Cooper Crouse-Hinds D2 W MDME 2400 Series User manual

WARNING
To avoid the risk of fire and electric shock, this product should be installed by a qualified electrician
only.
WARNING
To avoid electric shock: be certain power is OFF before and during installation and maintenance.
ATTENTION
Incorrect termination of supply wires may cause internal damage and will void warranty. To ensure
your D2 W MDME 2400 enjoys a long life, double check ALL your connections with this
Instruction Sheet before turning the power on.
CAUTION
For continued protection against risk of fire, replace the internal module fuse only with the same type
and rating.
CAUTION
Antennas used with this device must be installed to provide a separation distance of at least 20 cm
from all persons to satisfy RF exposure compliance.
DO NOT:
• Operate the transmitter when someone is within 20 cm of the antenna;
• Operate the transmitter unless all RF connectors are secure and any open connectors are properly
terminated;
• Operate the equipment near electrical blasting caps or in an explosive atmosphere.
SAVE THESE INSTRUCTIONS FOR FUTURE REFERENCE
D2 W MDME 2400 Series IF 1584
Wireless Ethernet Modem

D2 W MDME 2400 Wireless Ethernet Modem IF 1584 Rev. 1
IF 1584 Rev. 1 Page 2
Important Notice
Cooper Crouse-Hinds products are designed to be used in industrial environments by experienced
industrial engineering personnel with adequate knowledge of safety design considerations.
Cooper Crouse-Hinds radio products are used on unprotected, license-free radio bands with radio
noise and interference. The products are designed to operate in the presence of noise and
interference; however, in an extreme case, radio noise and interference could cause product operation
delays or operation failure. Like all industrial electronic products, Cooper Crouse-Hinds products
can fail in a variety of modes due to misuse, age, or malfunction. We recommend that users and
designers design systems using design techniques intended to prevent personal injury or damage
during product operation, and provide failure tolerant systems to prevent personal injury or damage in
the event of product failure. Designers must warn users of the equipment or systems if adequate
protection against failure has not been included in the system design. Designers must include this
Important Notice in operating procedures and system manuals.
These products should not be used in non-industrial applications or life-support systems without
consulting Cooper Crouse-Hinds first.
1. A radio license is not required in some countries provided the module is installed using the
aerial and equipment configuration described in the D2 W MDME 2400 Installation Guide.
Check with your local distributor for further information on regulations.
2. Operation is authorized by the radio frequency regulatory authority in your country on a non-
protection basis. Although all care is taken in the design of these units, there is no
responsibility taken for sources of external interference. Systems should be designed to be
tolerant of these operational delays.
3. To avoid the risk of electrocution, the aerial, aerial cable, serial cables, and all terminals of the
D2 W MDME 2400 module should be electrically protected. To provide maximum surge and
lightning protection, the module should be connected to a suitable earth, and the aerial, aerial
cable, serial cables, and module should be installed as recommended in the Installation Guide.
4. To avoid accidents during maintenance or adjustment of remotely controlled equipment, all
equipment should be first disconnected from the D2 W MDME 2400 module during these
adjustments. Equipment should carry clear markings to indicate remote or automatic
operation. E.g. "This equipment is remotely controlled and may start without warning.
Isolate at the switchboard before attempting adjustments."
5. The D2 W MDME 2400 module is not suitable for use in explosive environments without
additional protection.

