Mds 9810 User Manual
Microwave Data Systems Inc.
MDS 9810
900 MHz Spread Spectrum
Data T ransceivers
MDS 05-3301A01, Rev. C
JULY 2004
Installation & Operation Guide
Installation and Operation Guide
a
b
c
QUICK START GUIDE
Below are the basic steps for installing the transceiver. Detailed instructions are given in “INSTALLATION” on Page 14 of this guide.
1. Install and connect the antenna system to the radio
• Use good quality, low-loss coaxial cable. Keep the feedline as short as possible.
• Preset directional antennas in the direction of desired transmission.
2. Connect the data equipment to the radio’s INTERFACE connector
• Connection to the radio must be made with a DB-25 Male connector. Connections for typical systems are shown below.
• Connect only the required pins. Do not use a straight-through RS-232 cable with all pins wired.
• Verify the data equipment is configured as DTE. (By default, the radio is configured as DCE.)
DB-9 to DB-25 ExampleDB-25 to DB-25 Example
RTU
DB-25 DB-25
11
GND
2
TXD
3
RXD
RTS
4
(DTE)
CTS
5
6DSR
GND
20
77
DCD
8 8
As required for application
GND
2
TXD
3
RXD
4
4
RTS
5
5
CTS
DSR
6
GND
DCD
(DCE)
TRANSCEIVER
RTU
DB-9 DB-25
18
DCD
2
RXD
3
TXD
5
GND
(DTE)
6
20
DSR
7
RTS
CTS
As required for application
DCD
3
RXD
2
TXD
5
7
GND
DSR
6
4
RTS
CTS8
5
(DCE)
TRANSCEIVER
3. Apply DC power to the radio
• Observe proper polarity. The red wire is the positive lead; the black is negative.
4. Set the radio’s basic configuration with a Hand-Held Terminal (HHT)
• Set the baud rate/data interface parameters as follows. Use the BAUD xxxxx abc command,
where xxxxx equals the data speed and abc equals the communication parameters as follows:
= Data bits (7 or 8)
= Parity (N for None, O for Odd, E for Even
= Stop bits (1 or 2)
(Example: BAUD 9600 8N1 ) NOTE: 7N1, 8E2 and 8O2 are invalid data parameters.
5. Verify proper operation by observing the LED display
• Refer to Table 4 on Page 26 for a description of the status LEDs.
• Refine directional antenna headings for best received signal strength using the RSSI command.
• If difficulties are encountered, please refer to Table 14 on Page 56 for troubleshooting help.
TABLE OF CONTENTS
1.0 ABOUT THIS MANUAL.........................................................................................................1
2.0 PRODUCT DESCRIPTION...................................................................................................1
Transceiver Features........................................................................................................................2
Model Configuration Codes .............................................................................................................2
2.1 Spread Spectrum Radios—How Are They Different? ....................................................................3
2.2 Typical Applications .......................................................................................................................3
Multiple Address Systems (MAS) ....................................................................................................3
Simplex “Peer-to-Peer”.....................................................................................................................4
Peer-to-Peer with Repeater Assistance...........................................................................................4
Point-to-Point System.......................................................................................................................5
Tail-End Link (“MAS Extension”)......................................................................................................5
Repeater System—Traditional.........................................................................................................6
“Single-Radio” Repeater—Alternative Method.................................................................................6
2.3 Accessories ...................................................................................................................................7
3.0 INSTALLATION PLANNING.................................................................................................. 7
3.1 General Requirements ..................................................................................................................7
3.2 Site Selection ................................................................................................................................8
Terrain and Signal Strength .............................................................................................................9
Conducting a Site Survey ................................................................................................................9
3.3 A Word About Radio Interference ................................................................................................10
3.4 Antenna & Feedline Selection .....................................................................................................11
Antennas........................................................................................................................................11
Feedlines .......................................................................................................................................12
3.5 How Much Output Power Can be Used? .....................................................................................13
Transmitter Power vs. Antenna System Gain.................................................................................13
4.0 INSTALLATION...................................................................................................................14
4.1 Transceiver Installation ................................................................................................................15
4.2 Peer-to-Peer Systems .................................................................................................................19
Simplex Peer-to-Peer.....................................................................................................................19
Peer-to-Peer with Repeater Assistance.........................................................................................20
4.3 Tail-End Links ..............................................................................................................................21
Interface Wiring..............................................................................................................................21
Programming .................................................................................................................................22
4.4 Repeaters—Traditional Method ...................................................................................................22
Antennas........................................................................................................................................23
System Addresses.........................................................................................................................23
Interface Wiring..............................................................................................................................23
