Microwave Data Systems MDS TransNET 900, EL805 Operation Manual
Microwave Data Systems Inc.
MDS T ransNET 900
Model EL805
Spread Spectrum
Data T ransceiver
MDS 05-2708A01, Rev. B
AUGUST 2002
™
Installation & Operation Guide
Installation & Operation Guide
QUICK START GUIDE
1. Install and connect the antenna system to the transceiver
• Use a high-quality gain antenna, mounted in the clear.
• Use a low-loss feedline such as LMR 400.
• Preset directional antennas in the direction of desired transmission/reception.
2. Connect the data equipment to the radio’s DB-9F DATA connector
• Connect only the required pins. EIA-232, shown below, typically uses only
TXD, RXD and GND. (See Page 56 EIA-485 interface connections.)
• Verify the connected data equipment is configured as DTE. (Radio is DCE.)
DB-25
TXD
RXD
GND
RTS
(DTE)
CTS
DTR
DATA EQUIPMENT
DSR
DB-9
TXD
2
3
7
4
5
20
6
3
RXD
2
5
JUMPERS:
Only if required by RTU.
See manual for additional details.
GND
(DCE)
TRANSCEIVER
DB-9
TXD
RXD
GND
DTR
(DTE)
DSR
RTS
DATA EQUIPMENT
CTS
3
2
5
4
6
7
8
JUMPERS:
Only if required by RTU.
See manual for additional details.
3
2
5
DB-9
TXD
RXD
GND
3. Apply DC power to the radio. Use the supplied 2-pin connector
• Input voltage is 6–30 Vdc. Observe proper polarity. The left pin is positive (+)
and the right is negative (–). (See Page 16 for details.)
4. Configure with a PC terminal or TransNET Configuration Software
• Connect computer to radio’s DIAG connector. See Page 54 for cable wiring.
• Set the Mode using the
(Extension) command. (Note: Only
• Set a unique Network Address (1–65000) using
in the system
must
MODE M
(Master),
one
MODE R
Master is permitted in a system.)
ADDR
have the same network address.
(Remote), or
MODE X
command. Each radio
Tip: Use the last four
digits of the Master’s serial number to help avoid conflicts with other
MDS TransNET 900 networks.
• Set the baud rate/data interface parameters. Default setting is 9600 bps, 8
data bits, no parity, 1 stop bit. If changes are required, use the
abc
command where
xxxxx
equals the data rate (1200–115200 bps) and
BAUD xxxxx
equals the communication parameters as follows:
a
= Data Bits (7 or 8)
b
= Parity (N for None, O for Odd, E for Even
c
= Stop Bits (1 or 2)
NOTE:
7N1, 8E2 and 8O2 are not supported.
5. Verify proper operation by observing the LED display
(DCE)
TRANSCEIVER
abc
• Refer to Table 4 on Page 19 for a description of the status LEDs.
• Refine directional antenna headings for maximum received signal strength
using the
RSSI
command. (Remotes must be synchronized with the master.)
CONTENTS
1.0 ABOUT THIS MANUAL..........................................................1
2.0 PRODUCT DESCRIPTION....................................................1
2.1 Transceiver Features .......................................................1
2.2 Model Configuration Codes ............................................2
2.3 Spread Spectrum Radios—How Are They Different? .....3
2.4 Typical Applications .........................................................3
Multiple Address Systems (MAS)....................................3
Point-to-Point System ......................................................4
Adding a Tail-End Link to an Existing Network ................4
Extending a TransNET Network with a Repeater.............5
2.5 Accessories ....................................................................5
3.0 INSTALLATION PLANNING...................................................6
3.1 General Requirements ....................................................6
3.2 Site Selection ..................................................................7
Terrain and Signal Strength .............................................7
Conducting a Site Survey................................................8
3.3 A Word About Radio Interference ...................................9
3.4 Antenna & Feedline Selection .........................................10
Antennas..........................................................................10
Feedlines.........................................................................11
3.5 How Much Output Power Can be Used? ........................12
4.0 INSTALLATION ......................................................................13
4.1 Transceiver Installation ....................................................13
4.2 Configuring Multiple Remote Units .................................17
4.3 Tail-End Links ..................................................................17
4.4 Configuring a Network for Extensions .............................18
4.5 Using the Radio’s Sleep Mode (Remotes Only) ..............18
Sleep Mode Example.......................................................18
5.0 OPERATION ..........................................................................19
MDS 05-2708A01, Rev. B MDS TransNET 900 I&O Guide i
5.1 Initial Start-up .................................................................19
5.2 Performance Optimization ..............................................19
Antenna Aiming...............................................................20
Antenna SWR Check......................................................20
Data Buffer Setting..........................................................20
Hoptime Setting...............................................................20
Operation at 115200 bps.................................................20
Baud Rate Setting........................................................... 21
Radio Interference Checks..............................................21
6.0 RADIO PROGRAMMING......................................................21
6.1 Radio Programming Methods .........................................21
Terminal Interface............................................................21
PC-Based Configuration Tool..........................................21
6.2 User Commands ............................................................22
Entering Commands .......................................................22
6.3 Detailed Command Descriptions ....................................27
ADDR [1–65000]............................................................. 27
AMASK [0000 0000–FFFF FFFF]................................... 28
ASENSE [HI/LO].............................................................28
BAUD [xxxxx abc]............................................................28
BUFF [ON, OFF].............................................................28
CODE [NONE, 1…255]...................................................29
CTS [0–255].................................................................... 29
CTSHOLD [0–60000]...................................................... 30
DEVICE [DCE, CTS KEY]..............................................30
DLINK [xxxxx/ON/OFF]................................................... 30
DKEY ..............................................................................31
DTYPE [NODE/ROOT]....................................................31