Chapter One Introduction
Page 3 November 2008
CONTENTS
CHAPTER ONE INTRODUCTION............................................................................5
1.1 NETWORK TOPOLOGY.....................................................................................................5
1.2 GETTING STARTED QUICKLY..........................................................................................8
CHAPTER TWO INSTALLATION ...........................................................................9
2.1 GENERAL ......................................................................................................................9
2.2 ANTENNA INSTALLATION ...............................................................................................9
2.2.1 Dipole and Collinear Antennas................................................................................11
2.2.2 Directional Antennas...............................................................................................12
2.3 POWER SUPPLY.............................................................................................................13
2.4 SERIAL CONNECTIONS ..................................................................................................13
2.4.1 RS232 Serial Port. ...............................................................................................13
2.4.2 RS485 Serial Port. ...............................................................................................14
2.5 DISCRETE (DIGITAL)INPUT/OUTPUT ............................................................................15
2.5 DISCRETE (DIGITAL)INPUT/OUTPUT ............................................................................16
CHAPTER THREE OPERATION..........................................................................17
3.1 START-UP......................................................................................................................17
3.2 SELECTING A CHANNEL ................................................................................................19
3.3 CONFIGURING THE UNIT FOR THE FIRST TIME ..............................................................20
3.4.1 Set PC to Same Network as D2 W MDME 2400...................................................20
3.4.2 Set D2 W MDME 2400 to Same Network as PC....................................................23
3.4 NETWORK CONFIGURATION..........................................................................................25
3.5 ETHERNET DATA ..........................................................................................................27
3.6 NORMAL OPERATION....................................................................................................27
3.7 RADIO CONFIGURATION ...............................................................................................29
3.8 SPANNING TREE ALGORITHM /REDUNDANCY..............................................................31
3.9 MULTIPLE AP REPEATER MESH NETWORK ..................................................................32
WDS Configuration.............................................................................................................38
3.10 ROUTING RULES ...........................................................................................................40
3.11 WIRELESS MESSAGE FILTERING ...................................................................................42
3.12 SERIAL PORT CONFIGURATION .....................................................................................44
3.13.1 RS232 PPP Server. ..............................................................................................44
3.13.2 Serial Gateway.....................................................................................................49
3.13.3 Modbus TCP to RTU Gateway............................................................................50
3.13 DIGITAL INPUT/OUTPUT ...............................................................................................52
3.14 MODBUS I/O TRANSFER................................................................................................52
3.15 MODULE INFORMATION CONFIGURATION.....................................................................56
3.16 REMOTE CONFIGURATION ............................................................................................57
3.17 CONFIGURATION EXAMPLES.........................................................................................57

D2 W MDME 2400 Wireless Ethernet Modem IF 1584 Rev. 1
IF 1584 Rev. 1 Page 4
CHAPTER FOUR DIAGNOSTICS..................................................................................62
4.1 DIAGNOSTICS CHART....................................................................................................62
4.2 DIAGNOSTIC INFORMATION AVAILABLE.......................................................................63
4.2.1 Connectivity.........................................................................................................63
4.2.2 Monitor Communications....................................................................................64
4.2.3 Statistics...............................................................................................................65
4.2.4 Network Traffic Analysis. ...................................................................................65
4.3 TESTING RADIO PATHS.................................................................................................65
4.4 UTILITIES......................................................................................................................66
4.4.1 Ping..........................................................................................................................66
4.4.2 IPCONFIG...............................................................................................................68
4.4.4 Route........................................................................................................................69
CHAPTER FIVE SPECIFICATIONS ..........................................................................71
APPENDIX A FIRMWARE UPGRADE.........................................................................73
APPENDIX B GLOSSARY...............................................................................................79
APPENDIX C EUROPEAN COMPLIANCE..................................................................85

Chapter One Introduction
Page 5 November 2008
Chapter One INTRODUCTION
The D2 W MDME 2400 Industrial Wi-Fi Wireless Ethernet module provides wireless connections
between Ethernet devices or Ethernet wired networks (LANs). It complies with the IEEE 802.11b
standard. The D2 W MDME 2400 has an internal 2.4 GHz direct sequence spread spectrum (DSSS)
wireless transceiver, which can be used without a radio license in most countries. Users can select
one of 11 x 5 MHz wide channels, with the first channel centered at 2.412 GHz.
Note that regulations in North America and part of Europe permit all 11 channels to be
used in these countries. Please check with your Cooper Crouse-Hinds representative for
the permitted channel usage in your country.
The D2 W MDME 2400 unit also provides two serial connections as well as the Ethernet
connections. It is possible to use all three data connections concurrently, allowing the D2 W MDME
2400 to act as a Device Server. Wireless connections can be made between serial devices and
Ethernet devices; however, appropriate driver applications are required in the host devices to handle
the different data format. The D2 W MDME 2400 does provide connection functionality between
serial “Modbus RTU” devices and Ethernet “Modbus TCP” devices.
The D2 W MDME 2400 is available in two models with different RF power:
D2 W MDME 2400 1 100mW of RF power
D2 W MDME 2400 3 300mW of RF power
Note that European regulations do not permit more than 100mW of RF power to be used.
Operation in France, Italy, Luxembourg, Norway, and the Russian Federation is limited to
indoor use only. Refer to Appendix C for clarification. In the U.S., Canada, and
Australia, up to 1W of RF power may be generated. In other countries, please check with
your Cooper Crouse-Hinds representative.
The D2 W MDME 2400 has a standard RJ45 Ethernet connection which will operate at up to
100Mbit/sec. The module will transmit the Ethernet messages on the wireless band at rates between
1 and 11 Mbit/sec.
1.1 Network Topology
The D2 W MDME 2400 is an Ethernet device, and must be configured as part of an Ethernet
network. Each D2 W MDME 2400 must be configured
as:
An “Access Point” or a “Client,” and
A “Bridge” or a “Router.”
Client
Ethernet
Device
Access
Point

