Schweitzer Engineering Laboratories SEL-2020 User manual

SEL-2020
COMMUNICATIONS PROCESSOR
INSTRUCTION MANUAL
SCHWEITZER ENGINEERING LABORATORIES, INC.
2350 NE HOPKINS COURT
PULLMAN, WA USA 99163-5603
TEL: [phone] FAX: [phone]

!
CAUTION:Never work on the SEL-2020 with the
front or top cover removed, when the SEL-2020 is
energized.
!
ATTENTION: Ne jamais travailler sur le SEL-2020
avec le panneau avant ou du dessus enlevé, quand le
SEL-2020 est sous-tension.
!
CAUTION: There is danger of explosion if the battery
is incorrectly replaced. Replace only with Ray-O-Vac®
no. BR2335 or equivalent recommended by manufacturer.
Dispose of used batteries according to the manufacturer’s
instructions.
!
ATTENTION: Il y a un danger d’explosion si la pile
électrique n’est pas correctement remplacée. Utiliser
exclusivement Ray-O-Vac®No. BR2335 ou un équivalent
recommandé par le fabricant. Se débarrasser des piles
usagées suivant les instructions du fabricant.
!
CAUTION:The SEL-2020 contains devices sensitive
to electrostatic discharge (ESD). When working on the
device with front or top cover removed, work surfaces and
personnel must be properly grounded or equipment
damage may result.
!
ATTENTION: Le SEL-2020 contient des composants
sensibles aux décharges électrostatiques (DES). Quand
on travaille sur l’appareil avec le panneau avant ou du
dessus enlevé, les surfaces de travail et le personnel
doivent être correctement mis à la terre pour éviter les
dommages à l'équipement.
!
CAUTION: Frequent archive record clearing may
exceed EEPROM capabilities. See the discussion in the
Archive Data Region subsection of Section 9: Database.
If you completely clear an archive region that contains a
large number of records (thousands of records), it may
take a few minutes for the clearing to complete. During
this time, most SEL-2020 automatic data collection will
be suspended.
!
ATTENTION: De fréquentes suppressions d’archives
pourraient dépasser la limite des EEPROM. Se référer à
la discussion dans la sous-section Région des Données
d’Archives de la Section 9: Banque de Données. Si vous
supprimez une zone d’archives qui contient un grand
nombre d’enregistrements (par milliers), l’opération
pourrait prendre quelques minutes. Pendant ce temps, la
collecte automatique de données du SEL-2020 sera
suspendue.
!
CAUTION: Frequent archive record clearing may
exceed EEPROM capabilities. See the discussion in the
Archive Data Region subsection of Section 9: Database.
!
ATTENTION : Des suppressions fréquentes
d’enregistrements d’archives peuvent dépasser la limite
des EEPROM. Se référer à la discussion dans la sous-
section Région des Données d’Archives de la Section 9:
Banque de Données.
!
CAUTION: Frequent archive record clearing may
exceed EEPROM capabilities. Refer to the following
paragraphs.
!
ATTENTION: Des suppressions fréquentes
d’enregistrements d’archives peuvent dépasser la limite
des EEPROM. Se référer aux paragraphes suivants.
!
WARNING: Do not rely upon pins 5 and 9 for safety
grounding, because their current-carrying capacity is less
than control power short circuit and protection levels.
!
AVERTISSEMENT: Ne pas se fier aux broches 5 et
9 pour une mise à la terre sécuritaire: leur limite de
support en courant est inférieure au niveau de court-
circuit assuré par la protection.
!
WARNING: This device is shipped with default
passwords. Default passwords should be changed to
private passwords at installation. Failure to change each
default password to a private password may allow
unauthorized access. SEL shall not be responsible for any
damage resulting from unauthorized access.
!
AVERTISSEMENT: Cet appareil est expédié avec
des mots de passe par défaut. A l’installation, les mots de
passe par défaut devront être changés pour des mots de
passe confidentiels. Dans le cas contraire, un accès non-
autorisé à l’équipement peut être possible. SEL décline
toute responsabilité pour tout dommage résultant de cet
accès non-autorisé.
!
WARNING: Removal of this front panel exposes
circuitry which may cause electrical shock that can result
in injury or death.
!
AVERTISSEMENT:Le retrait du panneau avant
expose à la circuiterie qui pourrait être la source de chocs
électriques pouvant entraîner des blessures ou la mort.
!
DANGER: Contact with instrument terminals may
cause electrical shock which can result in injury or death. !
DANGER: Le contact avec les bornes de l’ instrument
peut causer un choc électrique pouvant entraîner des
blessures ou la mort.
The software (firmware), schematic drawings, commands, and messages are copyright protected by the United States Copyright Law and
International Treaty provisions. All rights are reserved.
You may not copy, alter, disassemble, or reverse-engineer the software. You may not provide the software to any third party.
All brand or product names appearing in this document are the trademark or registered trademark of their respective holders.
Schweitzer Engineering Laboratories, , SELOGIC, Connectorized, and Job Done are registered trademarks of Schweitzer Engineering
Laboratories.
The English language manual is the only approved SEL manual.
This document is covered by U.S. Patent Nos: 5,680,324 Foreign Patents Pending
Copyright © SEL 1995, 1996, 1997, 1998, 1999, 2000, 2001 (All rights reserved) Printed in USA.
This product is covered by the standard SEL 10-year warranty. For warranty details, visit www.selinc.com or contact your customer
service representative.

