Elcon MUX 2700 Instruction Manual
Instruction Manual 116/GB - PN. 991198 DOC. TEC.
INSTRUCTION MANUAL
MUX 2700
M U LT I P L E X E R
FOR MORE INFORMATIONS, VISIT THE DEDICATED HiS WEB SITE: www.elconhis.com
IM-ENG-116/GB
TABLE OF CONTENTS
1. INTRODUCTION ................................................................................................. page 2
2. UNPACKING AND STORAGE ............................................................................ “ 3
3. FUNCTIONAL DESCRIPTION ............................................................................ “ 4
3.1 Overview .................................................................................................... “ 4
3.2 Operation ................................................................................................... “ 6
3.3 LED indications ......................................................................................... “ 6
3.4 Power-up sequence ................................................................................... “ 6
3.5 Application guidelines ................................................................................ “ 7
3.6 Hardware architecture ................................................................................ “ 7
3.7 Software architecture ................................................................................. “ 8
4. HART INTERFACE SOLUTIONS OVERVIEW .................................................. “ 9
4.1 Presentation ............................................................................................... “ 9
4.2 1132/CON solution .................................................................................... “ 10
4.3 2108/64 HART D solution .......................................................................... “ 11
4.4 I.S. Integrated solutions (MUX2700 with HiD2000 Intrinsic Safety interfaces) .. “ 12
4.5 Electrical connections ................................................................................. “ 12
5. MAINTENANCE WORKSTATION OVERVIEW.................................................... “ 13
5.1 General ...................................................................................................... “ 13
5.2 Software packages .................................................................................... “ 13
6. MUX 2700 SPECIFICATIONS .......................................................................... “ 14
6.1 General ...................................................................................................... “ 14
6.2 Mechanical ................................................................................................. “ 14
6.3 Supply port ................................................................................................. “ 15
6.4 Signal port (HART) ..................................................................................... “ 15
6.5 Serial Port (RS-485) ................................................................................... “ 15
7. INSTALLATION AND CONFIGURATION ............................................................. “ 17
7.1 Operating environment .............................................................................. “ 17
7.2 DIP-switch configuration ............................................................................ “ 17
7.3 Connections and mounting ........................................................................ “ 19
7.4 Final checks ............................................................................................... “ 19
8. MAINTENANCE AND TROUBLESHOOTING ...................................................... “ 21
8.1 Maintenance .............................................................................................. “ 21
8.2 Off-line self-test procedure ......................................................................... “ 21
8.3 Additional troubleshooting .......................................................................... “ 21
9. QUALITY MANAGEMENT POLICY.................................................................... “ 22
10. WARRANTY..................................................................................................... “ 23
11. ACRONYSM .................................................................................................... “ 24
12. APPENDIX A: MUX 2700 ISOLATION STRUCTURE ................................... “ 25
FOR MORE INFORMATIONS, VISIT THE DEDICATED HiS WEB SITE: www.elconhis.com
WARNING!
This manual is copyright by Elcon Instruments. All rights reserved. No part of manual may be reproduced in part or in
whole without express written consent from Elcon Instruments. Elcon Instruments reserves the right to modify manual
or any part thereof at its discretion without prior notice.
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IM-ENG-116/GB
1. INTRODUCTION
This manual is intended to provide guidance for the installation, operation and maintenance of the Mux2700 HART
Signal Multiplexer (HSM) module. To avoid damage, failure or improper operation the contents of this manual
should be read and understood before installing and operating the instrument.
The Mux2700 HSM is a compact, plug-in module which is able to accept up to 32 HART channels and to feed them
into a single, faster communication line, which is in turn to be connected to a suitable Maintenance Workstation.
The Mux2700 module is intended for use as part of the Elcon HART Interface Solutions (H.I.S.), which provides
appropriate interconnection packages for various applications. H.I.S. makes available a wide set of Termination
Boards – with or without integrated isolators – to support different applications and to directly interface with the
main PLC/DCS equipment. The Mux2700 is simply to be inserted in the selected board to get full HART access to
the relevant field devices while preserving the traditional 4/20 mA analogue loop interfaces.