FEC [ON, OFF] ...............................................................31
HOPTIME [7, 28].............................................................31
INIT .................................................................................31
HREV..............................................................................32
KEY................................................................................. 32
MODE [M, R, X] ..............................................................32
OWM [xxxxx]................................................................... 32
OWN [xxxxx]....................................................................32
PORT [RS232, RS485]...................................................32
PWR [20–30]...................................................................34
ii MDS TransNET 900 I&O Guide MDS 05-2708A01, Rev. B
REPEAT [0–10]................................................................34
RETRY [0–10]..................................................................34
RSSI ................................................................................34
RTU [ON, OFF, 0-80].......................................................35
RX [xxxx]..........................................................................35
RXTOT [NONE, 0–1440] .................................................35
SAF [ON, OFF]................................................................35
SETUP.............................................................................35
SER .................................................................................36
SHOW PWR....................................................................36
SHOW SYNC...................................................................36
SKIP [NONE, 1...8]..........................................................36
SLEEP [ON, OFF]............................................................37
SREV...............................................................................37
STAT ................................................................................37
TEMP...............................................................................37
TX [xxxx]..........................................................................37
UNIT [10000–65000] .......................................................37
XADDR [0–31].................................................................38
XMAP [00000000-FFFFFFFF].........................................38
XPRI [0–31] .....................................................................38
XRSSI [NONE, –40...–120]..............................................38
ZONE CLEAR..................................................................38
ZONE DATA .....................................................................38
7.0 TROUBLESHOOTING...........................................................39
7.1 LED Indicators ................................................................40
7.2 Alarm Codes ...................................................................40
Checking for Alarms—STAT command............................40
Major Alarms vs. Minor Alarms........................................40
Alarm Code Definitions....................................................41
7.3 Troubleshooting Chart .....................................................42
7.4 Performing Network-Wide Remote Diagnostics ..............43
7.5 Internal Fuse Replacement .............................................44
8.0 RADIO FIRMWARE UPGRADES..........................................45
8.1 Obtaining new firmware ..................................................45
Saving a Web-site firmware file to your PC......................45
8.2 Installing firmware in your radio ......................................45
MDS 05-2708A01, Rev. B MDS TransNET 900 I&O Guide iii
9.0 OPERATING PRINCIPLES AND CONFIGURATION............46
9.1 Synchronization—Basic Network ...................................46
9.2 Extension Operation with SAF .......................................46
Retransmission and ARQ operation................................48
Synchronizing Network Units..........................................48
9.3 Configuration Parameters for Store & Fwd Services ...... 49
9.4 Security ..........................................................................51
10.0 TECHNICAL REFERENCE.................................................53
10.1 Product Specifications ..................................................53
10.2 Diagnostic Interface Connections (RJ-11) ....................54
10.3 Data Interface Connections (DB-9F) ............................ 54
Pin Descriptions—RS/EIA-232 Mode..............................55
Pin Descriptions—RS/EIA-422/485 Mode.......................56
10.4 dBm-Watts-Volts Conversion Chart .............................. 57
Copyright Notice
This Installation and Operation Guide and all software described herein are Copyright 2002 by
Microwave Data Systems Inc. All rights reserved. Microwave Data Systems Inc. reserves its
right to correct any errors and omissions in this manual.
MDS Quality Policy Statement
We, the employees of Microwave Data Systems, are committed to
understanding and exceeding our customer’s needs and expectations.
• We appreciate our customers’ patronage. They are our business.
• We promise to serve them and anticipate their needs.
• We are committed to providing solutions that are cost effective,
innovative and reliable, with consistently high levels of quality.
We are committed to the continuous improvement of all of our systems and
processes, to improve product quality and increase customer satisfaction.
RF Exposure Notice
RF EXPOSURE
ISO 9001 Registration
Microwave Data Systems adheres to the internationally-accepted ISO 9001 quality system standard.
Professional installation required. The radio equipment described in this guide emits radio frequency energy. Although the power level is low, the concentrated energy from a directional
antenna may pose a health hazard. Do not allow people to come closer than 23 cm (9 inches) to
the antenna when the transmitter is operating in indoor or outdoor environments. More information
on RF exposure is available on the Internet at www.fcc.gov/oet/info/documents/bulletins.
iv MDS TransNET 900 I&O Guide MDS 05-2708A01, Rev. B
UL/CSA Notice
This product is available for use in Class I, Division 2, Groups A, B, C & D Hazardous Locations. Such locations are defined in Article 500 of the National Fire Protection Association
(NFPA) publication
The transceiver has been recognized for use in these hazardous locations by two independent
agencies —Underwriters Laboratories (UL) and the Canadian Standards Association (CSA). The
UL certification for the transceiver is as a Recognized Component for use in these hazardous
locations, in accordance with UL Standard 1604. The CSA Certification is in accordance with
CSA STD C22.2 No. 213-M1987.
