AvaLAN AW900R2-PAIR User Manual

USER’S MANUAL

Industrial-grade, long-range wireless systems

AvaLAN

W I R E L E S S

900 MHz Outdoor Wireless RS-232 Bridge

AW900R2-PAIR

User’s Manual

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AW900R2-PAIR

© 2010 by AvaLAN Wireless Systems Inc. All rights reserved.

Revision 06.28.2010

125A Castle Drive

Madison, AL 35758

Sales: [phone]

Technical Support: [phone]

Customer Service: [phone]

Fax: [phone]

Thank you for your purchase of the AW900R2-PAIR Outdoor Wireless RS-232 Bridge.

If you have any questions when conguring your AvaLAN system, the best place to
get answers is to visit www.avalanwireless.com. You will also nd the latest updates
there.

If more assistance is needed, send email to [e-mail].

To speak to a live technician, please call technical support at the number below
during normal business hours.

This product is warranted to the original purchaser for normal use for a period of 360 days
from the date of purchase. If a defect covered under this warranty occurs, AvaLAN will repair
or replace the defective part, at its option, at no cost. This warranty does not cover defects
resulting from misuse or modication of the product.

Limited Warranty

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User’s Manual AW900R2-PAIR

Operational summary

RS-232 is a point-to-point serial data connection that requires just three wires:
Transmit Data, Receive Data and Ground. Because there is no handshake involved,
both ends must be congured for matching data timing and protocol or communica­tion will not occur. Also, it is possible to lose data if the receiving device cannot
keep up with the sending device. The AW900R2-PAIR supports data rates from 9600
Baud to 115,200 Baud and has a 4 KB data buffer. When properly congured, this
pair of radios behave just like an RS-232 cable but without the length constraint and
without a physical wire.

The AW900R2-PAIR is shipped from the factory pre-congured to meet most user’s
needs. If this conguration works for you, most of the rest of the information in this
manual is not relevant. The pre-conguration settings are:

• One radio is the Access Point or master and the other radio is the Subscriber
Unit or client.

• The RF frequency channel will automatically change to avoid interference.

• The Network ID and AES Encryption Key are all zeros.

• The serial port settings are 115200 Baud, 8 data bits, 2 stop bits, no parity.

• Tuning parameters are optimized for minimum latency: Next Byte Delay - 00,
Minimum Packet Size - 01, Maximum Packet Size - 024. These parameters are
explained on page 7.

AW900R2 radios may be re-congured by removing the cover and connecting a PC
to a USB port on the module inside. A utility program from AvaLAN is then run on
the PC that can set the conguration and check the link status. The LED display on
the inside module is also a very useful indicator of the condition of the wireless
connection.

The access point (AP) automatically scans for the best of the 12 available radio
frequency channels, encrypts RS-232 data received, and transmits it wirelessly to
the subscriber unit (SU). The AP is constantly monitoring the radio link and can
automatically change the channel if performance is degraded due to interference.
If two AP units from two different bridges are very close to one another, they may
interfere if operating on adjacent frequency channels. Place them at least 10 feet
apart or manually select non-adjacent channels for their operation. Also, the two
radios in the bridge should be placed at least 10 feet apart to avoid overloading the
radio receivers.

At each end of the wireless bridge, the RS-232 device wired to the AW900R2-PAIR
must have its transmit signal connected to the radio’s receive and vice versa. Mis­wiring will not cause damage, but will prevent communication.

User’s Manual

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AW900R2-PAIR

Electrical Connections

The AW900R2-PAIR 900 MHz Outdoor Wireless RS-232 Bridge contains two each of
the following items:

• Outdoor wireless RS-232 radios

• AW2-900 Omnidirectional Antennas

• RJ-45 to Screw Terminal 30 foot cables

• DB-9 Female to Screw Terminal breakout adapters

• 20” USB to Mini-USB Adapter Cables

• 120VAC to 12 VDC Wall Hanger Power Supplies

Antennas or other useful accessories such as pole-mounting brackets may be pur­chased from AvaLAN Wireless or our distributors.