Date Code 20010518 Manual Change Information i
SEL-2020 Instruction Manual
MANUAL CHANGE INFORMATION
The date code at the bottom of each page of this manual reflects the creation or revision date.
Date codes are changed only on pages that have been revised and any following pages affected
by the revisions (i.e., pagination). If significant revisions are made to a section, the date code on
all pages of the section will be changed to reflect the revision date.
Each time revisions are made, both the main table of contents and the affected individual section
table of contents are regenerated and the date code is changed to reflect the revision date.
Changes in this manual to date are summarized below (most recent revisions listed at top).
Revision
Date Summary of Revisions
The Manual Change Information section has been created to begin a record of revisions to
this manual. All changes wll be recorded in this Summary of Revisions table.
20010518 Reissued entire manual to reflect the following changes:
Updated to new manual format
Data Sheet, Specifications – Specified temperature range of external wires for
CSA certification
Appendix A, Firmware Versions – Additions
20010309 Inside Front Cover, Added Cautions, Warnings, and Dangers in English and
French
Data Sheet, Added new power supply option
Section 2, Added new power supply option to page 2-21 (all pages reissued)
Section 3, Additions (all pages reissued)
Section 10, Battery Replacement – Caution Additions; clarifications
throughout (all pages reissued)
20000512 Appendix B, Optional Internal Modem Information - Additions
20000427 Section 9, Table 9.5 – Additions, format changes throughout (all pages reissued)
Appendix I, Table I.2 – Addition
20000221 Section 6, Corrections – (pages 1 - 42 reissued)
Appendix A, Firmware Versions - Additions
Appendix B, Optional Internal Modem Information - Changes
991222 Section 6, Set M Examples - Additions
Section 6, Set G – Global Settings - Additions
Section 6, Table 6.17 - Additions
Section 6, Table 6.18 - Additions
Appendix A, Firmware Versions - Additions
Appendix I, Internal Indication Object - Additions

