Vega VEGABAR 81 User manual

Operating Instructions
Pressure transmitter with chemical seal
VEGABAR 81
Modbus and Levelmaster protocol
Document ID: 46293

2
Contents
VEGABAR 81 • Modbus and Levelmaster protocol
46293-EN-200529
Contents
1 About this document ............................................................................................................... 4
1.1 Function ........................................................................................................................... 4
1.2 Target group ..................................................................................................................... 4
1.3 Symbols used................................................................................................................... 4
2 For your safety ......................................................................................................................... 5
2.1 Authorised personnel ....................................................................................................... 5
2.2 Appropriate use................................................................................................................ 5
2.3 Warning about incorrect use............................................................................................. 5
2.4 General safety instructions............................................................................................... 5
2.5 EU conformity................................................................................................................... 5
2.6 NAMUR recommendations .............................................................................................. 6
2.7 Installation and operation in the USA and Canada ........................................................... 6
2.8 Environmental instructions ............................................................................................... 6
3 Product description ................................................................................................................. 7
3.1 Conguration.................................................................................................................... 7
3.2 Principle of operation........................................................................................................ 8
3.3 Supplementary cleaning procedures.............................................................................. 10
3.4 Packaging, transport and storage................................................................................... 11
3.5 Accessories.................................................................................................................... 11
4 Mounting................................................................................................................................. 13
4.1 General instructions ....................................................................................................... 13
4.2 Instructions for oxygen applications ............................................................................... 15
4.3 Ventilation and pressure compensation.......................................................................... 15
4.4 Process pressure measurement..................................................................................... 16
4.5 Level measurement........................................................................................................ 18
4.6 External housing ............................................................................................................ 18
5 Connecting to power supply and bus system .................................................................... 19
5.1 Preparing the connection ............................................................................................... 19
5.2 Connecting..................................................................................................................... 20
5.3 Wiring plan ..................................................................................................................... 22
5.4 External housing with version IP68 (25 bar) ................................................................... 23
5.5 Switch-on phase............................................................................................................. 25
6 Set up the sensor with the display and adjustment module............................................. 26
6.1 Insert display and adjustment module............................................................................ 26
6.2 Adjustment system......................................................................................................... 27
6.3 Measured value indication.............................................................................................. 28
6.4 Parameter adjustment - Quick setup .............................................................................. 29
6.5 Parameter adjustment - Extended adjustment................................................................ 29
6.6 Saving the parameterisation data................................................................................... 41
7 Setting up sensor and Modbus interface with PACTware .................................................. 42
7.1 Connect the PC.............................................................................................................. 42
7.2 Parameter adjustment with PACTware............................................................................ 43
7.3 Set instrument address .................................................................................................. 44
7.4 Saving the parameterisation data................................................................................... 45
8 Diagnosis, asset management and service ........................................................................ 46

3
Contents
VEGABAR 81 • Modbus and Levelmaster protocol
46293-EN-200529
8.1 Maintenance .................................................................................................................. 46
8.2 Diagnosis memory ......................................................................................................... 46
8.3 Asset Management function........................................................................................... 47
8.4 Rectify faults................................................................................................................... 49
8.5 Exchanging the electronics module................................................................................ 50
8.6 Exchange process module on version IP68 (25 bar) ...................................................... 50
8.7 Software update ............................................................................................................. 51
8.8 How to proceed if a repair is necessary.......................................................................... 52
9 Dismount................................................................................................................................. 53
9.1 Dismounting steps.......................................................................................................... 53
9.2 Disposal ......................................................................................................................... 53
10 Supplement ............................................................................................................................ 54
10.1 Technical data ................................................................................................................ 54
10.2 Chemical seal with vacuum applications........................................................................ 63
10.3 Device communication Modbus ..................................................................................... 66
10.4 Modbus register ............................................................................................................. 67
10.5 Modbus RTU commands ............................................................................................... 69
10.6 Levelmaster commands ................................................................................................. 72
10.7 CongurationoftypicalModbushosts ........................................................................... 75
10.8 Dimensions .................................................................................................................... 75
10.9 Industrial property rights................................................................................................. 83
10.10 Trademark ...................................................................................................................... 83
Safety instructions for Ex areas
TakenoteoftheExspecicsafetyinstructionsforExapplications.
These instructions are attached as documents to each instrument
with Ex approval and are part of the operating instructions.
Editing status: 2020-05-12

