MSA Senscient ELDS 1000, Senscient ELDS 2000 Operating Manual

Operating Manual

Senscient ELDS™ 1000 / 2000 Series

Open Path & Cross Duct Gas Detectors

A-5170-0 / Rev 15

Schlüsselstrasse 12
8645 Rapperswil-Jona
Switzerland

Manufacturer:
Senscient Ltd.
Units F1-F4 Arena Business Centre
Holyrood Close
Poole
Dorset
BH17 7FP
United Kingdom

© MSA 2017. All rights reserved

Read and understand this Instruction Manual before installing, operating or servicing
ELDS 1000 / 2000 Series OPGD systems.

Safety

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Safety

Ensure that you read and understand these instructions BEFORE operating the equipment.
Please pay particular attention to the safety Warnings / Special Conditions of Safe Use.

Warnings / Special Conditions of Safe Use

WARNING

1. The Senscient ELDS™ 1000 / 2000 Series gas detectors are Baseefa ATEX certified for use
in Hazardous (Explosive) Atmospheres; and CSA(UL) certified for use in Hazardous
(Classified) Locations/Zones.

2. For installations in Europe (ATEX Certified) install in accordance with IEC/EN60079-14.

3. For installations in North America and Canada install in accordance with ANSI/NFPA 70, the
Canadian Electrical Code C22.1 and the manufacturer’s instructions.

4. Elsewhere, the appropriate local or national regulations should be used.

5. ELDS™ 1000 / 2000 Series gas detectors must be properly earthed / grounded to protect
against electrical shock and minimise electrical interference. Internal and external
equipotential bonding facilities are provided for this purpose. For electrical installation design
considerations refer to section 3.3.

6. Operators must be fully aware of the action to be taken if the gas concentration exceeds an
alarm level.

7. ELDS 1000 / 2000 Series gas detectors do not contain any parts that can be replaced or
repaired by customers. If units require repair they must be safely removed from any
hazardous location / area in which they are installed, and returned to Senscient. Other than
the rear cover providing access to the terminals for connection purposes, the units are not
intended to be opened during operational service.

8. Test gases may be toxic and/or combustible. Refer to Material Safety Data Sheets for
appropriate warnings and handling procedures / precautions.

9. Do not drill holes in any housing as this will invalidate the explosion-proof protection.

10. In order to maintain electrical safety, units must not be operated in atmospheres with more
than 21% v/v oxygen.

11. Ensure that the bolts which secure the front flameproof enclosure are fully tightened. The
securing bolts are stainless steel M5 X 16mm socket head cap screws grade A4-70. To
ensure replacement suitability contact Senscient or their approved agent/distributor.

12. Do not open the enclosure in the presence of an explosive atmosphere. Keep cover tight
when energised

13. The apparatus is certified for use in Hazardous Areas at atmospheric pressures not
exceeding 1.1 bar (16 psi).

14. Install only in environments with ambient temperature ranges of -40°C to +60°C.

15. For Europe (ATEX), apparatus incorporates an integral threaded cable entry (M25 x 1.5).
Terminate cable only with a suitable equipment certified ATEX cable gland (not a
component). To maintain water and dust ingress protection seal threads with suitable non­hardening sealant as described in IEC/EN 60079-14.

Note: See control drawing for product specification allowing selection of cable glands.

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WARNING

16. For US/Canada the apparatus incorporates an integral threaded conduit entry (3/4”-14TPI).
Install a conduit seal within 18 inches. In order to maintain ingress protection seal threads
with a suitable material e.g. a non-hardening thread sealant or PTFE tape etc. See control
drawing at the end of this manual.

17. For all installations use cable / conductors rated for service at temperatures ≥ 85°C

18. At all times during transit, installation and commissioning protect lens from accidental direct
mechanical impact. Use Senscient OEM supplied packaging during transit.

19. The Transmitter and Receiver units must be mounted horizontally and protected from impact
i.e. do not mount at floor level or in areas where moving vehicles, personnel or loads may be
of concern regarding impact.

CAUTION

1. Use only approved parts and accessories with the Senscient ELDS™ 1000 / 2000 Series
gas detectors.

2. To maintain safety standards, commissioning and regular maintenance of
ELDS™ 1000 / 2000 Series gas detectors should be performed by qualified personnel.

3. Transit cases for the alignment telescope and gassing cell are manufactured from non­antistatic materials, and may, under certain circumstances become an electrostatic risk. It is
the user’s responsibility to take adequate precautions during transportation and use if taken
into hazardous areas.

Important Notices

1. Senscient Inc. can take no responsibility for installation and/or use of its equipment if this is
not done in accordance with the appropriate issue and/or amendment of the manual. The
purchaser should make Senscient aware of any External effects or Aggressive substances
that the equipment may be exposed to.

2. The user of this manual should ensure that it is appropriate in all details to the exact
equipment to be installed and/or operated. If in doubt, the user should contact Senscient Inc.
for advice.

3. Effect of explosive atmosphere on materials.
The Senscient ELDS™ 1000 / 2000 Series is manufactured from materials which exhibit good
resistance to corrosive substances and solvents. The Ex d enclosures are made from 316L
stainless steel and the explosion protected windows are made from robust and chemically
inert glass. Senscient are not aware of any significant effects of explosive atmospheres upon
these materials. The purchaser should make Senscient aware of any External effects or
Aggressive substances that the equipment may be exposed to.