UL/CSA Conditions of Approval: The transceiver is not acceptable as a stand-alone unit for use
in the hazardous locations described above. It must either be mounted within another piece of
equipment which is certified for hazardous locations, or installed within guidelines, or conditions
of approval, as set forth by the approving agencies. These conditions of approval are as follows:
1. The transceiver must be mounted within a separate enclosure which is suitable for the
intended application.
2. The antenna feedline, DC power cable and interface cable must be routed through conduit in
accordance with the National Electrical Code.
3. Installation, operation and maintenance of the transceiver should be in accordance with the
transceiver's installation manual, and the National Electrical Code.
4. Tampering or replacement with non-factory components may adv ersely affect the safe use of
the transceiver in hazardous locations, and may void the approval.
5. A power connector with screw-type retaining screws as supplied by MDS must be used.
When installed in a Class I, Div. 2, Groups A, B, C or D hazardous location, observe the following:
WARNING EXPLOSION HAZARD
has been switched off or the area is know to be non-hazardous.
Refer to Articles 500 through 502 of the National Electrical Code (NFPA 70) for further infor-
mation on hazardous locations and approved Division 2 wiring methods.
FCC Part 15 Notice
The MDS TransNET 900™ transceivers comply with Part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) this device may not cause harmful interference, and (2)
this device must accept any interference received, including interference that may cause undesired operation. This device is specifically designed to be used under Section 15.247 of the FCC
Rules and Regulations. Any unauthorized modification or changes to this device without the
express approval of Microwave Data Systems may void the user’s authority to operate this
device. Furthermore, this device is intended to be used only when installed in accordance with
the instructions outlined in this manual. Failure to comply with these instructions may also void
the user’s authority to operate this device.
Manual Revision and Accuracy
While every reasonable effort has been made to ensure the accuracy of this manual, product
improvements may result in minor differences between the manual and the product shipped to
you. If you have additional questions or need an exact specification for a product, please contact
our Customer Service Team using the information at the back of this guide. In addition, manual
updates can often be found on the MDS Web site at
NFPA 70
, otherwise known as the National Electrical Code.
Do not disconnect equipment unless power
www.microwavedata.com
.
MDS 05-2708A01, Rev. B MDS TransNET 900 I&O Guide v
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1.0 ABOUT THIS MANUAL
This manual presents installation and operating instructions of the
MDS TransNET 900™ transceiver for use by a professional installer. This
person is expected to install, operate, and perform basic system maintenance
on the described radio. Following installation, we suggest keeping this
manual near the equipment for future reference.
2.0 PRODUCT DESCRIPTION
The transceiver, shown in Figure 1, is a spread spectrum radio designed for
license-free operation in the 900 MHz frequency band. Employing Digital
Signal Processing (DSP) technology, it is highly reliable for long-distance
communications, even in the presence of weak signals or interference.
DSP technology also makes it possible to obtain information about radio
operation and troubleshoot problems, without going to the remote radio site.
Using appropriate software at the master station, diagnostic data can be
obtained on any DSP radio in the system, even while payload data is being
transmitted. (See “Performing Network-Wide Remote Diagnostics” on
Page 43.)
The MDS TransNET 900 is housed in a compact and rugged die-cast
enclosure that need only be protected from direct exposure to the weather. It
contains a single printed circuit board with all necessary components for
radio operation. No jumper settings or manual adjustments are required to
configure the radio for operation.
Figure 1.
MDS TransNET 900™
Transceiver
2.1 Transceiver Features
Listed below are several key features of the MDS TransNET 900 transceiver.
These are designed to ease the installation and configuration of the radio,
while retaining the ability to make changes in the future.
• 128 frequencies over 902–928 MHz, subdivided into eight frequency
zones
• Configurable operating zones to omit frequencies with constant
interference
• 65,000 available network addresses
MDS 05-2708A01, Rev. B MDS TransNET 900 I&O Guide 1
• Network-wide configuration from the master station; eliminates most
trips to remote sites
• Data transparency–ensures compatibility with virtually all
asynchronous SCADA system RTUs
• Peak-hold RSSI, averaged over eight hop cycles
• Operation at up to 115,200 bps continuous data flow
• Store-and-Forward repeater operation
• Data latency typically less than 10 ms
• Same hardware for master or remote configuration
• Supports RS/EIA-232 and RS/EIA-485 user interface
• Low current consumption—Less than 8 mA in “sleep” mode.
NOTE:
Some MDS TransNET 900 radio features may not be available on all radios,
based on the options purchased and the applicable regulatory constraints for
the region in which the radio will operate.
2.2 Model Configuration Codes
The model number code is printed on the radio enclosure, and provides key
information about how the radio was configured when it left the factory. See
Figure 2 for an explanation of the model number characters. (Note: This
information is subject to change and should not be used for product ordering.)