Diagnostic Limitations....................................................................................................................23
MDS 05-3301A01, Rev. C MDS 9810 Installation and Operation Guide i
4.5 “Single-Radio” Repeater—Alternative Method ............................................................................24
Interface Wiring..............................................................................................................................24
Software Programming (TDD Command)......................................................................................24
Limitations of Single-Radio Repeaters...........................................................................................25
4.6 Using the Radio’s Sleep Mode ....................................................................................................25
Sleep Mode Example.....................................................................................................................25
5.0 OPERATION....................................................................................................................... 26
5.1 Initial Start-up ..............................................................................................................................26
5.2 Performance Optimization ...........................................................................................................26
Antenna Aiming..............................................................................................................................27
Antenna SWR Check.....................................................................................................................27
Data Buffer Setting.........................................................................................................................27
Hoptime Setting .............................................................................................................................27
Baud Rate Setting..........................................................................................................................28
Radio Interference Checks.............................................................................................................28
6.0 PROGRAMMING................................................................................................................28
6.1 Hand-Held Terminal Connection & Start-up ................................................................................28
6.2 Hand-Held Terminal Setup ..........................................................................................................29
6.3 Keyboard Commands ..................................................................................................................30
Entering Commands......................................................................................................................30
Error Messages..............................................................................................................................31
6.4 Detailed Command Descriptions .................................................................................................35
ADDR [1...65000]...........................................................................................................................36
AMASK [0000 0000–FFFF FFFF]..................................................................................................36
ASENSE [HI/LO]............................................................................................................................36
BAUD [xxxxx abc]..........................................................................................................................36
BUFF [ON, OFF]............................................................................................................................37
CTS [0–255]...................................................................................................................................37
CTSHOLD [0-6000]........................................................................................................................38
DEVICE [DCE, CTS KEY].............................................................................................................38
DLINK [xxxxx] ................................................................................................................................39
DMGAP [xx]...................................................................................................................................39
DTYPE [NODE/ROOT/GATE/PEER].............................................................................................39
HOPTIME [XSHORT, 16, 20, 25, 32, SHORT, NORMAL, LONG] .................................................40
INIT................................................................................................................................................41
MODE [M, R, R-M].........................................................................................................................41
OWM [xxxxx]..................................................................................................................................42
OWN [xxxxx]..................................................................................................................................42
PWR [xx–30]..................................................................................................................................42
RSSI...............................................................................................................................................42
RTU [ON/OFF/0-80].......................................................................................................................43
RX [xxxx]........................................................................................................................................43
RXTOT [NONE, 0–1440]................................................................................................................43
SEND [n, -n, +n].............................................................................................................................43
SETUP...........................................................................................................................................44
SHOW [PORT, DC, PWR]..............................................................................................................45
SIMPLEX [ON, OFF]......................................................................................................................45
ii MDS 9810 Installation and Operation Guide MDS 05-3301A01, Rev. C
SKIP [NONE, 1...8] ........................................................................................................................46
SKIPSYNC [ON/OFF]....................................................................................................................46
SNR ...............................................................................................................................................46