D2 W MDME 2400 Wireless Ethernet Modem IF 1584 Rev. 1
IF 1584 Rev. 1 Page 6
You can also connect to the D2 W MDME 2400 via a RS232 or RS485 serial port using serial server
or PPP (point-to-point) protocol. PPP allows the D2 W MDME 2400 to connect serial
communications into the Ethernet network.
Access Point versus Client.
The Access Point unit acts as the “wireless
master” unit. The Access Point sets up the
wireless links to the Client units and controls the
wireless communications. The first diagram
shows two Ethernet devices being linked. One
D2 W MDME 2400 is configured as an Access
Point and one as a Client - in this example, it doesn’t
matter which unit is the Access Point.
The second diagram shows an existing LAN being
extended using D2 W MDME 2400s. In this
example, the Access Point should be configured at
the LAN end – although, the wireless link will still
work if the Client is at the LAN end.
An Access Point can connect to multiple Clients. In
this case, the Access Point should be the “central”
unit.
An Access Point could be
used as a “Repeater” unit
to connect two D2 W
MDME 2400 Clients
which do not have direct
reliable radio paths.
Multiple Access Points can be set up in a “mesh” network to provide multiple repeaters.
LAN
Ethernet Device
Client
Access
Point
LAN
Ethernet Device
Client
Access
Point
Client
Client
LAN
Ethernet device
Client
Access
Point
Client
LAN
Client
Access
Point
Client
Access
Point Access
Point
Client

Chapter One Introduction
Page 7 November 2008
Bridge versus Router.
Each D2 W MDME 2400 is configured with an IP address for the Ethernet side, and another for the
wireless side.
A Bridge connects devices
within the same Ethernet
network - for example,
extending an existing Ethernet
LAN. For a Bridge, the IP
address for the wireless side is
the same as the Ethernet side.
A Router connects devices on different LANs. The IP addresses for the Ethernet and wireless sides
are different.
In the above example, the
wireless link is part of LAN A,
with the Client unit acting as a
Router between LAN A and
LAN B. Alternatively, the
Access Point could be
configured as a Router - the
wireless link is then part of
LAN B.
If more than two Routers are required within the same radio network, then routing rules may need to
be configured (refer to Section 3.11, “Routing Rules,” for further details).
There is no limit to the number of Bridges in the same network – although, there is a limit of 128
Client units linked to any one Access Point.
Client
Router
LAN C
169.254.102.17
192.168.0.7
3
LAN A
Client
Bridge
Access Point
Bridge
192.168.0.34 192.168.0.72
Client
Router LAN B
169.254.109.40
192.168.0.74
LAN
Client
Bridge
Access Point
Bridge
192.168.0.34
192.168.0.34 192.168.0.72
192.168.0.72
LAN A Client
Router
Access Point
Bridge
192.168.0.34 LAN B
169.254.102.1
7

D2 W MDME 2400 Wireless Ethernet Modem IF 1584 Rev. 1
IF 1584 Rev. 1 Page 8
1.2 Getting Started Quickly
Most applications for the D2 W MDME 2400 require little configuration. The D2 W MDME 2400
has many sophisticated features; however, if you don’t require these features, this section will allow
you to configure the units quickly.
First, read Section 2, “Installation.” The D2 W MDME 2400 requires an antenna and a power
supply.
Power the D2 W MDME 2400 and make an Ethernet connection to your PC (for further
information on how to do this, refer to Section 3.4).
Set the D2 W MDME 2400 address settings as per Section 3.4.
Save the configuration - the D2 W MDME 2400 is now ready to use.
Before installing the D2 W MDME 2400, bench test the system. It is a lot easier to locate problems
when the equipment is all together.
There are other configuration settings which may or may not improve the operation of the system.
For details on these settings, refer to Section 3.

