT locknut at the top of the pressure tube against the top of the LVDT cap so
that it can no longer rotate on the LVDT. Remove the transit tape from the LVDT.
Refer now to wiring section or, if the transmitter is to be left in this condition for a period, check that the
cover seal is in good condition and re-fit the cover, then secure cover locking screw. Check any conduits are
suitably sealed against ingress of moisture.
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Fig VI : Transmitter head with cover removed.
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3.0
ELECTRICAL CONNECTION
The DT Series is a 2-wire dc loop-powered transmitter and requires a 24v dc nominal power supply.
Note that it is the responsibility of the installer to observe all local regulations and approval requirements, and
to use materials to suit the environmental conditions of the particular application. Check and obtain any
hazardous area work permits before applying power to the DT Series.
If you DT Series has been supplied with a Display module, note that you do not need to remove the cover of
the display for wiring. All field wiring is connected in the main head enclosure.
If the head cover is in place, locate and unscrew the cover locking grub screw and unscrew the cover from
the base.
Fig VI shows the layout inside the transmitter with the cover removed.
A terminal block is provided for power supply and screen connection, together with a pair of 2mm sockets
for connection of an ammeter to monitor the loop current.
There are 2 small sockets integrated into the terminal block for convenient connection of a Handheld
Communicator if required. (Use only an I.S. approved communicator if in a Hazardous area).
The small target and LED’s are used for bench calibration of the transmitter if required – refer to Section 4.0
Whilst the cover is removed, ensure that the 2 multi-way plugs are not disturbed in their sockets. (The plugs
will have been secured in their sockets at the factory with a sealing compound).
3.1
Power Supply
3.1.1.
Operating voltage
The DT Series will work satisfactorily provided the voltage at the transmitter terminals remains between 12
and 40V dc.
In considering the voltage of the power supply, allowance must be made for the voltage drop across any load
in series with the transmitter such as an indicator or the cable itself. The largest voltage drop will occur at the
maximum current which is 21mA under alarm conditions. See Fig.VII for a Load v Voltage graph which
defines the acceptable range of power supply voltages for any given installation.
Fig.VII : Load .v. Voltage
3.1.2.
Special Considerations for HART
If the HART communications facility built into the transmitter will be used at the time of installation or
during its future working life, then it is essential that a resistive load of at least 250 Ohms is connected in the
supply cable. This may be provided by other devices in the loop (Chart recorder, meter, etc.) or more usually
by installing a standard 270 Ohm 0.25W resistor in series with transmitter at the power supply. In this way the
master device will be able to signal to the transmitter without the power supply short-circuiting the data.
3.2
Cable type and length.
The cable should be single twisted pair shielded or multiple twisted pair with each pair shielded and an overall
shield to BS5308 or equivalent.
The terminal block will accept wire size up to 2.5mm2 (xzxSWG, 14AWG). It is recommended that the
minimum conductor size should be 1.0mm2 up to 5000ft total length and 20 AWG above 5000 ft., but the
user should always ensure that the voltage at the terminals is a minimum of 12v dc.
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3.2.1
Cable Capacitance
When used in Hazardous areas in an Intrinsically Safe circuit, refer to the Approval Pack supplied with this
transmitter for details of the maximum cable capacitance allowed.
3.2.2
Special considerations for HART
In addition, excessive cable capacitance will attenuate the HART signalling and so the capacitance must
anyway be limited if HART communications is to be used. The RC time constant for the network must not
exceed 650µs, e.g. if the network resistance is, say, 650W then the maximum network capacitance is 0.1µF.
HART transmitters are often given a Cn number where n is the multiple of 5000pF which the device presents
to the network. In the case of DT Series the value of n is 1 since its capacitance is well below 5000pF.
3.2.3.
Total loop resistance and capacitance
Additional equipment such as indicators or recorders may be inserted in the loop subject to the resistance and
capacitance limits discussed above.
3.2.4.
Multi-core cables
In multi-pair installations it is important that the other pairs do not interfere with the HART signalling – they
should only be used for other HART loops or for purely analogue signals.
3.2.5.
Cable trays
It is recommended that HART signal cables are not run alongside power cables.
3.3
Cable Gland
The cable gland entry thread is 1” NPT female – the enclosure is rated IP66 and so a suitable combination of
gland and cable should be selected. When used in a hazardous area, glands must comply with the relevant
Intrinsically Safe or Flameproof/Explosionproof requirements.
3.4
Connection
Connection of the supply cable is to the + and – terminals with the cable screen being connected to the ‘scn’
terminal. The cable screen should normally be earthed at the power supply end.
An external earth point is also provided.
3.5
Safety Barriers
In the case of passive barriers, allowance must be made for the additional voltage drop across the barrier
itself.
Care should be exercised in selecting a barrier or isolator especially if it will be necessary to pass HART
communications through the device.
Typical barriers are manufactured by :MTL
Stahl
Pepperl & Fuchs
Elcon
ABB
3.6
Lightning Protection
If local conditions dictate, it is recommended that a lightning suppresser is fitted. A typical manufacturer is
Telematic who can supply products suitable for IS as well as non-IS installations.
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3.7
Multi-drop installations ( DT Series in HART digital mode)
Up to 15 transmitters (unless in an I.S. loop – see below) may be connected in parallel with each other, and
each must be set to a different HART address between 1 and 15 (see Section vv). When HART transmitters
are connected in multi-drop mode, each transmitter draws a fixed current of 4mA, and allowance must be
made for the total maximum current that could be drawn (15 x 4mA = 60mA)
3.7.1.
Compatibility with other HART instruments.
Any 2-wire HART transmitter, regardless of the manufacturer, may be simply connected in parallel with
another to create a mutli-drop network. They may also be combined with separately powered, current
sourcing or sinking devices but care must be taken to ensure that the HART signal current passes through the
250W minimum impedance to establish communications. For full details of HART instrument availability,
refer to the HART Foundation publications or individual manufacturers literature.
3.7.2.
Intrinsically safe installations.
In multi-drop IS installations, typically a maximum of 5 transmitters may be connected to the loop in parallel,
thus limiting the current in the loop.
3.7.3.
Handheld Communicators
A handheld communicator (HHC) may be connected across the network (downstream of the minimum 250
Ohm loop resistance) to programme or interrogate a HART transmitter. Somme HHC’s support only a
subset of a transmitter’s functions, and will thus only access the transmitters Universal and Common Practice
commands. However, the DT Series is fully supportedby the Magne-Sonic CK!1 HHC and by the UNIVERSAL
275 HHC (provided the 275 is loaded with the transmitter’s Device Description – contact Magne-Sonic or
the HART Communications Foundation for details).
3.8
Final checks.
When all wiring is complete, check that the two multi-way plugs remain securely in their respective sockets.
Check that the cable gland is tightened into the conduit and a good seal is formed. If the transmitter is to be
commissioned at this point, refer now to Section 4.0. If not, check that the cover seal is in good condition,
then replace the cover and screw down fully to ensure the weatherproof rating of the enclosure is
maintained. (Do not attempt to overtighten as the torque you apply to the cover will be transmitted to the
pressure tube union and locking tab washer; these must not be loosened by overtightening of the cover).
Tighten the cover locking grub screw.
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4.0
COMMISSIONING
Your DT Series transmitter has been supplied calibrated to the requirements of the specific application advised
at the time of ordering. You should now refer to the Set-up Certificate supplied with the transmitter to check
this data is still valid.
If you wish to carry out some bench calibration or testing, refer now to Appendix C
4.1
In-Situ Commissioning
Important note : Some of the adjustments described below require the DT Series cover to be removed with
power on. Check and obtain any hazardous area work permits required before removing the cover.
4.1.2.
Initial power up
Turn on the power and check that the “Heartbeat” LED in the Caliplug beats at about once every 3 seconds.
If your transmitter is fitted with a display module, the display will show the software revision number (in the
format *.*), then change to show the measured value.
With the displacer element hanging on the spring and rod assembly, the displacer spring will be extended due
to the weight of the element hanging on it.
Your transmitter has been calibrated to give an accurate 4 – 20mA output proportional to level at a specific
set of operating conditions : SG, pressure and temperature. When experiencing these operating conditions,
the spring will behave differently to it’s normal performance in air at 20C, so the transmitter output at 20C
may not be as you expect.
The current output can be displayed on a milliameter connected at the two sockets provided or on the
HHC. However, if your transmitter has been calibrated for operation at temperatures above ambient,
you are likely to see higher values than this as the spring will be stiffer at 20C than at the operating
temperature, and hence the core is sitting higher in the LVDT coil. Once operating conditions are reached,
the spring will relax and the core will drop, giving an output of 4mA with the vessel empty.
4.2
Local calibration adjustments at operating conditions.
Once the vessel has reached process operating conditions, the following can be checked and adjusted if
required :If you wish to fine tune the 4 and 20mA points or to re-range the transmitter to give the 4-20mA output over
a different span, this can now be done. Note, the 4mA point can be positioned above the 20mA point to
reverse the operation of the transmitter, thus giving a falling current output with rising liquid level.
To maintain accuracy, it is recommended that the maximum turndown used is 3:1.
Zero level – 4mA point. With no liquid in the vessel, the output should be 4mA.
If the output is within 3.9 and 4.1mA, refer to 4.2.1 below to fine tune to exactly 4mA. If the output with
the vessel empty and at operating conditions is outside of these limits, it is likely that the position of the
LVDT in the transmitter head needs to be adjusted. Refer to Appendix C “LVDT Setting” before making
any further adjustments.
High level – 20mA point. This occurs with the displacer element almost fully covered with liquid (to within
10-15mm of the top of the parallel portion of the element), and the output should be 20mA.
These adjustments may be made locally with the Magnetic Scroller (MMS) and the Caliplug on the
transmitter (See Section 4.2.1. overleaf) , or may be made either locally or remotely using a SMART
Communicator (HHC) connected across the two wire loop. (For details of adjustments using the HHC, refer
now to Section 7.0).
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4.2.1.
Local calibration using the Magnetic Scroller (MMS) and the Caliplug with the transmitter at
operating pressure, temperature and SG.
4mA point : With the vessel empty or the liquid at the level required for 4mA output, insert the magnetic tip
of the MMS into the Caliplug port marked “Z”. Hold in until acceptance of the new setting is given by the
Caliplug LDD flashing at an increased rate of twice per second.
20mA point : With the liquid at the level required for 20mA output, insert the magnetic tip of the MMS into
the Caliplug port marked “S”. Hold in until acceptance of the new setting is given by the Caliplug LED
flashing at an increased rate of twice per second.
Ranging with a partially full vessel : If it is not possible to fill the vessel to the required 20mA level, the
transmitter can be ranged in a partially full vessel.
With liquid in the vessel at a level above the 4mA level, the current output can be incremented to a value that
represents this level. For example, with the vessel ¾ full, the current would be set at a value of 16mA.
Connect a milliammeter at the two sockets inside the enclosure.
To enter the ranging mode, hold the MMS on the small target icon on the internal nameplate for about 3
seconds. One (or both) of the 2 LED’s adjacent to the target icon will start to flash. Insert the magnetic tip
of the MMS into the “S” port of the Caliplug to increase the current out as shown on the milliammeter, or
the “Z” port to decrease the current at this level. Withdraw the MMS once the current level has been set to
the required level.
Hold the MMS on the target again to deactivate the LED’s and exit the ranging mode. Note, the instrument
will automatically exit the ranging mode if left for longer than 5 minutes.
Damping : The damping of the transmitter may be adjusted using the MMS and the Caliplug. The damping
value entered is actually a time constant in seconds which is applied as smoothing to the level reading and the
output current. A new value may be entered up to a value of 100 seconds. A large value will have the effect
of smoothing out rapid changes of level and will also smooth out the effects of turbulence. (It would be
highly unusual to select a value greater than 30 seconds.)
Insert the magnetic tip of the MMS into the “T” port of the Caliplug and hold in place for a number of
seconds equivalent to the damping that you require, noting that the LED flash rate increases to once per
second during setting of damping. Once the MMS is removed, the new damping value is set.
Your DT Series is now ready to operate.
Finally check all seals and conduits are in good condition and replace the transmitter head cover and secure
with the locking grub screw.
If you experience any unusual output or apparently faulty operation of your DT Series, refer to Section 4.3
“Adjustments to accommodate changes in process operating conditions and Section 5.0 “Fault finding”.
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4.3
Adjustments to accommodate changes in process operating conditions
It may be that actual process conditions are a little different to those envisaged at time of order and used to
set-up you DT Series.
Your DT Series has been factory set to give you the correct output under the operating conditions which you
quoted in your enquiry/order. If you intend to operate outside the parameters for which the DT Series has
been factory set, please read the notes below. These describe a variety of deviations and their implications.
Typical deviations are:
a.
b.
c.
d.
e.
f.
g.
More dense process liquid.
Less dense process liquid.
More dense upper liquid/gas.
Less dense upper liquid/gas.
Higher process temperature.
Lower process temperature.
The range is in the wrong place.
If you have a SMART HHC, the electronics can be reconfigured to accommodate different operating
conditions, but your working range may be affected. The transmitter output can be re-ranged, giving the
4-20mA output over the correct liquid level excursion, but this is achieved electronically by changing the
values of pre-programmed parameters. The base process value (PV) will still show as the true measured
value of the liquid level. Transmitter accuracy is little affected provided the process condition changes are
within the limits stated in each case. Refer now to Section 7.0 for details of how to make changes using the
HHC.
4.3.1.
Adjustments using the MMS to locally re-range the transmitter
Sometimes the effects of changed process operating conditions, provided that they are within the limits stated
in each case below, are minimal and simple re-ranging using the MMS tool to set new Zero and Span levels is
adequate.
Refer now to the various conditions below:-
a.
More dense process liquid.
Because the lift from the process liquid is increased, theoutput will show 100% (top level) when the
level in the vessel is below what you expect. We recommend that you accept this; re-ranging the DT Series to
give 20mA at full vessel conditions is not recommended as this may cause the LVDT to operate outside of its
calibrated range. At low level (0%) the output will correctly correspond with the level in the vessel.
b.
Less dense process liquid.
The lift from the process liquid is reduced and the output will never reach 100% (top level). The
process liquid will reach the top of the Displacer without providing the upthrust expected. The range will
thus be reduced at its top end. It is possible to re-range the DT SeriesL to output 20mA with the displacer
element fully covered in this less dense liquid refer to Section 4.2 on re-ranging. At low level (0%) the
DT Series output will correctly correspond with the level in the vessel.
c.
More dense upper liquid/gas.
The effect can be significant with an interface liquid, or where the gas above the process liquid is at a very
high pressure. The displacer will be covered by the process liquid at high level (100%) and at this point the
DT Series output will correspond with the level in the vessel. At the other extreme when the displacer is
entirely in the upper liquid/gas, the extra lift will cause the DT Series output to have a value higher than the
0% that you would expect from the level in the vessel. For example, when the interface reaches the bottom
of the displacer, the DT Series output might be 2%. If the interface falls further, no change in DT Series
output can occur. It is possible to re-range the DT Series to output 4mA (0%) when the displacer element is
covered with the more dense upper liquid or gas – refer to Section 4.2 on re-ranging.