The Mux2700 use the same effective and compact enclosure of the successful HiD series, including the innovative
“Quick Lock” mechanism to easily insert/remove the unit from the Termination Board without the need for any tool.
Key features summary:
• low power consumption , very small size;
• compact and proven HiD enclosure, “Quick Lock” capability;
• high noise immunity, industrial-level EMC compliance;
• two DC-blocking capacitors – non-polarised type – on each signal loop;
• optimal mechanical integration with other HiD solutions;
• fully compatible with existing MUX 1700 solutions;
• very low loop-interference risk (TUV fail-safe approval pending).
Warning !
The Mux2700 module is not certified for intrinsically safe applications and must not be used to directly interface
with hazardous-area located field devices. However, some H.I.S. solutions do allow the mounting of the Mux2700
on the same board where intrinsically safe isolators are located. In this case, the safety-related application areas
must be addressed by trained personnel which is fully acquainted with the principles of intrinsically safe system.
Elcon Instruments has published a complete tutorial entitled “Guide to Intrinsic Safety” covering most aspect of
intrinsic safety. The book can be obtained from Elcon Instruments free of charge.
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IM-ENG-116/GB
2. UNPACKING AND STORAGE
Upon receipt of the materials, you should immediately check the integrity of both packaging and contents. In case
of damage due to shipping, the receiver should promptly and properly report to the shipper supplying all necessary
information.
If the instruments are not for immediate use, a check is recommended about the compliance of the units specifications (as indicated on the label) with both order specifications and with the actual application requirements.
In case of storage of instruments and accessories, proper care should be taken to protect them from any possible
damage. Always store instruments in their sealed original packaging until they are installed. In addition, adequate
protection should be provided from:
• humidity and temperature excursions outside the specified range;
• aggressive or polluting atmospheres (e.g. SO2, H2S, mists, salts, smokes, dusts);
• access by insects/rodents that could damage packaging or content;
• mechanical shocks or intense vibrations.
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IM-ENG-116/GB
3. FUNCTIONAL DESCRIPTION
3.1 Overview
The Mux2700 HART Signal Multiplexer (HSM) provides 32 signal channels for connection to field located, “smart”
transmitters or control devices supporting digital communication according to the HART standard. The Mux2700
acts as a gateway between a Maintenance Workstation (MW) – typically a PC with suitable SW – and the field
instrumentation. The MW connects, in a multi-point configuration, with up to 31 Mux2700 using a fast RS-485 communication channel.
The HART protocol is a widely accepted technique by which standard 4/20 mA field devices can support digital
communication for configuration and maintenance purposes. A modulated, audio-frequency signal (Bell202 FSK) is
in fact superimposed to the analogue current loop providing a 1200 baud, half-duplex communication capability.
The HART protocol, being a widely accepted standard specified up to the application layer, permits an effective
integration, at the Maintenance Workstation level, of field devices from different manufacturers.
The Mux2700 HSM not only uses the HART protocol to communicate with the field devices but also to interface
with the Maintenance Workstation via an RS-485 link. In this way, an highly standardised solution is obtained.
Under the supervision of the Maintenance Workstation, the Mux2700 interrogates each field device, retrieving information which are then stored in an internal data-base. This internal data-base can then be accessed in real-time by
the MW which however, when required, can also directly communicate with any specific field device.