Chapter Two Installation
Page 9 November 2008
Chapter Two INSTALLATION
2.1 General
The D2 W MDME 2400 module is housed in a rugged aluminium case, suitable for DIN rail
mounting. Terminals will accept wires up to 2.5 sqmm (12 gauge) in size.
All connections to the module must be SELV. Normal 110-250V mains supply should not
be connected to any terminal of the D2 W MDME 2400 module. Refer to Section 2.3,
“Power Supply.”
Before installing a new system, it is preferable to bench test the complete system. Configuration
problems are easier to recognize when the system units are adjacent. Following installation, the
most common problem is poor communications caused by incorrectly installed antennas, radio
interference on the same channel, or the radio path being inadequate. If the radio path is a
problem (i.e. path is too long or obstructions are in the way), then higher performance antennas
or a higher mounting point for the antenna may rectify the problem. Alternatively, use an
intermediate D2 W MDME 2400 module as a repeater.
The foldout sheet D2 W MDME 2400 Installation Guide provides an installation drawing
appropriate to most applications. Further information is detailed below.
Each D2 W MDME 2400 module should be effectively earthed via the "GND" terminal on the
D2 W MDME 2400 module - this is to ensure that the surge protection circuits inside the D2 W
MDME 2400 module are effective.
2.2 Antenna Installation
The D2 W MDME 2400 module will operate reliably over large distances. The distance which
may be reliably achieved will vary with each application - depending on the type and location of
antennas, the degree of radio interference, and obstructions (such as buildings or trees) to the
radio path.
The maximum range achievable depends on the regulated RF power permitted in your country,
and whether you use separate transmit and receive antennas. With a single antenna, 5 km (3
miles) can be achieved in the U.S., Canada, and Australia (4W ERP), and 1 km in Europe
(100mW ERP). With separate transmit and receive antennas, more than 10 km (6 miles) can be
achieved in the U.S., Canada, and Australia, and more than 5 km in Europe.
To achieve the maximum transmission distance, the antennas should be raised above
intermediate obstructions so the radio path is true “line-of-sight.” The modules will operate
reliably with some obstruction of the radio path, although the reliable distance will be reduced.
Obstructions which are close to either antenna will have more of a blocking effect than
obstructions in the middle of the radio path. The D2 W MDME 2400 modules provide a
diagnostic feature which displays the radio signal strength of transmissions (refer to the
Diagnostics section for more information).

D2 W MDME 2400 Wireless Ethernet Modem IF 1584 Rev. 1
IF 1584 Rev. 1 Page 10
Line-of-sight paths are only necessary to obtain the maximum range. Obstructions will reduce
the range, however, may not prevent a reliable path. A larger amount of obstruction can be
tolerated for shorter distances. For short distances, it is possible to mount the antennas inside
buildings. An obstructed path requires testing to determine if the path will be reliable - refer to
Section 6 of this Instruction Sheet.
Where it is not possible to achieve reliable communications between two D2 W MDME 2400
modules, then a third D2 W MDME 2400 module may be used to receive the message and re-
transmit it. This module is referred to as a repeater. This module may also have a host device
connected to it.
The D2 W MDME 2400 unit has two antenna connections at the top of the module, allowing two
antennas to be fitted to the unit. The left connector (looking at the front) labeled “RX” is
connected only to the internal wireless receiver. The right connector labeled TX/RX is
connected to both the transmitter and receiver.
Note: when only one antenna is used, it must be connected to the right TX/RX connector.
Plant and Factory Installations.
Most installations in industrial plants and factories use single omni-directional antennas.
Installations can suffer from “multi-path fading” effects where multiple reflected radio signals
adversely affect the signal strength. This can be checked by moving the antenna a short distance
(10 cm or 4 inches) - if the signal increases significantly, then there are multi-path effects.
In a “static” installation, where the radio path is not changing, moving an antenna to the position
of maximum signal solves this problem. However, where the radio path changes because the D2
W MDME 2400 is mounted on moving equipment, or if there is moving equipment in the area,
then the solution is to use two antennas. Because the two connectors are separated, the RF signal
at each connector will be different in the presence of multi-path fading. The D2 W MDME 2400
unit will automatically select the higher RF signal.
Note that directional antennas are not normally used in plant and factory installations.
Line-of-sight Installations.
In longer line-of-sight installations, the range may be increased by using a high gain antenna on
the TX/RX connector. However, the gain should not cause the effective radiated power (ERP) to
exceed the permitted value. A second higher gain antenna can be connected to the RX connector
without affecting ERP - this will increase the operating range, provided the background noise in
the area is low.
Antennas.
Antennas can be either connected directly to the module connectors or connected via 50 ohm
coaxial cable (e.g. RG58 Cellfoil or RG213) terminated with a male SMA coaxial connector.
The higher the antenna is mounted, the greater the transmission range will be; however, as the
length of coaxial cable increases, so do cable losses.