4. The final and long term effectiveness of any Gas Detector depends heavily upon the user, who
must be responsible for its proper application, installation and regular maintenance.

Senscient Inc. reserves the right to change or revise the information supplied in this document
without notice and without obligation to notify any person or organisation of such revision or
change.

If further details are required that do not appear in this manual, contact Senscient or one of their
agents. Senscient will supply this manual in other languages of the European Union (countries
covered by the ATEX directive) upon request.

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Help Us to Help You

Every effort has been made to ensure the accuracy in the contents of our documents. However,
Senscient can assume no responsibility for any errors or omissions in our documents or their
consequences.

Senscient would greatly appreciate being informed of any errors or omissions that may be found in
our documents. To this end we request that if you believe there are any errors or omissions,
please send us an e-mail at [e-mail] describing the error or omission, so that we may
take the appropriate action.

Contents

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Contents

1. Introduction.................................................................................................................................. 8

1.1. Information Notices ........................................................................................................... 10

2. System Description ................................................................................................................... 11

2.1. Introduction ....................................................................................................................... 11

2.2. Transmitter ........................................................................................................................ 12

2.3. Receiver ............................................................................................................................ 13

2.4. Adjustable Mounting Bracket ............................................................................................ 14

2.5. Sunshades ........................................................................................................................ 15

2.6. Cross Duct Mounting Plates ............................................................................................. 17

2.7. SITE Installation & Maintenance Software........................................................................ 19

3. Installation Design & Engineering ........................................................................................... 31

3.1. Introduction ....................................................................................................................... 31

3.2. Siting and Mounting .......................................................................................................... 32

3.3. Electrical Connections....................................................................................................... 44

4. Installation & Commissioning .................................................................................................. 56

4.1. Unpacking an ELDS 1000 / 2000 Series System ............................................................. 56

4.2. Installation Procedure ....................................................................................................... 59

4.3. Alignment .......................................................................................................................... 64

4.4. Cross Duct – Alignment Requirements ............................................................................. 79

4.5. Commissioning Using SITE .............................................................................................. 83

4.6. ELDS Bluetooth™ Wireless Connection ......................................................................... 103

4.7. Installation Checklist ....................................................................................................... 105

5. Functional Testing .................................................................................................................. 108

5.1. Introduction ..................................................................................................................... 108

5.2. SimuGas™ Auto ............................................................................................................. 111

5.3. SimuGas™ Live .............................................................................................................. 113

5.4. SimuGas™ Levels .......................................................................................................... 114

6. Maintenance ............................................................................................................................. 115

6.1. Scheduled Inspection, Cleaning & Testing ..................................................................... 115

6.2. Cleaning Lens-Windows ................................................................................................. 116

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7. Problem Solving ...................................................................................................................... 118

7.1. The Commonest Problems, Issues or Misconceptions Affecting Successful Use of

ELDS OPGDs ................................................................................................................. 118

7.2. SITE Diagnostics Screen ................................................................................................ 120

7.3. Troubleshooting Tables................................................................................................... 125

7.4. Event Logs ...................................................................................................................... 129

8. Specifications .......................................................................................................................... 132

8.1. System ............................................................................................................................ 132

9. Certification.............................................................................................................................. 138

9.1. General............................................................................................................................ 138

10. Appendix A – Glossary ........................................................................................................... 143

10.1. Terminology .................................................................................................................... 143

10.2. Measurement Units ......................................................................................................... 143

10.3. Abbreviations .................................................................................................................. 144

11. Appendix B – Accessories & Spare Parts ............................................................................ 145

11.1. ELDS™ Accessories & Spare Parts ............................................................................... 145

12. Appendix C – Functional Testing Using Gas ....................................................................... 147

12.1. Introduction ..................................................................................................................... 147

12.2. Testing with the Gassing Cell ......................................................................................... 147

12.3. Testing Cross Duct ELDS Systems with the Refillable Gas Test Cell ............................ 153

13. Appendix D – Manufacturer’s EC Declarations .................................................................... 158

14. Appendix E – HART Communications .................................................................................. 161

14.1. Overview ......................................................................................................................... 161

14.2. Electrical Connections / Configuration ............................................................................ 161

14.3. Details of ELDS Data Available via HART ...................................................................... 164

15. Appendix F – MODBUS Communications ............................................................................ 168

16. Appendix G – Measurement Range Guidelines ................................................................... 172

17. Appendix H – 4-20mA Current Output Ranges .................................................................... 179

Introduction

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1. Introduction

The Senscient ELDS™ 1000 / 2000 Series is a range of open path, flammable and / or toxic gas
detectors that is currently available in the following versions.