ii Manual Change Information Date Code 20010518
SEL-2020 Instruction Manual
Revision
Date Summary of Revisions
Appendix I, Time Synchronization - Additions
991021 Appendix A, Firmware Versions - Additions
990805 Section 5, PORT n (Access Level 1) - Additions
Section 6, Additions (all pages reissued)
990319 Section 6, Table 6.3 - Additions
Section 6, Table 6.4 - Additions
Section 8, Table 8.2 - Additions
Section 9, Table 9.5 - Additions
Appendix G, Cross reference corrections
Message Strings, Additions
981202 Section 4, Example 1 - Additions
Appendix B, Optional Internal Modem Information - Additions
980724 Appendix A, Firmware Versions - Additions
980626 Section 3, Table 3.2 - Clarifications
980515 Section 6, Character String (Parse = 3) - Additions and Clarifications
Section 6, Parsing Delays - Additions
Section 8, Table 5.2 - Clarifications
Section 9, Figure 9.2 - Clarifications
Section 9, Port Status Register - Additions
Appendix A, Firmware Versions - Additions
Appendix E, Table E.1 & E.4 - Additions
Appendix F, SEL-2020 Compatibility - Additions
Appendix G, Modbus Protocol - Additions
Appendix H, Fast Operate Configuration - Clarification
Appendix I, Table I.2 - Additions
Appendix I, Internal Indication Object - Additions
Appendix I, Time Synchronization - Additions
980116 Appendix A, Firmware Versions - Additions
Appendix G, Example #1 - Clarification
971103 Appendix A, Firmware Versions - Additions

Date Code 20010518 Manual Change Information iii
SEL-2020 Instruction Manual
Revision
Date Summary of Revisions
971029 Appendix A, Firmware Versions - Additions
Appendix E, Table E.1 & E.4 - Additions
Appendix F, SEL-2020 Compatibility - Additions
Appendix G, Modbus Protocol - Additions
970825 Section 8, Table 8.2 - Additions
Section 8, SEL-2020 Strings - Additions
Appendix E, Table E.2 - Clarifications
970815 Section 4, Example 1 - Clarifications in the “View 1:Global” screen capture
and the “Set P 8” screen capture
Section 4, Example 9 - Additions in the “Set A 1” screen capture
Section 7, Processing Sequence - Clarifications
Section 8, Table 8.2 - Additions
Section 8, SEL-2020 Strings - Additions
Section 9, Table 9.2 - Additions and Deletions
Appendix A, Firmware Versions - Additions
Appendix H, - Formatting correction
Appendix I, Table I.3 - Clarifications and formatting corrections
(pages I-1 to I-14 reissued)
970729 Appendix, B, Optional Internal Modem Information - Additions
970521 Appendix A, Firmware Versions - Additions
970514 Section 9, Table 9.5 - Clarifications
970425 Section 1, Formatting
Section 2, Table 2.2 - Addition of new element
Section 2, Local Region - Additions
Section 6, SET M - Math/Data Movement Settings - Additions
(pages 6-35 to 6-59 reissued)
Section 6, Worksheet SET M - Clarifications
Section 8, Table 8.2 - Additions (all pages reissued)
Section 8, SEL-2020 Strings - Additions
Section 9, Table 9.6 - Additions (pages 9-12 to 9-21 reissued)
Section 9, Local Elements - Additions
Section 9, Table 9.7 - Additions
Section 9, Access by Bit - Additions