To power up a radio, make connections to it as shown in this diagram:

Connect both ends of the wireless link to their respective RS-232 devices, power
supplies and antennas in similar fashion. The radios use an RJ-45 connector for
data because they leverage the weatherproof solution already developed for our
Ethernet products. If the length or termination method of the cable supplied does
not meet your needs, an inexpensive CAT5 cable can be used by installing an RJ-45
plug on the radio end and terminating the other end however you need.

Provide some physical separation between two radio module antennas — at least
ten feet. If their antennas are in close proximity, the module radio receivers will be
overloaded, causing degradation in the bit error rate and slower link performance.

900 MHz
Antenna

RS-232

Data

Source

White-striped
wire: +12 VDC

Plain black

wire

Transmit

Receive

Ground

Rx (orange twisted pair)

+ (blue twisted pair)

Tx (green twisted pair)

GND (brown twisted pair)

Terminal Block

30’ Cable

Screw Terminals

to RJ-45

Weatherproof
Sealing Gland

12 VDC Power Supply

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User’s Manual AW900R2-PAIR

Conguration

Setting or changing the conguration (Baud rate, etc.) of the AW900R2-PAIR is done
via the USB interface on their internal modules. Follow these steps with both radios:

1. Remove the four screws holding the radio’s cover. The screws have a 1/8” Allen
hex head. Be careful not to damage the rubber sealing gasket or the lip on the box.
A labeled picture of the internal module may be found on page 10.

2. The PC that you will connect via USB to the module must have a USB 2.0 or later
port available and be running MS Windows XP or later. In addition, three critical
pieces of software must be installed; a driver, a utility and a dll.

3. Your PC requires a virtual COM port driver to allow communication with the USB
interface chip in the module. This driver may be downloaded from the chip manu­facturer’s website, http://www.ftdichip.com. On their site menu, select “Drivers”
and “VCP” (Virtual COM Port). Next, choose the driver corresponding to your PC’s
operating system and our chip, which is an FT232R. We tested Driver Version

2.06.02, dated 31 March 2010. Download the zip le from their site. You would also
be advised to download the installation guide for your operating system, available
from the link at the top of the driver selection page. Extract the driver zip le to a
folder of your choice, connect the module to your PC using the supplied USB cable
and follow the instructions in the installation guide. Once you are successful, you
should be able to open Windows Device Manager and see something like this in the
“Ports” section:

The device labeled “USB Serial Port (COM6) is the connection to the radio module.
Windows chooses which COM port number to assign, so yours is unlikely to be COM6.
In fact, every time you plug and unplug the USB or restart your computer, the as­signed COM port number will probably be different.

4. Next, you will need a conguration utility and its associated dll le from AvaLAN.
Go to our website, http://www.avalanwireless.com. Navigate to “Support” then
“Downloads.” Choose the “AvaLAN Evk Utility Lite” le and download the zip le.
This zip archive contains two les, EvkUtilityLite.exe and ZedGraph.dll. Extract both
of these to the same folder of your choice. The utility does not use the Windows
registry and can be placed anywhere, but the dll must be in the same folder.

User’s Manual

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AW900R2-PAIR

6. Use the dropdown menu labeled “Boot Cong Serial Port” to select the virtual
COM port connected to your AW900R2 radio. Note that the list is populated only
when EvkUtilityLite rst starts. If you change your cable connection or plug in an­other module, restart the utility to see the changes. Next click the “Get” button to
fetch the current conguration from the radio.

7. Here is an explanation of the parameters that may be set on the Boot Conguration
page:

Radio Conguration Meaning

AccessPoint/Subscriber
Unit

Buttons to select whether this radio is the master or the client of the pair.
Each RS-232 wireless link must have an Access Point at one end and a Sub­scriber Unit at the other.

Number of Subscriber
Units/Subscriber ID

A two digit number, leading zero required, that must be set to “01” for these
AW900R2 radios. (Other numbers are needed for multi-drop RS-485 versions.)

Channel 00-12 The RF channel for the radio. The frequencies corresponding to each channel

are shown in the table on page 11. Choose “00” for automatic channel selec­tion or set “01” to “12” for a xed choice.