 Senscient ELDS™ Series 1000 CH

4

- Methane Detector

 Senscient ELDS™ Series 1000 Ethylene, HF, HCl, NH

3

or CO2 Detectors

 Senscient ELDS™ Series 1000 XD – Cross Duct Methane Detector

 Senscient ELDS™ Series 2000 H

2

S - Hydrogen Sulfide Detector

 Senscient ELDS™ Series 2000 CH

4

+ H2S - Simultaneous Methane &

Hydrogen Sulfide Detector

The Senscient ELDS™ Series 1000 detector consists of a Transmitter unit that sends an infrared
laser beam to a separate Receiver unit that can be installed on a line-of-sight at a distance of up to
200m. The ELDS 1000 Series CH

4

detector can be located where there is a risk that a leak of
flammable methane gas may occur, to provide a rapid, early warning of such a hazard. The
ELDS™ 2000 variants are similar, except that there are two coinciding infrared laser beams, which
can either be used to detect two or more gases, or to detect a single, difficult gas with high
sensitivity (e.g. Hydrogen Sulfide).

All ELDS™ gas detectors operate on the principle of absorption of infrared laser light. Gases
absorb light at specific wavelengths depending on their molecular composition. Hydrocarbon
gases such as methane and propane absorb in the infrared region of the spectrum. If a cloud of
target gas is present, the specific wavelengths of the infrared laser light output by the ELDS™
Transmitter are absorbed by the gas, introducing Harmonic Fingerprints onto the signals reaching
the Receiver that are proportional to the amount of gas in the beam.

The Senscient ELDS™ Transmitter unit produces the precisely controlled infrared laser light
required to detect the target gases; whilst the Receiver unit contains an infrared detector and
advanced signal processing electronics which look for the Harmonic Fingerprint produced by the
presence of target gas in the beam-path. Each unit is housed in a robust 316L stainless steel
housing. The Receiver features two 4 - 20mA analogue outputs which are used to signal the
quantity of each target gas measured in the beam-path, for example 0-1LFL.m CH

4

and

0-250ppm.m H

2

S for the Series 2000 detector. These outputs provide a linear relationship with the

measured gas burden.

Note that open path detectors do not measure the point concentration of the target gas(es), rather
they measure the integrated concentration over the length of the measurement path between the
Transmitter and Receiver units. This means that the probable size of a gas cloud must be
considered when estimating the concentration of gas that might be present, with alarm levels
being set accordingly. The figures on the following page illustrate this.

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Each of these different gas clouds will produce the same ELDS reading of 1.0 LFL.m, however
only the 1

st

example where the gas cloud is very small actually has a potentially flammable

concentration within it.

THE TRANSMITTED LASER BEAM IS CLASS 1 (EYE-SAFE) PER IEC 60825.

Senscient ELDS™ is designed for use in the most demanding environments/applications and
provides a sensitive, fast and reliable response. The sophisticated ELDS™ open-path technology
provides immunity to sunlight and minimises the effects of environmental factors such as rain, fog,
ice, snow and condensation.

The Transmitter and Receiver units incorporate heated optics designed to minimise the build-up of
humidity, condensation, snow or ice on the glass lens-windows that could otherwise obscure the
optics in extreme conditions.

Both the Transmitter and the Receiver are microprocessor controlled with advanced self­diagnostics and fault finding facilities.

Local communication between an operator/technician and the gas detector system is provided via
SITE (Senscient Installation & Test Environment) software running on an industrial computer,
using an RS485 or Bluetooth™ wireless communication link to either the Transmitter or Receiver.
SITE provides the user with a menu-style interface to select and invoke commands for
commissioning and configuring the system; and for viewing the system status and readings.

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1.1. Information Notices

The types of information notices used throughout this handbook are as follows:

WARNING

Indicates hazardous or unsafe practice which could result in severe injury or death to personnel.

CAUTION

Indicates hazardous or unsafe practice which could result in minor injury to personnel, or product
or property damage.

Provides useful/helpful/additional information.

If more information beyond the scope of this technical manual is required please contact
Senscient.

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2. System Description

2.1. Introduction

Each Senscient ELDS™ 1000 / 2000 Series gas detector consists of two units, a Transmitter and
a Receiver. This separate Transmitter / Receiver configuration provides the most reliable basis for
open path gas detection. There are no transceiver units or retro-panels utilised in the Senscient
ELDS™.

There are several operating ranges of Senscient ELDS™ gas detector, e.g.:

Series 1000 CH

4

, 0 - 1000ppm.m, 0 - 1LFL.m 5 - 40m

40 - 120m

120 - 200m

Series 2000 CH4 0 - 1LFL.m + H2S 5 - 60m

Series 1000 XD CH4 0 - 10%LFL, 0 - 25%LFL, 0 100%LFL 0.5 - 5m

Series 1000 Ethylene 5 - 60m

40 - 120m

120 - 200m

Series 1000 HF 5 - 60m

60 - 120m

Series 1000 HCl 5 - 60m

Series 1000 NH3 5 - 40m

40 - 120m

Series 1000 CO2 5 - 40m

40 - 120m

Refer to Senscient for additional ranges and gases.

Sun Shade

Monitored Path

Tx and Rx Units

Alignment Adjustment

(horizontal and vertical)

Mounting Bracket

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When designing an installation for Senscient ELDS™ 1000 / 2000 Series it is important
that the correct range of the gas detector for each path to be monitored is selected and
specified.