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d.
Less dense upper liquid/gas
The displacer will be covered by the process liquid at high level (100%) and at this point the DT Series output
will correspond with the level in the vessel. At the other extreme, when the displacer is entirely in the upper
liquid/gas, the reduced lift will cause the DT Series output to give a value of 0% whilst the element is still
partially immersed in the lower liquid. We recommend that you accept this; re-ranging the DT Series to give
4mA (0%) when the displacer element is covered by the less dense upper liquid or gas is not recommended as
this may cause the LVDT to operate outside of its calibrated range.
e.
Higher process temperature.
The spring rate will be lower so the displacer will hang lower than it was designed to. The DT Series output
will indicate a lower level in the vessel than that which actually exists. This deviation will be greater at low
level than at high level. You should check from the graphs below, in Fig. VIII, that the new process
temperature does not require a longer Pressure Tube Assembly. If it does, talk to about what is best
to be done, otherwise the electronics will be damaged by excessive temperature.
Fig VIII : Temperature graphs
f.
Lower process temperature.
The spring rate will be higher so the displacer will hang higher than it was designed to. The DT Series output
will indicate a higher level in the vessel than that which actually exists. This deviation will be greater at low
level than at high level. Use the MMS to set zero at this point -–see Section NN. However, if the change in
process temperature from that quoted at time of order is greater than +/- 50C, the LVDT may operate
outside of its calibrated range at higher liquid levels.
g.
The range is in the wrong place.
Lengthening or shortening the suspension chain will put this right. Where the chain would need to be shorter
than one link, the only possibility is to fit a stand-off to the vessel/chamber.
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5.0
FAULT-FINDING & ERROR MESSAGES
5.1
No output
Check that the voltage at the transmitter terminals is greater than 12v dc.
Check that the polarity of the power applied is correct. (The DT Series is reverse polarity protected).
If the above is correct, check that the Caliplug LED is flashing at a frequency of about once every 3 seconds.
Check that the Caliplug connection lead is secure in its socket.
If a display is fitted, check that the display lead is secure in its socket and that the display is showing a reading.
If there is no Display or Caliplug LED activity, the DT Series should be returned to
local agent for repair or replacement.
5.2
your
Incorrect Output
If your DT Series does not have a display module fitted, but you are seeing an incorrect current output for a
known level in the tank, check the following:
Check that the correct displacer and spring/rod assembly have been fitted to the transmitter head. Each item
will be marked with the same Final Assembly Number (FAN). The FAN of the instrument can be found
from the Set-up Certificate supplied with each DT Series.
Check that the displacer element is hanging at the correct level below the transmitter mounting flange. Refer
to Section 2.4.
Check that the rod and core move freely in the pressure tube. A bent or damaged rod could result in sluggish
or incorrect output.
Check that the spring is not damaged. Any permanent deformation by over-extension will cause incorrect
readings.
Check that the liquid SG, operating pressure and temperature are all as given on the Set-up certificate. Some
site adjustments are possible. Refer to Section 4.3.
If the DT Series is assembled correctly and all components move freely, you should carry out a bench check as
detailed in Appendix C to ensure that the LVDT is positioned correctly.
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5.3
Display Module – Error Messages
The transmitter monitors its performance and reacts to any problems. If a display is fitted then a
description of the condition will be displayed. Additionally, for certain conditions, after a delay specified by
parameter P21, the current output will take the value as specified by parameter P22.
Only one alarm condition is displayed at any one time and so each has been allocated a priority. The table
below details the condition, its priority, its displayed code and whether it affects the current output.
Priority
1
2
3
4
5
6
7
8
9
10
Description
ROM Checksum Error
RAM Error
EEPROM Checksum Error
ADC reference too high
ADC reference too low
Sensor output too high
Sensor output too low
PV out of limits
Temperature out of limits
Current Saturated
Message
ROM
RAM
E²PROM
ADC H
ADC L
SO H
SO L
PV OL
°C OL
SAT
Current
Y
Y
Y
Y
Y
N
N
N
N
N
Message and action
5.3.1.
ROM, RAM, E2PROM, ADCH, ADCL
These are all error messages generated when internal self-checking reveals a fault. The DT Series should be
returned to your local agent for repair or replacement.
5.3.2.
SOH
This means that the core has travelled too high in the pressure tube and that the LVDT output is therefore
too high. Check that the displacer element is the correct element for this Transmitter. Carry out a bench
calibration to check that the LVDT is in the correct position. If the message only appears when there is
liquid in the vessel, check that the liquid SG is as expected and not too high.
5.3.3.
SOL
This means that the core is too low in the pressure tube and that the LVDT output is therefore too low.
Check that the displacer element is the correct element for this Transmitter. Carry out a bench calibration to
check that the LVDT is in the correct position. If the message only appears when there is liquid in the
vessel, check that the liquid SG is as expected and not too low.
5.3.4.
PVOL
Check as in SOH and SOL above.
5.3.5.
°COL
This indicates that the process temperature or a combination of the process and ambient temperatures have
resulted in the electronics becoming too hot or too cold. Using the HHC, check P46 and P47 to see the
maximum and minimum temperatures recorded. If the electronics has recorded a temperature
above 85°C then the electronics may have been permanently damaged. The DT Series should be returned to
your local agent for repair or replacement.
5.3.6.
SAT
This means the current output is saturated (outside the limits 3.8 to 20.5mA). Reset the 4 and 20mA points
using the MMS or a SMART HHC.
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6.0
MAINTENANCE
6.1
Routine Maintenance
There is very little maintenance required on the DT Series.
Take great care when removing the instrument from any vessel. This is a 2 man operation. The assembly
must be kept vertical when removing from the vessel to prevent damage to the spring and rod assembly.
Refer to Section 2.5.
All that need be checked during routine strip down is that the spring rod remains free to move in the pressure
tube and that any chamber or stilling tube is free of debris or build-up.
Refer to Section 2.5 when replacing the DT Series into the vessel.
6.2
Spares
The DT Series is a factory built instrument and there are no spare parts that can be fitted in the field. Should
the DT Series require any repair or replacement parts, it must be returned
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7.0
SMART COMMUNICATION
With a SMART HHC, you can make adjustments and calibrate at any point on the two wire
connection to the transmitter. You can also make many other adjustments and obtain operational and
diagnostic information using the HHC.
Alternatively, have a PC based software package calle H-View which allows you to make
adjustments and obtain readings through a standard PC. Contact your local agent for details.
If you have a CK HHC (Psion Organiser based) and the appropriate datapak, refer now to
Appendix D for details of assembly, connection and menu structure before reading on to the specific
adjustments listed below.
If you have another type of SMART communicator or computer based software tool, you must ensure that
the Device Description (DD) is correctly loaded or compiled to gain access to all of the MLT
parameters. If you do not have the DD loaded, you will only be able to access the Universal and
Common Practice commands.
Contact any HART Host Subscriber to update your communication device with the
latest DD.
The transmitter is a SMART instrument using the HART protocol to communicate with external
devices.
The HHC is a hand-held organiser based communication device fitted with a HART interface to
allow communication with HART instruments.
By connecting the HHC across the two wire loop at any point downstream of the minimum 250 Ohm loop
resistance, communication can be established. The terminal block of the DT Series has integral 2mm sockets
provided for this purpose.
Refer to Appendix D3.0 for details of HHC connection and operation.
The following paragraph details how to re-range and change damping using the HHC once communication
with the DT Series has been established.
7.1
Calibration adjustments at operating conditions.
Important note : Making changes to the position or span of the 4-20mA range with a communicator can
cause the transmitter to make step changes in the output. You should arrange to set your plant control loop
to “Manual” before making changes if this could be a problem.
7.1.1.
4mA point – from the “Program” menu / “Calibrate” sub-menu, access Parameter P16. The factory default
value is “0”.
Enter the desired new value of the PV (Process Value), normally the level in metres, required to give a 4mA
output, and confirm when prompted by pressing the “exe” key that this is correct. The new value is now
entered and saved.
Note, the 4mA point can be positioned above the 20mA point to reverse the operation of the transmitter,
thus giving a falling current output with rising liquid level.
7.1.2.
20mA point – from the “Program” menu / “Calibrate” sub-menu, access Parameter P15. The factory default
value is “A”. This represents “Automatic” and in this case means that the 20mA point is automatically set to
the maximum range of the transmitter. For example, a transmitter with a range of 600mm leaves the factory
with the 20mA point set at 0.6m.
Enter the desired new value of the PV (Process Value), normally the level in metres, required to give a 20mA
output, and confirm when prompted by pressing the “exe” key that this is correct. The new value is now
entered and saved.
7.1.3.
Damping – from the “Program” menu / “Engineer” sub-menu, access parameter P20. The factory default
value is 5s.
Enter the desired new value in seconds and press “exe” to confirm and save the new value.
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7.2
Further customisation using the SMART HHC
There are some other features of the transmitter that can be changed at this stage:
7.2.1.
Identity
The following parameters can be recalled from the “Program” menu / “Identity” sub-menu, and those shown
* below can be site configured :P00
P01
P02
P03
P04
P05
P06
MESSAGE
TAG
DESCRIPTION
DATE
FINAL ASSY No.
SENSOR SERIAL No
PASSWORD
*general purpose 32 character message
*transmitter identifier (8 characters)
*E.G. transmitter application or location (16 char)
Automatically updated on exit if changes made
Factory set – hardware assembly number
Factory set – LVDT serial number
* 3 level password system.
Simply enter any message or tag number as appropriate and the transmitter will retain this information in
memory for future identification. This is particularly useful if you are likely to interrogate the transmitter
using the HHC from a remote location.
Refer to Appendix D for more detailed information.
7.2.2.
Display
The display, if fitted, can be programmed to show specific information. The digital display is capable of
displaying two values; it will alternate between the value for “display 1” set on P23 and “display 2” set on
P24, accessible through the “Program” menu / “Engineering” sub-menu. The options available are fully
listed in Appendix D.
A typical configuration might be to alternate the measured level with the mA current output, useful during
commissioning. Once set up, the display may be changed back to show the measured level or, if more useful,
the percentage level.
7.2.3
Alarm delay time and action
The time elapsed before an alarm is signalled can be set in seconds on P21, accessible through the “Program”
menu / “Engineering” sub-menu.
The default time is 5s, but you may change this within the limits 1s to 1000s. It is unlikely you will need to set
a time greater than 30s.
The action taken after the delay time has elapsed can be selected using P22, accessible through the “Program”
menu / “Engineering” sub-menu. The default action on the current output is to hold the last reading, but
you may change this to drive to either 3.6mA or 21mA so that a control device can detect the alarm incident.
Refer to Appendix D for more detailed information.
7.2.4.
Units of Operation and Display
The units displayed on the display (if fitted) or the HHC when used can be changed from the default
“metres” using P12 accessible through the “Program” menu / “Calibrate” sub-menu.
Note that the numerical value of PV – the actual measurement of liquid level – will not change when the
display units are changed. To change from the default PV measurement in metres, use P13 Scaling Factor.
Refer to Appendix D for more detailed information.
7.2.5.
Standing Value
If there will still be liquid in the vessel when the displacer element is fully uncovered, the reading can be
adjusted to show this by adding the amount of the liquid remaining to the measured value. The PV of the
liquid, entered in the PV units defined on P12 and P13, is entered on P14, accessible through the “Program”
menu / “Calibrate” sub-menu.
7.2.6.
Non-liner Profiling
For applications where the relationship between height and contents is not linear, such as in a cylindrical tank
on its side, the DT Series can be programmed with a look-up table so that the microprocessor can convert
height to contents. The DT Series is factory programmed with a suite of standard tank shapes which may be
called up on P11, or the data for a custom look-up table is entered by the user on P30-P39, accessible
through the “Program” menu / “Special-P” sub-menu.
Refer to Appendix D12.0 for more detailed information.
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7.3
Adjustments to accommodate changes in process operating conditions using a SMART HHC.
7.3.1.
Temperature change
Changes in operating temperature cause the wetside assembly to hang at a different level than that planned.
The effect of the new temperature on the spring rate can be corrected by programming in the new operating
temperature on P25, accessible through the “Program” menu / “Engineering” sub-menu. This new value is
then used by the microprocessor to accurately calculate the level.
7.3.2
SG difference
The effects of SG change can be corrected by programming in the new operating SG on P26 (Lower fluid
SG) and P27 (Upper fluid SG), accessible through the “Program” menu / “Engineering” sub-menu.
An SG change of the lower liquid to an SG greater than originally programmed in will cause a 20mA output
to occur before the displacer element is fully covered. Programming in the new SG will correct this so that
the correct current output is given, but note that if the change in the lower SG from that used to factory
calibrate the instrument is greater than 10%, the output may become non-linear if the core operates outside
of the calibrated range of the LVDT.
Conversely, if the operating SG of the lower liquid is lower than the SG originally programmed in, the core
will not travel high enough to give a full 20mA output. Programming in the new operating SG will correct
this, effectively re-scaling the output to be correct. There is no danger in this instance of a non-linear output.
Changes in the upper SG will have the opposite effect to those described above.
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Installation, Operation and Maintenance Instructions • Displacer Level Transmitter
ORDERING INFORMATION
JDT
JDT
DISPLACER TRANSMITTER
CODE MATERIAL
C
Carbon Steel
S
316 SST
CODE ANSI RATING
0
150# R.F. ANSI
3
900# R.F. ANSI
1
300# R.F. ANSI
4
1500# RTJ ANSI
2
600# R.F. ANSI
5
2500# RTJ ANSI
CODE ENCLOSURES
F
Explosion proof Cl. I, Div. 1
S
EEx ia (CENELEC) I.S.
Grps. B, C & D
CODE TEMPERATURE RANGE – Select from Chart on page 3
A
Standard temperature
B
High temperature
CODE DISPLAY
N
Without display
D
With display
CODE CHAMBER – Type & Orientation
A
Not required – Top Mount Flanged
B
Side/bottom with no vent
C
Side/bottom with 1/2" NPT vent
D
Side/bottom with 3/4" NTP vent
F
Side/bottom with 3/4" flanged vent
G
Side/side with 1/2" NPT drain & no vent
H
Side/side with 3/4" NPT drain & no vent
J
Side/side with 1" NPT drain & no vent (std.)