4
1 About this document
VEGABAR 81 • Modbus and Levelmaster protocol
46293-EN-200529
1 About this document
1.1 Function
This instruction provides all the information you need for mounting,
connection and setup as well as important instructions for mainte-
nance,faultrectication,theexchangeofpartsandthesafetyofthe
user. Please read this information before putting the instrument into
operation and keep this manual accessible in the immediate vicinity
of the device.
1.2 Target group
This operating instructions manual is directed to trained personnel.
Thecontentsofthismanualmustbemadeavailabletothequalied
personnel and implemented.
1.3 Symbols used
Document ID
This symbol on the front page of this instruction refers to the Docu-
ment ID. By entering the Document ID on www.vega.com you will
reach the document download.
Information, note, tip: This symbol indicates helpful additional infor-
mation and tips for successful work.
Note: This symbol indicates notes to prevent failures, malfunctions,
damage to devices or plants.
Caution: Non-observance of the information marked with this symbol
may result in personal injury.
Warning: Non-observance of the information marked with this symbol
may result in serious or fatal personal injury.
Danger: Non-observance of the information marked with this symbol
results in serious or fatal personal injury.
Ex applications
This symbol indicates special instructions for Ex applications.
• List
The dot set in front indicates a list with no implied sequence.
1 Sequence of actions
Numbers set in front indicate successive steps in a procedure.
Battery disposal
This symbol indicates special information about the disposal of bat-
teries and accumulators.

5
2 For your safety
VEGABAR 81 • Modbus and Levelmaster protocol
46293-EN-200529
2 For your safety
2.1 Authorised personnel
All operations described in this documentation must be carried out
onlybytrained,qualiedpersonnelauthorisedbytheplantoperator.
During work on and with the device, the required personal protective
equipment must always be worn.
2.2 Appropriate use
The VEGABAR 81 is a pressure transmitter for process pressure and
hydrostatic level measurement.
Youcannddetailedinformationabouttheareaofapplicationin
chapter "Product description".
Operational reliability is ensured only if the instrument is properly
usedaccordingtothespecicationsintheoperatinginstructions
manual as well as possible supplementary instructions.
2.3 Warning about incorrect use
Inappropriate or incorrect use of this product can give rise to applica-
tion-specichazards,e.g.vesseloverllthroughincorrectmounting
or adjustment. Damage to property and persons or environmental
contamination can result. Also, the protective characteristics of the
instrument can be impaired.
2.4 General safety instructions
This is a state-of-the-art instrument complying with all prevailing
regulations and directives.The instrument must only be operated in a
technicallyawlessandreliablecondition.Theoperatorisresponsi-
ble for the trouble-free operation of the instrument.When measuring
aggressive or corrosive media that can cause a dangerous situation
if the instrument malfunctions, the operator has to implement suitable
measures to make sure the instrument is functioning properly.
The safety instructions in this operating instructions manual, the na-
tional installation standards as well as the valid safety regulations and
accident prevention rules must be observed by the user.
For safety and warranty reasons, any invasive work on the device
beyond that described in the operating instructions manual may be
carried out only by personnel authorised by the manufacturer. Arbi-
traryconversionsormodicationsareexplicitlyforbidden.Forsafety
reasons,onlytheaccessoryspeciedbythemanufacturermustbe
used.
To avoid any danger, the safety approval markings and safety tips on
the device must also be observed.
2.5 EU conformity
ThedevicefullsthelegalrequirementsoftheapplicableEUdirec-
tives.ByaxingtheCEmarking,weconrmtheconformityofthe
instrument with these directives.

