AvaLAN Wireless AW900R2 User Manual

AvaLAN

W I R E L E S S

AW900R2-EVAL

USER’S MANUAL

900 MHz Wireless RS-232 Module

Evaluation Kit

Industrial-grade, long-range wireless systems

AW900R2-EVAL

Thank you for your purchase of the AW900R2-EVAL Wireless RS-232 Module Evaluation
Kit.

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.

User’s Manual

Limited Warranty

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.

© 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]

Technical support [phone] www.avalanwireless.com

PAGE 2

User’s Manual AW900R2-EVAL

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 supports data rates from 9600 Baud
to 115,200 Baud and has a 4 KB data buffer. When properly congured, a pair of
AW900R2 modules behave just like an RS-232 cable but without the length con­straint and without a physical wire.

Conguring a wireless link with the AW900R2 requires the establishment of six
elements:

• One radio must be congured as the Access Point (AP) and the other one must
be congured as the Subscriber Unit (SU).

• Both radios must share a common Network Name, a 32-bit identier.

• Both radios must share a common 128-bit encryption key.

• The AP and SU must agree on which radio frequency channel they are using.
This can be manually set or allowed to change automatically.

• The serial port settings: Baud rate, number of data and stop bits and sense of
Parity bit, must match between each radio and the RS-232 device wired to it,
although the radio link may have different settings at each end.

• The AP and SU must share a common set of tuning parameters: Next Byte
Delay, Minimum Packet Size and Maximum Packet Size.

AW900R2 modules are congured through a built-in USB port with a utility program
from AvaLAN. The LED display on the module PC board 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 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 SU should be placed at least 10
feet from the AP to avoid overloading the radio’s receiver.

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

Technical support [phone] www.avalanwireless.com

PAGE 3

AW900R2-EVAL

User’s Manual

Electrical Connections

The AW900R2-EVAL 900 MHz Wireless RS-232 Module Evaluation Kit contains two
each of the following items:

• AW900R2 Wireless Ethernet Modules

• AW2-900 Omnidirectional Antennas

• AW-P8 Antenna to Radio Connectors

• 20” USB to Mini-USB Adapter Cables

• 120VAC to 6 VDC Wall Hanger Power Supplies

Additional quantities of any of these components may be purchased from AvaLAN
Wireless or our distributors.

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

PC with

Windows XP

or later

Status LEDs

USB

900 MHz
Antenna

Plain black wire

White-striped wire

Reset Switch

(cycles power)

RS-232

Data

Source

Transmit

Receive

Ground

Note:

The USB connection is not needed after the link is
congured and operating normally. If the USB cable
is connected, the module can draw its power from
it. (A high-power USB port is required.)

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.

Technical support [phone] www.avalanwireless.com

PAGE 4

User’s Manual AW900R2-EVAL

Physical Dimensions

66 mm

23 mm

58 mm

18 mm

55 mm

63 mm

15 mm

25 mm

33 mm

18 mm

900 MHz Channels

Channel Center Frequency

0 Auto Mode
1 903.12500 MHz
2 905.20833 MHz
3 907.29167 MHz
4 909.37500 MHz
5 911.45833 MHz
6 913.54167 MHz
7 915.62500 MHz
8 917.70833 MHz

9 919.79167 MHz
10 921.87500 MHz
11 923.95833 MHz
12 926.04167 MHz

Technical support [phone] www.avalanwireless.com

PAGE 5