K
Side/side with 1/2" NPT drain & vent
L
Side/side with 3/4" NPT drain & vent
M
Side/side with 1" NPT drain & vent
N
Side/side with 3/4" drain & no vent
P
Side/side with 3/4" flanged drain & 3/4" NPT vent
Q
Side/side with 3/4" flanged drain & 3/4" flanged vent
PROCESS CONNECTIONS
CODE CHAMBERED
CODE TOP MOUNTED
01
Screwed 1" NPT
60
3" 150# R.F. ANSI
02
1" Socket Weld
61
3" 300# R.F. ANSI
11
1" ANSI #150 RF
62
3" 600# R.F. ANSI
12
1" ANSI #300 RF
65
4" 150# R.F. ANSI
13
1" ANSI #600 RF
66
4" 300# R.F. ANSI
14
1" ANSI #900 RF
67
4" 600# R.F. ANSI
18
1" ANSI #1500 RTJ
69
6" 150# R.F. ANSi
21
1 1/2" ANSI #150 RF
80
2 1/2" NPT
3" NPT
22
1 1/2" ANSI #300 RF
90
23
1 1/2" ANSI #600 RF
24
1 1/2" ANSI #900 RF
28
1 1/2" ANSI #1500 RTJ
31
2" ANSI #150 RF
32
2" ANSI #300 RF
33
2" ANSI #600 RF
34
2" ANSI #900 RF
38
2" ANSI #1500 RTJ
C
O
F
A
N
B
01
26
TYPICAL MODEL NUMBER
Appendix B
Bolting tor
que details : Carbon steel bolts only
torque
Min torques in Nm (lbf.ft) Max torque = min + 10%
IMPORTANT :For use with carbon steel bolts only
If ordinary carbon steel or similar lower quality bolts are used the torques recommended are as shown
below.
The gasket sealing force created by the application of these torques is not sufficient to withstand full
flange pressure rating. To achieve full rating, use high tensile steel bolts as below.
If in doubt about your bolt/sealing application consult your engineering department or gasket
manufacturer.
Flange
3"
4"
6"
Flange
DN65
DN80
DN100
DN125
DN150
#150
54 (40)
54 (40)
95 (70)
#300
95 (70)
95 (70)
PN16
58 (43)
58 (43)
58 (43)
58 (43)
113 (83)
PN40
58 (43)
58 (43)
113 (83)
194 (143)
194 (143)
20 (15)
20 (15)
A
G
Bolt torques for SPIRAL WOUND gaskets with
a compression stop: high tensile steel bolts only.
Bolt size
Nm
lbf.ft
5/8''
3/4''
7/8''
1''
1 - 1/8''
1 - 1/4''
122
203
325
499
722
101
90
150
240
368
533
750
Gasket compression for joints without
compression stops: high tensile steel bolts only.
Initial gasket
thickness
1.6mm
2.5mm
3.2mm
4.4mm
6.4mm
Compressed
thickness
1.3/1.4mm
1.9/2.0mm
2.3/2.5mm
3.2/3.4mm
4.6/5.1mm
Compression
0.2/0.3mm
0.5/0.6mm
0.7/0.9mm
1.0/1.2mm
1.3/1.8mm
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Appendix C
C.
C.1.0
Bench checking - LVDT setting (20C)
Using the Set-Up Certificate
Refer to the Set-up Certificate and read the value of the weight that must be hung on the spring to simulate a
mid point or Null position of the core in the LVDT.
Remove the displacer element and chain (noting which chain link is used to hang the element) and hang the
weight in place.
Hold the magnetic tip of the Magnetic Scroller (MMS) against the small target icon on the internal
nameplate for about 3 seconds. If the LVDT cap is in the correct position, the two LED’s adjacent to the
target will flash alternately.
If adjustment is required, only 1 of the LEDs will flash. Slacken the locknut at the top of the LVDT cap.
Note which LED is flashing and slowly turn the LVDT cap in the direction of the arrow against the flashing
LED until both LEDs flash alternately.
The LVDT cap can now be re-secured in position. Tighten the LVDT locknut at the top of the pressure tube
against the top of the LVDT casing so that the cap can no longer rotate on the LVDT.
To exit this mode, hold the MMS against the target for a few seconds and the LEDs will cease flashing. If
left, the instrument will automatically exit this mode after a period of about 4 minutes.
Re-fit the Displacer element and chain assembly using the correct chain link, and ensure the locking nut on
the chain adaptor is securely tightened.
C.2.0
Calibration check using water at 20°C
It is possible to check the transmitter output if the vessel or system is to be filled with water at any time.
Refer now to the Set-up Certificate where you will find a graph / chart showing the mA output for a given
water level at 20°C. Simply immerse the displacer element in water to the given level and check that the
output is as stated.
C.3.0.
The Calibration Certificate
If requested at the time of order, a Calibration Certificate will have been supplied with your DT Series.
This certificate is NAMAS traceable and shows the transmitter mA output for a given weight applied to the
spring. (This weight is equivalent to the displacer downforce in grams applied). When calibrating your
transmitter in accordance with this certificate, you must use suitably calibrated and certified weights and
instruments at the ambient temperature shown on the certificate to replicate the transmitter outputs stated.
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Fig D1 CK* HHC assembly
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Appendix D
D.
D.1.0.
HANDHELD COMMUNICATOR –
CK*
Hand Held Communicator – Assembly Instructions
The CK* SMART Hand Held Communicator is supplied as a kit of items (Figure DI) which are
assembled as follows:
D.1.1
Remove the lower sliding cover (1) of the Psion organiser (2) completely to expose the battery compartment
lid (3) at the base of the keypad, and the two slots for Datapaks behind the right hand side of the keypad.
D.1.2
Remove the lower of the two blank Datapak mouldings and insert the preprogrammed SMART
Datapak (4), pressing the unit home. This lower slot is the “C” slot in Psion Organiser memory.
D.1.3
Remove the battery compartment lid (3) and insert the 9V battery (5), positive terminal first. Replace the
battery compartment lid (3) and the lower sliding cover (1) over the base of the Psion Organiser. Leave the
keyboard exposed.
D.1.4
At the top of the Psion Organiser above the LCD, slide the cover across to the right to expose the connector.
Insert the SMART interface unit (6) in this slot.
D.1.5
The lead used to connect the cabling is plugged into the SMART interface unit. On the
CK1 and CK3 this is via a 3.5mm jack plug. On the -CK2 a multi pin plug is used.
The latter also has the hook-on connectors built into the leads instead of push on crocodile clips.
D.1.6
The SMART Interface Unit has another socket at the top left hand side for connection of a
standard Psion external power unit as an alternative to battery operation.
D.2.0.
Notes
D.2.1
Although it is possible to insert two Datapaks into the HHC, this is not recommended as a conflict between
them can occur.
D.2.2
The CK* Datapaks enable communication with both MSP100 ultrasonic level transmitters and
DT Series displacement level transmitters, and also gives generic support for all other HART transmitters.
D.2.3
When not in use, remove the SMART Interface unit from the HHC to prolong battery life.
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Fig DII. : Loop diagram
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D.3.0.
Requirements for SMART Operation (Refer to Fig. DII)
D.3.1
The Displacer transmitter requires a DC supply voltage of 12 volts at its terminals for satisfactory
operation (V3).
D.3.2
Resistance between any two SMART Interface connection points must exceed 250 ohms. (R1).
D.3.3
For the minimum DC supply voltage (V1) to be calculated, the voltage drops in the loop at 20mA must be
assessed. The absolute minimum value of V1 will therefore be 17 volts, since 5 volts is required for the
voltage drop across R1 at 20mA. (See Note 2 below).
D.3.4
If R1 is 250 ohms or more the SMART communicator can be connected between B1-B2, or C1-C2, or D1D2 or E1-E2. It is also allowable to connect across the SMART Load resistor R1, on B1-A1, or across any
resistance in the circuit that exceeds 250 ohms.
D.3.5
The standard CK1 SMART communicator cannot be taken into a hazardous area, so should not be
used at points D1-D2 and E1-E2 unless no hazard exists. The CK2 or an MTL 611 fitted with a
CK4 Datapak can be connected at these points in the hazardous area.
D.3.6
The current loop load resistance R2 can be considered to be part of the 250 ohms needed as the SMART
Load resistor. In this case R1 + R2 must exceed 250 ohms, and the communicator can be connected between
C1-C2, D1-D2, E1-E2, or C1-A1.
Technical Notes:
1.
At no time can the SMART communicator be attached across A1-A2, since the DC supply effectively short
circuits the transmitted and returned digital communications signals.
.2.
The minimum DC Voltage V1 required for satisfactory 20mA loop operation can be calculated from the
formula –
V1 > 12 + V2 + [20 x 10-3 x (R1 + R2 + R3 + R4 +R5)
D.3.6.3. An alternative way of looking at this voltage requirement is in terms of the maximum loop resistance that can
be tolerated, which has to be less than (V1 – V2 – 12) x 50 ohms.
The maximum allowable value for VI is 40 Volts in terms of the transmitter : any zener barriers will
define alower maximum voltage level.
D.3.6.4. The HART protocol itself sets the maximum values that can apply to the loop resistances, labelled R1 to R5.
The total load on the loop (R1 + R2 + R3 + R4) must not exceed 1100 ohms.
In addition the maximum length of cable in a loop working on the HART protocol is specified as 3000
metres on a single screened loop cable, or 1500 metres if multicore multi-loop cabling is used.
D.4.0.
How to connect the SMART Communicator
Assemble the Psion based SMART Communicator unit as shown in Fig. DI fitting the battery, 100 SMART
Datapak, SMART Interface unit and lead. The push on crocodile clips are optional.
Power the Transmitter from a DC supply as shown in Figure DII. A 250 ohm (or higher value) load
resistance must be incorporated in the loop.
The SMART Communicator is self powered and draws no current from the loop.
The two wires from the SMART Communicator are interchangeable – it does not matter which way round
they are connected.
a)
These two wires can be plugged into the terminal block inside the lid of the transmitter, using the 2mm
plug connectors provided on the CK1 or CK3. They are connected to terminals + and – i.e. in
parallel with the DT Series.
b)
Alternatively connection can be made via the crocodile clips or hook on probes to each wire of the 2 wire
current loop at a convenient terminal box or strip.
c)
At the control room the two wires can be connected either across the “SMART” Load resistor or between a
terminal on the chart recorder/indicator and the other side of the loop.
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D.5.0.
Hand Held Communicator : Operation
Language
Initially the Psion Organiser will power up and display the Psion Copyright message, when the ON button is
pressed. Then a choice of languages will be offered. This applies to the operation of the Psion Organiser
functions only, DT Series programme, although Datapaks will be available in different
languages.
DT Series Programme
The main menu selection of the Psion Organiser is automatically amended to include the option
when the Datapak is fitted. This cannot be permanently repositioned nor deleted.
Time
The only data in the Psion Organiser used by the programme is the date held in the Organiser
memory. On making changes to an DT Series the date will be stored in the transmitter
microprocessor, as shown by the Psion Organiser. To set this clock, select TIME, press MODE, select SET,
and use the arrows to select the correct date and time on the display. Then press EXE to start the clock, and
ON/CLEAR to return to the main menu.
Disconnecting SMART Interface
To disconnect the interface unit it is necessary to press down the catch in the top centre face of the unit to
release the lock, when the interface can be pulled vertically away. The Psion programme knows when the
interface is not present and will no longer seek to find an instrument connected – it will only allow
OFFLINE programming. Naturally, no diagnostic parameters are made available.
Note : Programme Lock-up
This will occur if the interface unit is disconnected from the Psion before it has finished all communications,
or as a function of the Psion ON button features. The LCD is frozen:
D6.0
a)
Reconnect the interface unit, to allow completion of the procedure.
b)
If the Lock-up has occurred after pressing the ON/CLEAR button, it probably results from the
Psion Organiser “CLEAR” function which stops/freezes all programmes running at the time. The
programme can be restarted by pressing any button again (except Q).
c)
If the Lock-up occurs as a result of an incomplete procedure, there is no easy release process. The
LCD on the SMART Communicator is frozen. Once the buffer store for instructions has been filled
with 16 command key instructions, a bell like sound is made when any further button is pressed.
The best escape route is to remove the battery to totally clear the memory of the Psion. Beware that
this will also clear the date, diary and alarm memories of the Psion Organiser itself. Clearing the
memory occurs after approx. 30 seconds with no battery, or immediately on pressing ON/CLEAR
after the battery has been removed.
Intrinsically safe SMART Communicator
The CK2 SMART Communications kit is based on the intrinsically safe MTL 611 (a variant of the
Psion LZ) with an intrinsically safe DT CNF41 SMART HART Protocol Interface and a specially
programmed IS Datapak for the Transmitter.
This can be treated exactly the same as the standard Communications kit and the programme is as described
in this manual. If fitted with the correct battery this unit is certified intrinsically safe, and can be used in a
Zone 1 hazardous area. It can therefore be used to communicate with a transmitter using the D1D2 or E1-E2 connection points quoted in Fig. DII even when these are in Zone 1.
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D.7.0
How to drive a Psion based SMART Communicator
Familiarity with the Psion
The Psion is supplied with several manuals to described its function. The main keyboard functions that are
important are the yellow keys. Press “ON” and see the functions of the arrows to move the cursor around
the selections in the menu. Press “EXE” to see the Psion functions. Note that a short cut to selecting a
menu item is to press the key with the initial letter of the required selection – for example “O” switches the
unit “OFF”.
Note that if the “CALC” option is selected, the keyboard changes from the “Alphabet” marked on the keys,
to the “numbers” and symbols marked above the keys. The Psion selects the expected function required of
the keyboard. This function can be changed back by depressing the “SHIFT” key.
Menu
If “Magne-Sonic” is selected from the start up menu on the Psion, by pressing “EXE” the space available in the
A memory of the Psion is checked. If there is insufficient then a message is displayed and the program
returns to the main menu. Data, Note Pad or Diary files in A must be removed to allow the program to run.
The SMART Communicator then establishes whether the SMART interface unit is plugged in or not.
MOBREY
Diary
Notes
Find
Calc
World
10:41
Save
Time
Alarm
When the SMART interface is not connected, the Communicator does not look for an instrument – it offers
OFF-LINE programming (Refer to……..NOTE RE SELECT INSTRUMENT).
When the SMART interface is connected to the Psion, on selecting the “Magne-Sonic” menu item the
programme seeks an instrument that is expected to be functioning on a 4-20mA loop (the loop that is
expected to be connected to the SMART interface cables).
MOBREY V3.1
SEEKING INSTRUMENT
PLEASE WAIT
If the loop is not powered, or the interface cables are not properly connected to the loop, or the loop
impedance/resistance values are incorrect, the unit will fail to find the transmitter.
NO SINGLE LOOP
INSTRUMENT CONNECTED
RETRY (Y)es or (N)o
If the transmitter is programmed to respond as a numbered sensor on a multi sensor loop, it will
also fail to communicate to the SMART communicator at this point. (See multidrop operation Section
D16.0).
When an Transmitter is located on the loop, this is identified and further instructions awaited.
MLT100
FOUND
TAG
TANK 1
ACCESS (Y)es or (N)o
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Alternatively an Unknown Instrument may have been found, i.e. a HART instrument that is not a DT Series or
MSP100 (see section 3.6 for further details). This will cause a similar message and prompt to be displayed.
UNKNOWN INSTRUMENT
TAG FLOW1
ACCESS (Y)es or (N)o
In either case pressing “Y” will cause the following prompt to be displayed:
UPLOAD ALL
PARAMETERS
NOW?
