Sel MIRRORED BITS FGR-115MB User guide

Date Code 20070803 SEL Application Guide 2000-02
Application Guide Volume II AG2000-02
M IRRORED B ITS® Communications
With FreeWave Technologies Spread
Spectrum Radios (Model FGR-115MB)
David Costello and Ken Fodero
I NTRODUCTION
M IRRORED B ITS
®
communications is an innovative technique that provides low-cost, high
performance communications directly between relays. The communications message contains
information to exchange internal logic directly between relays. Applications for M
IRRORED B ITS
include line protection pilot schemes, remote device control and monitoring, relay remote
tripping, automated sectionalizing and load restoration, bus protection, and much more.
Freewave FGR-115MB
Transceiver
NO. 1
(slave)
SEL-351S-7 Relay
(RXID=1, TXID=2)
SEL-351R Cabinet
FreeWave FGR-115MB
Transceiver
NO.1
(master)
Antenna
NO. 3
Surge Protection
NO. 7
RF Coaxial Cable
NO. 4
12 Vdc from Adapter
12 Vdc from SEL-351R
RF Coaxial Cable
NO. 4
Surge Protection
NO. 7
10 Miles, Line-of-Sight
Optical
Fiber
NO. 6
Antenna
NO. 3
SEL-351R-1
(RXID=2, TXID=1)
SEL-2815M (DTE)
NO. 5
SEL-2815M (DCE)
NO. 5
SEL-C285 Cable
NO. 2
SEL-351R Relay
(RXID=2, TXID=1)
Figure 1: Example Installation (Refer to Table 1)
SEL added a new protocol setting option, MB8, so that the M IRRORED B ITS message structure is
compatible with communication devices which require a specific character bit count, such as
point-to-point spread spectrum (900 MHz) radios.

2
SEL Application Guide 2000-02 Date Code 20070803
SEL devices compatible with spread spectrum radios include the SEL-300 and SEL-400 series
relays and recloser controls, as well as the SEL-2100 Logic Processor and the SEL-2505 Remote
I/O Module.
R ADIO S ELECTION
This application guide shows the settings and connections required to establish M IRRORED B ITS
communications when using the FreeWave
®
Technologies, Inc. model FGR-115MB spread
spectrum transceiver.
One important consideration when choosing a radio for use with M
IRRORED B ITS is how
effectively the brand emulates full-duplex communications. Radios are effectively half-duplex
devices, while M
IRRORED B ITS requires that each relay constantly transmit and receive data.
FreeWave has worked with SEL to optimize the FGR-115MB to the
M IRRORED B ITS MB8
communications data structure. Those radios that do not adequately emulate full duplex can still
be used. However, two radios must be used per location (one dedicated to transmit data and the
other to receive data). Please test to ensure compatibility.
Also, radios with no built-in error detection work best with M
IRRORED B ITS as they only add a
few milliseconds to the overall relay-to-relay communication data delay. Radio
resynchronization time can also momentarily delay a signal. Because speed is critical in pilot
protection schemes, be sure to check the radio specifications carefully for data delay and
resynchronization characteristics.
The FGR-115MB radio operates in a non-licensed 900 MHz frequency range. It has a point-to-
point range of up to 10 miles, based on an unobstructed line-of-sight.
S ECURITY
M IRRORED B ITS repeatedly sends data in an encoded message. Each of eight data bits is sent
three times within each message. Received messages are checked for data bit consistency, parity,
framing, overrun, and timing. In addition, an addressing scheme is used so that only relays set as
pairs can communicate to one another.
The FGR-115MB radio also contains some features that improve security and minimize
interference. Each radio’s serial number is encoded into its transmission. Each radio has a “Call
Book” setting and will only accept messages from radio serial numbers listed in its call book
(e.g., the master radio would have the slave radio’s serial number listed in its call book, and vice
versa). In addition, the “FreqKey” setting allows the user to modify the frequency hopping
patterns of the transceivers to minimize interference with other radios or devices in the area; the
radio has 15 pseudo-random patterns to choose from.
M ONITORING R ADIO P ERFORMANCE
The performance of the radios and channel can be monitored using a variety of methods. SEL
relays with M
IRRORED B ITS constantly monitor the channel performance. Logic bits ROK
(instantaneous channel monitor), RBAD (ROK drop-out for a settable time), and CBAD
(long-term channel unavailability exceeding a settable threshold) can be used to trigger event
reports, create a sequential events recording, or alarm SCADA via output contact closure or
EIA-232 communications. In addition, the relays generate a detailed Communications Data Log,
which records the latest 255 channel failures, including a time and date stamp, cause of each
error, and outage duration. Refer to the instruction manual of the SEL device for more details on
each of these features.