Network Name A 32-bit value (8 Hex digits, 0 to 9 and A to F) that must be the same for the

two radios of the link. If you have multiple links operating in the same vicin­ity, give each pair of radios a unique value.

AES Private Key A 128-bit value (32 Hex digits) that must be the same for the two radios in

the link. This key is used to encrypt the transmitted data and decrypt the
received data.

5. Run EvkUtilityLite.exe and you should see a window like this:

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User’s Manual AW900R2-PAIR

Serial Port Settings These settings must match the RS-232 device wired to the radio.

Baud Rate Drop down menu providing 6 choices from 9600 Baud to 115,200 Baud (serial

data rate).

Data Bits Selectable 7 or 8 data bits (8 is the most common choice)

Parity Selectable among “none”, “even”, “odd”, “mark” or “space” (“none” is the

most common choice)

Stop Bits Select 1 or 2 stop bits (2 is the most common choice)

Tuning Parameters These affect the behavior of the RF packet transmissions relative to the

incoming serial data. We suggest leaving these at the default values unless
the nature of the serial data or the requirements of the protocol being used
demand otherwise.

Next Byte Delay The amount of time the bus must be idle after the Minimum Packet Size has

expired before the radio sends everything in it’s serial buffer. Values of 00 to
10 may be chosen, with a default of 00. Each unit of time is the reciprocal of
the Baud Rate (e.g. 104 µs at 9600 Baud).

Minimum Packet Size Expected packet size bytes. Values of 01 to 99 may be chosen, with a default

of 01. Packets smaller than this will wait to see if additional packets arrive
during this time window. If additional packets arrive, they will be combined
into a single transmission.

Maximum Packet Size Maximum number of bytes per transmission. Values from one more than

the Minimum Packet Size to 768 may be chosen with a default of 024 bytes.
Packets larger than this size will be sent over the RF as fragments and reas­sembled at the receiver radio.

8. Here is additional information about the tuning parameters. The data protocol
you are using may require certain groupings of the bytes or particular timing of the
information:

• If you want minimum latency so that data is received as soon as possible after
it is sent, select a Next Byte Delay of 00 and a Minimum Packet Size of 01.

• If you are sending large blocks of data, a Minimum Packet Size of 01 can cause
the AW900R2’s buffer to overow and bytes will be lost. The value can be in­creased to a maximum that depends on the Baud Rate, corresponding to about

5.3 milliseconds:

Baud Rate Largest Minimum Packet Size

9600 5

19200 10

38400 20

57600 30

76800 40

115200 60

User’s Manual

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AW900R2-PAIR

• Dumping a large volume of data at a xed high Baud rate runs the risk of data
corruption if anything (tuning, noise retries, channel switching, etc.) causes
the 4 KB buffer in the sending radio to be overwritten.

9. The AW900R2’s chosen conguration can be saved to a local data le for future
use by clicking the “Save” button. You might want to do this when conguring both
ends of the link since the AccessPoint/Subscriber Unit choice is the only difference.
The conguration can then be retrieved using the “Load” button. In each case, a le
explorer popup allows you to save and retrieve the cong le to a location of your
choice. The default lename is EVK.conf.

10. When you are ready to upload the conguration to the AW900R2 module, click
the “Send” button. This uploads the conguration and causes the module to reboot.
You can reboot without upload by clicking “Reboot Target.” Keep straight which
COM port belongs to which USB interface. It is common to connect the two modules
of a link at the same time to two different USB ports and if you get confused about
which port is which, the wrong conguration can be overwritten.

11. After both modules of the link are congured and rebooted, they should suc­cessfully nd each other and link. The successful accomplishment of this linkage
can be determined either by the Stats & Spectrum tab in EvkUtilityLite or by seeing
the correct pattern of LEDs on the modules.

12. Click the Stats & Spectrum tab at the top of the EvkUtilityLite window. Make
sure that you select the right COM port with the dropdown menu at the top. (It
will not change automatically to match the port selected on the Boot Conguration
tab.) This page will appear:

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User’s Manual AW900R2-PAIR

13. A snapshot of the module’s status can be retrieved by clicking the “Get Stats”
button. Here is an explanation of the values returned:

Name Meaning

RSSI Received Signal Strength Indication in dBm. This is useful when aligning

antennas or evaluating path attenuation.