(Y)es or (N)o
Pressing “Y” will result in all the parameters being read into the HHC. If “N” is pressed then the delay
imposed by a full upload can be avoided. If parameters in the D0 to D8 and P0 to P69 are accessed later on
all the parameters in that group will be uploaded. Thus only the parameters of interest need to be uploaded,
with the minimum delay. A full upload must be done at some stage if the parameters in the instrument are
saved, printed, or used to program another instrument.
The asterisks show each transfer of digital information. If one transfer is incorrect, or corrupted, the
Communicator will advise and ask for an action decision – an example of one of these error messages is –
NO RESPONSE FROM
TRANSMITTER
RETRY (Y)es or (N)o
A retry will attempt to obtain the same data again, whereas the “No” decision will jump that data transfer and
collect the next set of data, to try to gain whatever information is available. The data loaded in the Working
register for the missing parameters will be the default values, instead of those present in the instrument.
Typically, a full upload data collection time is between 30 and 45 seconds.
The main screen describing the equipment now gives transmitter identify information – i.e.
MLT100
TAG TANK ALL
MLT100 XDUCER
ACCEPT (Y)es or (N)o
Line 2 of the display is the Tag number loaded as Parameter 01, and Line 3 is the Description loaded into
P02. If this is not acceptable the program suggests a return to the Psion menu functions. If it is acceptable,
pressing the Y button will give access to the FUNCTION menu of the Program. The
transmitter parameters are now loaded into the SMART Communicator (Psion Organiser) memory in the
WORKING Register.
Future work on this data can be carried out whilst the SMART communicator is connected to the loop, in
which case all changes will be immediately sent to the DT Series, or after disconnection of the Communicator,
in which case the amended programme will have to be stored in the “OFFLINE” register of the
communicator.
The Psion Organiser has four separate registers of data relating to the transmitter. These registers
are named WORKING, SAFE, OFF-LINE and DEFAULT, and are explained in Section D13.0. All changes
and operations occur in the Working Register, identified by W on the right hand end of line 2 on the display.
The other registers are for storage and transfer of data between transmitters or for reference.
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Chart DIII : PSION HHC menu structure
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Microprocessor Parameters
D8.0
Introduction and FUNCTION menu
The microprocessor in the transmitter retains the calibration required for the particular application
or tank involved, once this has been entered into the memory (EEPROM). On the initial interrogation of the
transmitter, this information is transferred to the SMART Communicator using the HART protocol, which
defines the command structure and message format.
When received by the SMART Communicator, these messages are loaded into the WORKING register
(which resides in the Psion Organiser memory), which then adds the descriptions and other information
shown on the 4 line liquid crystal display. The operator is presented with the information he requested, in a
meaningful format in relation to the application.
The first selections of the transmitter programme use a menu structure, where the operator
identifies the part of the programme required from a list of options available. The detailed information
under each menu item can be inspected, after selection, by scrolling through the listing. Each item is given an
identifier in the top right hand corner of the screen, identified by a parameter reference number, to allow
accurate recording of the data interrogated and to simplify communications relating to this data.
The programme is divided into two main sets of data, selected from the FUNCTION menu. The
FUNCTION menu is the first programme screen presented when the data from the transmitter is accepted
and interrogation is to begin.
***** FUNCTION *****
Monitor
Program
Backup
Fixed data
D**
Help
The structure of the programme built around this display screen is shown in Chart DIII.
MONITOR – The data presented on selecting MONITOR is the live “read only” information from the
transmitter, for example the liquid level in the tank, and the value of the current output. These parameters
are labelled D, for Display information parameters, and are indexed between D10 and D25. The Display
parameters are described and listed in Section D10.0
PROGRAM – The data presented on selecting PROGRAM is the operator adjustable data used to configure
the transmitter for the particular application. These are “read/write” parameters, labelled P for Program
parameter, and are indexed from P00 to P69. The Program parameters are described and listed in Section
D10.0
FIXED DATA – These are the factory preset display parameters, identifying the equipment type,
serial number, software information, etc.
BACK UP – This menu item controls the transfer of data between registers or a file available in the Psion
Organiser memory: operation is described in Section D13.0.
D** - Allows direct access to a Display parameter by entering the relevant code number.
HELP – The HELP information display screens give some introductory advice on the use of the keys on the
Psion Organiser and the Programme structure.
D8.1
Monitor/Display Parameters – D**
Access and programme structure
The Display Parameters (D**) are separated into three blocks giving three types of operator read only
information. These are shown in Fig. DIII.
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Chart DIII : PSION HHC menu structure
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FIXED DATA – is accessed from the FUNCTION menu, and defines factory set identification codes.
These are D00 to D08.
READINGS – are the actual level measurement values live from the transmitter, and are the process
measurements of interest to the operator. These are D10-D15, and are accessed from the MONITOR menu.
DIAGNOSTICS – are the live values and data of interest to the transducer maintenance engineer, to assess
the performance of the transmitter. These are D20-D25, accessed from the MONITOR menu.
All the Display parameters can be accessed directly from the FUNCTION menu by selecting the appropriate
identification number, e.g. D20.
ENTER PARAMETER No
D The live data recalled on the displays D10-D15 and D20-D25 are updated continuously by the SMART
Communicator every 0.5 seconds, and so represents the latest available information from the
transmitter. When monitoring these parameters the Psion Organiser is active and so will not switch itself off
(the normal action after 5 minutes without any keyboard input).
Additional messages and codes are displayed in a priority order on the LCD when the Display parameters are
in use, to indicate exceptional tank conditions or operational problems.
D8.2
PROGRAM Parameters – P**
Access and Programme Structure
The PROGRAM Parameters are separated into six blocks. Five of these blocks are available for operator
access to configure the transmitter as required for the particular application, or adjust the normal
mode of operation of the unit. The sixth block of parameters is for use by service engineers or
under direct instructions from them. Access to all the PROGRAM parameters is made via the PROGRAM
menu, as shown in Figure DIII.
The five blocks of PROGRAM parameters are as follows:
CALIBRATE – The normal operator adjustments equivalent to zero and span, units, tank shape and standing
value. Parameters P11-P18.
ENGINEER – The more technical operator parameters, establishing response time, alarm delay time,
sensitivity, temperature and specific gravity. Parameters P20-P27.
IDENTITY – These are the plant identifiers – for example tag numbers, function description, plus serial
numbers and password entry. Parameters P00-P06.
P** - Allows direct access to a PROGRAM parameter by entry of the relevant code number. (This is the only
access route for the service engineer parameters P44-P48 and P51-P69.
SPECIAL P(ROFILE) – When selected on P11, the special profile of 10 points on a non linear relationship
between liquid height and process value are entered via Parameters 30-39.
REF-CAL – This allows 4 and 20mA points of the range of the displacer used to represent zero and max PV
to set by reference to the current level of liquid.
These PROGRAM parameters are read/write parameters, so that when a particular parameter is recalled its
value can be changed by one of three methods – either entering a new value on the blue numeral key pad, or
on the alphabet keys for a text entry parameter, or by scrolling sideways. Each of the parameters uses only
one of these methods : sideways scrolling is prompted by the appearance of horizontal arrows on line 3 of
the LCD. When the new value is on the display correctly, this is entered using the “EXE” key. The SMART
Communicator immediately then transmits the change to the transmitter. If the value is incorrect or
the operator wants to revert to the original value, the CLEAR/ON key will reinstate the existing parameter
value on the display, without affecting the transmitter.
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Within the memory of the Psion Organiser there are four separate registers for each of the PROGRAM
Parameters. These registers are known as WORKING, SAFE, OFFLINE and DEFAULT, and are further
described in Section D13.0. All programme changes are made in the WORKING register, and these are the
values sent to the Transmitter memory. The display can be cycled through the registers by using the
MODE key, and the initial letter of the register currently displayed is shown at the right hand end of the
second line – the same line as the parameter value. Individual parameters can be moved into the WORKING
register from other registers, by pressing the EXE key whilst the required register value is displayed.
WORKING REGISTER
Holds the same value as is currently in the transmitter.
SAFE REGISTER
Use as a backup, can only be sent to the same transmitter as it was loaded from.
OFF-LINE REGISTER
General purpose register, use to program a transmitter offline or transfer data between transmitters of the
same type.
DEFAULT REGISTER
The normal ex-factory values.
When a new value is programmed into certain parameters a warning message OUTPUT MAY BE
CHANGED is displayed with the option to proceed with or abort this change. This may be of importance
where the output, either digital or analogue, is controlling some process, such that a sudden change could
cause problems.
D9.0
Keyboard Functions
ON/CLEAR KEY
Aborts data entry if this has been started, else returns to the previous menu.
EXE KEY
When display is read/write parameter, writes the value on line 2 or the list selection on line 3 to the
transmitter.
- AND ¯ ARROW KEYS
Used to step through a parameter block in numerical order.
MODE KEY
Used to access the WORKING, SAFE and OFF-LINE registers and the DEFAULT value while a read/write
parameter is being displayed. The selected register is indicated by W, S, O or D on the right hand side of line
2.
¬ AND ® ARROW KEYS
Used to select an item from a list when <> is displayed on the right of line 3.
P** AND D** ENTRY
Allows direct access to a parameter via its number. Other parameters in the same group can then be accessed
by the - and ¯ arrow keys.
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D10.0
Parameter List
The performance of the DT Series is controlled by parameters stored in its non-volatile memory. Some of these
parameters are set at the factory and some are set by the customer. Further parameters are produced by the DT Series
to provide information about its performance. The parameters used to set up the transmitter are called Program or
“P” parameters. The parameters produced by the transmitter to provide information to the user are called Diagnostic
or “D” parameters. All parameters used in the DT Series are listed below. All of these parameters are accessible using
a Handheld Communicator. Only parameters P15, P16 and P20 may be changed using the MSP-MMS magnetic
scroller. Further details are provided in Section D11.0
PROGRAM PARAMETERS
IDENTITY GROUP
P00
P01
P02
P03
P04
P05
P06
MESSAGE
TAG
DESCRIPTION
DATE
FINAL ASSY No
SENSOR SERIAL No
PASSWORD
general purpose 32 character message
transmitter identifier (8 characters)
of, say, transmitter application or location (16 char)
when last change made to sensor
hardware assembly number
LVDT serial number
3 level password system
CALIBRATE GROUP
P11
P12
P13
P14
P15
P16
P17
P18
CURVE PROFILE
PV DISPLAY UNITS
PV SCALE FACTOR
STANDING VALUE
CALIBRATION MAX
CALIBRATION MIN
LEVEL FOR MAX PV
LEVEL FOR MIN PV
curve shape option
select units associated with the PV
PV max value
value of PV at zero level
PV for 20mA output
PV for 4mA output
height up displacer at which PV is maximum
height up displacer at which PV is minimum
ENGINEERING GROUP
P20
P21
P22
P23
P24
P25
P26
P27
SMOOTHING TIME
ALARM DELAY
ALARM ACTION
DISPLAY 1
DISPLAY 2
PROCESS TEMP
SG LOWER
SG UPPER
time constant applied to output
time before alarm action P22 is taken
current out on alarm condition detection
parameter to be displayed on display module
optional second parameter to be displayed
used to compensate system for process temp
specific gravity of the lower liquid
specific gravity of the upper liquid
CURVE PROFILE GROUP
P30
P31
P32
P33
P34
P35
P36
P37
P38
P39
10% HT
20% HT
30% HT
40% HT
50% HT
60% HT
70% HT
80% HT
90% HT
100% HT
%PV at 10% liquid height
%PV at 20% liquid height
%PV at 30% liquid height
%PV at 40% liquid height
%PV at 50% liquid height
%PV at 60% liquid height
%PV at 70% liquid height
%PV at 80% liquid height
%PV at 90% liquid height
%PV at 100% liquid height
PROTECTED GROUP
P44
P45
P46
P47
P48
ELEC TEMPERATURE
TEMP COEFFICIENT
TEMPERATURE MAX
TEMPERATURE MIN
BYTE READ/WRITE
for sensor assembly correction
for temperature correction of sensor assembly
the highest sensor temperature reading
the lowest sensor temperature reading
diagnostic tool for service engineer only
P51
P52
P53
DISPLACER LENGTH
DISPLACER CS AREA
DISPLACER WEIGHT
length of displacer element
cross-sectional area of displacer
weight of suspended parts
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P54
P55
SPRING MATERIAL
SPRING RATE
spring material selectable from menu
linear extension rate of spring
P58
P59
TEMP SETUP
SG SETUP
process temperature assumed at factory setup
SG of upper fluid assumed at factory setup
P60
P61
P62
P63
P64
P65
P66
P67
P68
P69
MIN SENSOR OUTPUT
LVDT COEFF 1
LVDT COEFF 2
LVDT COEFF 3
LVDT COEFF 4
LVDT COEFF 5
LVDT GAIN FACTOR
LVDT RATE
UPPER SENSOR LIMIT
LOWER SENSOR LIMIT
base value of D21
first order coefficient for polynomial correction
second order coefficient for polynomial correction
third order coefficient for polynomial correction
fourth order coefficient for polynomial correction
fifth order coefficient for polynomial correction
to normalise LVDT output
rate of change of LVDT output
maximum usable value of sensor output D21
minimum usable value of sensor output D21
DIAGNOSTIC PARAMETERS
FIXED DATA GROUP
D00
D01
D02
D03
D04
D05
D06
D07
D08
MANUFACTURER ID
TRANSMITTER TYPE
PREAMBLE BYTES
UNIV COMMAND REV
TS COMMAND REV
SOFTWARE REV
HARDWARE REV
FLAGS
DEVICE ID NUMBER
MOBREY
MLT100 order code
no. of bytes to set up modulation
protocol revision conformed to
MOBREY command specification
instrument software version number
instrument hardware version number
see HART protocol specification
factory-set unique address of sensor
READINGS GROUP
D10
D11
D12
D13
D14
D15
PROCESS VALUE
LEVEL
CURRENT OUTPUT
PERCENT OUTPUT
ULLAGE
ALARM REPORT
output calculated from the level
immersed length of displacer
proportional to PV - limits set on P15 and P16
current output as % of full scale
space available (refill quantity)
active alarms/warnings - press ® for next alarm
DIAGNOSTICS GROUP
D21
D22
D23
D24
D25
NORMALISED
COMPENSATED
RAW LVDT OUTPUT
PERCENT OF RANGE
TEMPERATURE
sensor output after linearisation & smoothing
sensor output after temp compensation
unprocessed sensor output
% of range of level of interest between P17 & P18
sensor temperature monitored or preset using P44
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D11.0
Parameter Descriptions
The DT Series stores a wide range of parameters, enabling it to perform more functions than a simple 4 to 20mA
transmitter. Some of these parameters are required to comply with the HART protocol whilst others, for example,
enable the transmitter to calculate and display the contents of a non-linear vessel in true volumetric units.
The DT Series “Program” parameters each have default values which are loaded into the transmitter’s memory when
first manufactured. Some of these values are adjusted at the factory to suit the customer’s application. Several of the
parameters have upper and lower limits outside of which they should not be set. These limits are defined within the
transmitter itself and, in the case of Handheld Communicators supplied are also set in the Communicator.