SREV.............................................................................................................................................47
STAT...............................................................................................................................................47
TDD [ON/OFF]...............................................................................................................................47
TEMP.............................................................................................................................................48
TX [xxxx]........................................................................................................................................48
UNIT [10000–65000]......................................................................................................................48
ZONE DATA ...................................................................................................................................49
ZONE CLEAR................................................................................................................................50
7.0 TROUBLESHOOTING........................................................................................................ 50
7.1 LED Indicators .............................................................................................................................50
7.2 Alarm Codes ................................................................................................................................51
Checking for Alarms—STAT command..........................................................................................51
Major Alarms vs. Minor Alarms......................................................................................................51
Alarm Code Definitions..................................................................................................................52
7.3 Performing Network-Wide Remote Diagnostics ..........................................................................53
DLINK [xxxxx] ................................................................................................................................55
DTYPE [NODE/ROOT/GATE/PEER].............................................................................................55
7.4 Troubleshooting Chart .................................................................................................................56
RF
Exposure
8.0 TECHNICAL REFERENCE.................................................................................................56
8.1 Technical Specifications ..............................................................................................................56
8.2 RSSI Checks with a Voltmeter .....................................................................................................58
8.3 Data Interface Connections (DB-25) ...........................................................................................58
8.4 Bench Testing Setup ....................................................................................................................61
8.5 Using Radio Configuration Software ...........................................................................................61
Connecting a PC............................................................................................................................62
Upgrading the Radio’s Software ....................................................................................................62
8.6 dBm-Watts-Volts Conversion Chart .............................................................................................63
9.0 GLOSSARY OF TERMS.....................................................................................................63
Copyright Notice
This Installation and Operation Guide and all software described herein are protected by
right: 2004 Microwave Data Systems
Inc. All rights reserved.
Microwave Data Systems reserves its right to correct any errors and omissions in this document.
copy-
Operational Safety Notice
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. All
antennas used with this transmitter, whether indoor or outdoor mounted, must be installed to provide a separation distance of at least
ating in conjunction with any other antenna or transmitter. In mobile applications (vehicle
23 cm from all persons, and must not be co-located or oper-
MDS 05-3301A01, Rev. C MDS 9810 Installation and Operation Guide iii
mounted) the above separation distance must be maintained at all times. More information on RF
exposure is available on the Internet at
is intended to guide a professional installer to install, operate and perform basic system maintenance on the described radio.
www.fcc.gov/oet/info/documents/bulletins . This manual
CSA/
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 publication NFPA 70, oth-
erwise known as the National Electrical Code.
The product has been recognized for use in hazardous locations by the Canadian Standards Association
(CSA), which also issues the US mark of approval (CSA/
CSA STD C22.2 No. 213-M1987. The product has been evaluated in accordance with the following standards:
• CSA Std C22.2 No. 142-M1987 - Process Control Equipment
• CSA Std C22.2 No. 213-M1987 - Non-Incendive Electrical Equipment for Use in Class I, Division 2
• ANSI/UL Std No. 508 - Industrial Control Equipment
• UL Std No. 1604 - Electrical Equipment for Use in Class I and II, Division 2; Class III Hazardous (Clas-
US
Notice
Hazardous Locations
sified) Locations
US
). The CSA Certification is in accordance with
ISO 9001 Registration
Microwave Data Systems' adherence to this internationally accepted quality system standard provides one of the strongest assurances of product and service quality available.
MDS Quality Policy Statement
We, the employees of Microwave Data Systems, are committed to achieving total customer satisfaction in everything we do.
Total Customer Satisfaction in:
• Conception, design, manufacture and marketing of our products.
• Services and support we provide to our internal and external customers.
Total Customer Satisfaction Achieved Through:
• Processes that are well documented and minimize variations.
• Partnering with suppliers who are committed to providing quality and service.
• Measuring our performance against customer expectations and industry leaders.
• Commitment to continuous improvement and employee involvement.
iv MDS 9810 Installation and Operation Guide MDS 05-3301A01, Rev. C
FCC Notice, U.S.A.
The transceiver complies 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 indented 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 Revisions/Updates
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 exacts 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 www.microwavedata.com.
MDS 05-3301A01, Rev. C MDS 9810 Installation and Operation Guide v
vi MDS 9810 Installation and Operation Guide MDS 05-3301A01, Rev. C
1.0 ABOUT THIS MANUAL
This guide presents installation and operating instructions for the
MDS 9810 transceiver. Following installation, we suggest keeping this
guide near the equipment for future reference.