OPERATION
(X) Remote/Master
BAND
(9) 900 MHz
EL805
ENCLOSURE
(1) With Enclosure
AGENCY
(N) None
(F) FCC/IC
19N
ANX
OPTIONS
(A) None
Figure 2. MDS TransNET 900 transceiver model configuration codes
MTG. BRACKETS
(A) Standard
(B) None
N
SAFETY CERT.
(N) N/A
(F) UL/CSA
OPTION
(N) None
SPARE
(N) None
DIAGNOSTICS
(N) None
(W) Network-wide
2 MDS TransNET 900 I&O Guide MDS 05-2708A01, Rev. B
2.3 Spread Spectrum Radios— How Are They Different?
The main difference between a traditional (licensed) radio and the
MDS TransNET 900 transceiver is that this unit “hops” from channel to
channel many times per second using a specific hop pattern applied to all
radios in the network. A distinct hopping pattern is provided for each of the
65,000 available network addresses, thereby minimizing the chance of
interference with other spread spectrum systems. In the USA, and certain
other countries, no license is required to install and operate this type of radio
system, provided that RF power and antenna gain restrictions are observed.
2.4 Typical Applications
Multiple Address Systems (MAS)
This is the most common application of the MDS TransNET 900 transceiver.
It consists of a central control station (master) and two or more associated
remote units, as shown in Figure 3. An MAS network provides
communications between a central host computer and remote terminal units
(RTUs) or other data collection devices. The operation of the radio system is
transparent to the computer equipment. When used in this application, the
transceiver provides an excellent alternative to traditional (licensed) MAS
radio systems.
Invisible place holder
MDS TransNET
Remote
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RTU
MDS TransNET
Remote
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RTU
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MDS TransNET
Master
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MDS TransNET
Remote
RTU
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RTU
MDS TransNET
Remote
Host System
Figure 3. Typical MAS network
MDS 05-2708A01, Rev. B MDS TransNET 900 I&O Guide 3
Point-to-Point System
A point-to-point configuration (Figure 4) is a simple arrangement consisting
of just two radios—a master and a remote. This provides a half-duplex
communications link for the transfer of data between two locations.
Invisible place holder
MDS TransNET
Master
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MDS TransNET
Remote
T
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Host System
Figure 4. Typical point-to-point link
Adding a Tail-End Link to an Existing Network
A tail-end link can be used to extend the range of a traditional (licensed) MAS
system. This might be required if an outlying site is blocked from the MAS
master station by a natural or man-made obstruction. In this arrangement, an
MDS TransNET 900 radio links the outlying remote site into the rest of a
licensed MAS system by sending data from that site to an associated
MDS TransNET 900 installed at one of the licensed remote sites. (See
Figure 5).
As the data from the outlying site is received at the licensed remote site, it is
transferred to the licensed radio (via a local cable connection) and is then
transmitted to the MAS master station in the usual manner. Additional details
for tail-end links are given in Section 4.3 (Page 17).
Invisible place holder
REPEATER STATION
Master Station
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MDS x710B
Series Radio
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Null-Modem Cable
MDS TransNET
Master
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MDS TransNET
Remote
Radio
Remote
Radio
RTU
MAS SYSTEM (LICENSED OR UNLICENSED)
RTU
LICENSE-FREE SPREAD SPECTRUM SYSTEM
Remote
RTU
P
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OUTLYING
REMOTE SITE
Figure 5. Typical tail-end link arrangement
4 MDS TransNET 900 I&O Guide MDS 05-2708A01, Rev. B
Extending a TransNET Network with a Repeater
Similar to a Tail-End Link, Store-and-Forward (SAF) offers a way to
physically extend the range of a TransNET network, but in a simplified
economical manner. SAF operates by dividing a network into a vertical
hierarchy of two or more sub-networks. Extension radios (designated as
MODE X) serve as single-radio repeaters that link adjacent sub-networks,
and move data from one sub-network to the next one.
Invisible place holder
RTU
RTU
REPEATER STATION
MDS TransNET
Extension
MODE X
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MDS TransNET
Remote
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OUTLYING
RTU
REMOTE SITE
MDS TransNET
MDS TransNET
Remote
MODE R
Master
MODE M
MDS TransNET
Remote
MODE R
RTU
Figure 6. TransNET Repeater Network
2.5 Accessories
MDS TransNET 900 transceivers can be used with one or more of the
accessories listed in Table 1. Contact the factory for ordering details.
Table 1. Accessories
Accessory Description MDS Part No.
AC Power
Adapter
Small power supply module designed for continuous service. UL approved. Input: 120/220;
Consult factory
Output: 12 Vdc @ 500 mA (20 Watts)
Omnidirectional
Antennas
Yagi Antenna Rugged directional antennas suited for use at
Rugged antennas suited for use at Master
stations. Consult MDS for details.
Remote stations. Consult MDS for details.
Various
6.4 dB gain:
97-3194A13
10 dB gain:
97-3194A14
Bandpass Filter Antenna system filter to aid in eliminating inter-
20-2822A02
ference from paging system transmissions.