Chapter Two Installation
Page 11 November 2008
The net gain of an antenna/cable configuration is the gain of the antenna (in dBi) less the loss in
the coaxial cable (in dB). The maximum net gain of the antenna/cable configuration connected
to the TX/RX connector is 0dB in Europe (100mW ERP). In the U.S., Canada, and Australia
(4W ERP), the maximum gain is 12dB for the D2 W MDME 2400 3 or 16dB for the D2 W
MDME 2400 1. There is no gain restriction for antennas connected to the RX connector.
The gains and losses of typical antennas are:
Antenna Gain (dBi)
Dipole 2
Collinear 5 or 8
Directional 10 - 28
Cable type Loss (dB per 10 m / 30 ft)
RG58 Cellfoil -6
RG213 -5
LDF4-50 -1.5
The net gain of the antenna/cable configuration is determined by adding the antenna gain and the
cable loss. For example, a 5dBi antenna with 10 meters of Cellfoil has a net gain of -1dB (5dB –
6dB).
Installation Tips.
Connections between the antenna and coaxial cable should be carefully taped to prevent ingress
of moisture. Moisture ingress in the coaxial cable is a common cause for problems with radio
systems, as it greatly increases the radio losses. We recommend that the connection be taped,
first with a layer of PVC tape, then with a vulcanizing tape such as “3M 23 tape,” and finally
with another layer of PVC UV stabilized insulating tape. The first layer of tape allows the joint
to be easily inspected when troubleshooting, as the vulcanizing seal can be easily removed.
Where antennas are mounted on elevated masts, the masts should be effectively earthed to avoid
lightning surges. For high lightning risk areas, surge suppression devices between the module
and the antenna are recommended. If the antenna is not already shielded from lightning strike by
an adjacent earthed structure, a lightning rod may be installed above the antenna to provide
shielding.
2.2.1 Dipole and Collinear Antennas.
A dipole or collinear antenna transmits the same amount of radio power in all directions - as
such, they are easy to install and use. The dipole antenna with integral 5 meters (15 feet) cable
does not require any additional coaxial cable; however, a cable must be used with the collinear
antennas.
Collinear and dipole antennas should be mounted vertically, preferably 30 cm (1 foot) away from
a wall or mast to obtain maximum range.

D2 W MDME 2400 Wireless Ethernet Modem IF 1584 Rev. 1
IF 1584 Rev. 1 Page 12
2.2.2 Directional Antennas.
Directional antennas can be:
A Yagi antenna with a main beam and
orthogonal elements;
A directional radome, which is
cylindrical in shape; or
A parabolic antenna.
A directional antenna provides high gain
in the forward direction, but lower gain in
other directions. This may be used to
compensate for coaxial cable loss for
installations with marginal radio path.
Yagi antennas should be installed with the
main beam horizontal, pointing in the
forward direction. If the Yagi is
transmitting to a vertically mounted omni-
directional antenna, then the Yagi
elements should be vertical. If the Yagi is
transmitting to another Yagi, then the
elements at each end of the wireless link need to be in the same plane (horizontal or vertical).
30 cm minimum
COLLINEAR
ANTENNA
MAST
EARTH STAKE
IF GROUND
CONDITIONS ARE
POOR, INSTALL
MORE THAN ONE
STAKE
INSTALL AERIAL ABOVE
LOCAL OBSTRUCTIONS
TX/RX
MODEM
SURGE
ARRESTOR
(OPTIONAL)
COAXIAL CABLE
WEATHERPROOF
CONNECTORS WITH
“3M 23” TAPE
STRESS RELIEF
LOOP
PROVIDE GOOD
GROUND
CONNECTION TO
MAST, MODULE
AND SURGE
ARRESTOR
GND
D2 W MDME
Antenna installed
with drainholes
down
Coax feed
loo
p
ed
90o