Certain parameters, when changed, can cause a step change in the output. In these cases the HHC will prompt for
confirmation before making the change. This gives the user the opportunity to, say, put the control loop into manual.
This section of the manual details the function of each parameter in numerical order, together with its default value
and limits if applicable. A typical screen from the HHC is shown for each parameter.
P00
MESSAGE
The MESSAGE is a 32 character alphanumeric text string which may be stored in the transmitter so that the user may,
for example, record details of the application.
The default value is: DISPLACER LEVEL TRANSMITTER
MESSAGE
P00
********************
GENERAL PURPOSE 32
CHARACTER MESSAGE
P01
TAG
The TAG is an 8-character identifier. It is displayed whenever the HHC establishes communication with a HART
transmitter.
The default value is: MLT
TAG
P01
********
TRANSMITTER
IDENTIFIER (8 CHAR)
P02
DESCRIPTION
The DESCRIPTION is a 16-character field which may, say, be used to provide further detail on the application.
The default value is: MLT TRANSMITTER
DESCRIPTION
P02
**************
TRANSMITTER USE OR
LOCATION (16 CHAR)
P03
DATE
The DATE may be used to store the date when the last changes are made to the transmitter’s configuration. The
CK1 HHC automatically loads the correct date if it makes any such changes.
The default value is typically: 01/01/97
DATE WAS
P03
** *** ****
WHEN LAST CHANGE
MADE TO SENSOR
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P04
FINAL ASSY No
The Final Assembly Number is a Unique Number allocated to the transmitter at the factory.
FINAL ASSY No PO4
********
HARDWARE ASSEMBLY
NUMBER
P05
SENSOR SERIAL No
The Sensor Serial Number is the serial number of the LVDT which provides the level input signal to the electronics.
SENSOR SERIAL No PO5
********
INSTRUMENT SERIAL
NUMBER
P06
PASSWORD
The Password controls changes to the parameters within the transmitter. It has 3 possible values:
CLOSED – this prevents any changes to parameter settings
OPEN – this allows configuration of the transmitter to suit the application
OPENx this additionally allows access to the “protected” parameters which relate to the calibration of the
transmitter. These should not be adjusted without reference to the factory.
The default value is: OPEN
PASSWORD
*****
P06
P11
CURVE PROFILE
The DT Series can provide an output proportional to volume, flow or contents in a non-linear application. The DT
system is pre-programmed with a selection of common non-linear profiles detailed in the Non-linear Profiling section
of this manual. These profiles may be selected using the ¬ and ® keys. Selecting “Special” allows the user to plot
his own curve.
The default value is: Linear
CURVE PROFILE P11
******
ß à
******
CURVE SHAPE OPTION
Refer to Appendix E for further details of this facility.
P12
PV DISPLAY UNITS
The Process Value (PV) may be configured to display a wide range of variables from Levels to Volumes. P12 enables
the user to associate appropriate units to the calculated value, and these units will be displayed on the optional integral
display and on the HHC.
The default value is: metres
PV DISPLAY UNITS P12
******
ß à
******
RESET MATHS ON P13
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P13
PV SCALE FACTOR
The PV Scale Factor enables the transmitter to provide an answer in the customer’s preferred units. Typically it may
be used to give an answer of volume in cubic metres. The value of P13 should be set to the maximum (100%) value
of the PV. If the value is set to Automatic then the transmitter takes the displacer length (or the span defined by P17
and P18) as its full-scale range and adjusts the output accordingly. See also the appendix on the Block Diagram.
The default value is: Automatic
PV SCALE FACTOR P13
*********
MAX VALUE
AUTOMATIC (A) = P51
P14
STANDING VALUE
A displacer level transmitter can only give a meaningful output over the length of its displacer. If, however, the vessel
still has some contents when the level is at the bottom of the displacer then this value may be added to the PV by
entering the difference value in P14. P14 may be positive or negative.
The default value is: 0.0
STANDING VALUE P14
**** **
VALUE OF PV
AT ZERO LEVEL
P15
CALIBRATION MAX
After calculating the PV, the transmitter will normally output a 4-20mA signal proportional to the value. P15 may be
used to set the value of PV which is used to represent 20mA. A value of Automatic will use the displacer length to
specify the height at which to output 20mA. This parameter and P16 may also be adjusted via the Caliplug – see
section on Commissioning.
The default value is: Automatic
Can also be set by using the ref cal option on the program menu.
CALIBRATION MAX P15
******* **
PV FOR 20mA OUTPUT
AUTOMATIC (A) = P51
P16
CALIBRATION MIN
After calculating the PV, the transmitter will normally output a 4-20mA signal proportional to the value. P16 may be
used to set the value of PV which is used to represent 4mA. This parameter and P15 may also be adjusted via the
Caliplug – see section on Commissioning.
The default value is: 0.0
Can also be set by using the ref cal option on the program menu.
CALIBRATION MIN P16
******* **
PV FOR 4mA OUTPUT
P17
LEVEL FOR MAX PV
The top end of the displacer is not necessarily the level which is required to represent the maximum PV. P17 can be
used to specify another level for this purpose and subsequent calculations will be based upon this revised point. See
also the appendix on the Block diagram.
The default value is: Automatic, meaning the max. PV is at the top of the displacer.
Can also be set by using the ref cal option on the program menu.
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LEVEL FOR MAX PV P17
****** m
HEIGHT UP DISPLACER
AUTOMATIC (A) = P51
P18
LEVEL FOR MIN PV
The bottom end of the displacer is not necessarily the level which is required to represent zero PV. P18 can be used
to specify another level for this purpose and subsequent calculations will be based upon this revised point.
The default value is: 0.0
Can also be set by using the ref cal option on the program menu.
LEVEL FOR MIN PV P18
****** m
HEIGHT UP DISPLACER
20
SMOOTHING TIME
In circumstances where the level is unstable it may be beneficial to adjust the amount of damping applied to the PV
and current output. P20 may be set to any value between 0 and 100 seconds. This parameter may also be adjusted via
the Caliplug – see section on Commissioning.
The default value is: 5 seconds
SOOTHING TIME P20
** s
TIME CONSTANT USED
ON OUTPUT DATA
P21
ALARM DELAY
The transmitter continuously monitors its performance and will signal an alarm if certain parameters go outside of
pre-determined limits. Under these circumstances it will signal that an alarm condition exists as described under P22
below. P21 may be used to set the delay between the alarm condition occurring and the transmitter signalling.
The default value is: 5 seconds
ALARM DELAY P21
** s
DELAY BEFORE ALARM
ACTION(P22) IS TAKEN
P22
ALARM ACTION
The transmitter continuously monitors its performance and will signal an alarm if certain parameters go outside of
pre-determined limits. See appendix on Error Messages for possible alarm conditions. An alarm condition is
signalled by:
Setting an Alarm bit in every HART message
Flashing an Alarm message on the display (if fitted)
Setting its current output to a user-defined state set by P22.
The options for P22 are to set the current to 3.6mA, 21mA or to Hold the last reading.
The default value is: Hold
ALARM ACTION P22
****
ß à
****
CURRENT OUT ON FAULT
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P23
DISPLAY 1
The display module, if fitted, can be programmed to display any 1 or 2 parameters from a selection of parameters.
P23 is used to define Display 1. The ¬ and ® keys may be used to make the selection. The choice is from:
PV
Level
Current (Output)
Percent (Current Output)
Ullage
Sensor Outputs
D21à D23
Percent of PV Range
D24
Temperature
D25
The default value is: PV
DISPLAY 1 SELECT P23
***
ß à
***
IF FITTED
P24
DISPLAY 2
In a similar way to P23, P24 can be used to define a second display which will flash alternately with Display 1 on the
display module. It has the same choice as for P23 except for the addition of “none” if no second display is required.
When flashing, the 2 displays are distinguished by the Display 1 and Display 2 being accompanied by arrows - and ¯
respectively.
The default value is: none
DISPLAY 2 SELECT P24
***
***
ß à
IF FITTED - OPTIONAL
P25
PROCESS TEMP
The process temperature has an effect on the performance of the transmitter. This effect will have been allowed for
in the factory calibration. If, however, the temperature is significantly different from that originally specified, it may
be compensated for by entering a revised value in P25. If set to Automatic then the value from the temperature
sensor in the enclosure is used.
The default value is: Automatic
PROCESS TEMP
P25
***** °C
USED TO COMPENSATE
FOR PROCESS TEMP
P26
SG LOWER
The performance of a Displacer Level Transmitter is dependent on the specific gravities of the Lower and Upper
fluids. The transmitter will have been calibrated for certain SGs in the factory but, subject to certain limitations,
revised values may be entered in P26 and P27 to match the true process conditions.
The default value is: 1.0
SG LOWER
P26
****
SPECIFIC GRAVITY
OF LOWER LIQUID
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P27
SG UPPER
See also P26 above. At the factory, the transmitter will have been calibrated for certain process conditions. The SG
of the upper fluid is stored in P27 and P59. The value in P59 should not be changed but P27 may be adjusted to
match revised process conditions.
The default value is: 0.0
SG UPPER P27
****
SPECIFIC GRAVITY
OF UPPER LIQUID
P30 to P39
NON-LINEAR PROFILE POINTS
When a non-linear profile has been selected by P11, the profile is plotted using parameters P30 to P39. Each plot
point represents the percentage of maximum PV corresponding to 10% increments in level. The range of this level
is defined by P17 and P18 relative to the bottom end of the displacer. For further details see Non-linear Profiling in
D12.0
The default values provide a linear output.
PROFILE POINT 1 P30
%LEVEL FOR PV(%P13)
10% LEVEL @ 10.0%ß
20% LEVEL @ 20.0%
IMPORTANT NOTE :
Parameters P44 to P69 are vital to the calibration of the transmitter and should not be adjusted without
authority from qualified personnel, for which password access will be required.
P44
ELEC TEMPERATURE
The level sensor and its associated electronics have a small temperature co-efficient and so to optimise accuracy a
temperature sensor provides automatic compensation. However, the measured value can be overridden using P44.
The default value is: Automatic
ELEC TEMPERATURE P44
** °C
FOR SENSOR ASSEMBLY
CORRECTION - A=AUTO
P45
TEMP COEFFICIENT
The temperature co-efficient of the level sensor and its associated electronics is stored in P45 and provides automatic
temperature compensation.
The default value is optimised for the transmitter.
TEMP COEFFICIENT P45
***
FOR TEMP CORRECTION
OF SENSOR ASSEMBLY
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P46
TEMPERATURE MAX
The transmitter monitors the temperature of the electronics and LVDT sensor and records the maximum measured
value for later recall. Any value greater than 50°C is recorded automatically in P46.
TEMPERATURE MAX P46
** °C
THE HIGHEST SENSOR
TEMPERATURE READING
P47
TEMPERATURE MIN
The transmitter monitors the temperature of the electronics and LVDT sensor and records the minimum measured
value for later recall. Any value less than -10°C is recorded automatically in P47.
TEMPERATURE MIN P47
** °C
THE LOWEST SENSOR
TEMPERATURE READING
P48
BYTE READ/WRITE
This parameter allows the Service Engineer access to useful data. This facility must not be used without direction
from qualified personnel.
BYTE READ/WRITE P48
ADD
DATA
ONLY ENTER DATA FOR
WRITE OPERATIONS
P51
DISPLACER LENGTH
The transmitter is normally calibrated over the full length of the displacer. P51 is factory configured with the
displacer length in metres.
DISPLACER LENGTH P51
**** m
P52
DISPLACER CS AREA
To perform its calculations, the transmitter needs to know the cross-sectional area of the displacer. P52 is factory
configured with the area in square centimetres.
DISPLACR CS AREA P52
*** cm2
CROSS-SECTIONAL
AREA OF DISPLACER
P53
DISPLACER WEIGHT
To perform its calculations, the transmitter needs to know the weight of the suspended components including the
displacer. P53 is factory configured with this total weight in grams.
DISPLACER WEIGHT P53
**** g
INCLUDING ATTACHED
ROD, ACTUATOR etc
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P54
SPRING MATERIAL
To perform its calculations, the transmitter needs to know the characteristics of the spring material. P54 specifies the
spring material from which the transmitter can calculate the relevant characteristics.
SPRING MATERIAL
***
***
P54
ß à
P55
SPRING RATE
To perform its calculations, the transmitter needs to know the rate of the spring. P55 is factory configured with the
actual spring rate in gram per centimetre.
SPRING RATE
P55
*** g/cm
LINEAR EXTENSION
RATE OF SPRING
P58
TEMP SETUP
To optimise the design of the transmitter, it is necessary to know the process temperature in which the transmitter
will be operating. This is stored in P58. If the actual process temperature is significantly different from that advised
at the time of order, then the revised value should be entered in P25 – no change should be made to P58.
TEMP SETUP
P58
*** °C
PROCESS TEMPERATURE
ASSUMED AT SETUP
P59
SG SETUP
To optimise the design of the transmitter, it is necessary to know the specific gravity of the upper fluid in which the
transmitter will be operating. This is stored in P59. If the actual upper SG is different from that advised at the time
of order, then the revised value should be entered in P27 – no change should be made to P59.
SG SETUP
P59
***
SG OF UPPER FLUID
ASSUMED AT SETUP
P60
MINIMUM SENSOR OUTPUT
During factory calibration, the value of the LVDT level sensor output at zero level is recorded and stored as P60.
This is the reference value upon which the transmitter bases its calculations.
MIN SNSR OUTPUT P60
**** mV
BASE VALUE OF D21
P61 to 65
LVDT COEFFICIENTS 1 to 5
To provide a linear output over the operating range, the LVDT sensor output is linearised by a fifth order polynomial.
These polynomial co-efficients are stored as P61 to P65.
LVDT COEFF 1
P61
****
VALUE FOR POLYNOMIAL
CORRECTION
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P66
LVDT GAIN FACTOR
In order to allow interchangeability of the LVDT sensor, the output is normalised to achieve a common span. The
gain factor is stored as P66
LVDT GAIN FACTOR P66
****
TO NORMALISE LVDT
OUTPUT
P67
LVDT RATE
After processing the LVDT output the overall sensor system produces an electronic output proportional to linear
movement. P67 defines the sensitivity of the sensor in milli-volts per cm.
LVDT RATE
P67
*** mV/cm
RATE OF CHANGE OF
LVDT OUTPUT
P68
UPPER SENSOR LIMIT
The LVDT sensor is calibrated over a range where linear operation is guaranteed. In exceptional circumstances its
output may extend beyond the calibrated range and under these circumstances the transmitter will provide a warning.
P68 stores the limit of the calibrated region at the upper end of the LVDT travel.
UPPER SNSR LIMIT P68
***
MAXIMUM USABLE VALUE
OF SENSOR OUTPUT D21
P69
LOWER SENSOR LIMIT
See also P68 above. P69 stores the limit of the calibrated region of LVDT movement at the lower end of the LVDT
travel.
LOWER SNSR LIMIT P69
***
MINIMUM USABLE VALUE
OF SENSOR OUTPUT D21
The following “D” parameters are diagnostics read-only parameters which are either fixed in the transmitter at
manufacture (D00 to D08) or produced within the transmitter as a result of measurements taken (D10 to D25).