TNC-to-N
Adapter Cable
3 foot/1 meter length of coaxial cable used to
connect the radio’s TNC antenna connector to
97-1677A159
a Type-N style commonly used on large diameter coaxial cables.
MDS 05-2708A01, Rev. B MDS TransNET 900 I&O Guide 5
Table 1. Accessories
(Continued)
TNC-to-N
Adapter Cable
TNC-to-N RF
Adaptor Plug
RS/EIA-232
Cable
RJ-11 to DB-9
Adapter Cable
Flat-Surface
Mtg. Brackets
Mtg. Bracket
Screws
19˝ Rail Mtg.
Brackets
6 foot/1.8 meter length of coaxial cable used to
connect the radio’s TNC antenna connector to
a Type-N style commonly used on large diameter coaxial cables.
Adapts radio’s antenna connector to Type-N
style commonly used on large diameter coaxial cables.
Shielded data cable fitted with DB-9 male and
DB-9 female, 6 ft./1.8 meter.
For connecting a PC terminal to the transceiver via the radio’s DIAG(notics) connector.
Used for programming and diagnostics.
Brackets: 2” x 3” plates designed to be
screwed onto the bottom of the transceiver for
surface-mounting the radio.
Screws: 6-32/1/4˝ with locking adhesive.
(Industry Standard MS 51957-26)
Adaptor for mounting the radio in a standard
19-inch equipment rack.
97-1677A160
97-1677A161
97-1971A03
03-3246A01
82-1753-A01
70-2620-A01
Consult factory
3.0 INSTALLATION PLANNING
The installation of the radio is not difficult, but it does require some planning
to ensure station reliability and efficiency. This section provides tips for
selecting an appropriate site, choosing an antenna system, and reducing the
chance of harmful interference.
3.1 General Requirements
There are three main requirements for installing the radio—adequate and
stable primary power, a good antenna system, and the correct interface
between the transceiver and the data device.
Figure 7 shows a typical remote station arrangement. Master stations are
similar, but an omni-directional antenna is normally used instead of a
directional type, and a host computer replaces the data terminal equipment.
6 MDS TransNET 900 I&O Guide MDS 05-2708A01, Rev. B
Invisible place holder
DATA TERMINAL
EQUIPMENT
MDS TransNET 900s
POWER SUPPLY
13.8 VDC @ 500 mA
(6–30 Vdc)
Figure 7. Typical remote station arrangement
ANTENNA
SYSTEM
LOW-LOSS FEEDLINE
3.2 Site Selection
For a successful installation, careful thought must be given to selecting proper
sites for the master and remote stations. Suitable sites should provide the
following:
• Protection from direct weather exposure
• A source of adequate and stable primary power
• Suitable entrances for antenna, interface or other required cabling
• Antenna location that provides an unobstructed transmission path in the
direction of the associated station(s)
These requirements can be quickly determined in most cases. A possible
exception is the last item—verifying that an unobstructed transmission path
exists. Radio signals travel primarily by line-of-sight, and obstructions
between the sending and receiving stations will affect system performance. If
you are not familiar with the effects of terrain and other obstructions on radio
transmission, the discussion below will provide helpful background.
Terrain and Signal Strength
While the 900 MHz band offers many advantages over VHF and lower UHF
frequencies for data transmission, it is also more prone to signal attenuation
from obstructions such as terrain, foliage or buildings in the transmission
path.
MDS 05-2708A01, Rev. B MDS TransNET 900 I&O Guide 7
A line-of-sight transmission path between the master station and its
associated remote site(s) is highly desirable and provides the most reliable
communications link. A line-of-sight path can often be achieved by mounting
the station antenna on a tower or other elevated structure that raises it to a
level sufficient to clear surrounding terrain and other obstructions.
The importance of a clear transmission path relates closely to the distance to
be covered by the system. If the system is to cover only a limited geographic
area, say up to 3 miles (4.8 km), then some obstructions in the
communications path can usually be tolerated with minimal impact. For
longer range systems, any substantial obstruction in the communications path
could compromise the performance of the system, or block communications
entirely.
Much depends on the minimum signal strength that can be tolerated in a given
system. Although the exact figure will differ from one system to another, a
Received Signal Strength Indication (RSSI) of –85 dBm or stronger will
provide acceptable performance in many cases. While the equipment will
work at lower signal strengths, this provides a “fade margin” to account for
variations in signal strength which may occur from time-to-time.
Conducting a Site Survey
If you are in doubt about the suitability of the radio sites in your system, it is
best to evaluate them before a permanent installation is begun. This can be
done with an on-the-air test (preferred method); or indirectly, using
path-study software.
An on-the-air test is preferred because it allows you to see firsthand the
factors involved at an installation site and to directly observe the quality of
system operation. Even if a computer path study was conducted earlier, this
test should be done to verify the predicted results.
The test can be performed by first installing a radio and antenna at the
proposed master station site and then visiting each remote site with a
transceiver and a hand-held antenna.