iv Manual Change Information Date Code 20010518
SEL-2020 Instruction Manual
Revision
Date Summary of Revisions
Appendix A, Firmware Versions - Additions
Appendix G, Modbus Protocol - Additions (all pages reissued)
970408 Section 2, Receive Messages and Data - Addition in Solicited Messages and
Data
Section 2, Database Structure - Additions in D1 to D8 Regions
Section 2, Data Parsing Options - Additions in Non-“20” Message Response
Section 2, SET A - Auto Message Settings (Ports 1 - 16) - Addition in
DELAYn
Section 3, Alarm Contact Connection - Clarification
Section 4, Figure 4.8 - Clarification
Section 4, Example 6, Operation - Clarification
Section 4, Example 6, Set the SEL-2020, Step-By-Step - Addition in 3b
screen capture
Section 4, Example 9, Set the SEL-2020, Step-By-Step - Clarification
Section 5, Table 5.1 - Add DEFRAG command
Section 5, AUTOn (Access Level 1) - Additions
Section 5, DEFRAG (Access Level 2) - Additions
Section 5, Help (Access Level 0) - Additions
Section 5, SEL-2020 COMMAND SUMMARY - Add DEFRAG command
Section 6, Table 6.3, Add SETTLE1 and SETTLE2 settings
Section 6, Table 6.4, Add SETTLE1 and SETTLE2 settings
Section 6, Data Parsing Options - Additions
Section 6, Data Parsing Options - Addition of Parse Option 5
Section 6, Figure 6.6 - Additions
Section 6, Figure 6.7 - Additions
Section 6, Table 6.10 - Additions
Section 6, Automated Control - Additions
Section 6, Setting Sheets - Additions
Section 8, Table 8.2 - Additions
Section 8, Message Sequences - Addition of example
Section 8, SEL-2020 STRINGS Summary Sheet - Additions
Section 9, Local Data Region (LOCAL) - Additions
Section 9, Data Regions (D1-D8) - Additions
Appendix A, Firmware Versions - Additions

Date Code 20010518 Manual Change Information v
SEL-2020 Instruction Manual
Revision
Date Summary of Revisions
Appendix B, Dial Strings - Clarification
Appendix E, Table E.1 - Addition of new relays
Appendix E, Table E.4 - Addition of new relays
Appendix F, SEL-2020 Compatibility - Addition of new relays
Appendix G, Hardware Connections and RTS Line Usage - Additions
Appendix G, Message Framing - Additions in Read Coil Status, Clarification
in Force Single Coil
Appendix G, Table G.1 - Clarification in SEL-279, Addition of new relays,
Clarification in SEL-551
Appendix G, Table G.2 - Addition of new relays, Clarification in SEL-551
Appendix G, Table G.3 - Addition of new relays, Clarification in SEL-
167/267, Clarification in SEL-167D/267D
Appendix G, Table G.4 - Addition of new relays
Appendix G, Table G.5 - Addition of new relays, Clarification in SEL-587
Appendix G, Table G.6 - Addition of new relays, Clarification in SEL-587
Appendix G, Table G.7 - Addition of new relays
Appendix G, Table G.8 - Addition of new relays

Date Code 20010518 Table of Contents i
SEL-2020 Instruction Manual
SEL-2020 INSTRUCTION MANUAL
TABLE OF CONTENTS
SECTION 1: INTRODUCTION
SECTION 2: GENERAL DESCRIPTION
SECTION 3: INSTALLATION
SECTION 4: “JOB DONE” EXAMPLES
SECTION 5: COMMANDS
SECTION 6: SETTINGS
SECTION 7: SELOGIC®CONTROL EQUATIONS
SECTION 8: MESSAGE STRINGS
SECTION 9: DATABASE
SECTION 10: MAINTENANCE
APPENDICES
Appendix A: Firmware Versions
Appendix B: Optional Internal Modem Information
Appendix C: LMD Protocol
Appendix D: ASCII Reference Table
Appendix E: Planning Sheets
Appendix F: SEL-2020 Compatibility
Appendix G: Modbus®Protocol
Appendix H: Configuration and Fast Operate Commands
Appendix I: Distributed Network Protocol (DNP) V3.00
SUMMARY CARDS

DateCode20010518 Introduction i
SEL-2020 Instruction Manual
TABLE OF CONTENTS
SECTION 1: INTRODUCTION 1-1
Overview of the Manual................................................................................................................1-1
Background Information .......................................................................................................1-1
Section Highlights .................................................................................................................1-2
Appendices ............................................................................................................................1-2
List of Acronyms, Abbreviations, and Glossary Terms................................................................1-3
Initial Checkout.............................................................................................................................1-3
Data Sheet