Chapter Two Installation
Page 13 November 2008
Directional radomes should be installed with the central beam horizontal and must be pointed
exactly in the direction of transmission to benefit from the gain of the antenna. Parabolic
antennas should be mounted as per the manufacturer’s instructions, with the parabolic grid at the
“back” and the radiating element pointing in the direction of the transmission.
Ensure that the antenna mounting bracket is well connected to “ground/earth.”
2.3 Power Supply
The D2 W MDME 2400 module can be powered from a 9 - 30VDC power supply. The power
supply should be rated at 1 Amp. The positive side of the supply must not be connected to earth.
The supply negative is connected to the unit case internally. The DC supply may be a floating
supply or negatively grounded.
The power requirements of the D2
W MDME 2400 unit are 240mA
@ 12V or 150mA @ 24VDC.
This is inclusive of radio and
Ethernet ports active, and serial
port plugged in. Transmission
current is nominally 350mA at
12V (200mA at 24V) for the
100mW RF unit, and 500mA at 12V (350mA at 24V) for the 300mW RF unit.
A ground terminal is provided on the back of the module. This terminal should be connected to
the main ground point of the installation in order to provide efficient surge protection for the
module (refer to the Installation Diagram for more information).
2.4 Serial Connections
2.4.1 RS232 Serial Port.
The serial port is a 9-pin DB9 female, and provides for connection to a host device as well as a
PC terminal for configuration, field testing, and factory testing. Communication is via standard
+
_
B
A
-
+
COM
DIO
D2 W MDME
2400
9 - 30
VDC
RS485
SUPPLY
D2 W MDME
DB9
MALE
DTE HOST
DB9
FEMALE
D2 W MDME
DB9
MALE
DCE HOST
DB9
MALE

D2 W MDME 2400 Wireless Ethernet Modem IF 1584 Rev. 1
IF 1584 Rev. 1 Page 14
RS232 signals. The D2 W MDME 2400 is configured as DCE equipment with the pin-outs
detailed below.
Hardware handshaking using the CTS/RTS lines is provided. The CTS/RTS lines may be used
to reflect the status of the local unit’s input buffer. The D2 W MDME 2400 does not support
XON/XOFF.
Example: cable drawings for connection to a DTE host (a PC) or another DCE hosts (or modem) are
detailed above.
DB9 Connector Pin-outs:
Pin Name Direction Function
1 DCD Out Data carrier detect –
2 RD Out Transmit Data – Serial Data Output
3 TD In Receive Data – Serial Data Input
4 DTR In Data Terminal Ready -
5 SG Signal Ground
6 DSR Out Data Set Ready - always high when unit is powered on.
7 RTS In Request to Send -
8 CTS Out Clear to send -
9 RI Ring indicator -
2.4.2 RS485 Serial Port.
The RS485 port provides for communication between the D2 W MDME 2400 unit and its host
device using a multi-drop cable. Up to 32 devices may be connected in each multi-drop network.
As the RS485 communication medium is shared, only one of the units on the RS485 cable may
send data at any one time. Thus, communication protocols based on the RS485 standard require
some type of arbitration.
RS485 is a balanced, differential standard, but it is recommended that shielded, twisted pair
cable be used to interconnect modules to reduce potential RFI. It is important to maintain the
polarity of the two RS485 wires. An RS485 network should be wired as indicated in the diagram
below and terminated at each end of the network with a 120 ohm resistor. On-board 120 ohm
resistors are provided and may be engaged by operating the single dip switch in the end-plate
next to the RS485 terminals. The dip switch should be in the “1” or “on” position to connect the
resistor. If the module is not at one end of the RS485 cable, the switch should be off.

Chapter Two Installation
Page 15 November 2008
HOST D2 W MDME 2400 HOST
RS485 CONNECTIONS
120Ω
RS485
SUPPLY
RS232
DIP SWITCH FOR 120
Ω
120
Ω
HOST HOST
D2 W MDME
2400
+
-
+
-
+
-
RS485 CONNECTION USING TERMINATING RESISTO
R
ETHERNET
DIO
DEFA
U
LT
S
DIP
S
WIT
C
H