With the hand-held antenna positioned near the proposed mounting spot, a
technician can check for synchronization with the master station (shown by a
lamp on the front panel) and measure the reported RSSI value. If
SYNC
lit
adequate signal strength cannot be obtained, it may be necessary to mount the
station antennas higher, use higher gain antennas, or select a different site. To
prepare the equipment for an on-the-air test, follow the general installation
procedures given in this guide and become familiar with the operating
instructions given in Section 5.0, beginning on Page 19.
If time is short, and a site survey is impractical, a computer path study is a
good alternative. Factors such as terrain, distance, transmitter power, receiver
sensitivity, and other conditions are taken into account to predict the
performance of a proposed system. Contact MDS for more information on
path study services.
8 MDS TransNET 900 I&O Guide MDS 05-2708A01, Rev. B
3.3 A Word About Radio Interference
The MDS TransNET shares the frequency spectrum with other services and
other Part 15 (unlicensed) devices in the USA. As such, near 100% error free
communications may not be achieved in a given location, and some level of
interference should be expected. However, the radio’s flexible design and
hopping techniques should allow adequate performance as long as care is
taken in choosing station location, configuration of radio parameters and
software/protocol techniques.
In general, keep the following points in mind when setting up your
communications network:
1. Systems installed in rural areas are least likely to encounter interference;
those in suburban and urban environments are more likely to be affected
by other devices operating in the license-free frequency band and by
adjacent licensed services.
2. If possible, use a directional antenna at remote sites. Although these
antennas may be more costly than omnidirectional types, they confine the
transmission and reception pattern to a comparatively narrow lobe, which
minimizes interference to (and from) stations located outside the pattern.
3. If interference is suspected from a nearby licensed system (such as a
paging transmitter), it may be helpful to use horizontal polarization of all
antennas in the network. Because most other services use vertical
polarization in this band, an additional 20 dB of attenuation to
interference can be achieved by using horizontal polarization.
4. Multiple MDS TransNET 900 systems can co-exist in proximity to each
other with only very minor interference as long as they are each assigned
a unique network address. Each network address has a different hop
pattern.
5. If constant interference is present in a particular frequency zone, it may
be necessary to “lock out” that zone from the radio’s hopping pattern.
The radio includes built-in tools to help users remove blocked frequency
zones. Refer to the discussion of the
information. In the USA, a maximum of four zones may be skipped, per
FCC rules. Check the regulatory requirements for your region.
6. Interference can also come from out-of-band RF sources such as paging
systems. Installation of a bandpass filter in the antenna system may bring
relief. (Recommended: MDS P/N 20-2822A02)
7. Proper use of the
RETRY
and
REPEAT
with heavy interference.
SKIP
command (Page 36) for more
commands may be helpful in areas
The
command sets the maximum number of times (1 to 10) that a
RETRY
radio will re-transmit upstream data over the air. Values greater than 1
successively improve the chances of a message getting through when
interference is a problem.
The
REPEAT
command sets a fixed number of unconditional
retransmissions for downstream data.
MDS 05-2708A01, Rev. B MDS TransNET 900 I&O Guide 9
8. The RF power output of all radios in a system should be set for the lowest
level necessary for reliable communications. This lessens the chance of
causing unnecessary interference to nearby systems.
3.4 Antenna & Feedline Selection
Antennas
The equipment can be used with a number of antennas. The exact style used
depends on the physical size and layout of a system. Contact your MDS
representative for specific recommendations on antenna types and hardware
sources.
In general, an omnidirectional antenna (Figure 8 and Figure 9) is used at the
master station site in an MAS system. This provides equal coverage to all of
the remote sites.
NOTE:
Antenna polarization is important. If the wrong polarization is used, a signal reduction of 20 dB or more will result. Most systems using a gain-type omnidirectional antenna at the master station employ vertical polarization of the signal;
therefore, the remote antenna(s) must also be vertically polarized (elements
oriented perpendicular to the horizon).
When required, horizontally polarized omnidirectional antennas are also available. Contact your MDS representative for details.
Figure 8.
Omnidirectional antenna
(mounted to mast)
At remote sites and point-to-point systems, a directional Yagi antenna
(Figure 9), is generally recommended to minimize interference to and from
other users. Antennas are available from a number of manufacturers.
10 MDS TransNET 900 I&O Guide MDS 05-2708A01, Rev . B
Invisible place holder
Figure 9. Typical Yagi antenna (mounted to mast)
Feedlines
The choice of feedline used with the antenna should be carefully considered.
Poor-quality coaxial cables should be avoided, as they will degrade system
performance for both transmission and reception. The cable should be kept as
short as possible to minimize signal loss.
For cable runs of less than 20 feet (6 meters), or for short range transmission,
an inexpensive type such as Type RG-8A/U may be acceptable. Otherwise,
we recommend using a low-loss cable type suited for 900 MHz, such as
Times Microwave LMR 400® or Andrew Heliax®.
Table 2 lists several types of feedlines and indicates the signal losses (in dB)
that result when using various lengths of each cable at 900 MHz. The choice
of cable will depend on the required length, cost considerations, and the
amount of signal loss that can be tolerated.