Date Code 20010518 Introduction 1-1
SEL-2020 Instruction Manual
SECTION 1: INTRODUCTION
Section 1 provides you with a useful introduction to this manual and to the SEL-2020
Communications Processor. This section includes four parts: an Overview of the Manual; a List
of Acronyms, Abbreviations, and Glossary Terms; Procedure for Initial Checkout; and an
SEL-2020 Data Sheet with specifications.
We, the employee owners of Schweitzer Engineering Laboratories, Inc., are dedicated to making
electric power safer, more reliable, and more economical. The SEL-2020 Communications
Processor is designed to meet that goal.
We appreciate your interest in SEL products and we are dedicated to making sure you are
satisfied. If you have any questions about the SEL-2020 or the manual, please contact us at :
Schweitzer Engineering Laboratories, Inc.
2350 NE Hopkins Court
Pullman, WA USA 99163-5603
Tel: [phone]
Fax: [phone]
We guarantee prompt, courteous, and professional service.
We appreciate any comments and suggestions about new products or product improvements that
would help us make your job easier.
OVERVIEW OF THE MANUAL
Background Information
This manual is designed to help you make the most effective use of the SEL-2020
Communications Processor, from the most basic to the most advanced applications. Each section
begins with a detailed table of contents followed by a short paragraph summarizing the main
areas of the section. The manual also includes the following helpful aids:
• Cross-references.
• Sample screens with notations
• Numbered steps for sequential instructions and diamond-shaped bullets for nonsequential
instructions.
• Many explanatory figures, tables, and illustrations.
• Caution symbols to ensure your safety and the protection of the equipment.
• Pull-out lists on SEL-2020 commands and on special characters and pre-defined strings.

1-2 Introduction Date Code 20010518
SEL-2020 Instruction Manual
Section Highlights
The following list summarizes the main purpose of each section:
• Section 2: General Description, describes the SEL-2020’s special features and their
benefits to the user.
• Section 3: Installation, includes information and procedures you should be familiar with
to install the SEL-2020 safely and effectively.
• Section 4: “Job Done” Examples, describes SEL-2020 operations and user interface
with nine examples that include a variety of common applications.
• Section 5: Commands, describes the command set that you use to control, monitor,
operate, and set the SEL-2020. This section also includes the rules governing the use of
these commands. A list summarizing the commands appears at the end of this section and
on a blue pull-out card at the back of the book.
• Section 6: Settings, provides detailed information about the commands used to configure
and control the SEL-2020 and explains how you should respond to the SEL-2020 settings
prompts. The SEL-2020 setting sheets are included at the end of Section 6: Settings.
• Section 7: SELOGIC®Control Equations, covers SELOGIC Control Equation operation,
inputs, syntax, and outputs.
• Section 8: Message Strings, provides information about the characters, and pre-defined
strings that you can use in a number of SEL-2020 settings. At the end of this section and
also on a blue pull-out card at the end of the book is a summary list of special characters
and pre-defined strings.
• Section 9: Database, describes the structure of the SEL-2020 database and the various
ways data within the database can be accessed.
• Section 10: Maintenance, describes the minimal maintenance steps you should follow to
keep the SEL-2020 operating properly. This section also includes a guide to
troubleshooting and alarm diagnosis.
Appendices
The following appendices provide supplemental reference information:
• Appendix A: Firmware Versions
• Appendix B: Optional Internal Modem Information
• Appendix C: LMD Protocol
• Appendix D: ASCII Reference Table
• Appendix E: Planning Sheets
• Appendix F: SEL-2020 Compatibility
• Appendix G: Modbus®Protocol
• Appendix H: Configuration and Fast Operate Commands
• Appendix I: Distributed Network Protocol (DNP) V3.00