Radio Block Error Rate Percentage of radio data blocks that are incorrectly received.

Radio Failed Packets Count of failed data packets since the last reboot. This may remain zero

because of retries even when the Radio Block Error Rate climbs because of
a poor connection.

Radio Passed Packets Count of successful data packets since the last reboot.

Radio Total Packets Total packets transmitted since last reboot.

Radio Average TX Size Average bytes transmitted per packet, a function of the serial data source

and the selected tuning parameters.

Radio Average RX Size Average bytes received per packet, a function of the serial data source and

the selected tuning parameters.

Current RF Channel The RF channel currently in use. If a xed channel is congured, this

number should match. If automatic selection, this number may change
from time to time as the radios look for the channel with the lowest block
error rate.

Connected Subscribers/
Subscriber Key

This number should always be 1 for the AW900R2.

RF Connected True if the two radios are linked and able to exchange data. False other-

wise.

Radio Active True if the radio has a valid conguration and is linked or searching for a

link. False otherwise.

Radio Version 900 MHz Full Band for this product.

Radio Firmware Release The version of the rmware running in this module. Check www.avalan-

wireless.com from time to time to see if a later version is available.

14. The Spectrum Scan may be used to identify interference issues. When “Get
Spectrum Scan” is clicked, the module’s transmitter is disabled, interrupting the
serial data ow. The receiver is tuned across the 900 MHz band and the RSSI is plot­ted for each frequency. You can select the frequency step size and the number of
samples to be taken and averaged at each frequency. The smaller the step size and
the larger the number of samples averaged, the longer the scan will take. If you
perform a scan from the Subscriber Unit, you will see large transient spikes caused
by the Access Point scanning the channels because the Subscriber Unit has gone off
line. Scanning from the Access Point will show a better picture of external interfer­ence sources. After a spectrum scan, the radio will resume normal operation.

15. The LEDs on the AW900R2 PC board can be very useful in determining whether
the link is operating normally or if not, where the trouble might be. The next page
shows where these LEDs are located and the meaning of each. When you are satis­ed that the AW900R2-PAIR radios are operating correctly, replace their covers.

User’s Manual

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AW900R2-PAIR

LED Function Color

SER RX Blinks when module is receiving RS-232 data Green
SER TX Blinks when module is transmitting RS-232 data Green
RF RX Blinks when module is receiving RF data Green
RF TX Blinks when module is transmitting RF data Green
CH1 By adding the numbers that are lit, you can determine the cur-

rent radio channel. Valid channels are 1 to 12, CH16 and CH32
are not used. For the frequency of each channel, see the table
on page 5.

Green

CH2
CH4
CH8
CH16
CH32
Shows link quality (more

lit the better) or indicates
“key exchange mode” if
blinking sequentially

Excellent link quality: no retransmissions Green
Very good link quality: few retransmissions Green
Good link quality: occasional retransmissions Amber
Fair link quality: some retransmissions Amber
Poor link quality: frequent retransmissions Red

No link quality: no link available Red
PWR Lit when the module has DC power Red
USB RX Located between the USB and power connectors, these LEDs

indicate activity through the USB port.

Amber

USB TX Amber

If LEDs CH1 to CH8 are cycling in a binary count and only the bottom link quality
LED is lit, the radio is active and searching for another module to link to. When link
is accomplished, the Channel LEDs will stop, showing the RF channel selected and
the link quality LEDs will show the signal strength.

DIP Switches

(only used
during factory testing)

LEDs

Reset Switch:

Press momentarily to
cycle power and reboot
the module.