Table 2. Length vs. loss in coaxial cables at 900 MHz
Cable Type
LMR 400 0.39 dB 1.95 dB 3.9 dB 11.7 dB
1/2 inch
HELIAX
7/8 inch
HELIAX
1 1/4 inch
HELIAX
1 5/8 inch
HELIAX
10 Feet
(3.05 Meters)
0.23 dB 1.15 dB 2.29 dB 6.87 dB
0.13 dB 0.64 dB 1.28 dB 3.84 dB
0.10 dB 0.48 dB 0.95 dB 2.85 dB
0.08 dB 0.40 dB 0.80 dB 2.4 dB
50 Feet
(15.24 Meters)
100 Feet
(30.48 Meters)
300 Feet
(91.44 Meters)
(not recommended)
MDS 05-2708A01, Rev. B MDS TransNET 900 I&O Guide 11
3.5 How Much Output Power Can be Used?
The transceiver is normally supplied from the factory set for a nominal
+30 dBm (1 Watt) RF power output setting; this is the maximum transmitter
output power allowed under FCC rules. The power must be decreased from
this level if the antenna system gain exceeds 6 dBi. The allowable level is
dependent on the antenna gain, feedline loss, and the transmitter output power
setting. Power considerations for the MDS TransNET 900 are discussed
below.
NOTE:
In some countries, the maximum allowable RF output may be
limited to less than 1 watt (e.g., 100 mW / +20 dBm). Be sure to
check for and comply with the requirements for your area.
To determine the maximum allowable power setting of the radio, perform the
following steps:
1. Determine the antenna system gain by subtracting the feedline loss (in
dB) from the antenna gain (in dBi). For example, if the antenna gain is
9.5 dBi, and the feedline loss is 1.5 dB, the antenna system gain would be
8 dB. (If the antenna system gain is 6 dB or less, no power adjustment is
required.)
2. Subtract the antenna system gain from 36 dBm (the maximum allowable
EIRP). The result indicates the maximum transmitter power (in dBm)
allowed under the rules. In the example above, this is 28 dBm.
3. If the maximum transmitter power allowed in your region is less than 30
dBm, use the
accordingly.
For convenience, Table 3 lists several antenna system gains and shows the
maximum allowable power setting of the radio. Note that a gain of 6 dB or
less entitles you to operate the radio at full power output—30 dBm (1 watt).
Table 3. Antenna system gain vs. power output setting (USA)
minus Feedline Loss in dB†)
* Most antenna manufacturers rate antenna gain in dBd in their literature. To
† Feedline loss varies by cable type and length. To determine the loss for
PWR
command (described on Page 34) to set the power
Antenna System Gain
(Antenna Gain in dBi*
6 (or less) 30 36
82836
10 26 36
12 24 36
14 22 36
16 20 36
convert to dBi, add 2.15 dB.
common lengths of feedline, see Table 2 on Page 11.
Maximum Power
Setting
(in dBm)
EIRP
(in dBm)
12 MDS TransNET 900 I&O Guide MDS 05-2708A01, Rev . B
4.0 INSTALLATION
Figure 10 shows a typical transceiver shipment. Check the contents against
the packing list secured to the outside of the shipping box. Accessories and
spare parts kits, if any, are wrapped separately. Inspect all items for signs of
damage and save all packing materials for possible re-shipment.
Invisible place holder
M
D
S
X
x
x
x
MOUNTING
BRACKETS
INSTALLATION &
OPERATION GUIDE,
AND SOFTWARE
2-PIN
POWER PLUG
SPARE FUSE
Figure 10. Typical Transceiver Shipment
Items ar not shown at the same scale.
User documentation will be provided as a paper manual and/or as a PDF on
the “MDS TransNET 900™ Support Package CD” (P/N 03-2708A01). The
CD includes:
• Installation & Operation Guide in PDF (a.k.a. Adobe Acrobat™)
• TransNET Configuration Software
If a paper copy is required but not provided with your shipment, please
consult MDS.
(CD AND/OR MANUAL)
4.1 Transceiver Installation
The following is an overview of a typical procedure for installing the
transceiver. In most cases, these steps alone will be sufficient to complete the
installation. Should further information be required, contact the factory using
the information given on the inside back cover of this manual.
If you are installing a tail-end link system, you should also review Section 4.3
(Page 17) for important details on configuration.
NOTE:
1. Mount the transceiver to a stable surface using the brackets supplied with
MDS 05-2708A01, Rev. B MDS TransNET 900 I&O Guide 13
It is recommended that the master station be installed first. In this way, it will be
possible to quickly check the operation of each associated remote station as it
is placed on the air.
the radio. (Fasteners/anchors are not supplied.) Figure 11 shows the
dimensions of the transceiver case and its mounting brackets. If possible,
choose a mounting location that provides easy access to the connectors
on the end of the radio and an unobstructed view of the LED status
indicators.
Invisible place holder
2.75
(7.0 cm)
6.63
(16.64 cm)
1.62
(4.15 cm)
Figure 11. Transceiver mounting dimensions
Figure 12 shows the four connectors on the MDS TransNET 900 and their
functions.