D2 W MDME 2400 Wireless Ethernet Modem IF 1584 Rev. 1
IF 1584 Rev. 1 Page 16
2.5 Discrete (Digital) Input/Output
The D2 W MDME 2400 has one on-board discrete/digital I/O channel. This channel can act as
either a discrete input or discrete output. It can be monitored, set remotely, or alternatively used
to output a communications alarm status.
If used as an “input,” the I/O channel is suitable for voltage-free contacts (such as mechanical
switches) or NPN transistor devices (such as electronic proximity switches). PNP transistor
devices are not suitable. Contact wetting current of approximately 5mA is provided to maintain
reliable operation of driving relays.
The digital input is connected between the "DIO" terminal and common "COM." The I/O circuit
includes an LED indicator which is lit when the digital input is active; that is, when the input
circuit is closed. Provided the resistance of the switching device is less than 200 ohms, the
device will be able to activate the digital input.
The I/O channel may also be used as a discrete output. The digital outputs are transistor
switched DC signals, FET output to common rated at 30VDC 500 mA.
The output circuit is connected to the "DIO" terminal. The digital output circuit includes an
LED indicator which is lit when the digital output is active.
DIO
GND D2 W MDME
2400
Voltage-free
contact input
V
-
_
+ DC
Load
Max 30VDC
0.5A
DIO
GND D2 W MDME
2400

Chapter Three Operation
Page 17 November 2008
Chapter Three OPERATION
3.1 Start-up
“Access Point” Start-up.
An Access Point (AP) unit starts and immediately begins transmitting periodic messages, called
beacons, on the configured channel. Beacons include capability information that a Client may
examine in order to identify if the Access Point is suitable for link establishment. Clients will only
attempt to establish a link with an Access Point whose beacon indicates a matching SSID. Access
Points do not initiate link establishment.
“Client” Start-up.
When a Client powers up, it scans for beacons from Access Points. While a link is not established,
the Client cyclically scans all available channels for a suitable Access Point. The Client will
attempt to establish a link with an Access Point only if it has matching SSID and other compatible
capabilities as indicated by the beacon. If more than one suitable Access Point is discovered, the
client will attempt to establish a link with the Access Point that has the strongest radio signal.
Link Establishment.
Once a Client identifies a suitable Access Point for link establishment, it attempts to establish a link
using a two step process – “Authentication” and “Association.” During Authentication, the Client
and Access Point check if their configurations permit them to establish a link. Once the Client has
been authenticated, it will then request an Association to establish a link.
Status of the wireless link is indicated via the LINK LED. For an Access Point, the LINK LED will
be OFF while no links have been established. Once one or more links have been established, the
LINK LED is ON. For a Client, the LINK LED will reflect the connection status to an Access
Point. Link status is also displayed on the “Connectivity” page of the web interface.
After the link is established, data may be transferred in both directions. The Access Point will act
as a master unit and will control the flow of data to the Clients linked to it. Clients can only
transmit data to the AP to which they are connected. When a Client transfers data to another Client,
it first transmits the data to the AP which then forwards the data to the destined Client.
Presence of a “link” does not mean that the connected unit is authorized to communicate over radio.
If the encryption keys are incorrect between units in the same system, or a dissimilar encryption
scheme is configured, the LINK LED will light; however, data may not be passed over the wireless
network.
A maximum of 255 Clients may be linked to an Access Point.

D2 W MDME 2400 Wireless Ethernet Modem IF 1584 Rev. 1
IF 1584 Rev. 1 Page 18
How a Link Connection is Lost.
The Access Point refreshes the link status with a Client every time a message is received from that
Client. If nothing is received from a Client for a period of 120 seconds, the Access Point sends a
“link-check” message. If there is no response to the link-check, a de-authenticate message is sent
and the link is dropped.
A Client monitors beacons from an Access Point to determine whether the link is still present. If
the Client can no longer receive beacons from the AP, the AP is considered to be out of range and
the link is dropped. Whenever a Client is not connected to an AP, it will cyclically scan all
available channels for a suitable AP.
Roaming.
Clients may also roam between Access Points. If a Client receives a beacon from an AP with a
stronger signal than the current AP (providing SSID is the same and capability information is
compatible), it may disconnect from the first AP and establish a link with the second AP. This
functionality permits a Client to have mobility while maintaining a link with the most suitable AP.
LED Indication.
The following table details the status of the indicating LEDs on the front panel under normal
operating conditions.
LED Indicator Condition Meaning
OK GREEN Normal operation
OK RED Supply voltage too low
Radio RX GREEN flash Radio receiving data
Radio RX RED flash Weak radio signal
Radio TX Flash Radio transmitting
Radio LINK ON On when a radio communications link is
established
Radio LINK OFF Communications failure or radio link not
established
Radio LINK GREEN flash
RED flash
Serial port receiving
CTS low
LAN ON Link established on Ethernet port
LAN Flash Activity on Ethernet port
Serial GREEN flash RS232 serial port activity
Serial RED flash RS485 serial port activity
DIO ON
Digital output ON or input is grounded