6
2 For your safety
VEGABAR 81 • Modbus and Levelmaster protocol
46293-EN-200529
The EU conformity declaration can be found on our homepage.
Duetothedesignofitsprocessttings,thedevicedoesnotsubject
of EU pressure device directive if it is operated at process pressures
≤200bar.1)
2.6 NAMUR recommendations
NAMUR is the automation technology user association in the process
industry in Germany. The published NAMUR recommendations are
acceptedasthestandardineldinstrumentation.
ThedevicefullstherequirementsofthefollowingNAMURrecom-
mendations:
• NE 21 – Electromagnetic compatibility of equipment
• NE53–Compatibilityofelddevicesanddisplay/adjustment
components
• NE107–Self-monitoringanddiagnosisofelddevices
For further information see www.namur.de.
2.7 Installation and operation in the USA and
Canada
This information is only valid for USA and Canada. Hence the follow-
ing text is only available in the English language.
Installations in the US shall comply with the relevant requirements of
theNationalElectricalCode(ANSI/NFPA70).
Installations in Canada shall comply with the relevant requirements of
the Canadian Electrical Code.
2.8 Environmental instructions
Protection of the environment is one of our most important duties.
That is why we have introduced an environment management system
with the goal of continuously improving company environmental pro-
tection.Theenvironmentmanagementsystemiscertiedaccording
to DIN EN ISO 14001.
Pleasehelpusfullthisobligationbyobservingtheenvironmental
instructions in this manual:
• Chapter "Packaging, transport and storage"
• Chapter "Disposal"
1) Exception:Versions with measuring ranges from 250 bar. These are subject
of the EU Pressure Device Directive.

7
3 Product description
VEGABAR 81 • Modbus and Levelmaster protocol
46293-EN-200529
3 Product description
3.1 Conguration
The scope of delivery encompasses:
• VEGABAR 81 pressure transmitter
The further scope of delivery encompasses:
• Documentation
– Quick setup guide VEGABAR 81
– Testcerticateforpressuretransmitters
– Instructions for optional instrument features
– Ex-specic"Safety instructions" (with Ex versions)
– Ifnecessary,furthercerticates
Information:
Optional instrument features are also described in this operating
instructions manual.The respective scope of delivery results from the
orderspecication.
This operating instructions manual applies to the following instrument
versions:
• Hardware from 1.0.0
• Software from 1.3.5
Note:
Youcanndthehardwareandsoftwareversionoftheinstrumentas
follows:
• On the type plate of the electronics module
• In the adjustment menu under "Info"
Thetypelabelcontainsthemostimportantdataforidenticationand
use of the instrument:
7
6
4
5
2
3
1
Fig. 1: Layout of the type label (example)
1 Product code
2 Field for approvals
3 Technical data
4 Serial number of the instrument
5 QR code
6 Symbol of the device protection class
7 ID numbers, instrument documentation
Scope of delivery
Scope of this operating
instructions
Type label

8
3 Product description
VEGABAR 81 • Modbus and Levelmaster protocol
46293-EN-200529
The type label contains the serial number of the instrument. With it
youcanndthefollowinginstrumentdataonourhomepage:
• Product code (HTML)
• Delivery date (HTML)
• Order-specicinstrumentfeatures(HTML)
• Operating instructions and quick setup guide at the time of ship-
ment (PDF)
• Order-specicsensordataforanelectronicsexchange(XML)
• Testcerticate(PDF)-optional
Move to "www.vega.com"andenterinthesearcheldtheserial
number of your instrument.
Alternatively, you can access the data via your smartphone:
• Download the VEGA Tools app from the "Apple App Store" or the
"Google Play Store"
• Scan the DataMatrix code on the type label of the instrument or
• Enter the serial number manually in the app
Theinstrumentcontainstwodierentelectronicsinitshousingcham-
bers:
• The Modbus electronics for power supply and communication with
the Modbus-RTU
• The sensor electronics for the actual measuring tasks
2
1
Fig. 2: Position of Modbus and sensor electronics
1 Modbus electronics
2 Sensor electronics
3.2 Principle of operation
VEGABAR 81 is suitable for applications in virtually all industries. It is
used for the measurement of the following pressure types.
• Gauge pressure
• Absolute pressure
• Vacuum
Measured products are gases, vapours and liquids.
The chemical seal systems of VEGABAR 81, which are optimally
adapted to the process, also allow measurement of highly corrosive
and hot products.
The VEGABAR 81 is suitable for the measurement of the following
process variables:
Serial number - Instru-
ment search
Electronics design
Application area
Measured products
Measured variables