NOTE: Earlier versions of this manual also covered the MDS 24810
(2.4 GHz) transceiver, which has been discontinued by MDS.
An electronic version of the earlier manual is available for
download at www.microwavedata.com.
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
microprocessor control and Digital Signal Processing (DSP) technology, the unit 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 the 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 53.)
The transceiver is housed in a compact and rugged die-cast aluminum
case 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 adjustments are required to configure the radio for operation.
Invisible place holder
SERIAL NUMBER
LABEL
LED INDICATORS (4)
EXTERNAL
INTERFACE
CONNECTOR
(DB-25)
DIAGNOSTICS
CONNECTOR (RJ-11)
13.8 VDC POWER
CONNECTOR
ANTENNA CONNECTOR
(TYPE “N”)
Figure 1. MDS 9810 Transceiver
MDS 05-3301A01, Rev. C MDS 9810 Installation and Operation Guide 1
Transceiver Features
Listed below are several key features of the transceiver. These are
designed to ease the installation and configuration of the radio, while
retaining the ability to make changes in the future.
• 1,019 frequencies over 902–928 MHz, subdivided into eight
frequency zones
• Configurable operating zones to omit frequencies with constant
interference
• 65,000 available network addresses
• 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 19200 bps continuous data flow;
38400 bps non-continuous
THIS INFORMATION IS
SUBJECT TO CHANGE.
DO NOT USE FOR
PRODUCT ORDERING.
• Same hardware for all supported data rates:
1200, 2400, 4800, 9600, 19200, 38400 bps asynchronous
• Same hardware for master or remote configuration
• Data latency typically less than 10 ms
• Supports EIA-232 (formerly called RS-232) user interface
• Low current consumption–30 mA or less average draw in
“sleep” mode.
Model Configuration Codes
The radio model number is printed on the end of 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.
Invisible place holder
OPERATION
X= Remote/Master
PACKAGE
1= Transceiver only
98
POWER SETTING
1= 10.5 - 30 Vdc*
X
N
0
AGENCY APPROVAL
N= N/A
F= FCC/IC
SAFETY APPROVAL
N= N/A
U= FM/UL/CSA
MOUNTING BRACKETS
A= Standard
B= None
DIAGNOSTICS
0= None
1= Non-Intrusive
* Units shipped prior to Revision “U” (November 1999) may be configured for 25 Vdc maximum DC input.
Figure 2. Transceiver Model Configuration Codes
2 MDS 9810 Installation and Operation Guide MDS 05-3301A01, Rev. C
Invisible place holder
2.1 Spread Spectrum Radios—How Are They
Different?
The main difference between a traditional (licensed) radio system and
the MDS 9810 transceiver is that these units “hop” 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.
2.2 Typical Applications
Multiple Address Systems (MAS)
This is the most common application of the 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
REMOTE RADIO
RTU
REMOTE RADIO
REMOTE RADIO
RTU
REMOTE RADIO
RTU
RTU
REMOTE RADIO
RTU
HOST SYSTEM
MASTER RADIO
(MDS 9820 Shown)
Figure 3. Typical MAS Network
MDS 05-3301A01, Rev. C MDS 9810 Installation and Operation Guide 3
Simplex “Peer-to-Peer”
Peer-to-peer communication is possible using the transceiver’s simplex
mode. With this arrangement (Figure 4), two or more remote units can
share information by direct communication with each other in addition
to communicating with a central master radio. This is possible because
the transmit and receive frequencies for each hop channel are the same
at each radio when simplex mode is enabled. If adequate transmission
paths exist, each radio can communicate with all other units in the network. Additional details for peer-to-peer systems are provided in
Section 4.2 (Page 19).
Invisible place holder
RTU
REMOTE RADIO
PEER-TO-PEER
MASTER RADIO
RTU
RTU
HOST SYSTEM
PEER-TO-PEER
RTU
REMOTE RADIO
REMOTE RADIO
PEER-T
O-PEER
REMOTE RADIO
Figure 4. Typical simplex “Peer-to-Peer” Network
Peer-to-Peer with Repeater Assistance
Peer-to-peer communication is also possible using this alternate
arrangement (see Figure 5). It overcomes the range limitations of a simplex peer-to-peer system by using a repeater to re-transmit the signals of
all stations in the network. The repeater consists of two radios—one programmed as a remote using master frequencies (
MODE R-M
command),
and the other programmed as a conventional master. Additional details
for peer-to-peer systems are given in Section 4.2 (Page 19).