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IM-ENG-116/GB
1
up
to
32
1
up
to
32
1
up
to
32
To
DCS - PLC I/O
CARDS
(To Control Room)
TERMINATION BOARD
RS 485
FROM
FIELD
DEVICES
SUPPLY
1
up
to
32
1
up
to
32
1
up
to
32
1
up
to
32
DCS/SCADA SYSTEM
1
up
to
32
1
ZONE 1
II C
up
to
32
CONTROL ROOM
(Hart or Non Hart
Compatible)
Model
2116/HAT/
Model
2116/HAT/
RADIO MODEM
UHF Microwave
P.C. MAINTENANCE WORKSTATION
NON HAZARDOUS LOCATION
PCU # 1
CATALYTIC CRACKER
PORTABLE
NOTEBOOK
or LAPTOP
Model
2116/HAT/
RADIO
MODEM
HHC
Remote instrument
maintenance
monitoring for
unmanned
platform or
remote site
ZONE 1
II C
32
32
32
32
up
up
up
up
Model
1
1
2116/HAT/
to
to
To Further
Boards
Model
1
to
1
to
2116/HAT/
Model
2116/HAT/
PCU # 2
BOILER
• Hazardous Non Hazardous Locations of Smart Instruments
• Local or Remote Instruments Maintenance
• Suitable for Existing Smart Field Device Transmitter, Valves, Mas Flow
• Multiple
• Independent to DCS System
• ISO 9000 Reporting
MUX 2700
PCU # 3 REFORMER
TANK
FARM
To Further
Boards
ZONE 2
II B
To Further
Boards
MUX
MUX
MUX
2700
2700
MUX
2700
2700
MUX
2700
1 up to 32 1 up to 32 1 up to 32
NON HAZARDOUS LOCATION
MUX
2700
ZONE 1
II B
To Further
Boards
FIG. 1
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IM-ENG-116/GB
3.2 Operation
The Mux2700 HSM module implements HART protocol commands and acts as a gateway device between the
Maintenance Workstation (MW) and the field devices. It responds to commands received from the MW (RS-485
interface) as a slave device and issues commands to the HART slaves (field channels) acting as either a Primary
or Secondary Master (according to the HART specification).
A modified version of the HART protocol was implemented on the RS-485 physical layer to obtain a fast and reliable communication with the Maintenance Workstation. In this way, standard HART messages can be used by the
MW for an effective, seamless integration of field devices from different manufacturers.
The Mux2700 can continuously poll each connected field device the get the specified primary (or secondary) HART
variable, automatically updating the internal data-base. This is called scan operation, and can be enabled or disabled by the Maintenance Workstation (the Mux are factory set in the “Scan-Off” condition). When in the “Scan-On”
mode, the MW can generate a warning message whenever a field device stop communicating (e.g. because it is
disconnected from the loop).
At power-up, the Mux2700 always performs a locate activity, that is to say, it polls all the 32 channels to find any
connected – and communicating – field device and to rebuild the required, internal access tables. The locate activity can be started also by the Maintenance Workstation, and this is usually required to be able to communicate
with a new field device connected to the Mux after power-up. The locate time can range from 15 to 60 seconds,
depending on the specified retry counts (the Mux are factory set with a retry count = 3, resulting in around one
minute of locate time).
In addition to providing access to the HART-capable field instruments, the Mux2700 module is itself, in all respect,
an HART device with parameters and internal functions available to the user (e.g. Tag, Description and unique DIN
– Device Identification Number).
3.3 LED indications
The information provided by the Mux 2700 LED (mounted at the panel front) is summarised in the following table:
Colour Name Function
Yellow HART TX ongoing HART communication with field devices
Green PWR ON supply indicator (can blink at power-up)
Red FAULT internal fault indication (power-up detection only)
3.4 Power-up sequence
In the following, the normal Mux 2700 power-up sequence is described. This is always the standard power-up
behaviour, unless SW8 (at the panel front) is set into the Test position.
• Immediately after power-up, the Green LED goes immediately On.
• An internal self-test is then performed and, if any problem is detected, the Red LED goes fixed On (on some
Mux versions, the Green LED could blink during self-test).
• The Yellow LED then start blinking, indicating that the Mux 2700 is performing the locate activity, that can last
up to around one minute (N.B. when the field multi-drop option is available and active, the locate time could be
up to15 minutes).