9
3 Product description
VEGABAR 81 • Modbus and Levelmaster protocol
46293-EN-200529
• Process pressure
• Level
Fig. 3: Process pressure measurement VEGABAR 81
The VEGABAR 81 is equipped with a chemical seal. It consists of a
stainless steel diaphragm and a transmission liquid.
A chemical seal has two tasks:
• Separation of the sensor element from the medium
• Transmission of the process pressure to the sensor element
1
2
3
4
Fig. 4: Conguration of a chemical seal
1 Sensor element
2 Sealed screw
3 Transmission liquid
4 Stainless steel diaphragm
Thechemicalsealisavailableindierentversions,seechapter
"Dimensions".
The process pressure acts on the sensor element via the isolat-
ing diaphragm.The process pressure causes a resistance change
which is converted into a corresponding output signal and output as
measured value.
Chemical seal
Measuring system

10
3 Product description
VEGABAR 81 • Modbus and Levelmaster protocol
46293-EN-200529
Measuringrangesupto40bar:piezoresistivesensorelementwith
a transmission liquid, measuring ranges from 100 bar: a dry strain
gauge (DMS) sensor element.
1
3 4
2
Fig. 5: Conguration of a measuring system with piezoresistive sensor element
1 Sensor element
2 Base element
3 Transmission liquid
4 Diaphragm
1
2
3
Fig. 6: Conguration of a measuring system with strain gauge (DMS) sensor
element
1 Sensor element
2 Process diaphragm
3 Pressure cylinder
Relative pressure: the measuring cell is open to the atmosphere.
The ambient pressure is detected in the measuring cell and compen-
sated.Itthushasnoinuenceonthemeasuredvalue.
Absolute pressure: the measuring cell contains vacuum and is
encapsulated.The ambient pressure is not compensated and does
henceinuencethemeasuredvalue.
The measuring system is completely welded and thus sealed against
the process.
Theprocessttingissealedagainsttheprocessbyasuitableseal.It
mustbeprovidedbythecustomer,dependingontheprocesstting
also included in the scope of delivery, see chapter "Technical data",
"Materials and weights".
3.3 Supplementary cleaning procedures
The VEGABAR 81 is also available in the version "Oil, grease and
silicone-free".These instruments have passed through a special
Pressure types
Seal concept

11
3 Product description
VEGABAR 81 • Modbus and Levelmaster protocol
46293-EN-200529
cleaning procedure to remove oil, grease and paint-wetting impair-
ment substances (PWIS).
The cleaning is carried out on all wetted parts as well as on surfaces
accessible from outside.To keep the purity level, the instruments are
immediately packed in plastic foil after the cleaning process.The
purity level remains as long as the instrument is kept in the closed
original packaging.
Caution:
The VEGABAR 81 in this version may not be used in oxygen ap-
plications. For this purpose, instruments are available in the special
version "Oil, grease and silicone-free for oxygen applications".
3.4 Packaging, transport and storage
Your instrument was protected by packaging during transport. Its
capacity to handle normal loads during transport is assured by a test
based on ISO 4180.
The packaging consists of environment-friendly, recyclable card-
board. For special versions, PE foam or PE foil is also used. Dispose
of the packaging material via specialised recycling companies.
Transport must be carried out in due consideration of the notes on the
transport packaging. Nonobservance of these instructions can cause
damage to the device.
The delivery must be checked for completeness and possible transit
damage immediately at receipt. Ascertained transit damage or con-
cealed defects must be appropriately dealt with.
Up to the time of installation, the packages must be left closed and
stored according to the orientation and storage markings on the
outside.
Unless otherwise indicated, the packages must be stored only under
the following conditions:
• Not in the open
• Dry and dust free
• Not exposed to corrosive media
• Protected against solar radiation
• Avoiding mechanical shock and vibration
• Storage and transport temperature see chapter "Supplement -
Technical data - Ambient conditions"
• Relative humidity 20 … 85 %
With instrument weights of more than 18 kg (39.68 lbs) suitable and
approved equipment must be used for lifting and carrying.
3.5 Accessories
The instructions for the listed accessories can be found in the down-
load area on our homepage.
Packaging
Transport
Transport inspection
Storage
Storage and transport
temperature
Lifting and carrying