In order to avoid the problems associated with gas detectors being used beyond their
specified ranges or when incorrectly aligned, a procedure within the Senscient
Installation & Test Environment (SITE) checks for correct gas detector type, operating
range and signal levels before allowing an ELDS OPGD to be commissioned.

The Transmitter and Receiver are each mounted upon robust, adjustable mounting brackets. The
design of the mounting and alignment arrangement for the Senscient ELDS™ 1000 / 2000 Series
is highly accommodating, making it simpler to realise a good installation in a variety of locations
and environments. Installation details are given in section 3.

2.2. Transmitter

The Senscient ELDS™ Transmitter produces up to two controlled-divergence beams of infrared
laser light from solid-state laser diodes. The outputs from the laser diodes are partially collimated
using a faceted lens, the facets of which introduce the controlled-divergence that is necessary to
reduce system alignment sensitivity. The Transmitter operates continuously.

THE TRANSMITTED LASER BEAM IS CLASS 1 (EYE-SAFE) PER IEC 60825.

The Transmitter contains a small retained sample of the target gas(es) to be detected by the
system; and uses this retained sample as a reference to maintain its laser diode(s) in Harmonic
Fingerprint lock. By continuously maintaining Harmonic Fingerprint lock it is possible to be certain
that whenever target gas(es) enter the system’s beam-path this will introduce Harmonic
Fingerprints onto the laser signal(s), which will be seen and measured by the Receiver.
Maintaining Harmonic Fingerprint lock maintains detector calibration and ensures that SimuGas™
simulations faithfully simulate the presence of a pre-defined quantity of target gas(es) in the beam­path. This is the basis of the SimuGas on-demand functional test technology incorporated in
Senscient’s ELDS OPGDs.

220mm

300mm

245mm

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The Transmitter also incorporates links which can be used to communicate with an industrial
computer. Using SITE and these communication links, an industrial computer can be employed to
perform alignment checks, commissioning, configuration, functional testing, diagnostic procedures
and SimuGas™ tests.

The Transmitter window is heated to minimise condensation, frosting and the build-up of snow.

Three connections to the Transmitter are required, +24V, 0V and GND (for electrical safety).

2.3. Receiver

The Senscient ELDS™ Receiver collects infrared laser light from the Transmitter and determines
the size of any Harmonic Fingerprint components that have been introduced onto the beam(s) to
establish the quantity of any target gases present in the beam-path

The Receiver collects and concentrates infrared laser light from the Transmitter onto a single,
infrared detector using an aspheric, condensing lens-window. The detector output is amplified and
processed by a sophisticated electronic signal processing system which effectively removes any
ambient light and extracts Harmonic Fingerprint information related to the quantity of target gas in
the beam-path. The detector amplification chain incorporates an advanced Automatic Gain Control
(AGC) system that enables it to compensate for the wide range of signal levels that can be
received due to effects arising from rain, fog, snow, dirt etc. This enables the ELDS 1000 / 2000
Series to continue operating reliably in the harshest conditions that are likely to be encountered at
Oil & Gas installations around the world.

The solid state, InGaAs photodiode detectors used in the Senscient ELDS™ 1000 / 2000 Series
provide an exceptional dynamic range and superb temperature and long term stability. These
properties contribute significantly to the solar immunity and stability of the Senscient ELDS™
1000 / 2000 Series.

The primary output(s) of the Receiver are two 4-20mA loop outputs which can be configured for
source, sink or two-wire isolated operation. The outputs are factory calibrated to provide the
appropriate full scale range for the measured species and model variant. The output is typically
calibrated in units of LFL.m or ppm.m (see section 10.2 for the explanation of LFL.m and other
terms).

The Receiver also incorporates links which can be used to communicate with an industrial
computer. Using SITE and these communication links, an industrial computer can be employed to
perform alignment checks, commissioning, configuration, functional testing, diagnostic procedures
and SimuGas™ tests.

The Receiver window is heated to minimise condensation, frosting and the build-up of snow.

300mm

220mm

245mm

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Between four and eight connections to the Receiver are required, depending upon the number and
configuration of the 4-20mA outputs used. These connections are required to provide +24V, 0V,
4-20mA(1), 4-20mA(2) and GND (for electrical safety).

The ELDS system does not have any gas alarm set functions. The 4-20mA signal outputs from the
Receiver are non-latching. If the ELDS system is intended to indicate a potentially flammable gas
concentration then any auxiliary equipment (e.g. control room plc, control unit or monitoring
apparatus etc.) shall have an alarm set point that is latching, requiring a deliberate action to reset.
If two or more set or alarm functions are provided the lower may be non-latching.

2.4. Adjustable Mounting Bracket

The adjustable mounting brackets for the ELDS 1000 / 2000 Series are:

 Purpose-built for the Transmitter and Receiver.

 Provide coarse and fine adjustment for quick, simple system alignment.

 Rigid, stable and robust.

 Made from 316L stainless steel.

The coarse horizontal adjustment facility enables a Transmitter or Receiver to be quickly pointed in
the approximate direction of its counterpart and provides a full 360º of rotation. The fine horizontal
adjustment facility enables a Transmitter or Receiver to be precisely aligned and locked-off with
respect to its counterpart, and has an adjustment range of ±25º.