Chapter Three Operation
Page 19 November 2008
Increasing frequency
1 6 11
2 7
3 8
4 9
5 10
LED Indicator Condition Meaning
DIO OFF
Digital output OFF and input is open circuit
The Ethernet RJ45 port incorporates two indication LEDs. The LINK LED comes on when there is
a connection on the Ethernet port, and will blink off briefly when activity is detected on the
Ethernet port. The 100MB LED indicates that the connection is at 100 MBit/Sec. The 100MB
LED will be off for 10MB/Sec connection.
Other conditions indicating a fault are described in Chapter Six, “Troubleshooting.”
3.2 Selecting a Channel
The D2 W MDME 2400 conforms to the IEEE 802.11 Wireless LAN specification. The D2 W
MDME 2400 supports 11 radio channels, each 5 MHz wide, in the range 2412 MHz to 2462 MHz.
Only one of these channels is used for a connection. The desired channel is selected and configured
at the Access Point, and is then used for all beacon transmissions and connections. Clients scan all
11 channels for a suitable Access Point and then adopt the same channel as the AP when a
connection is established. Although each channel is only 5 MHz wide, the radio transmission is
much wider. Hence, the channels overlap. The following diagram shows the RF energy
distribution for a Wi-Fi transmission:
Most of the energy is in a central 22 MHz wide “lobe,” centered around the channel frequency;
however, there are also side lobes extending either side.
If we ignore the side lobes and consider each Wi-Fi
message as a 22 MHz wide transmission, then the
following diagram represents how transmissions in
each channel overlap.
If there is more than one Wi-Fi AP within the same
wireless range, then it is important that the APs are
on channels as far apart as possible. If there are only
two APs, set them to 1 and 11. If there are three, set
them to 1, 6, and 11.
It is also important that the correct channel is
selected for the region. Channels 1 to 11 are
approved for North America (FCC), Europe (ETSI), Canada (IC), and Australia (ACMA).
Channels 10 and 11 are approved for use in Spain and France. Refer to the relevant regulatory
authority for the region as to which radio channels are approved for use.
f-33 f-22 f-11 f f+11 f+22 f+33
RF power distribution in a Wi-Fi transmission with channel central frequency, f

D2 W MDME 2400 Wireless Ethernet Modem IF 1584 Rev. 1
IF 1584 Rev. 1 Page 20
Default Configuration
The default factory configuration of the D2 W MDME 2400 is:
•Client/Bridge/.
•IP address192.168.0.1XX, where XX is the last two digits of the serial number (the default IP
address is shown on the printed label on the back of the module).
•Netmask 255.255.255.0.
•Username is “user” and the default password is “user.”
The D2 W MDME 2400 will temporarily load some factory default settings if powered up with the
factory default switch (on the end-plate of the module) in SETUP position. When in SETUP mode,
wireless operation is disabled. The previous configuration remains stored in non-volatile memory
and will only change if a configuration parameter is modified and the change saved.
Do not forget to set the switch back to the RUN position and cycle power at the conclusion
of configuration for resumption of normal operation.
3.3 Configuring the Unit for the First Time
The D2 W MDME 2400 has a built-in web server containing web pages for analysis and
modification of configuration. The configuration can be accessed using Microsoft®Internet
Explorer. This program is shipped with Microsoft Windows or may be obtained freely via the
Microsoft web site.
Configuration of IP address, gateway address, and subnet mask may also be accessed via the RS232
serial port.
Accessing Configuration for the First Time.
There are two methods for accessing the configuration inside a D2 W MDME 2400. The first
method requires changing your computer settings so that the configuring PC is on the same network
as the D2 W MDME 2400 with factory default settings. This is the preferred method and is much
less complicated than the second method. You will need a “straight-through” Ethernet cable
between the PC Ethernet port and the D2 W MDME 2400. The factory default Ethernet address for
the D2 W MDME 2400 is 192.168.0.1XX, where XX are the last two digits of the serial number
(check the label on the back of the module).
The second method requires setting an IP address in the D2 W MDME 2400 such that it is
accessible on your network without having to change your network settings.
3.4.1 Set PC to Same Network as D2 W MDME 2400.
Connect the Ethernet cable between unit and the PC configuring the module.