3
Date Code 20070803 SEL Application Guide 2000-02
In addition to the detailed monitoring done by the relay, the FGR-115MB also maintains radio
performance statistics that can be accessed by any terminal emulator.
It is important to note that these radios operate in a license free band. This means that radios used
by others could occasionally interfere.
C OMMISSIONING T ESTS
A time delay is incurred when sending a M IRRORED B ITS message from one SEL relay to another.
To determine the delay attributed to the communications media (propagation delay), in this case
the spread spectrum radios, use the test procedure outlined in SEL Application Guide 98-11:
Testing the SEL-321-1 Relay-to-Relay Digital Logic Communication Time Delay. The typical
back to back operate times (exclusive of the radio delays) for M
IRRORED B ITS message at 38400
is 4.2 ms for the SEL-321-1 and SEL-2505 and 8.3 ms for all other SEL M
IRRORED B ITS
products.
R ELAY S ETTINGS AND C ONNECTIONS
The required port settings for an SEL-351S Relay are shown below. Settings for any relay in the
SEL-351 and SEL-311 family of relays would be the same. To establish communications via the
radio, the most critical settings are PROTO, SPEED, RTSCTS, RXID, and TXID.
=>SHO P 2 <Enter>
Port 2
PROTO = MB8A
SPEED = 38400 RTSCTS= N RBADPU= 60 CBADPU= 1000
RXID = 1 TXID = 2 RXDFLT=XXXXXXXX
RMB1PU= 1 RMB1DO= 1 RMB2PU= 1 RMB2DO= 1
RMB3PU= 1 RMB3DO= 1 RMB4PU= 1 RMB4DO= 1
RMB5PU= 1 RMB5DO= 1 RMB6PU= 1 RMB6DO= 1
RMB7PU= 1 RMB7DO= 1 RMB8PU= 1 RMB8DO= 1
Set PROTO equal to MB8x, where xequals A or B depending on which M IRRORED B ITS channel
is being used. Note, this setting is slightly different in the SEL-2100 or SEL-321 Relay.
Set SPEED equal to 38400.
Set RTSCTS (hardware handshaking) to N to disable that option.
Set the RXID equal to one and TXID equal to two at the Master End. At the remote or Slave
End, set the RXID equal to two and the TXID to one. The relays use these addresses so that the
master relay only receives messages sent by a relay with the matching transmit address and vice
versa.
To connect the relay to the radio, use an SEL-C285 cable, DB-9 male to DB-9 male straight-
through. If complete electrical isolation is desired between the radio and antenna and the relay’s
EIA-232 communications port, use the SEL-2815M Fiber-Optic Transceivers and fiber-optic
cable to connect the relay to the radio as shown in Figure 1.
The required port settings for SEL-400 series relays are shown below. To establish
communications via the radio, the most critical settings are PROTO, MBT, SPEED, STOPBIT,
TXID, RXID, and TXMODE. All other settings are per the application requirements.
=>>SHO P 3 <Enter>
Port 3 (Continued on next page)

4
SEL Application Guide 2000-02 Date Code 20070803
Protocol Selection (Continued from previous page)
PROTO := MBA
Communications Settings
MBT := N SPEED := 38400 STOPBIT := 2
Mirrored Bits Protocol Setting
TX_ID := 2 RX_ID := 1 RBADPU := 10 CBADPU := 20000
TXMODE := P MBNUM := 8 RMB1FL := P RMB1PU := 1
RMB1DO := 1 RMB2FL := P RMB2PU := 1 RMB2DO := 1
RMB3FL := P RMB3PU := 1 RMB3DO := 1 RMB4FL := P
RMB4PU := 1 RMB4DO := 1 RMB5FL := P RMB5PU := 1
RMB5DO := 1 RMB6FL := P RMB6PU := 1 RMB6DO := 1
RMB7FL := P RMB7PU := 1 RMB7DO := 1 RMB8FL := P
RMB8PU := 1 RMB8DO := 1
Set PROTO equal to MBx, where x equals A or B depending on which M IRRORED B ITS channel
is being used. Set MBT equal to N to disable that option.
Set SPEED equal to 38400.
Set STOPBIT equal to 2.
Set the RXID equal to one and TXID equal to two at the Master End. At the remote or Slave End,
set the RXID equal to two and the TXID to one. The relays use these addresses so that the master
relay only receives messages sent by a relay with the matching transmit address and vice versa.
Set TXMODE equal to P (Paced).
To connect the relay to the radio, use an SEL-C285 cable, DB-9 male to DB-9 male straight-
through. If complete electrical isolation is desired between the radio and antenna and the relay’s
EIA-232 communications port, use the SEL-2815M Fiber-Optic Transceivers and fiber-optic
cable to connect the relay to the radio as shown in Figure 1.
R ADIO S ETTINGS AND C ONNECTIONS
The FGR-115MB has settings that require adjustment prior to installation. Invoke the setup
program by connecting the radio to any terminal emulator program, using the DB-9
straight-through cable supplied with the radio. Set the terminal baud rate to 19200, and put the
radio in setup mode by pressing the Setup Button; when setup mode is invoked, all three LEDs on
the radio turn green, and a menu is displayed on the terminal screen as shown below.
MAIN MENU
SEL Version 5.72 06-27-2001
Standard Hop Table
Modem Serial Number 897-0002
(0) Set Operation Mode
(1) Set Baud Rate
(2) Edit Call Book
(3) Edit Radio Transmission Characteristics
(4) Show Radio Statistics
(5) Edit MultiPoint Parameters
(6) TDMA Menu
(Esc) Exit Setup
Enter Choice
Simply enter menu choices and selections to make the following settings enabled. Start with the
Set Operation mode (0).