The fine vertical adjustment facility enables a Transmitter or Receiver to be precisely aligned and
locked-off with respect to its counterpart and has an adjustment range of ±15º.

Alignment details are given in section 4.

Clamp nut

Mounting bracket

adjusting screw (2 off)

Adjustment clamp

lock screw

Pivot block adjusting

screw (2 off)

Clamp nut

Mounting Lug (on unit body)

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2.5. Sunshades

In order to provide Sun shading which is optimal for a wide range of operating climates, there are
two sunshades available for use with ELDS™ units.

2.5.1 Standard Sunshade

The standard sunshade is suitable for use in cold, temperate and moderately warm climates; and
is fitted along the mounting bar on the top of each ELDS™ unit. This sunshade’s position is
adjustable in order to facilitate use of the alignment telescope or provide easier access to the
electrical connections inside the terminal compartment.

The standard sunshade is fixed by a single retaining screw as illustrated. Loosen this in order to
allow adjustment of the position of the sunshade. Tighten the retaining screw to ensure that the
sunshade remains in the desired position.

Sunshade

Retaining Screw

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2.5.2 Enhanced Sunshade

The enhanced sunshade is designed for use in hot climates where intense, direct sunlight has the
potential to significantly increase the operating temperature of ELDS™ units unless greater
shading from solar radiation is provided. The enhanced sunshade is fitted above the mounting
bracket, attached to the same pole, wall or mounting structure that the mounting bracket is
attached to (see illustration below).

Depending upon the particular details of the installation, it may be necessary to temporarily
remove the enhanced sunshade in order to gain access to the terminal compartment or use the
alignment telescope. Make sure to re-fit the enhanced sunshade after completing any activities
that temporarily require its removal.

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2.6. Cross Duct Mounting Plates

Cross Duct ELDS systems are designed to be mounted on the opposite sides of flat, parallel­walled ducts using one of three (3) available variants of Mounting Plate, or the standard Adjustable
Mounting Bracket (ELDS VZ unit only).

The installation designer’s attention is drawn to the fact that each Transmitter or Receiver
unit of a Cross Duct ELDS system weighs approximately 10kg, which may be sufficient to
cause unwanted bending of duct walls, especially if the duct walls are thin.

2.6.1 Standard Cross Duct Mounting Plate

The standard, 400mm x 400mm mounting plate substantially spreads the weight / load and
provides localised reinforcement of the duct wall; and is therefore recommended for use wherever
possible – and in particular on thin-walled ducts.

2.6.2 Small Cross Duct Mounting Plate

The small, 250mm x 250mm mounting plate is capable of being mounted on smaller ducts; but
consideration needs to be given as to how the weight / load will affect the duct wall when units are
so mounted. Local reinforcement / bracing of the duct wall may be required.

The installation Design Authority is responsible for ensuring that the method chosen for
mounting Cross Duct ELDS units on the intended duct is sufficiently rigid and stable.

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2.6.3 Retrofit Cross Duct Mounting Plate

The 180mm x 180mm retrofit mounting plate is capable of being mounted on the same mounting
holes as an earlier generation of Cross Duct unit supplied by another manufacturer. There is a
reasonable likelihood that mounting Cross Duct ELDS units on ducts using the retrofit mounting
plate will cause bending of the duct wall. Consequently, this method of mounting Cross Duct ELDS
units should only be considered for retrofit applications where it is impossible or impractical to
engineer a superior mounting arrangement. In such circumstances, the installation Design
Authority should also consider local reinforcement / bracing of the duct wall to reduce bending;
and / or the use of alignment adjustment bushings* to provide compensation for such bending.

NB: Customer / user should retain the original installation’s internal plates - to which this retrofit
mounting plate will be attached.

The installation Design Authority is responsible for ensuring that the method chosen for
mounting Cross Duct ELDS units on the intended duct is sufficiently rigid and stable.

* Alignment adjustment bushings are available from Senscient (Part Number A-5126-0) for use
with Cross Duct ELDS systems where the duct walls are highly out-of-parallel, or have bent under
load by an amount greater than the angular tolerance of the Cross Duct ELDS system. Provided
that the angular errors arising from these sources are less than ±5° (per side) and the duct wall
deformation is relatively stable, the alignment adjustment bushings should be capable of returning
the alignment of Cross Duct ELDS systems to within their operational angular tolerance.
(NB: Alignment adjustment of ELDS VZ units is made possible by use of the standard Adjustable
Mounting Bracket.)

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2.6.4 Thermal Window for Cross-Duct Units

In order to allow ELDS Cross Duct units to be mounted upon ducts which may temporarily reach
internal temperatures that are higher than the maximum upper service temperature for which
ELDS systems are certified (+60ºC), a mounting arrangement which includes a thermal window is
available. This arrangement insulates an ELDS unit’s lens-window from hot gases inside the duct,
allowing ELDS XD units to continue being used provided that air temperatures outside of the duct
are within the certified range.

Provided that there is adequate ventilation; and any in-duct temperature excursion is not of too
long a duration (≤ 15 minutes), it should be possible to mount and operate XD ELDS units on
ducts where air / gas temperatures inside the duct of up to 120ºC are temporarily present. Longer
term operation at high duct temperatures, or operation in conditions of restricted ventilation would
require measurement of the temperatures that the XD ELDS units become exposed to - in order to
ensure that the maximum certified operating temperature of +60ºC is not exceeded.