D00 MANUFACTURER ID
For HART communications to operate correctly, the transmitter must identify its manufacturer. The manufacturer’s
code number automatically forms part of the communications address. The code is 59
MANUFACTURER ID D00
59
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D01 TRANSMITTER TYPE
D01 stores the type code for the transmitter head.
TRANSMITTER TYPE D01
DISPLACER LEVEL
TRANSMITTER
D02 PREAMBLE BYTES
D02 tells a HART master device how many preamble bytes it should send in its messages to the transmitter in order
to guarantee reliable communications. Sending too many bytes would simply slow down the communications update
rate. In the DT Series the value is fixed at 5.
PREAMBLE BYTES D02
5
NO OF BYTES TO SET
UP MODULATION
D03 UNIV COMMAND REV
D03 identifies the major revision of the HART protocol with which the transmitter complies. In the case of the
DT Series it is revision 5.
UNIV COMMAND REV D03
5
PROTOCOL REVISION
CONFORMED TO
D04 TS COMMAND REV
Over a lifetime of a product type, extra functionality may be introduced by adding extra variables or commands. To
signal this to a HART master device, D04 contains details of the Transmitter Specific Command revision
TS COMMAND REV D04
**
COMMAND
SPECIFICATION
D05 SOFTWARE REV
Extra software functionality, which does not affect HART, may be identified to the user by D05, the Software
Revision.
SOFTWARE REV
D05
**
INSTRUMENT SOFTWARE
VERSION NUMBER
D06 HARDWARE REV
The presence of any hardware changes may be identified to the user by D06, the Hardware Revision.
HARDWARE REV D06
**
INSTRUMENT HARDWARE
VERSION NUMBER
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D07 FLAGS
The Flags byte, D07, gives a HART master details of the transmitter’s HART functionality.
FLAGS
D07
**
SEE HART PROTOCOL
SPECIFICATION
D08 DEVICE ID NUMBER
The Device ID Number is a unique number which forms part of the transmitter’s HART address and ensures that no
two HART transmitters ever have the same address.
DEVICE ID NUMBER D08
FACTORY-SET UNIQUE
ADDRESS OF SENSOR
D10 PROCESS VALUE
The DT Series is fundamentally a level measuring device and by default the Process Value or PV will be the level of
the lower liquid. However, as described elsewhere in this manual, the level value can be processed to provide an
answer in terms of volume, mass or even flow. This resultant PV is displayed with its units as parameter D10.
PROCESS VALUE
D10
***** **
OUTPUT CALCULATED
FROM THE LEVEL
D11 LEVEL
The length of the displacer element that is immersed in the lower liquid is displayed as D11. The PV is calculated
from this basic level measurement
LEVEL
D11
***** m
IMMERSED LENGTH
OF DISPLACER
D12 CURRENT OUTPUT
The current output is related to the PV by parameters P15 and P16. Its value, in mA, is displayed as D12.
CURRENT OUTPUT
D12
***** mA
PROPORTIONAL TO PV
LIMITS SET P15+P16
D13 PERCENT OUTPUT
A convenient alternative way of viewing the answer is as a percentage. D13 displays the PV as a percentage based on
the limits set on P15 and P16. If the current output is active, that is not in multi-drop mode, then this also represents
the percentage of current output – e.g. if the current is 12mA then D13 is 50%.
PERCENT OUTPUT
D13
***** %
CURRENT OUTPUT AS
% OF FULL SCALE
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D14 ULLAGE
The Ullage space is the difference in the present PV and the maximum value defined by P15. In other words it is the
amount in PV units required to fill the vessel so as to give 20mA current output.
ULLAGE
D14
***** **
SPACE AVAILABLE
(REFILL QUANTITY)
D15 ALARM REPORT
The DT Series monitors its performance and detects if there is any malfunction or if any values go out of normal
limits. The parameters it monitors are listed in Appendix D14.0. The HHC displays a full text message when the
condition is first detected and then truncates it to a 2 character code at the right hand end of the display. Only one
condition, the highest priority one, can be displayed at a time. However, D15 can be inspected to scroll through full
descriptions of all active alarms.
ALARM REPORT
D15
*******************
PRESS à FOR NEXT
ALARM
D21 NORMALISED LVDT OUTPUT
The Level Sensor in the DT Series is a Linear Variable Differential Transformer (LVDT). The LVDT output goes
through several stages of processing as shown in the Block Diagram in Appendix E. D21 is the LVDT sensor output
value after temperature compensation, linearisation, scaling, and smoothing.
NORMALISED
D21
**** mV
SENSOR OUTPUT AFTER
POLYNOMIAL+SMOOTHING
D22 COMPENSATED LVDT OUTPUT
D22 is the LVDT sensor output value after temperature compensation.
COMPENSATED
D22
****
SENSOR OUTPUT AFTER
TEMP COMPENSATION
D23 RAW LVDT OUTPUT
D23 is the LVDT sensor output value before any processing.
RAW LVDT OUTPUT
****
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D24 PERCENT OF RANGE
The DT Series produces a value (D11) for the liquid level relative to the bottom of the displacer element. However,
this may not be the range of interest and P17 and P18 re-define where the minimum and maximum levels should be.
D24 represents the position of the liquid level between these 2 limits.
PERCENT OF RANGE D24
**** %
D25 TEMPERATURE
The DT Series measures the temperature in the enclosure so that it may make corrections for changes in temperature
if necessary. D25 displays this measured value unless it is overridden by fixing the temperature with P44.
TEMPERATURE
D25
*** °C
MONITORED OR PRESET
USING P44
REFERENCE CALIBRATE
The Ref_cal section allows the actual level of the liquid being measured to be used to set the current output and PV
range parameters.
The sensor output option allows P17 and P18 to be set. The current output option allows P15 and P16 to be set.
In both cases the present value of the parameter to be changed is displayed, with a prompt to continue. If selected
the potential new value for the selected parameter is displayed and continually updated, with an” INPUT STABLE”
prompt, if “Y” is pressed then the displayed value is written to the selected parameter. If “N” is pressed the process
returns to the previous screen.
At any stage, in either reference calibrate procedure, if the CLEAR/ON key is pressed then a return to the
PROGRAM menu is immediately made.
D12.0.
Using the Tank profile facility
P11 Curve Profile
CURVE PROFILE
P11
LINEAR
1
NON-LINEAR < - - >
CURVE SHAPE OPTION
Default value LINEAR
This parameter establishes the relationship to be used between the liquid level (or height) and the process value
derived from that level. The process value then drives the current loop.
The allowed selections on Parameter 11 are scrolled using the left and right arrows. Allowed selections are LINEAR
and then seven non-linear functions – SPECIAL, CYLINDER, SPHERICAL, CONICAL 1, CONICAL 2, FLUME
and VNOTCH WEIR. These are as follows:
D12.1
LINEAR – The process value (transmitter 4-20mA output) is a linear multiplier of the liquid height above
the zero reference, in metres.
For a tank with constant cross section, the volume of the contents can be shown as the process value by selecting
LINEAR on P11, and entering the maximum volume on P13. The units of measurement – gallons, litres, etc. – are
then set on P12. See Fig DIV
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Tank Contents Curve Profiles for Standard Tank Shapes
Fig. D.IV - Linear vessel or sump
P17 Lev elfor m ax
P.V. (100% )
D atum
(default=dia. m )
P18 Lev elfor m in
P.V. (0% )
P14 S tanding level
Unless factory calibrated to your specific instructions, the DT Series will give a 4-20mA output proportional to level over it’s full length,
with 4mA representing a level of 0m at the end of the displacer element. You can re-range on site if necessary (See 4.2).
If the displacer element does not cover the full depth of the tank, there is provision to add a standing level to the calculations. Simply
enter the level, in metres, on P14, and the DT Series will give a proportional output over the length of the displacer. Note that the
output will now never reach 4mA, as the displacer length is now only a part of the full output range. You will need to re-set P17, the
Process Value for a 20mA output, by increasing the value by the standing level.
Example :
Displacer length 1.50m.
: P17 = 1.50 / P18 = 0m / P14 = 0m
To allow for a standing level of 0,5m : P17 = 2.0m / P18 = 0m / P14 = 0.5m
Resulting output signal
: 8mA at 0.5m and below, 20mA at 2.0m.
To operate in units other than metres, the “PV Scale factor” P13 can be used. (See D11.0 )
Example : To operate in feet, set P13 to the maximum value of the PV. For a displacer length of 1.5m, where PV max is 1.5m, set
P13 to (1.5 x 1.094 ) = 1.641.
If you wish to re-range the transmitter, you can reset P17 and/or P18 so that the transmitter output is proportional to level over this
new range. Note, P17 and P18 are ALWAYS entered in metres.
To operate in litres, set P13 to the volume in litres equivalent to the length of the displacer element. For an element of length of
1.5m in a vessel of dia 2m, set P13 to 1.5 x ( p2.02) x 1000 = 4712litres
4
If there is a standing level (or volume) to be taken into account, this is entered on P14 as previously described, but note that the units
MUST BE entered in the same units as the readout. i.e. feet or litres in the above examples. Whatever units are chosen for the readout,
the display and / or HHC can be configured to suit using P12.
P12 Units
PV DISPLAY UNITS P12
Metres
W
Metres
< - - >
RESET MATHS ON P13
Default value metres
The units used to display the Process Value are set on Parameter 12. These units are also used to set the milliamp
output span and zero points on P15 and P16. The allowed units are scrolled by using the horizontal arrows. If the
units required are not present, then the displays can show no units by selecting “none” – possibly the actual units in
use can be entered in P00 (Message).
The bottom line on the display of P12 reminds the operator that if units of measurement are changed, then the
maths values on the scaling parameters (e.g. P13) should be recalculated and amended.
P13 Scale Factor
PV SCALE FACTOR P13
1.0000
W
MAX VALUE
AUTOMATIC (A) = P51
Default value 1.00
The PV Scale Factor provides the mathematics used to relate the Process Value to the liquid height, which is initially
measured by the transmitter in metres above the reference level.
This function can also be used to display height of liquid in feet or millimetres or other linear units, by adjusting P12
and P13 appropriately.
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D12.2
“NON-LINEAR” – All the non-linear functions selected have a curve or profile to relate the process
value/output measurement to the liquid height. The functions therefore relate liquid volume contents to
height in a non-linear tank, or liquid flow in an open channel to the height upstream of an obstruction such
as a weir or flume.
For all selections other than LINEAR it is necessary to select the correct, site related values for Parameters 12 and 13
as shown on in the following diagrams. The various non-linear profiles available are as follows:
Technical Note : The transmitter accepts the non-linear profiles from the SMART Interface in the form of
a 10 point plot of percentage of maximum process value against percentage of maximum level, and then uses
interpolation to produce values for intermediate points. The Psion Organiser calculates the ten points to be loaded
in the memory according to the curve profile selected on P11. The values of these ten points can be seen
on Parameters 30-39 : direct access to change these parameters is only available when the SPECIAL profile is selected
on P11.
CYLINDRICAL – When the PV output required is to represent the volume contents in a horizontally mounted
cylindrical tank, this curve is selected. The dimension of the equivalent ideal tank are entered as shown in Fig. D.IV,
assuming the tank is horizontal and has effectively flat ends.
SPHERICAL – To provide the PV output as volume contents in a spherical tank, this curve is selected. The
equivalent ideal spherical tank dimensions are entered in the parameters 10-14 as shown in D.IV. If the actual tank
measurement range is limited by transducer positioning or tank shape to part of a sphere, the ideal full sphere
dimensions must be used. The 4-20mA output can then be restricted to operation over a smaller volume span if
required.
CONICAL – For rectangular or cylindrical tanks with a conical bottom two patterns are provided to suit different
tank aspect ratios. These are CONICAL 1 AND conical 2, shown in D.IV.
CONICAL 1 is for tanks where the major part of the tank height is taken up with the cone. The profile creates an
imaginary tank where the linear section is the same height as the conical section, and P13 and P14 are entered for this
imaginary tank. This profile is applicable on all tanks where the maximum height to be measured is less than twice
the conical section height, H. Note that the zero reference distance and the conical height is measured from the apex
of the cone – where it would be without considering discharge pipework, etc.
CONICAL 2 is used for tanks which have a much smaller proportion of the height as a cone. It is applicable for
tanks where the maximum measurement is up to 5 times the conical section height above the apex of the cone. For
higher tanks the non-linearity introduced by the conical section becomes insignificant, and a LINEAR profile should
be used.
D12.3
SPECIAL – If the curve profile labelled SPECIAL is chosen, access is allowed to parameters P30-P39 to
draw the unique profile for this site, tank or flume, according to data available. The microprocessor in the
transmitter then interpolates between these ten points to give an accurate curve fit for the PV output.
The standard procedure for using the SPECIAL profile is shown in Fig D.V, with some examples. It is necessary to
have either tabulated or graphical data to relate the required process value to the liquid height, to derive the required
profile points.
Technical Notes: The origin (0,0) of the graph of PV versus height is used in the interpolation as the start point.
Profile Point 10 occurs at the height used as the maximum level, normally the top of the displacer unless repositioned by P17. It is possible that the PV value corresponding to this height is less than 100% of Parameter 13.
This means that for ease of calculations of percentages, P13 can be selected as any value above the maximum
required to be monitored.
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SPECIAL PROFILE Parameters P30-39
For a non-linear relationship between PV and Liquid Level, Parameters 30 to 39 set out the 10 point graph relating
the two functions. When Parameter 11 is used to a select a pre programmed function – e.g. contents of a cylindrical
horizontally mounted tank – CYLINDRICAL) Parameters 30-39 are automatically allocated values recalled from the
memory of the Psion Organiser SMART Datapak. These values cannot be changed by accessing Parameters 30-39 –
they are effectively “Read Only” parameters. This is useful in that the curve used is defined and shown. (Beware that
if LINEAR is selected on P11 the Parameters P30-39 retain their previous values – the LINEAR profile ignores P3039). Any attempt to write new values to these parameters will receive the screen response.
PROFILE POINTS
PROTECTED BY P11
When Parameter 11 is set to the “SPECIAL” non-linear profile, access is allowed for the operator to write values into
P30-P39, as described in Figure 9, to construct a special profile relating PV to height. Both of these are expressed as
percentages of the maximum or “full” value in Parameters 30 to 39.
The profile points are scrolled on the same screen, to allow previous points to be monitored. For example, the display
showing Point 4, Parameter 33, is as follows, where the arrow indicates the value which is to be adjusted:
PROFILE POINT 4 P33
30% LEVEL @ 25.2%
40% LEVEL @ 37.3% ¬
50% LEVEL @ 50.0%
The initial screen shown for Parameter 30 reminds the operator that the Liquid Level is expressed as a percentage of
the P14 value, and the PV corresponding to this level is expressed as a percentage of P13.