4 MDS 9810 Installation and Operation Guide MDS 05-3301A01, Rev. C
REPEATER STATION
REMOTE-MASTER*
Invisible place holder
REMOTE
RTU
MASTER
REMOTE
RTU
REMOTE
* Special operating mode.
See Programming section of manual.
HOST COMPUTER
Pin 3 Pin 2
REMOTE
RTU
Figure 5. Typical Peer-to-Peer Network with Repeater Assistance
Point-to-Point System
A point-to-point configuration (Figure 6) is a simple arrangement consisting of just two radios—a master and a remote. This provides a simplex or half-duplex communications link for the transfer of data between
two locations.
Invisible place holder
HOST
SYSTEM
MASTER RADIO
RTU
REMOTE RADIO
Figure 6. Typical Point-to-Point Link
Tail-End Link (“MAS Extension”)
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 9810 radio links the outlying remote site into the
rest of a licensed MAS system by sending data from that site to an associated MDS 9810 installed at one of the licensed remote sites. (See
Figure 7).
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 21).
MDS 05-3301A01, Rev. C MDS 9810 Installation and Operation Guide 5
MASTER
STATION
REMOTE
RADIO
REPEATER
Null-Modem
Cable
Invisible place holder
POINT
SPREAD
-T
O-POINT
SPECTRUM
MDS 9810 / 9820
MASTER RADIO
LINK
RTU
REMOTE
RADIO
RTU
MDS 9810
/ 9820
REMOTE RADIO
REMOTE
RADIO
RTU
MAS SYSTEM (LICENSED OR UNLICENSED) MDS 9810/9820 LINK TO AN OUTLYING SITE
Figure 7. Typical Tail-End Link Arrangement
Repeater System —Traditional
Although the range between MDS 9810 radios is typically 10 to15 miles
over average terrain, it is possible to extend the range considerably by
connecting two units together at one site in a “back-to-back” fashion to
form a repeater, as shown in Figure 8. Additional details for repeater
systems are given in Section 4.4 (Page 22).
Invisible place holder
POINT-TO-POINT LINK
MASTER
RADIO
REPEATER LINK
Null-Modem Cable
MASTER
RADIO
REMOTE RADIO
RTU
REMOTE RADIO
REMOTE RADIO
HOST COMPUTER
RTU
REMOTE RADIO
RTU
Figure 8. Typical Repeater System Configuration
“Single-Radio” Repeater —Alternative Method
A repeater may also be established using a single MDS x810 Transceiver. This type of repeater cannot operate in full-duplex mode as with
the traditional repeater described above. However, if a loss in transmission speed and efficiency can be tolerated, it may be a viable solution in
some systems.
6 MDS 9810 Installation and Operation Guide MDS 05-3301A01, Rev. C
A single-radio repeater works similar to the system shown in Figure 8,
but consists of just one transceiver at the repeater site. It works by buffering (storing) incoming messages and retransmitting them a short time
later. Accordingly, there will be a delay in transmissions through this
type of repeater. Additional details for Single-Radio repeater s are given
in Section 4.5 (Page 24).
2.3 Accessories
The transceiver 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 P/N
Power Supply
Kit
Hand-Held
Terminal Kit
(HHT)
RTU Simulator Test unit that simulates data from a remote
Radio
Configuration
Software
Paging Filter Antenna system filter used to reduce RF
Paging Filter Antenna system filter used to reduce RF
EIA-232 to
EIA-422
Converter
For powering the transceiver from an AC source. 01-3682A01
Terminal that plugs into the radio’s RJ-11
DIAG(NOSTICS) connector. Allows radio
programming, diagnostics & control. Includes
carrying case, cable set and manual.
terminal unit. Comes with polling software that
runs on a PC. Useful for testing radio operation.