5
Date Code 20070803 SEL Application Guide 2000-02
SET MODEM MODE
Modem Mode is 10
(0) Point to Point Master
(1) Point to Point Slave
(2) Point to MultiPoint Master
(3) Point to MultiPoint Slave
(4) Point to Point Slave/Repeater
(5) Point to Point Repeater
(6) Point to Point Slave/Master Switchable
(7) Point to MultiPoint Repeater
(A) SEL Master(10)
(B) SEL Slave(11)
(Esc) Exit to Main Menu
Enter Choice
The modem mode setting is used to designate the radio and relay at one end of the line as the
master, and the coordinating radio and relay as the slave. The designation is arbitrary, but one
must be the master and one the slave.
SET BAUD RATE
Modem Baud is 038400
(0) 230,400
(1) 115,200
(2) 76,800
(3) 57,600
(4) 38,400
(5) 19,200
(6) 9,600
(7) 4,800
(8) 2,400
(9) 1,200
(A) Data, Parity 0
(B) MODBus RTU 0
(C) RS232 / 485 0
(D) Setup Port 2
(E) TurnOffDelay 0 TurnOnDelay 0
(E) TurnOffDelay 0
(F) TurnOffDelay 0
(Esc) Exit to Main Menu
Enter Choice
The baud rate must be set to 38400 to match the relay’s baud rate.
The eight data bits, no parity, and one stop bit selection equals a total of nine bits. That matches
the MB8 bit count (six data bits, even parity, and two stop bits for a total of nine). The radio will
interpret the parity bit and the first stop bit as the seventh and eighth data bits. Note, setting the
PROTO setting in the relay to MB will not work.
MODEM CALL BOOK
Entry to Call is 00
Entry Number Repeater1 Repeater2
(0) 897-0001
(1) 000-0000
(2) 000-0000
(3) 000-0000
(4) 000-0000
(5) 000-0000
(6) 000-0000
(7) 000-0000
(8) 000-0000
(9) 000-0000
(C) Change Entry to Use (0-9) or A(ALL)
(Esc) Exit to Main Menu
Enter all zeros (000-0000) as your last number in list

6
SEL Application Guide 2000-02 Date Code 20070803
The modem call book is where we enter the remote radio’s serial number. The serial number is
found on the outside case of each radio or in the main menu header when set-up mode is invoked.
Radios will only receive messages from a relay listed in its call book.
RADIO PARAMETERS
WARNING: Do not change parameters without reading manual
(0) FreqKey 5
(1) Max Packet Size 8
(2) Min Packet Size 9
(3) Xmit Rate 1
(4) RF Data Rate 3
(5) RF Xmit Power 9
(6) Slave Security 0
(7) RTS to CTS 0
(8) Retry Time Out 255
(9) Lowpower Mode 0
(Esc) Exit to Main Menu
Enter Choice
The Frequency Key (FreqKey) is used to minimize interference from other radios in the area.
Insure that the master and slave pair of radios are set on the same hopping pattern, but different
from other transceivers in the area (if known).
From the radio parameters menu enter “0” followed by an “F” to set the hop table size to 112 and
the hop freq offset to zero.
RADIO PARAMETERS
WARNING: Do not change parameters without reading manual
(0) FreqKey 5
(1) Max Packet Size 8
(2) Min Packet Size 9
(3) Xmit Rate 1
(4) RF Data Rate 3
(5) RF Xmit Power 10
(6) Slave Security 0
(7) RTS to CTS 0
(8) Retry Time Out 255
(9) Lowpower Mode 0
(A) High Noise 0
(B) MCU Speed 1
(C) RemoteLED 0
(Esc) Exit to Main Menu
Enter Choice 0
Enter New Frequency Key (0-E) (F for more)F
(0) Hop Table Version 0
(1) Hop Table Size 112
(2) Hop Freq Offset 0
(Esc) Exit to Radio Menu
Enter Choice
Once these settings are entered, return to the main menu and press ESC to discontinue the setup
mode; the radio should immediately begin normal operation.
To connect the radio to the antenna, use a low-loss RF coaxial cable. FreeWave recommends the
use of tuned surge protection, installed between the radio and the antenna; this device can be
installed at either end, or in the middle of the coaxial cable.