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User’s Manual AW900R2-PAIR

Technical specications

Characteristic Specication/Description

Serial Baud Rate 9600, 19200, 38400, 57600, 76800, 115200

RS-232 Signal Character­istics

See data sheet for Maxim 3221 chip (www.maxim-ic.com)

RF transmission rate 1.536 Mbps

RF Output Power +21 dBm (4 Watts EIRP with 15 dBi antenna)

Receiver Sensitivity -97 dBm at 10-4 Bit Error Rate

Range Up to 40 miles line-of-sight with 15 dBi antennas

RF channels/bandwidth 12 non-overlapping with 2.0833 MHz spacing and 1.75 MHz

bandwidth, automatic selection or manual via USB

Adjacent band rejection SAW receiver lter attenuates cellular and pager interference

Error correction Sub-block error detection and retransmission

Encryption 128-bit AES, meets FIPS 197 Standard

Evk Utility Management
Tools

Serial port conguration, encryption keys, tuning parameters,
QoS statistics, spectrum analyzer

Status LEDs power, RF activity, serial data activity, channel, link quality

Connectors RF: RPTNC Female; RS-232 and power: RJ-45 weatherproof

with cable sealing gland; 30’ cable with screw terminals
included as well.

Power consumption Transmit: 0.54 Watts, Receive: 0.45 Watts

Voltage 5-45 VDC

Power regulation Switching regulator

Transmit current draw 140 ma at 12 VDC

Operating Temperature
Range

-40 ºC to +80 ºC

Enclosure Die cast aluminum, powder-coated, gasket-sealed connectors

and cover. Meets IP66 for water and dust resistance.

Size 6 by 8 by 20 cm, 0.8 Kg, connectors included

Mounting holes on bottom ange, 52 by 190 mm by 4 mm dia.

900 MHz Channels

Channel Center Frequency Channel Center Frequency

0 Auto Mode 7 915.62500 MHz
1 903.12500 MHz 8 917.70833 MHz
2 905.20833 MHz 9 919.79167 MHz
3 907.29167 MHz 10 921.87500 MHz
4 909.37500 MHz 11 923.95833 MHz
5 911.45833 MHz 12 926.04167 MHz
6 913.54167 MHz

User’s Manual

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AW900R2-PAIR

FCC Certication

The AW900R2 OEM RF Module complies with Part 15 of the FCC rules and regulations.
Compliance with labeling requirements, FCC notices and antenna regulations is required.
IMPORTANT: The AW900R2 OEM RF Modules have been certied by the FCC for use with
other products without any further certication (as per FCC section 2.1091). Changes or
modications not expressly approved by AvaLAN could void the user’s authority to operate
the equipment.
IMPORTANT: OEMs must test their nal product to comply with unintentional radiators
(FCC section 15.107 and 15.109) before declaring compliance of their nal product to Part 15
of the FCC Rules.
IMPORTANT: The AW900R2 OEM RF Modules have been certied for xed base station
and mobile applications. If modules will be used for portable applications, the device must
undergo SAR testing.

Labeling Requirements

In order to inherit AvaLAN’s FCC Certication, compliance requires that the following be
stated on the device:

Contains FCC ID: R4N-AW900MR
The enclosed device 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.

The Original Equipment Manufacturer (OEM) must ensure that FCC labeling requirements are
met. This includes a clearly visible label on the outside of the nal product enclosure that
displays the contents shown in the box above.

User’s Manual Requirements

In order to inherit AvaLAN’s FCC Certication, compliance requires that the following be
stated in the user’s manual:

Compliance Statement ( Part 15.19 )

This device 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.

Warning ( Part 15.21 )

Changes or modications not expressly approved by the party responsible for compliance could void the user’s
authority to operate the equipment.
RF Exposure ( OET Bulletin 65 )
To comply with FCC RF exposure requirements for mobile transmitting devices, this transmitter should only be used
or installed at locations where there is at least 20cm separation distance between the antenna and all persons.

Information to the User - Part 15.105 (b)

This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to part 15
of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a resi­dential installation. This equipment generates, uses and can radiate radio frequency energy and, if not installed and
used in accordance with the instructions, may cause harmful interference to radio communications. However, there
is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful
interference to radio or television reception, which can be determined by turning the equipment off and on, the
user is encouraged to try to correct the interference by one or more of the following measures:

--Reorient or relocate the receiving antenna.

--Increase the separation between the equipment and receiver.

--Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.

--Consult the dealer or an experienced radio/TV technician for help.