Windows-based software that allows radio
programming and control using a PC. Includes
on-line instructions. (See Section 8.5 (Page 61)
for PC connection details.)
interference from paging transmitters operating
in the 905-915 MHz band.
interference from paging transmitters operating
in the 902-927 MHz band.
External adapter that converts the radio’s DATA
INTERFACE connector to EIA-422 compatible
signaling. May be required for long cable runs
(over 50 feet/15 meters).
02-1501A01
03-2512A01
03-3156A01
20-2822A01
20-22822A02
03-2358A01
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.
MDS 05-3301A01, Rev. C MDS 9810 Installation and Operation Guide 7
Figure 9 shows a typical remote station arrangement. At a remote station, a directional antenna is normally used, and a Remote Terminal Unit
(RTU) or other telemetry equipment replaces the host computer normally used in a master station.
Invisible place holder
REMOTE TERMINAL
13.8 VDC
POWER
CABLE
UNIT
REMOTE RADIO
13.8 VDC
POWER
SUPPLY
ANTENNA SYSTEM
(Directional Type
Normally Used)
LOW-LOSS FEEDLINE
Figure 9. Typical Remote Station Arrangement
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:
• 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
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.
(s)
8 MDS 9810 Installation and Operation Guide MDS 05-3301A01, Rev. C
Terrain and Signal Strength
While the 900 MHz band offers many advantages over VHF and lower
UHF frequencies for data transmission, they are also more prone to
signal attenuation from obstructions such as terrain, foliage or buildings
in the transmission path.
A line-of-sight transmission path between the master station and its
associated remote site
(s) is highly desirable and provides the most reli-
able 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 transmission path can usually be tolerated with minimal impact. For
longer range systems, any substantial obstruction in the transmission
path could compromise the performance of the system, or block transmission 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 –90 dBm or
stronger will provide acceptable performance in many systems. 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. RSSI can be measured with a Hand-Held Terminal
connected to the remote radio’s
DIAG(NOSTICS) connector. (See Section
6.0, beginning on Page 28.)
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. (An RTU simulator—MDS Part
No. 03-2512A01—can be connected to each radio in the network to simulate data during this test.)
MDS 05-3301A01, Rev. C MDS 9810 Installation and Operation Guide 9
With the hand-held antenna positioned near the proposed mounting
spot, a technician can check for synchronization with the master station
(shown by a lit
SYNC lamp on the front panel) and measure the reported
RSSI value. If 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 26.
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.
3.3 A Word About Radio Interference
The transceiver shares frequency spectrums 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. (The use of a directional antenna may
not be possible in a simplex peer-to-peer network, where all remotes
are designed to communicate with one another.)
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.
10 MDS 9810 Installation and Operation Guide MDS 05-3301A01, Rev. C
4. Multiple MDS 9810 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 dif ferent 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 software to help users identify
and remove blocked frequenc y zones from its hopping pattern. Refer
to the discussion of
ZONE DATA (Page 49) and SKIP (Page 46) com-
mands for more information.
6. If interference problems persist even after removing blocked zones,
try reducing the length of data streams. Groups of short data streams
have a better chance of getting through in the presence of interference than do long streams.
7. The 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 10) 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.
MDS 05-3301A01, Rev. C MDS 9810 Installation and Operation Guide 11
Invisible place holder
Figure 10. Typical Omnidirectional Antenna
At remote sites and point-to-point systems, a directional antenna, such
as a Yagi is generally recommended to minimize interference to and
from other users. Antennas are available from a number of manufacturers.
Invisible place holder
Figure 11. 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 RG8A/U may be acceptable.
Otherwise, we recommend using a low-loss cable type suited for 900
MHz, such as Heliax
12 MDS 9810 Installation and Operation Guide MDS 05-3301A01, Rev. C
®
.
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
IMPORTANT
The maximum
EIRP allowed under
FCC/IC rules is +36
dBm. Follow this
section carefully to
ensure compliance.