• The Yellow LED should then go Off, unless the scan operation is enabled or the Maintenance Workstation is
directly communicating with a field device.
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IM-ENG-116/GB
3.5 Application guidelines
The Mux2700 HSM is not normally intended to be designed by the user in a specific application, but to be used as
part of the Elcon HART Interface Solutions (H.I.S.) offering, which provides appropriate interconnection packages
for a wide range of applications, as well as a set of compatible Maintenance Workstation solutions. This makes the
Mux2700 application straightforward, because most “tricky” interface and compatibility issues have already been
solved, and a ready to use, plug-and-play solution can be provided.
As an example, when “HART filters” are required to ensure the compatibility with a specific PLC/DCS, these are
usually directly integrated at the H.I.S. level.
However, there can be situations, as with “general-purpose”, screw-terminals H.I.S. boards, in which some care in
wiring and installation is required to set-up a working system. An overview of some H.I.S. solutions is presented in
section 4., please also refer to the relevant H.I.S. documentation for more information.
As a general guideline, it is worth noting that the Mux2700 input channels must be connected across the 4/20 mA
loop in such a way as to see parallel resistance not lower than 200 Ω (250 Ω recommended). If this is not the case,
the available HART signal could be too week to guarantee a reliable communication. A problem of this type can be
found with an analogue-input card with a low internal current-sense resistor, or with any loop-connected device
that, in spite of having an high DC resistance, presents too low an impedance on the 4/20 mA loop at HART frequencies (1200 / 2200 Hz).
In addition, it is always recommended to connect the “+” input terminal at higher DC voltage level with respect to
the “–“ input terminal (that will be in many cases at a GND level).
3.6 Hardware architecture
The heart of the Mux2700 HSM module is the microprocessor (CPU). One CPU serial port – together with the
HART modem and the related analogue circuits – implements the physical layer of the HART protocol. A second
CPU serial port is used to drive the opto-isolated RS-485 interface.
The internal architecture of the Mux2700 Multiplexer is depicted in the following block diagram of Fig. 2. As you can
see, the HART modem is multiplexed on the 32 available field channels to get a cost-effective and compact solution.
A
A31
24V
A1
+
A3
SCREEN
POWER
SUPPLY
UNIT
RS-485
INTERFACE
OPTO
ISOL.
CPU
MUX
HART
MODEM
0.68µF
A
2.2µF
0.68µF
2.2µF
+
+
A30B
A32
C32
CH1
B32
C1
CH32
B1
A4,A5,A6
FIG. 2
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IM-ENG-116/GB
A full three-port isolation is also provided. The power supply section is in fact galvanically isolated from both the
analogue multiplexing section and from the RS-485 serial line.
Each input channel is also DC-isolated from the input GND by two non-polarised capacitors. The dual capacitor
solution, usually not to be found on comparable products, avoid the need of having a single common ground for all
input signals. In this way, it is also possible to connect to any “floating” loop without any loss of isolation
In general, the three-port isolation combined with the dual-capacitor approach result in an effective and reliable
solution, with such advantages as:
• undesired ground loops can be easily avoided;
• existing isolation between different ports can be preserved;
• very low risk of disturbing the 4/20 mA loop signal, also in case of fault.
I fact, the Mux2700 architecture is such that any internal single fault never result in any interference with an input
connected 4/20 mA loop. For this reason, the MUX 2700 can be used as a monitoring device within safety-sensitive
applications.
3.7 Software architecture
The Mux2700 HSM is not normally intended to be designed by the user in a specific application, but to be used as
part of the Elcon HART Interface Solutions (H.I.S.) offering, which includes a set of compatible Maintenance
Workstation solutions.
This means that the user doesn’t have to worry about either the internal details of the unit software functions nor
about the specific RS-485 protocol features. In fact, the Maintenance Workstation software make most of these
details “invisible” to user by providing an user-friendly, graphical man-machine interface.
When you have any special need or problem, please contact Elcon for additional information.
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