7
Date Code 20070803 SEL Application Guide 2000-02
The FGR-115MB radio requires 12 Vdc power. The radio comes with a 120 Vac adapter, which
is handy for laboratory testing. A dc-to-dc converter will likely need to be supplied if the radio is
installed in a substation control building. For pole-mounted installations, as shown in Figure 1,
the SEL-351R Recloser Control can provide the 12 Vdc power.
I NITIAL C HECKOUT
The easiest way to ensure that the relays are communicating is to use the target command, as
shown below.
=>TAR ROKA <Enter>
LBOKB CBADB RBADB ROKB LBOKA CBADA RBADA ROKA
0 0 0 0 0 0 0 1
The result shown here is from an SEL-351S Relay. ROKA is asserted, meaning that the two
relays have established M
IRRORED B ITS communications. For longer-term channel tests, use the
suggestions described in Monitoring Radio Performance.
E QUIPMENT L IST
The following equipment list details the required components and connections, as shown in
Figure 1. A pole, tower, or other means of elevating the antenna is not shown.
Table 1: Equipment List
No. Item Description Approx. Cost
1 900 MHz Spread-
Spectrum Transceiver
FreeWave Technologies, Inc.
1
Model FGR-115MB.
12 Vdc power, 1 W output, 10 mile line-of-sight,
120 Vac-to-12 Vdc adapter and 6' DB-9M-to-DB-9F
straight-through programming cable included.
www.freewave.com
[phone]
$1350
2 SEL-C285 cable DB9M-to-DBM straight-through cable $25
3 Yagi Antenna FreeWave Technologies, Inc.
2
Model EAN0900YA.
10 dB, directional, 32" long.
$130
4 Low-Loss RF Cable FreeWave Technologies, Inc.
3
Model ASC0504NN.
50' length (other lengths available).
$140
5 Fiber-Optic
Transceiver
SEL
4
Model SEL-2815M.
EIA-232 DB-9M-to-Fiber-Optic Transceiver.
$362
6 Fiber-Optic Cable SEL
4
Model C800FZST.
Terminated Cable, 25' or less (other lengths
available)
$115
7 Surge Protection Northern Technologies,
Model QWS-920N
5
.
N Type M-to-F ¼ shorting stub coaxial protector
tuned for 870 - 970 MHz.
www.northern-tech.com
[phone]
$135

8
SEL Application Guide 2000-02 Date Code 20070803
Notes:
1. SEL has tested the FGR-115MB radio to verify its operation with the settings and
connections listed in this document. Other radios may also be used; performance may
vary between different manufacturers.
2. Other antennas may also be used.
3. Other low-loss RF cable may be used.
4. Other fiber-optic transceivers and cable may be used. Note, the fiber-optic transceivers
are not required, but provide complete isolation between the radio and antenna and the
relay.
5. Other surge protection may be used (PolyPhaser, etc.). This unit is recommended by
FreeWave for use with their radios.
F ACTORY A SSISTANCE
We appreciate your interest in SEL products and services. If you have questions or comments,
please contact us at:
Schweitzer Engineering Laboratories, Inc.
2350 NE Hopkins Court
Pullman, WA 99163-5603 USA
Telephone: [phone]
Fax: [phone]
www.selinc.com • [e-mail]
Or contact:
FreeWave Technologies
1880 S. Flatiron Court
Boulder, CO 80301 USA
Telephone: [phone]
Fax: [phone]
Internet: www.freewave.com
© 2000–2007 by Schweitzer Engineering Laboratories, Inc.
All rights reserved.
Mirrored Bits Communications With FreeWave Technologies
Spread Spectrum Radios (Model FGR-115MB)
All brand or product names appearing in this document are
the trademark or registered trademark of their respective
holders. No SEL trademarks may be used without written
permission.
SEL products appearing in this document may be covered by
US and Foreign patents.
*AG2000-02*