2.7. SITE Installation & Maintenance Software

SITE (Senscient Installation and Test Environment) is a software application provided by
Senscient to enable the installation, commissioning and testing of all types of ELDS OPGD
products; and is supplied pre-installed on ATEX or CSA (UL) certified industrial computers. Due to
the complexity of the computing and communications technologies employed by SITE, Senscient
can only provide support to users that are running SITE on factory tested and approved platforms.

SITE is capable of communicating with ELDS units either over RS485 or Bluetooth™ * wireless
communications links. The RS485 connection is made via a USB:RS485 adaptor included as part
of the installation kit. The Bluetooth™ connection is built into the industrial computer and is factory
activated and configured for use with SITE and ELDS units. More detailed information and
guidance with respect to the type of communication link to use when working with ELDS units is
provided in sections 4.5 to 4.7.

*All ELDS units can be commissioned using the RS485 communications link, regardless of their
type or age. From November 2011 onwards, Bluetooth™ communications were added alongside
RS485 with the introduction of Mod State 1, open-path, ELDS units. (The Mod State of ELDS units
can be found on the certification / serial number label on the terminal compartment cover.)

The necessary steps to commission a system using SITE are outlined in section 4.5 and some key
maintenance and problem solving guidance is provided in section 7.2. The following sections here
provide an overview of SITE itself.

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2.7.1 SITE Main Screen

The SITE screen is divided into two areas. At the top are a sequence of ‘buttons’ that are used to
access installation and maintenance facilities, to connect SITE to ELDS units and also to provide
access to this Technical Manual.

The area at the bottom provides access to various administration functions via the Admin button,
and also allows individual access to the Tx or Rx to be selected for operations initiated by the
Config, Event Log and Installation buttons.

An outline description of these functions is provided in the following sections, however more
detailed information is also provided in later sections of this document as individually detailed
below.

Note that the SITE version is presented at the top of the screen, 2.6.15.13400 in this example.
When SITE first starts this number is truncated to just the first 3 number groups (which is sufficient
to uniquely identify the SITE version), however clicking on the number will reveal the additional
group which defines the precise software build version as illustrated here.

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2.7.2 Comms Setup

Selecting the Comms Setup button will open a separate dialogue as illustrated below which
facilitates connecting SITE to an ELDS Tx, Rx or both. Further details of this are provided in
section 4.5 as part of the commissioning instructions.

The majority of the functions available in SITE only become active once a connection to an ELDS
unit is made in this way. As illustrated above most of the buttons except Comms Setup,
User Manual and Admin are ‘greyed’ and unavailable until a connection is made.

The connection to an ELDS unit can be either via a wired (RS485) connector or via a Wireless RF
(Bluetooth) link, the appropriate option is initiated by selecting the required “radio button” selector.
The additional Modbus option is provided to allow units that are configured for Modbus operation
to be reverted back to ELDS communication over the RS485, this is necessary in order to utilise
any other facilities within SITE to maintain or inspect a unit via the RS485 link. Once connected via
the “MODBUS” option in this connection dialogue box it is possible ‘un-select’ Modbus operation in
the unit by navigating to the Config/Modbus page and clicking the option to disable Modbus.
Details of configuring Modbus are described in detail in section 2.7.6.

Once a connection is made then one of the indicators TX or RX at the bottom of the main SITE
screen will turn green and become slightly larger as illustrated here:

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In this case both an ELDS Transmitter and Receiver has been connected, the ‘active’ connection
is to the Transmitter (the TX button is green and larger). To select the Receiver simply use the
mouse or touchpad to select (click on) the RX button which will then change to green and become
larger.

2.7.3 Installation

The installation button allows an ELDS Transmitter (see section 4.5.1 for more detail) or Receiver
(see section 4.5.2 for more detail) to be installed.

It is essential to install an ELDS Transmitter first when installing an ELDS system. This is
because essential calibration information must be copied from the Transmitter to the
Receiver, so SITE must access the appropriate Transmitter before any attempt is made to
install a particular Receiver. Once a Transmitter has been installed by SITE it will
remember the details of that unit and so it is not necessary to re-install the Transmitter if
the Receiver needs to be re-installed at a later date.

Select the appropriate unit to be installed (TX or RX) before selecting the Installation option.

2.7.4 Test/Diagnostics

The Test/Diagnostics button provides access to key information and test functions regarding the
connected ELDS unit(s). These functions are described in detail in section 7.2 with specific
information regarding the Receiver and Transmitter being in sections 7.2.1 and 7.2.2 respectively.

This option will provide information on either the Transmitter or Receiver or both depending
on which ELDS units are connected. If only one unit is connected then the whole of the
screen is filled with information regarding just that unit. If both a Transmitter and Receiver
then the screen will split vertically with the Receiver information on the left side and the
Transmitter on the right side.

2.7.5 Event Log

This button provides access to the internal ‘event’ log of the selected ELDS unit.