12
3 Product description
VEGABAR 81 • Modbus and Levelmaster protocol
46293-EN-200529
The display and adjustment module is used for measured value indi-
cation, adjustment and diagnosis.
The integrated Bluetooth module (optional) enables wireless adjust-
ment via standard adjustment devices.
The interface adapter VEGACONNECT enables the connection of
communication-capable instruments to the USB interface of a PC.
Slave sensors of VEGABAR series 80 enable in conjunction with
VEGABAR81anelectronicdierentialpressuremeasurement.
The VEGADIS 81 is an external display and adjustment unit for VEGA
plics®sensors.
The VEGADIS adapter is an accessory part for sensors with double
chamber housings. It enables the connection of VEGADIS 81 to the
sensor housing via an M12 x 1 plug.
The protective cover protects the sensor housing against soiling and
intense heat from solar radiation.
Screwedangesareavailableindierentversionsaccordingtothe
following standards: DIN 2501, EN 1092-1, BS 10, ASME B 16.5,
JIS B 2210-1984, GOST 12821-80.
Welded sockets are used to connect the sensors to the process.
Threaded adapters enable simple adaptation of sensors with stand-
ardthreadedttings,e.g.toprocess-sidehygieneconnections.
PLICSCOM
VEGACONNECT
Slave sensors
VEGADIS 81
VEGADIS adapter
Protective cover
Flanges
Welded sockets and
adapters

13
4 Mounting
VEGABAR 81 • Modbus and Levelmaster protocol
46293-EN-200529
4 Mounting
4.1 General instructions
Note:
For safety reasons, the instrument must only be operated within the
permissibleprocessconditions.Youcannddetailedinformationon
the process conditions in chapter "Technical data" of the operating
instructions or on the type label.
Hence make sure before mounting that all parts of the instrument ex-
posed to the process are suitable for the existing process conditions.
These are mainly:
• Active measuring component
• Processtting
• Process seal
Process conditions in particular are:
• Process pressure
• Process temperature
• Chemical properties of the medium
• Abrasionandmechanicalinuences
Protect your instrument against moisture ingress through the following
measures:
• Use a suitable connection cable (see chapter "Connecting to
power supply")
• Tighten the cable gland or plug connector
• Lead the connection cable downward in front of the cable entry or
plug connector
This applies mainly to outdoor installations, in areas where high
humidity is expected (e.g. through cleaning processes) and on cooled
or heated vessels.
Note:
Makesurethatthedegreeofcontaminationspeciedinchapter
"Technical data" meets the existing ambient conditions.
Note:
Make sure that during installation or maintenance no moisture or dirt
can get inside the instrument.
To maintain the housing protection, make sure that the housing lid is
closed during operation and locked, if necessary.
Deviceswiththreadedttingarescrewedintotheprocessttingwith
a suitable wrench via the hexagon.
See chapter "Dimensions"forwrenchsize.
Process conditions
Protection against mois-
ture
Screwing in

14
4 Mounting
VEGABAR 81 • Modbus and Levelmaster protocol
46293-EN-200529
Warning:
The housing or the electrical connection may not be used for screw-
ing in! Depending on the device version, tightening can cause dam-
age, e. g. to the rotation mechanism of the housing.
If there is strong vibration at the mounting location, the instrument
version with external housing should be used. See chapter "External
housing".
Thepermissibleprocesspressurerangeisspeciedby"MWP"(Maxi-
mum Working Pressure) on the type label, see chapter "Structure".
The MWP takes the element of the measuring cell and processing
ttingcombinationwiththeweakestpressureintoconsiderationand
mayappliedpermanently.Thespecicationreferstoareference
temperature of +20 °C (+68 °F). It also applies when a measuring cell
with a higher measuring range than the permissible pressure range of
theprocessttingisinstalledorder-related.
In order to prevent damage to the device, a test pressure may only
exceedthespeciedMWPbrieyby1.5timesatreferencetempera-
ture.Thepressurestageoftheprocessttingaswellastheoverload
resistance of the measuring cell are taken into consideration here
(see chapter "Technical Data").
Inaddition,atemperaturederatingoftheprocesstting,e.g.with
anges,canlimitthepermissibleprocesspressurerangeaccording
to the respective standard.
The permissible process pressure range is stated on the type label.
The instrument should only be operated with these pressures if the
mountingaccessoryusedalsofullsthesevalues.Thisshouldbeen-
suredbysuitableanges,weldedsockets,tensionringswithClamp
connections, sealings, etc.
Higher process temperatures often mean also higher ambient
temperatures. Make sure that the upper temperature limits stated in
chapter "Technical data" for the environment of the electronics hous-
ing and connection cable are not exceeded.
1
2
Fig. 7: Temperature ranges
1 Process temperature
2 Ambient temperature
Vibrations
Permissible process
pressure (MWP) - Device
Permissible process
pressure (MWP) - Mount-
ing accessory
Temperature limits