Date Code 20010518 Introduction 1-3
SEL-2020 Instruction Manual
LIST OF ACRONYMS, ABBREVIATIONS, AND GLOSSARY TERMS
Acronym/
Abbreviation Definition
ASCII American National Standard Code for Information Interchange
CPU Central Processor Unit
CTS Clear-To-Send
DNP Distributed Network Protocol
EEPROM Electronically Erasable Programmable Read-Only Memory
EIA Electronic Industries Association
ESD Electrostatic Discharge
FID Firmware Identification
Flash Memory Nonvolatile memory (retains data when power is removed)
GOES Geostationary Operational Environmental Satellite
GPS Global Positioning System
HMI Human Machine Interface
IED Intelligent Electronic Device
IRIG-B Inter-Range Instrumentation Group (U.S. Government)
LMD LMD Protocol
LPS Linear Power Supply
LSB Least Significant Bit
MOV Metal Oxide Varistor
MSB Most Significant Bit
Parse To separate an item into its component parts and decide which
parts to keep
PS Power Supply
RTS Request-To-Send
RTU Remote Terminal Unit
RXD Receive
SCADA Supervisory Control and Data Acquisition
TTL Transistor-Transistor Logic (0 Vdc to +5 Vdc)
TXD Transmit
XON Transmit ON character
XOFF Transmit OFF character
INITIAL CHECKOUT
Perform the following steps to ensure that the SEL-2020 communicates:
1. Visually inspect the SEL-2020 for loose or damaged parts.
2. Connect and apply power to the SEL-2020. (See the PWR SUP field on the rear-panel
nameplate for power requirements.) If you do not have the proper voltage source available,
use a power supply, like the SEL-LPS, to power the unit.
3. Press and hold the LED TEST button and confirm that all LEDs illuminate.
4. Connect a terminal (or computer equipped with terminal emulation software) to the front-
panel connector Port F of the SEL-2020 using an SEL-C234A cable or equivalent.

1-4 Introduction Date Code 20010518
SEL-2020 Instruction Manual
5. Set the computer terminal or emulation software to operate at:
• 2400 baud
• 8 data bits
• 1 stop bit
• no parity
6. Press <ENTER> and verify that a “*” prompt is returned.
7. Type ACCESS<ENTER> to change to Access Level 1. Enter the factory-set password by
typing OTTER<ENTER> at the password prompt. You will see a screen similar to the
following:
*ACCESS<ENTER>
*ACCESS<ENTER>*ACCESS<ENTER>
*ACCESS<ENTER>
Password: ? OTTER<ENTER>
OTTER<ENTER>OTTER<ENTER>
OTTER<ENTER>
EXAMPLE 2020 - S/N 94153001 Date: 01/02/90 Time: 06:54:03
Level 1
*>
8. Type STATUS<ENTER> and verify that a status report similar to the one below appears on
your terminal. The RAM memory size should be 512 kb or 1024 kb. If you ordered optional
Flash memory, verify that Flash reports 2048 kb. If you did not order optional Flash
memory, Absent is reported as in the screen below. Confirm that IRIG-B input, I/O board,
and modem configurations match your expectations. The status and communications
statistics are shown for the 16 rear-panel ports and the front-panel port. Refer to the
STATUS command explanation in Section 5: Commands for more detailed information.

Date Code 20010518 Introduction 1-5
SEL-2020 Instruction Manual
*>>STATUS<ENTER>
*>>STATUS<ENTER>*>>STATUS<ENTER>
*>>STATUS<ENTER>
COMMUNICATIONS PROCESSOR - S/N 95012004 Date: 03/02/95 Time: 15:32:24
FID=SEL-2020-R100-V0-D950324
SELF-TESTS
RAM ROM EEPROM FLASH P.S. SET BATTERY
512 kb OK OK Absent OK OK OK
IRIG-B Input: Present
I/O Board: Installed
Modem: Installed
Port Status Success Rate SET M Database Delays
1 Inactive None
2 Inactive None
3 Inactive None
4 Inactive None
5 Inactive None
6 Inactive None
7 Inactive None
8 Active None
9 Active None
10 Inactive None
11 Inactive None
12 Inactive None
13 Inactive None
14 Inactive None
15 Inactive None
16 Inactive None
F Active 100% None
*>>
Refer to the SEL-2020 Data Sheet in this section of the instruction manual, and Section 2:
General Description for more information about the operation and features of the SEL-2020.