The ELDS unit selected for interrogation is determined by the TX or RX buttons at the
bottom of the SITE main screen. The larger (green) button identifies the unit that will be
examined.

The following screen is presented and will normally be populated by the most recent 50 events
recorded in the ELDS unit selected.

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The format and options of this event viewer screen are described in the following sections.

Header

The header information is presented in the top-left corner of the Events screen. Some key
information about the unit and SITE version is presented along with the time of the download
(based on the internal time in the ELDS unit) as well as an indication of the events selected. In this
example the display has selected (read) 50 events from the unit, however the total number of
events available is 57. Note that ELDS units can hold up to 186000 events, this is a rolling buffer
so once it becomes full the oldest events are discarded as new events are stored.

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View Options

It is possible to filter the ‘class’ of events that are presented in the view by selecting/deselecting
the options in this area (top-right of the Events screen). By default all event classes are presented,
deselect the desired options to remove the associated events from the presentation.

Event List

The events are presented in the table area as illustrated here. Each event has an ID number which
is effectively an ‘index’ to the event number within the ELDS unit, a Date/Time field which indicates
the time that the event was created, a general Description field and for some events also a Detail
field. The System column refers to the event class (as is identified by the View Options above).

Some events within an ELDS unit relate to system processes and are not normally
displayed for users. These ‘housekeeping’ events have ID numbers associated

and explain

why the ID numbers may have ‘gaps’ as is the case in this example above.

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It is possible to re-order the displayed events by clicking on the header of any of the columns. In
this example the events are ordered by ascending ID number (the default when the events are first
read). Pressing the ID column header will reverse this order, or pressing any of the other column
headers will order the events by the data in the appropriate column.

A detailed description of the events that may be displayed is presented in section 7.4 below.

Read Options

SITE will initially read the last 50 events from the connected unit, however it is possible to
select/read further events if required by using the Previous or Next buttons at the bottom left of the
Events screen. Each press of these buttons will read the selected number of additional events
from the unit (determined by the numeric selection box).

If further events are not available then the appropriate button will be greyed and unavailable.

Output Options

The contents of the Event display can be output / saved to allow them to be incorporated into other
PC applications or to be supplied back to Senscient.

Pressing the Save button (bottom right of the Events screen) will output the data in an ‘internal’
format that can be used by Senscient to examine the event data in full detail. This is the preferred
format for supply of individual event information to Senscient (but note that Senscient generally
recommends supplying full ‘snapshots’ rather than just the events, see section 2.7.8).

Alternatively, if the “Save as text” checkbox is selected then the data is output as text format in a
“comma separate variable” (*.csv) file. Selecting this format is most useful if users wish to import
the event data into a spreadsheet for presentation or analysis.

Once the Save button is pressed a standard Windows File dialogue box is presented that allows
the user to select the location and name of the file that will be written.

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2.7.6 Config

This button provides access to configuration information and to processes that allow the
configuration to be changed once a unit has been installed.

A new screen is presented with a range of options as illustrated below:

The screen is arranged with several ‘tabs’ or pages of information and in addition up to 3 context
sensitive buttons at the bottom. The ‘tabs’ displayed will depend on the unit (Tx or Rx) and also on
the connection type. The example here is for a Receiver. A Transmitter will not include the
“Zero Unit”, or “4-20mA Configuration” options but will include a “SimuGas” option.

Info

This tab contains key information regarding the unit including the unit identity, firmware release
and configuration. In addition it provides access to three configurable items relating to Bluetooth
access, the control of the window heaters on the unit and the behaviour of Beam-Block in the
presence of gas.

Bluetooth Enabled/Disabled indicates if Bluetooth communication is currently facilitated on the
unit. By default all ELDS units are shipped with Bluetooth communication active, however some
customers may choose to inhibit this communication protocol for security reasons. The Bluetooth
support can be disabled or enabled as appropriate by checking the associated checkbox. In the
example above the Bluetooth is currently active so unchecking this checkbox will immediately
disable the Bluetooth connectivity in the unit. Note that access to this feature is restricted by
password access (see section 2.7.8 below). More details of how to disable Bluetooth are provided
in section 4.5.3 below.

Desert Mode is a feature to allow the control of the window-heaters on the ELDS unit to be
changed such that they are likely to be ‘off’ for a majority of the time in hot environments. This will
ensure that the power consumption and internal temperature of the ELDS unit will be minimised
and ensure the longest possible life of the internal components. It is recommended that the
“Desert” feature be enabled on units deployed in hot environments where daytime temperature is
likely to routinely exceed 25°C.

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Beamblock Priority over Gas controls how the unit responds when the beam is blocked in the
presence of gas. Normally, ELDS units signal an error current (2.5mA by default) to indicate that
the beam is blocked. In the presence of gas, however, this behaviour is changed such that the last
gas value detected is maintained on the 4-20mA outputs whenever a beam-block occurs.
Optionally users can change this behaviour (for firmware versions 002.010.009 or later) such that
the ELDS does not ‘latch’ the last gas level but rather will signal the Beam-Block current even if
gas was being reported when the obstruction occurs.

Zero Unit

Units are normally ‘zeroed’ during installation; however it is also possible to repeat the zero
process at any time. This is recommended if a unit is physically disturbed (for example if the
alignment is inadvertently changed) or if units exhibit fingerprint or bad zero errors.