15
4 Mounting
VEGABAR 81 • Modbus and Levelmaster protocol
46293-EN-200529
4.2 Instructions for oxygen applications
Oxygen and other gases can be explosive when brought into contact
with oils, grease and plastics, so the following measures must also be
taken:
• All components of the system, e.g. measuring instruments, must
becleanedinaccordancewiththerequirementsofrecognized
regulations or standards
• Depending on the seal material, certain temperatures and pres-
sures must not be exceeded in oxygen applications, see chapter
"Technical data"
Danger:
Instruments for oxygen applications must be unpacked just before
mounting.Afterremovingtheprotectivecoveroftheprocesstting,
the label "O2"willbevisibleontheprocesstting.Penetrationofoil,
grease and dirt should be avoided. Danger of explosion!
4.3 Ventilation and pressure compensation
Thelterelementintheelectronicshousinghasthefollowingfunc-
tions:
• Ventilation of the electronics housing
• Atmospheric pressure compensation (with relative pressure meas-
uring ranges)
Caution:
Thelterelementcausesatime-delayedpressurecompensation.
Whenquicklyopening/closingthehousingcover,themeasuredvalue
can change for approx. 5 s by up to 15 mbar.
Foraneectiveventilation,thelterelementmustbealwaysfreefrom
buildup.Incaseofhorizontalmounting,turnthehousingsothatthe
lterelementpointsdownwardaftertheinstrumentisinstalled.This
provides better protection against buildup.
Caution:
Donotuseahigh-pressurecleaner.Thelterelementcouldbedam-
aged, which would allow moisture into the housing.
Thefollowingparagraphsdescribehowthelterelementisarranged
inthedierentinstrumentversions.
Oxygen applications
Filter element - Function

16
4 Mounting
VEGABAR 81 • Modbus and Levelmaster protocol
46293-EN-200529
33
2
1
Fig. 8: Position of the lter element
1 Plastic double chamber housing
2 Aluminium, stainless steel (precision casting) double chamber
3 Filter element
4.4 Process pressure measurement
Keep the following in mind when setting up the measuring system:
• Mount the instrument above the measuring point
Possiblecondensationcanthendrainointotheprocessline.
1
2
3
Fig. 9: Measurement setup for process pressure measurement of gases in
pipelines
1 VEGABAR 81
2 Blocking valve
3 Pipeline
Keep the following in mind when setting up the measuring system:
• Connect via a siphon
• Do not insulate the siphon
• Fill the siphon with water before setup
Filter element - Position
Measurement setup in
gases
Measurement setup in
vapours

17
4 Mounting
VEGABAR 81 • Modbus and Levelmaster protocol
46293-EN-200529
1
4
3
2
1
2
3
4
Fig. 10: Measurement setup for the process pressure measurement of gases in
pipelines
1 VEGABAR 81
2 Blocking valve
3 Siphon in U or circular form
4 Pipeline
A protective accumulation of water is formed through condensation
in the pipe bends. Even in applications with hot steam, a medium
temperature < 100 °C on the transmitter is ensured.
Keep the following in mind when setting up the measuring system:
• Mount the instrument below the measuring point
Theeectivepressurelineisalwayslledwithliquidandgasbubbles
can bubble up to the process line.
3
1
2
Fig. 11: Measurement setup for the process pressure measurement of liquids in
pipelines
1 VEGABAR 81
2 Blocking valve
3 Pipeline
Measurement setup in
liquids