Cable Type
RG-8A/U 0.85 dB 4.27 dB 8.54 dB 42.70 dB
1/2 inch HELIAX 0.23 dB 1.15 dB 2.29 dB 11.45 dB
7/8 inch HELIAX 0.13 dB 0.64 dB 1.28 dB 6.40 dB
1 1/4 inch HELIAX 0.10 dB 0.48 dB 0.95 dB 4.75 dB
1 5/8 inch HELIAX 0.08 dB 0.40 dB 0.80 dB 4.00 dB
10 Feet
(3.05 Meters)
50 Feet
(15.24 Meters)
100 Feet
(30.48 Meters)
500 Feet
(152.4 Meters)
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/IC rules. The power must be
decreased from this level if the antenna system gain exceeds 6 dBm. The
allowable level is dependent on the antenna gain, feedline loss, and the
transmitter output power setting. Power considerations for various
antenna systems 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.
Transmitter Power vs. Antenna System Gain
To determine the maximum allowable power setting of the radio, follow
the steps below. It is imperative that professional system planning
include cable loss or attenuators to ensure that the FCC/IC limit of 36
dBm EIRP is not exceeded under any circumstances.
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.
MDS 05-3301A01, Rev. C MDS 9810 Installation and Operation Guide 13
3. If the maximum transmitter power allowed is less than 30 dBm, use
the
PWR command (described on Page 42) to set the power accord-
ingly.
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)
Antenna System Gain
(Antenna Gain in dBi*
minus Feedline Loss in dB†)
6 (or less) 30 36
72936
82836
10 26 36
Maximum Power
Setting
(in dBm)
EIRP
(in dBi
* Many antenna manufacturers rate antenna gain in dBd in their
literature. To convert to dBi, add 2.15 dB.
† Feedline loss varies by cable type and length. To determine the
loss for common lengths of feedline, see Table 2 on Page 13.
4.0 INSTALLATION
Figure 12 shows a typical transceiver product shipment, along with an
optional Hand-Held Terminal (HHT). 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.
14 MDS 9810 Installation and Operation Guide MDS 05-3301A01, Rev. C
Invisible place holder
F5
E
F4
3
D
F3
J
2
6
C
F2
I
1
O
5
B
F1
A
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9
(
H
N
4
T
8
G
.
)
M
S
7
F
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K
–
Y
0
L
R
#
X
ENTER
=
Q
SPACE
W
,
ESC
P
BKSP
V
+
U
SHIFT
CTRL
Z
HAND-HELD
TERMINAL
(OPTIONAL)
INSTALLATION &
OPERATION GUIDE
13.8 VDC
POWER CABLE
TRANSCEIVER
Figure 12. Typical Transceiver Shipment
Below are the basic steps 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 at the number given
on the inside back cover of this manual.
If you are installing a peer-to-peer, tail-end link or repeater system, you
should also review Sections 4.2 (Page 19) and 4.3 (Page 21) for important details on antennas, cabling and software settings.
NOTE: 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.
4.1 Transceiver Installation
1. Mount the transceiver to a stable surface using the brackets supplied
with the radio. (Fasteners/anchors are not supplied.) Figure 13
shows the dimensions of the transceiver case and its mounting
bracket. 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.
MDS 05-3301A01, Rev. C MDS 9810 Installation and Operation Guide 15
Alternate
Position
1.75"
2.75"
70 mm
4.44 CM
Invisible place holder
6.63"
168 mm
8.5"
216 mm
2.0"
50 mm
7.25"
184 mm
CAUTION
POSSIBLE
EQUIPMENT
DAMAGE
5.625"
143 mm
2.25"
57 mm
Figure 13. Transceiver Mounting Dimensions
The screws holding the brackets to the radio are 5⁄16 inch (8 mm). If
replacement screws are used for any reason, they must not exceed
this length to avoid damage to the radio’s PC board.
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 (Page 11).
NOTE: 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.
3. Connect the data equipment to the transceiver’s
DATA INTERFACE
connector. Use only the required pins for the application—Do not
use a fully pinned (25 conductor) cable. Typical applications require
the use of Pin 2 (transmit data—TXD), Pin 3 (received data—RXD)
16 MDS 9810 Installation and Operation Guide MDS 05-3301A01, Rev. C
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