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Antenna Primary PowerData
Diagnostic
(Communications)
(Payload)
(6–30 Vdc)
Figure 12. Interface Connector Functions
2. Install the antenna and antenna feedline for the station. Antennas should
be mounted in the clear and in accordance with the manufacturer’s
instructions. Additional information on antennas and feedlines is
contained in Section 3.4 on Page 10.
NOTE:
3. Connect the data equipment to the transceiver’s
Strong fields near the antenna can interfere with the operation of the low level
RTU circuits and change the reported values of the data being monitored. For
this reason, the antenna should be mounted at least 10 feet (>3 meters) from
the radio, RTU, sensors and other components of the system.
DATA
connector. Use
only the required pins for the application.
14 MDS TransNET 900 I&O Guide MDS 05-2708A01, Rev . B
Typical RS/EIA-232 applications require the use of Pin 2 (receive
data—RXD and Pin 3 (transmit data—TXD). Some systems may require the
use of Pin 7 (Request-to-send—RTS). Figure 13 and Figure 14 show a
detailed views of the
DATA
connector for EIA/RS-232 and EIA/RS-485,
respectively.
If hardware flow control is desired, Pin 7 (RTS) and Pin 8 (CTS) may also be
connected. A more detailed discussion of pin functions is provided in see
“Data Interface Connections (DB-9F)” on page 54.
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Pin Function
1
5
96
1.....Data Carrier Detect (DCD)
2.....Receive Data (RXD)
3.....Transmit Data (TXD)
4.....Sleep (GND = Sleep)
5.....Signal Ground (GND)
6.....Alarm Output (+5/-5 Vdc)
7.....Ready-to-Send (RTS)
8.....Clear-to-Send (CTS)
9.....Reserved for Special Uses (Do not connect)
Figure 13. DATA Connector Pin Functions, EIA/RS-232 Mode
NOTE:
The data cabling between the transceiver and the connected device should be
kept as short as possible. For EIA/RS-232 operation, the maximum recommended cable length is 50 feet/15 meters.
As viewed from outside the radio
Invisible place holder
Pin Function
1
5
96
Figure 14. DATA Connector Pin Functions, EIA/RS-485 Mode
4. Measure and install the primary power for the transceiver. It must be
within 6-30 Vdc and be capable of providing 7.5 watts over this voltage
range. (Typical current draw is 510 mA @13.8 Vdc; 1.25A @6 Vdc.) A
power connector with screw-terminals is provided with each unit. Strip
the wire leads to 0.25"/6 mm. Be sure to observe proper polarity. The left
pin is the positive input; the right is negative. (See Figure 15.)
CAUTION
POSSIBLE
EQUIPMENT
DAMAGE
1.....Not Used (Open)
2.....TXD + (Transmit Data +), Non-inverting driver output
3.....RXD + (Receive Data +), Non-inverted receiver input
4.....Sleep (GND = Sleep)
5.....Signal Ground (GND)
6.....Not Used (Open)
7.....RXD – (Receive Data –), Inverting receiver input
8.....TXD – (Transmit Data –), Inverted driver output
9.....Reserved for Special Uses (Do not connect)
As viewed from outside the radio
The radio must be used only with negative-ground systems. Make sure the polarity of the power source is correct. The unit is protected from reverse polarity by an
internal diode and fuse.
MDS 05-2708A01, Rev. B MDS TransNET 900 I&O Guide 15
Lead
Binding
Screws (2)
Invisible place holder
Wire Ports (2)
Figure 15. Power Connector
(Polarity: Left +, Right –)
CAUTION
POSSIBLE
EQUIPMENT
DAMAGE
The power connector used with the TransNET series is
similar to that used by other MDS products, such as the
MDS 9810 and MDS x710 family. The connectors are
not equal and the use of the other style connector may
provide unreliable connections and a spark may be created.
Only the power connector , sho w in Figure 15 with scre w
terminals and two retainer screws should be used with
the MDS TransNET 900.
5. Set the radio’s basic configuration with a PC terminal connected to the
DIAG
(nostics) connector via an RJ-11 to DB-9 adapter cable, MDS
P/N 03-3246A01. (A cable of this type may be constructed using the
information shown in Figure 20 on Page 54.) For more information on
connecting a PC terminal and preparing it for use, refer to Section 6.1 on
Page 21.
The three essential settings for the TransNET Transceiver are as follows:
Mode—Master, Remote, or Extension
Network Address—a unique number from 1–65000
Data Interface Parameters—bps, data bits, parity, stop bits
a. Set the Mode using the MODE M (Master), MODE R (Remote), or
MODE X (Extension) command. (Note: There can be only one master
radio in a system.)
If any MODE X radios are used in the network, SAF must be turned
on at the Master station. The MODE X radio must be programmed
with an Extended Address (XADDR). Units that need to hear the
MODE X radio must be programmed with an appropriate XPRI and/or
XMAP value. (See “Simple Extended SAF Network” on page 47 for
more information.)
b. Set a unique Network Address (1–65000) using ADDR command.
Each radio in the system must have the same network address. Tip:
Use the last four digits of the master’s serial number to help avoid
conflicts with other users.
16 MDS TransNET 900 I&O Guide MDS 05-2708A01, Rev . B
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