PROFILE POINT 1 P30
¬ % LEVEL for PV(%P13)
10% LEVEL @ 10.0% ¬
20% LEVEL @ 20.0%
Default values
Maximum values
Minimum values
60
LINEAR Profile
100%
0%
IP2020
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Special profile relationship between process alue and liquid height
Example :
P36 is a Profile Point 7. Find X co-ordinate that represents 70% of the max height (P17-P18). On graph obtain Y
co-ordinate and express as percentage of max value (P13). Enter this percentage as P36.
Fig. D. V.
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HAND HELD COMMUNICATOR REGISTERS
D13.0 SAFE, WORKING, OFFLINE, DEFAULT, Registers
Introduction to Registers
From the FUNCTION screen, whilst interrogating an transmitter, there is a selection titled “BACKUP”.
This allows the data now stored in the WORKING register (i.e. the transmitter data) to be transferred to a
separate secure memory, to either retain it while making changes to the transmitter (i.e. as a “revert to the
original program” insurance data store) or to save it in memory so that it can be copied or consulted back in the
office. The registers available are shown in Fig DVI, and are listed as:
WORKING REGISTER
This is literally the work sheet where all work is done – all changes made to the parameters on the SMART
Communicator keyboard are made to the data in the WORKING Register. While the Communicator is attached
across the 4-20mA loop, the WORKING register is exactly the same as the transmitter memory, so all
changes made to the WORKING register are also made to the transmitter itself. The transmitter memory
and the WORKING register in the SMART Communicator are identical. If communication between the two units
fails, then changes attempted in the WORKING register will be rejected.
Note : The SMART Communicator can be unaware of changes to the transmitter memory made by (a) a
Primary Master (such as H-View) also attached to this transmitter loop, and (b) the local zero and span on the
DT Series.
The data existing in the WORKING register is overwritten (and therefore lost) when new data is loaded from another
register, or when the SMART communicator is reconnected to an DT Series loop, because the start up routine will load
this new memory into the WORKING register. To save any data that has been entered in an “Off-loop”
state (i.e. back in the office) the data must be held in the OFFLINE register (see below).
It is recommended that the data in the WORKING register is transferred OFFLINE before disconnection of the
SMART communicator from the loop, if it is likely to be needed for reference back in the office. However, the data
in the WORKING register is retained in the Psion memory after this disconnection, and can still be interrogated until
overwritten by new data.
SAFE REGISTER
The SAFE Register is literally a register where the current calibration data can be stored and kept SAFE,
while changes are made on the WORKING register and the SMART Communicator is attached to the loop. If these
WORKING register changes then prove ineffective or not required, the SAFE register data can be recalled into the
WORKING register (and therefore to the transmitter) to reset all the parameters to their original
values – i.e. the values in the transmitter when the last “Backup” operation transferring the data to the SAFE register
was carried out. The data in the SAFE register can only be loaded into the WORKING REGISTER when the
communicator is attached to the same transmitter that was the source of the data – i.e. the transmitter with
the same unique identifier (D08). It is not possible to transfer programmes between instruments using the SAFE
register.
The SAFE register is retained even when the Communicator is disconnected from the loop, powered down, and then
reconnected to another loop, collecting new data in the WORKING register. It is not accessible until the correct
transmitter loop is interrogated, so that the check on the D08 Unique Identifier has been satisfied.
OFF-LINE REGISTER
This is the register used for transfer of programmes between one unit and the next, or from a programme developed
on the SMART Communicator at the office desk, stored OFF-LINE and then down loaded into an
transmitter on the plant later. Such data transfer is achieved by connecting the SMART Communicator across the
relevant loop, loading the WORKING register with the current program (see below) then
transferring the OFF-LINE stored data into the WORKING register – this overwrites the previous programme in
(both the transmitter memory and the WORKING Register).
An obvious precaution in the above procedure after loading the WORKING register with the current
transmitter data, is to transfer this data to the SAFE register in case the OFF-LINE sorted new programme does not
give the expected result – if necessary the DT Series can be restored to its original programme status by transferring
the SAFE register data to the WORKING register.
The OFF-LINE register is retained when the communicator is disconnected from the loop or powered down. It is
only wiped when a new set of data is transferred to the OFF-LINE register from the WORKING register.
Only one set of parameters can be stored in the OFF-LINE register at once.
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MEMORY LOCATIONS IN SMART COMMUNICATOR
SAFE
register
SAFE register keeps data from on
specific transmitter secure, and only
allows transfer to/from that
transmitter
u
MSP100
transmitter
memory
WORKING
register
WORKING register. All changes are
made in this register. When on a loop,
this shows the MSP100 transmitter
memory.
u
u
OFFLINE is used to save data for
work or interrogation in the office,
or transfer between MSP100
transmitters.
OFFLINE
Register
The exfactory values can be
reloaded into the WORKING
register by recalling the DEFAULT
Register
DEFAULT
values
Fig. DVI :
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DEFAULT REGISTER
This is the register of all the normal ex factory settings for the Transmitter. It is a useful start or reference
point for programming any transmitter, since the values set in each parameter are known and only those that need
reprogramming have to be amended. The DEFAULT values can also be used to reset any transmitter to ex
factory status, therefore wiping any other programme amendments made previously.
D13.2
Manipulation and Transfers between registers
a) Offline operation
The screens showing the Transfer functions of data between registers provide step by step instruction for achieving
such data transfer (See Figure D.VIi). There are also facilities for allowing the normal interface between the Psion
Organiser and a printer or personal computer to provide output of the programme data.
The options presented on the LCD are amended when the SMART Communicator senses that a loop is not present
or the Interface unit is not plugged into the Psion. In such cases OFF-LINE operation is offered or selected
automatically (See Figure D.VII). After changes to the PROGRAM screens which modify data in the WORKING
Register, these changes must be saved in the OFF-LINE Register or to a Data File using the TRANSFER function.
b)
Loop transfers
The BACK-UP selection on the main FUNCTION menu allows manipulation of the data held in the
various registers shown in Figure D.VI. Since all transfers are to or from the WORKING Register, the
initial screen
SELECT DATA SOURCE
Safe
Working
File
Off Line
Defaults
Immediately transfers data to the WORKING Register if SAFE or OFFLINE are selected. If the
source is a Data File then a location and a File name are prompted for and the data is transferred to the
OFFLINE
Register followed by a transfer from OFFLINE to WORKING. This final transfer can
be prevented by pressing “N” when asked to accept that the output may be changed. If the data source
is the WORKING Register, the screen prompts for a full upload if any parameters have not yet been
read then asks for a destination decision.
SELECT DATA
DESTINATION
Safe
File
Off-line
To know where to place the data. Transfer to a Data File will prompt for a location and a file name.
The location is either the internal memory at A or a Data or Rampak in the upper side slot which is B.
The filename can be up to 8 characters long. In this case the WORKING Register remains unchanged
after the data transfer.
Please note that Parameters in the range P44 to P69 are not transferred to the WORKING Register in
any BACK-UP data transfer. These parameters are left as set up by the Service Engineer for that
particular transmitter.
D.13.3
Printout or PC transfer of programme data
When used “Off-Line” the Hand Held Communicator can be instructed to transfer the programme
memory into a PC or print a list of the parameters and the values in the working register on a paper
printer. This is achieved using the Standard Psion COMMS LINK routines and interfaces.
To send or receive data from a PC the COMMS LINK must be plugged in and connected to the PC
port and the CL program must be running on the PC. See the COMMS LINK manual for further
details.
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OFF-LINE MEMORY TRANSFERS
D0 - D8 :
M LT100
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The Psion will set itself up for transfer to or from a PC when this option is selected.
The file name is any valid MS DOS file name including path names and extensions. The PSION/HART
program restricts the length of the input to 17 characters.
The actual transfer to a PC is a complete list of parameter numbers (P0-P69 and D0-D8), of the memory
values in the WORKING register. Certain parameters have numeric codes to identify the option (normally
chosen in text, such as LINEAR or HOLD). Do not modify this data while it is in the PC file.
To printout the parameter list the COMMS LINK must first be set up to match the requirements of the
attached printer with regards to the Baud Rate, start bits, stop bits and protocol. To test the printer and get
the desired settings, use the AUTO function in the SETUP menu, and experiment with the HAND settings,
try XON + DTR first.
The printout includes the parameter number, title and value of all the valid parameters in the range P0 and
P69 and D0 to D8. Where necessary the value will be related text instead of the value in the data file, e.g.
“HOLD” instead of 2.
D.13.4
Display of Parameter Data
The four different registers relate only to the \Programmed Parameters in the memory. When
interrogating an transmitter, a typical parameter display would show:
STANDING VALUE
**** **
VALUE OF PV
AT ZERO LEVEL
P14
W
The W shown on the second line right hand end indicates that this displayed value is the value present in the
WORKING register. This can be compared with the SAFE, OFFLINE or DEFAULT equivalent values by
pressing the “MODE” button, which cycles through these registers. The data displayed is labelled with the
initial letter of the register selected. This is useful for comparing transmitters (between W and O) or noting
changes on this transmitter (Between W and S). A transfer of this single parameter can be made into the
WORKING register by pressing “EXE” when the desired alternative register value is shown on the LCD –
the display will show the letter changing to W to acknowledge the transfer.
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D.14.0
ERROR MESSAGES ON THE HHC
D.14.1
Alarm and Error Messages
Throughout the programming of the Transmitter using the SMART Communicator, any failure of a
communication message or other problem in the SMART interface will be advised with a message on the
Liquid Crystal Display. Certain error messages prompt for an operator input or decision, for example,
whether the procedure should be repeated. These need simple “Yes” or “No” responses. Other errors, for
ex ample, “No response from transmitter” when programme parameters are being changed, will produce a
reset of the parameter value back to the original value in the WORKING Register.
In the first interrogation of the transmitter, each asterisk shown on the LCD represents a message, which can
contain up to 10 parameters. In the event of a failure of this communication, the option of a retry or move
to the next set of parameters is offered. It is always preferred to use “Retry” to collect a full set of data. (See
Section D7.0)..
Transmitter Status Messages
Further operational alarm/error messages are shown on the LCD when any display parameter is selected.
When either Readings or Diagnostic parameters (D10-D36) are shown, the SMART Communicator is
interrogating the transmitter every 0.5 seconds, and the information returned includes various
message signals concerning the current status of the returned echo. These messages are displayed on the
LCD line 2 for two seconds when the condition is first detected, instead of the Display parameter value.
After this display period the condition message is abbreviated to a two letter code shown on the right hand
side of the LCD, as long as the condition persists These status messages are updated every 10 seconds. Only
one status message is displayed at a time, in a priority order, as listed below, to see all the alarms present use
D15.
CURRENT SATURATED (CS)
The echo currently monitored is from a process value outside the pre-programmed 4-20mA range, so the
current is either at 4mA or 20mA and is possibly not valid.
TEMPERATURE LIMIT (TL)
This indicates that the process temperature or a combination of the process and ambient temperatures have
resulted in the electronics becoming too hot or too cold. Using the HHC, check P46 and P47 to see the
maximum and minimum temperatures recorded. If the electronics has recorded a temperature
above 85°C then the electronics may have been permanently damaged. The DT Series should be returned to
your local agent for repair or replacement.
SENSOR OUTPUT HIGH (SH)
This means that the core has travelled too high in the pressure tube and that the LVDT output is therefore
too high. Check that the displacer element is the correct element for this Transmitter. Carry out a bench
calibration to check that the LVDT is in the correct position. If the message only appears when there is
liquid in the vessel, check that the liquid SG is as expected and not too high.
SENSOR OUTPUT LOW (SL)
This means that the core is too low in the pressure tube and that the LVDT output is therefore too low.
Check that the displacer element is the correct element for this Transmitter. Carry out a bench calibration to
check that the LVDT is in the correct position. If the message only appears when there is liquid in the
vessel, check that the liquid SG is as expected and not too low.
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There are also various microprocessor fault messages which should be shown on the LCD, indicating
significant problems with the sensor microprocessor. For all these error conditions reference should be made
to the factory, and it will probably be necessary to return the unit for repair. The messages and codes are:
ROM CHECKSUM
EEPROM SIGNATURE
EEPROM CHECKSUM
RAM TEST
ADC REFERENCE HIGH
ADC REFERENCE LOW
RC
ES
EC
RT
AH
AL
When an Unknown instrument is being interrogated, a universal set of error messages is used:
DEVICE MALFUNCTION
PV OUT OF LIMITS
NON PV OUT OF LIMITS
CURRENT SATURATED
14.2
DV
PL
NL
CS
Invalid Data Entry
When the Operator tries to enter a command or parameter value which is invalid, the message on the screen
will indicate this. Typical messages occur as follows:
“INVALID INPUT”
(Rejected by the Psion Organiser)
“INVALID DATA”
(Rejected by the transmitter)
- Parameter value entered is outside the limits allowed for that parameter, or resetting of this parameter is not
allowed as per the data entered.
“IN WRITE PROTECT MODE”
- The Password is “Closed” or does not allow access to this parameter.
“INVALID PARAMETER NUMBER”
- Parameter number entered is not know by DT Series.
“PASSWORD NOT OPEN”
- If the Password in the transmitter memory *see in the WORKING Register of the SMART
Communicator) is set “CLOSED”, then it will not be possible to load data from the SAFE or OFFLINE
register. The Password protects the data in the DT Series.
“INVALID ACTION NOT THE SAME INSTRUMENT”
- If an attempt is made to transfer SAFE register data to the WORKING register of an transmitter
which is not the origin of the SAFE register data, this will not be allowed. The message indicates that D08
on the currently connected loop is not the same as the D08 in the SAFE register.
“PROFILE POINTS PROTECTED BY P11”
- The Special Curve Profile Parameters P30-P39 can only be adjusted when the “Special” Curve is selected
on P11. Any other curve selected on P11 will define P30-P39 If P11 has selected “LINEAR” then
Parameters P30-P39 are ignored and their values are irrelevant.
“INSTRUMENT IN MULTIDROP MODE”
- The current output control circuitry in the transmitter is only active when the DT Series is
operating on a 4-20mA loop. In a multidrop configuration the current is set to 4mA, and trimming and
current set commands are inoperative.
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14.3
Communication Errors
Communications between the transmitter and the SMART interface/Psion organiser are subject to
error checking and acknowledgement signals according to the HART protocol. This means that only valid
messages are accepted, and if the message is invalid then it will be rejected.
The screen of the LCD will indicate if a message has not been received correctly. This is perhaps most likely
to be seen when the Display parameters are being used, since these are updated with a new value in a message
every 0.5 seconds. If the message is received incorrectly, the second and third lines of the display will show
one of the following messages:
VERTICAL PARITY ERROR IN REPLY
OVERRUN ERROR IN REPLY
FRAMING ERROR IN REPLY
LONGITUDINAL PARITY ERROR IN REPLY
BUFFER OVERFLOW IN REPLY
Which describe the cause of the fault.
There is an identical group of errors in the outgoing message:
VERT PARITY ERROR IN OUTGOING MESSAGE
OVERRUN ERROR IN OUTGOING MESSAGE
FRAMING ERROR IN OUTGOING MESSAGE
LONGDNL PARITY ERROR IN OUTGOING MESSAGE
BUFFER OVERFLOW IN OUTGOING MESSAGE
If this occurs frequently, it is appropriate to check the electrical connections to the instrument loop, the
presence of the SMART load resistor and that the SMART Communicator is attached at the correct position
in the loop.