Change Tag

The unit ‘tag’ is normally assigned during installation but may be amended at any subsequent time
as required.

4-20mA Configuration

This tab provides information on the range of ‘fault’ conditions that apply to the unit and which will
be signalled over the 4-20mA current loop. A description of the configuration of this is provided in
section 4.5.2, item 8 therein. This tab provides repeat access to this facility should the original
arrangement require adjustment at a later time.

MODBUS

MODBUS support is available from all current ELDS units and is also historically supported for
most units. Units are not shipped with MODBUS support active and this tab provides a mechanism
to allow MODBUS to be configured and activated as required.

MODBUS shares the RS485 communication link, once MODBUS is activated then normal
interaction with the unit using SITE can only be undertaken using the Bluetooth link.
Ensure that Bluetooth communication is available with a unit prior to activating MODBUS
as without it further modifications or inspection of the unit with SITE will not be possible.

MODBUS can be activated through either a Bluetooth connection or via an RS485 link, however
Senscient recommend the use of a Bluetooth link when activating MODBUS. The following options
are presented on the MODBUS screen.

The Address must be assigned as required and must be in the range 1 to 247. This is a unique
value that identifies the unit on the MODBUS link.

Baud defines the communication speed that will apply, the default setting is normally 9600
however other rates are supported and can be selected as required.

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Parity defines the parity checking that will be applied to the link. The default is ‘none’ but other
options are available as required from the drop-down list.

Once the required settings are selected check the “Check to Enable” option and then press the OK
button at the bottom right of the dialogue. This will write the changes to the ELDS unit and enable
the interface.

If this change is made via the RS485 link then SITE will not be able to communicate further
with the unit and will disconnect. This process may take a short while to complete in this
case.

SimuGas

This tab is provided on Tx units and allows the user to examine and change the time of day that
the automatic SimuGas process will occur.

For older ELDS units the SimuGas time can be selected over the range Midnight (0 hours, 0
minutes) to 03:00 am (3 hours, 0 minutes). Units with firmware versions 002.010.018 or later will
support SimuGas at any time of the day. The time can be specified in 10 minute increments. When
any change is made the “Apply“ button will become enabled and will write the required changes to
the unit if clicked.

For older firmware version it is also the case that the revised SimuGas time will not apply until the
pending SimuGas occurs, for such versions SITE will provide a warning following “Applying“ the
change and offer the user the opportunity to re-start the Tx (which will then correctly establish the
revised SimuGas time). For later firmware versions this step is not necessary and will not be
presented.

2.7.7 User Manual

This provides a convenient link to this manual.

2.7.8 Admin

This provides a range of ‘administration’ items as illustrated below:

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Mode

This provides access to a ‘log in’ screen and allows Senscient personnel or approved users to
access more advanced features of SITE. Appropriate passwords to access these features are
provided by Senscient; Senscient will normally require that users have additional training regarding
the additional features provided.

Snapshot

This will instruct SITE to download a complete ‘picture’ of the connected unit. This ‘snapshot’ may
take up to 2 minutes to acquire and will be automatically uploaded to the Senscient ‘service’ server
if an internet connection is available. In addition the snapshot is stored on the PC running SITE
and may be copied from there. The snapshot will be located in the following location within
“My Documents”

\Senscient\SITE\Log\nnnn

Here nnnn represents the unit serial number of the ELDS unit, for example S01234. Note that the
physical location of “My Documents” varies depending on the version of Windows being used on
the PC. Generally users should find a link to the appropriate place located in the “Start” button or
on their desktop.

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Custom ELDS Config

This provides a direct access to the facility to adjust or configure the 4-20mA loop fault currents
and behaviours (see section 2.7.6 above and also section 4.5.2 item 8 below).

Updates

This provides access to SITE updates. It also can provide access to firmware updates but this
facility is limited to authorized users and is not described in further detail here.

If a “SITE update” is available then this sub-item will be accessible and selecting it will
automatically update the copy of SITE on the PC. Note that this process does take a few minutes
to complete. All these options are dependent on internet access.

Senscient recommends that users keep their SITE version updated by periodically checking this
option and updating when new versions of SITE become available. New versions generally
provide enhanced/improved features and in addition may correct issues that might arise.

Backup

This provides the option to create a ‘zip’ backup of the current SITE installation information. This is
located in the following location within “My Documents”

\Senscient\SITE\SBU

and takes the form of a ‘zipped’ folder which contains a record of the units that have been installed
by SITE on the PC.

There is also an option to ‘Purge’ the current configuration. These options are provided to facilitate
some advanced trouble-shooting options for Senscient engineers and are not intended for
customer use.

Options

Contact Us, provides a convenient link to Senscient support through the email client on the PC
running SITE.

Auto Install, provides a means to enable an advanced feature of ELDS which is not currently
activated. This is a ‘place holder’ for future enhancements involving more flexible installation
options.

Remote Assistance is an advanced feature that may be utilised by authorized users or Senscient
engineers.

Expert Diagnosis

This is an advanced feature provided for use by Senscient Engineers. This option is not available
to normal users of SITE.