SCHWEITZER ENGINEERING LABORATORIES
2350 NE Hopkins Court  Pull an, WA  99163-5603  USA
Phone: [phone]  Fax: [phone]
E- ail: [email protected]  Internet: www.selinc.co
SEL-2020 Communications Processor
Data Sheet
General Description: The SEL-2020 Communications Processor is a breakthrough for substation
communication and integration. It combines multiport communications, databases and processing,
nonvolatile memory, timekeeping and synchronization, alarm monitoring, and auxiliary control into one
compact, powerful, economical, easy-to-use, and rugged device.
• Automatically maintains databases for metering, events, and targets.
• Powerful 32-bit computer simultaneously supports 38400 baud on all master ports and 19200 baud on
all other ports.
• SELOGIC®control equations coordinate commands, messages, and I/O.
• Auto-configuration features simplify application settings with SEL relays.
• Versatile data-processing power handles most relays, meters, and SCADA systems.
• One device integrates most small substations.
• Easily cascaded for economical large-station solutions.
• Communications processing reduces burden on SCADA and other equipment.
• Handles binary and ASCII communications for versatile application.
• Can be a Modbus®RTU or Distributed Network Protocol (DNP) V3.00 Level 2 slave to ease data
collection and system control.

2
PRODUCT OVERVIEW
SEL-2020 Description
The SEL-2020 Communications Processor (SEL-2020) provides many special features needed in
today's substations for communicating with a variety of microprocessor-based devices, including
digital fault recorders, sequential events recorders (SER), digital meters, and digital relays. The
SEL-2020 can function as a simple, but intelligent, port switch. Or it can provide sophisticated
communication and data handling capability required for advanced substation integration
projects. Data are collected, processed, and stored in the SEL-2020 database, permitting quick
distribution of selected data to an RTU (remote terminal unit) or other device. Figure 1 shows an
example block diagram configuration of the SEL-2020 with various SEL relays and peripheral
devices connected.
Enhanced/Intelli ent Port Switchin
Unlike conventional port switches, the SEL-2020 can support communications on all active ports
— simultaneously — at baud rates up to 19200 or 38400 depending on port configuration. This
means that you can communicate locally through the SEL-2020 with one connected intelligent
electronic device (IED) at the same time that someone else is communicating remotely through
the same SEL-2020 to another connected IED. Other intelligent features, like the SEL-2020 auto-
configuration function, make setup and operation much easier than with simple port switches. In
advanced applications, where the SEL-2020 is used to collect, store, and distribute information,
the simultaneous communication function provides an uninterrupted flow of information from all
active IEDs to an RTU or station integration computer; at the same time you can communicate
through the SEL-2020, either locally or remotely, with one of the connected relays or IEDs.
Data Collection, Processin , Stora e, Distribution
You can collect, store, process, and distribute target, meter, event, status, and other information
— virtually all information available from an SEL relay and a variety of information available
from other IEDs — with the SEL-2020, using a simple, but powerful, set of communication
commands. Likewise, the SEL-2020 reduces the processing burden for these external devices by
separating selected data from IEDs so that only the essential information is delivered and in the
form and format required.
Substation Inte ration and Network Interface
Communication and information handling features make the SEL-2020 ideal for substation
integration projects, eliminating the need for separate substation network architecture. On larger
integration projects, the SEL-2020 reduces or eliminates the need for costly network interface
devices, otherwise required for each IED. Inclusion of Modbus and DNP support eases integra-
tion with systems that support Modbus or DNP.
Time Synchronization
The SEL-2020 can synchronize the time clocks in attached devices, such as SEL relays, that
accept a demodulated IRIG-B time signal. The demodulated IRIG-B signal is regenerated in the
SEL-2020 from an external modulated or demodulated source, such as a GOES or GPS satellite
clock receiver. If no IRIG-B source is available, the demodulated IRIG-B time signal is gener-
ated internally by the SEL-2020.