The “IN OUTGOING MESSAGE” group of error messages if displayed while accessing the Programme
Parameters implies that the message from the SMART Communicator was not received correctly by the
DT Series. Therefore the instructions in the message would have been rejected, and the Parameters remain
unchanged at their previous value. This previous value will be shown on the LCD screen on the SMART
Communicator after the error message, to prompt the operator to repeat the last parameter value amendment.
During a Register transfer this message will automatically cause the Communicator to hold transmission, and
suggest a retry because of the error.
The “IN REPLY” group of error messages if displayed when programming the instrument, signals a more
significant communications failure. This indicates that the acknowledgement of the change instruction sent
to the DT Series was incorrect. It is not known whether the |Parameter value in the DT Series was changed or
not. The SMART Communicator assumes that it was not changed, and reverts to the original (pre change)
value : this prompts the operator to re-enter the required new value. It is important that the Parameter is reentered, to ensure that the Working register memory in both the Psion and the DT Series contain the same
data.
If either of the above two Outgoing or Reply Comms Error messages occurs in a Backup menu transfer
between registers, it is advisable to repeat the Backup operation to complete the data transfer, or check that
the memory has been transferred correctly.
The message “NO RESPONSE FROM TRANSMITTER! Indicates a failure of the power on the loop or a
failure of the connection of the SMART interface across the loop or the address of the instrument has been
changed. Connection should be re-established if possible.
The message “LOCKED OUT BY BUS ACTIVITY” indicates there are either two secondary masters on the
bus or a primary master is continuously trying to access an instrument that does not exist.
The message “INCOMPLETE REPLY” indicates that a start of a message was detected but the message was
not completed in the time allowed. This is most likely to be due to a power failure or a loss of connection.
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D.15.0 Current Loop Checks and Trimming
.
Introduction
The 4-20mA transmitter has no customer or service engineering adjustable potentiometers on the
printed circuit boards. All current trimming of the 4mA and 20mA set points is achieved via the SMART
communicator. Because this is a “live” interaction, the access to this function is via the MONITOR functions
and screen on the Communicator.
Select “Current – Output” and the screen displayed is
** CURRENT OUTPUT **
Set current
Trim-maximum
Trim-maximum
These three functions are as follows:
D.15.1
Set current
This selection is used for transmitters attached to a single 4-20mA loop to check for correct
functioning of all the equipment – the communications and the other loop indicators and
outputs.
By selecting the “Set-current” option the screen prompts the operator to choose a current value for the loop,
for example 12mA.
ENTER NEW VALUE
12On pressing “EXE”, the current in the loop is set to this value, and the loop indicators and trips can be
checked for function and calibration. The LCD screen changes to suggest selection of a new value if
necessary. To abort the procedure press ON/CLEAR
CURRENT OUTPUT =
12 mA
ENTER NEW VALUE
Some specific error messages are used to prevent the loop current being set outside the valid 4-20mA limits.
D15.2
Trim Current
If the procedure shown above suggests that there is a calibration difference between the output and
other current monitoring equipment on the loop, it will be necessary to use a calibrated meter to establish
which unit is in error. Using the “Set current” routine of Section 3.4.2. the DT Series can be instructed to
provide outputs between 4 and 20mA that the DT Series considers correct. If these are in error, the “Trim
current” routine is used as follows:
The “Trim current” selection sets the current output of the DT Series either at maximum (supposed to be
20mA) or minimum (supposed to be 4mA) depending on the option selected. For maximum the display
shows:
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CURRENT OUTPUT IS
NOW 20mA. MEASURE
CURRENT AND USE - & ¯
TO TRIM THE OUTPUT
Follow the instructions and if the current output is in error, i.e. not 20mA, use the - and ¯ arrows as
trimming signals to adjust the value to be exactly 20mA. Each press of the arrow causes an audible signal and
adjusts the output value by a discrete step. (approx 6mA)
This process should then be repeated for the 4mA setting. Once the current output is seen to be correct the
ON/CLEAR key is used to escape.
Mode Cancelled Warning
If while trimming or fixing the current the analog output returns to its normal mode the message FIXED
CURRENT MODE CANCELLED will be displayed. This could occur for three reasons, master has sent
the appropriate command, the DT Series has been powered off then on again, or the output in fixed current
mode has been at the same value for 20 minutes.
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D16.0
Multidrop or Bus Operation
16.1
Introduction
The Level transmitter, when supplied from the factory with standard ex-factory programming, is
suitable for operation on a single instrument loop – i.e. it is configured to set the current in such a 4-20mA
loop to the value dictated by the liquid level measured.
Part of the HART capability and conformance is that the same sensor is able to be configured for operation
on a multi-sensor loop – this is variously referred to as “Multi-drop” or “Bus” operation. To function in this
manner the transmitter draws 4mA only, and is connected in parallel with various other similar sensors. Each
transmitter on the Bus is given a unique address, between 1 and 15, and in its simplest form a digital
communications system is used on the single loop to collect data from each address. The DT Series is able to
be configured in this way, and so provides the capability of upgrading to digital signalling on one Multi-drop
loop when this is eventually installed on the plant.
16.2
Simple Addresses
The simple addresses available for transmitters are 0-15. All standard ex-factory simple addresses
are set to zero (unless special programming has been requested).
Address 0 – is used for any DT Series transmitter providing control of a 4-20mA loop proportional to PV
Addresses 1-15 – are used for DT Series or any other HART transmitter on a Multi-drop/multi-sensor loop.
Each transmitter (or sensor) draws a fixed 4mA from the power supply on the loop, and responds to digital
interrogations labelled for the specific address.
16.3
Extended Addressing
The Extended Addressing facility of the HART Revision 5.1 Protocol is available with the DT Series. This
makes access to instruments on a Multi-drop loop slightly simpler, since the specific instrument can be
identified by Tag Number or Unique Identifier codes.
The Tag Number is that coding entered on the programme parameter P1. This has the standard ex-factory
value DT Series, unless the purchase order has specifically identified a different Tag.
The Unique Identifier is a set of three code numbers specified by the HART protocol, to identify the
equipment manufacturer (by code), the instrument type (by code), and the serial number (as on the label on
the transmitter).
The manufacturer’s code number in the HART protocol is 59. DT Series Type No. is 41. (MSP100
is 21, Pressure Transmitter is 19). The sensor serial number is loaded into the memory as
parameter D08, the device ID number. This is also written on the transmitter label.
16.4
Access to a Multi-drop/Bus Transmitter
The SMART communicator is attached across the two wires which provide the power for all the transmitters,
in the same way as for a single transmitter loop. The load resistance between the communicator and the
power supply is still essential. The current drawn by each sensor is 4mA, with all transmitters in parallel, so
the total current can be calculated. Obviously with the 15 transmitters attached, the load resistor of 250
ohms will create a voltage drop of 15V, so the power supply would have to provide 27V minimum. With
intrinsically safe barriers and Cenelec approved systems, a maximum of 4 transmitters are expected to be
allowed on the hazardous side of any barrier. (See Approval Documentation).
When the DT Series selection is made from the Main Psion menu, the initial loop interrogation seeks a
standard 4-20mA single loop transmitter. The screen shows the message –
NO SINGLE LOOP
INSTRUMENT CONNECTED
RETRY (Y)es or (N)o
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The search must now be made for a Multi-drop instrument. Press N for No, and the option for OFFLINE
programming suggested. This is rejected by pressing N and then MULTI-DROP PROGRAMMING is
offered, which is accepted.
**** MULTIDROP ****
Simple-addressing
Extended-addressing
Here the option between SIMPLE and EXTENDED addressing is chosen. If SIMPLE addressing is chosen
SIMPLE ADDRESSING
** SIMPLE ADDRESS **
Select
Poll
Change
Three routes are now offered. If the transmitter address (1-15) is known, it can be accessed using the
SELECT option, which will then advise that is found at that address.
ENTER ADDRESS
MLT100 FOUND
TAG TANK 4
ACCESS( Y)es or (N)o
On accessing the transmitter data the first screen will give the tag number (P01) and description (P02) to
confirm the transmitter interrogated.
MLT100
TAG TANK 4
MLT100 XDUCER
ACCEPT (Y)es or (N)o
If the transmitter addresses are unknown, each address (1-15) can be interrogated in turn by selecting the
POLL function. This will identify all the equipment located on the Bus.
The CHANGE function is the only function that allows the system to interface between addresses 1-15 and
address 0. The screens prompt entry of address numbers – an example would be
ENTER OLD ADDRESS
1
ENTER NEW ADDRESS
0
Here the Multi-drop/Bus system transmitter address 1 is having its address amended to 0 – i.e. it is being
changed back to a single loop 4-20mA transmitter function. On pressing EXE the change is requested
confirmed –
CHANGING ADDRESS 1
TO ADDRESS 0
ACCEPT (Y)es or (N)o
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EXTENDED ADDRESSING
The alternative of EXTENDED addressing has two selections
* EXTENDED ADDRESS *
Tag-number
Identifier
The Tag Number can therefore be used directly, or alternatively the Identifier option can be selected to recall
equipment, type and sensor serial number
INSTRUMENT TYPE NO
2
SERIAL NUMBER
1102
D.16.5 Initial Multi-drop loop creation
This requires care and logic to avoid confusion. In most cases the equipment supplied will be loaded with the
ex-factory standard parameters, which will all have the simple address 0. (Special factory programming of the
transmitter may have set up a different address for each transmitter, but this will be the exception).
Since all units with address 0 are 4-20mA transducers, installation immediately on a Multi-transmitter single
power supply loop might cause excessive current drain on the loop. A separate problem is that each sensor
will require individual connection to a loop so that it is the only one having address 0, to allow the SMART
Communicator to change this to the desired address between 1-15.
It is therefore recommended that each transmitter is set up in the workshop on a simple loop, and that the
initial address is amended, taking note of the unique transmitter number (on the label outside the transmitter
but also recorded on D08). Then when the transmitters are installed on the plant, this same transmitter
number (read from the label) can be recorded against the tank description or tag number, so allowing the
correct calibration of the transmitter for this tank (later from the control room).
In order not to confuse the “average” operator, MULTI-DROP addressing is not mentioned on interrogating
a simple 4-20mA level transmitter. To access the MULTI-DROP menus it is necessary to reject the
instrument found at address 0.
Then Press Y, EXE, to reach the Simple Address Screen
** SIMPLE ADDRESS **
Select
Poll
Change
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D.17.0 Unknown Instrument
This limited support for unknown transmitter is provided so that the identification and basic performance of
any transmitter can be obtained without having to change to another HHC. This is of particular use in multidrop networks where all the currently occupied addresses need to be identified when selecting an address for
an additional transmitter on the loop.
If the transmitter detected is not an DT Series or MSP100 then Unknown Transmitter is displayed and an
access to the parameters is prompted for. If this is selected then the parameters that are present on all
transmitters are uploaded, after first setting up any files that are required.
Because the transmitter is Unknown some parameters can only be read.
A single menu allows access to all the available parameters.
UNKNOWN INSTRUMENT
Identity Fixed _data
Monitor Output
Sensor_info
D.17.1
D.17.2
The following three groups of parameters have the same meaning as those for an DT Series.
IDENTITY
P0 to P5
FIXED DATA
D0 to D8
MONITOR
D10 to D15
The last two groups provide a subset of instrument’s calibration data :OUTPUT
P10 Alarm Code
P10 to P16
This shows whether the current will go to maximum if the sensor fails in the
instrument.
P11 Transfer
This can be used to apply a non-linear relationship between the measured value
and the digital and analog outputs.
P12 Range Units
The units used on the next two parameters.
P13 Calibration Max
The Primary Variable value for 20mA output.
P14 Calibration Min
The Primary Variable value for 4mA output.
P15 Damping
The smoothing to be applied to the digital and analog outputs.
P16 Write Protect Code
The state of any parameter write protection.
SENSOR INFO P20 to P23
P20 Limit/Span Units
The units used for the next three parameters
P21 Upper Limit
The maximum value the sensor will measure.
P22 Lower Limit
The minimum value the sensor will measure.
P23 Minimum Span
The smallest allowable difference between calibration max (P13) and calibration
min (P14).
If the instrument conforms to revision 5 or higher of the HART protocol then the manufacturer of the instrument
will be available. If it is of an earlier revision then only the model number will be available.
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D18.0
SMART Interfaces – Compatibility
D18.1
Introduction
The SMART Level Measurement Transmitter uses the HART digital communications protocol.
This was originally developed by Rosemount Inc. in USA, and uses Bell 202 Frequency Shift Key signalling on top of
a 2 wire DC loop supply. The system conforms to Revision 5.1 of the HART protocol.
Various other manufacturers use this same HART protocol and produce sensor equipment that can be attached to 420mA or digital loops. Similarly there are other hand held communicators that use the HART protocol to interrogate
transmitters in such loops. Not all manufacturers’ equipment conforms to the Revision 5.3 of the protocol.
At present the major SMART communicators working to a HART protocol are
CK1 and –CK2
HART Communicator Model 275 manufactured by Rosemount
Rosemount Model 268
Measurement Technology MTL 611 and CNF 41
H-View
This is a rapidly developing field, and the specification of these units is continually being updated. Each updating
produces better interoperability and user friendly operation. However, even equipment conforming to the same
Revision of the protocol from different manufacturers cannot be regarded as compatible, because each sensor has a
unique programme structure.
D18.2
Communicators recognising transmitters
As at May 1992 only the Arcom System HLINE and the CK1 or CK2 SMART Communications kits
recognise and can fully interrogate the transmitters.
Other HART protocol Revision 5 communicators can talk to the transmitter but only register this on their
display as an “Unknown Instrument” (DD available mid 98 which will allow 275 to be used).
D18.3
Transmitters recognised by the SMART Communicators
The CK1 and –CK2 SMART Communicators can identify and interrogate all variants of the DT Series
MSP100 ultrasonic level transmitters.
and
If a SMART Communicator is connected to a loop with another type of transmitter, for example the
Rosemount 1151 pressure transmitter, it will record the presence of an “Unknown instrument”. Various parameters
can be read (see Section D17.0) and a limited set of common parameters can be changed.
D18.4
Use of multiple SMART Communicators
The HART SMART protocol allows only two SMART digital communicators to be active on the same loop at once.
Only one of these can be a hand held communicator (known as “Secondary Master”) such as the CK1 or
the Rosemount 275 : the second must be a permanent monitoring system such as H-View (which is
designated as a ”Primary Master”).
If two hand held communicators are connected to the same loop at the same time and both try to communicate at
once there will be a conflict in the messages and neither unit will function correctly.
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APPENDIX E
Block Diagram / Flowchart
Fig. E1 below shows the processing of the data within the transmitter. The transmitter is set up by P
parameters and, as the data is processed, diagnostic information is produced which is available as D parameters.
These parameters are identified alongside the diagram.
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