18
4 Mounting
VEGABAR 81 • Modbus and Levelmaster protocol
46293-EN-200529
4.5 Level measurement
Keep the following in mind when setting up the measuring system:
• Mount the instrument below the min. level
• Donotmounttheinstrumentclosetothellingstreamoremptying
area
• Mount the instrument so that it is protected against pressure
shocks from the stirrer
Fig. 12: Measurement setup for the level measurement
4.6 External housing
1
2
3
4
5
Fig. 13: Conguration, process module, external housing
1 Pipeline
2 Process module
3 Connection cable process assembly - External housing
4 External housing
5 Signal cable
Measurement setup
Conguration

19
5 Connecting to power supply and bus system
VEGABAR 81 • Modbus and Levelmaster protocol
46293-EN-200529
5 Connecting to power supply and bus
system
5.1 Preparing the connection
Always keep in mind the following safety instructions:
• Carryoutelectricalconnectionbytrained,qualiedpersonnel
authorised by the plant operator
• If overvoltage surges are expected, overvoltage arresters should
be installed
Warning:
Onlyconnectordisconnectinde-energizedstate.
The operating voltage and the digital bus signal are routed via sepa-
rate two-wire connection cables.
Thedataforpowersupplyarespeciedinchapter"Technical data".
Note:
Power the instrument via an energy-limited circuit (power max. 100 W)
acc. to IEC 61010-1, e.g.
• Class 2 power supply unit (acc. to UL1310)
• SELV power supply unit (safety extra-low voltage) with suitable
internal or external limitation of the output current
The instrument is connected with standard two-wire, twisted cable
suitable for RS 485. If electromagnetic interference is expected which
is above the test values of EN 61326 for industrial areas, shielded
cable should be used.
Use cable with round cross section for instruments with housing and
cable gland. Use a cable gland suitable for the cable diameter to
ensurethesealeectofthecablegland(IPprotectionrating).
Make sure that the entire installation is carried out according to the
Fieldbusspecication.Inparticular,makesurethatthebusistermi-
nated with suitable terminating resistors.
Make sure that the cable screen and grounding are carried out ac-
cordingtoFieldbusspecication.Werecommendtoconnectthe
cable screening to ground potential on both ends.
In systems with potential equalisation, connect the cable screening
directly to ground potential at the power supply unit and the sensor.
The cable screening in the sensor must be connected directly to the
internal ground terminal.The ground terminal outside on the housing
must be connected to the potential equalisation (low impedance).
Metric threads
In the case of instrument housings with metric thread, the cable
glands are screwed in at the factory.They are sealed with plastic
plugs as transport protection.
Safety instructions
Voltage supply
Connection cable
Cable screening and
grounding
Cable glands

20
5 Connecting to power supply and bus system
VEGABAR 81 • Modbus and Levelmaster protocol
46293-EN-200529
Note:
You have to remove these plugs before electrical connection.
NPT thread
In the case of instrument housings with self-sealing NPT threads, it is
not possible to have the cable entries screwed in at the factory. The
free openings for the cable glands are therefore covered with red dust
protection caps as transport protection.
Note:
Prior to setup you have to replace these protective caps with ap-
proved cable glands or close the openings with suitable blind plugs.
On plastic housings, the NPT cable gland or the Conduit steel tube
must be screwed into the threaded insert without grease.
Max. torque for all housings, see chapter "Technical data".
5.2 Connecting
The voltage supply and signal output are connected via the spring-
loaded terminals in the housing.
Connection to the display and adjustment module or to the interface
adapter is carried out via contact pins in the housing.
Information:
The terminal block is pluggable and can be removed from the
electronics.To do this, lift the terminal block with a small screwdriver
and pull it out. When reinserting the terminal block, you should hear it
snap in.
Proceed as follows:
1. Unscrew the housing lid
2. Loosen compression nut of the cable gland and remove blind
plug
3. Remove approx. 10 cm (4 in) of the cable mantle (signal output),
strip approx. 1 cm (0.4 in) insulation from the ends of the indi-
vidual wires
4. Insert the cable into the sensor through the cable entry
Connection technology
Connection procedure