Murata Electronics North America WSN802G User Manual

IC Radio Standards Specification: RSS-210

ACS Report Number: 09-0120 - 15C

Model(s): WSN802GC, WSN802GP

Certification Exhibit

FCC ID: HSW-WSN802G

IC: 4492A-WSN802G

FCC Rule Part: 15.247

Manufacturer: RFM / Cirronet Inc.

Manual

5015 B.U. Bowman Drive Buford, GA 30518 USA Voice: 770-831-8048 Fax: [phone]

www.RFM.com

WSN802G Series

802.11g Wireless Sensor
Network Modules

Preliminary

Integration Guide

©2009 by RF Monolithics, Inc. E-mail:

Technical support +1.678.684.2000 Page 1 of 51

tech [e-mail]

WSN802G - 04/30/09

www.RFM.com

Important Regulatory Information

FCC ID: HSW-WSN802G

IC: 4492A-WSN802G

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.

This Class B digital apparatus complies with Canadian ICES-003.

Cet appareil numérique de la classe B est conforme à la norme NMB-003 du Canada.

FCC User Information

“NOTE: 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 equipment to an outlet on a circuit different in which the receiver is connected.

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

Warning: Changes or modifications to this device not expressly approved by RFM Inc.

could void the user’s authority to operate the equipment.

Industry Canada

This Class B digital apparatus meets all requirements of the Canadian Interference Causing Equipment
Regulations. 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.

Cet appareillage numérique de la classe B répond à toutes les exigences de l'interférence canadienne
causant des règlements d'équipement. L'opération est sujette aux deux conditions suivantes: (1) ce
dispositif peut ne pas causer l'interférence nocive, et (2) ce dispositif doit accepter n'importe quelle
interférence reçue, y compris l'interférence qui peut causer l'opération peu désirée.

“To reduce potential radio interference to other users, the antenna type and its gain should be
so chosen that the equivalent isotropically radiated power (e.i.r.p.) is not more than that
permitted for successful communication.”

©2009 by RF Monolithics, Inc. E-mail:

Technical support +1.678.684.2000 Page 2 of 51

tech [e-mail]

WSN802G - 04/30/09

www.RFM.com

RF Exposure

The WSN802G module is approved for mobile operation provided the following conditions are
met.

The antenna(s) used for this transmitter must be installed to provide a separation distance of at
least 20 cm from all persons and must not be co-located or operating in conjunction with any
other antenna or transmitter.

This device has been designed to operate with the antennas listed below, and having a maximum
gain of 12 dBi. Antennas types not included in this list or having a gain greater than 12 dBi are
strictly prohibited for use with this device. The required antenna impedance is 50 ohms.

Mobile Mart OMNI249 9 dBi Omni Antenna

RFM 12 dBi Patch Antenna

Additional equivalent antennas may be substitute if they are the same type and have equal or less
gain without a new equipment authorization application. All antennas used with this device must
be approved by RFM/Cirronet and must employ a unique antenna coupler

OEM Installation and Compliance Labeling

The WSN802G module is labeled with its own FCC and IC ID number, and, if the ID numbers are
not visible when the module is installed inside another device, then the outside of the device into
which the module is installed must also display a label referring to the enclosed transmitter
module.

This exterior label can use wording such as the following:

“Contains Transmitter Module FCC ID: HSW-WSN802G” or
“Contains FCC ID: HSW-WSN802G”

The same requirements are used in Canada.

“Contains Transmitter Module IC: 4492A-WSN802G” or
“Contains IC: 4492A-WSN802G”

Any similar wording that expresses the same meaning may be used. The Grantee may either
provide such a label, an example of which must be included in the application for equipment
authorization, or, must provide adequate instructions along with the module which explain this
requirement. In the latter case, a copy of these instructions must be included in the application for
equipment authorization.

See Section 3.10 of this manual for regulatory notices and labeling requirements. Changes or modifica­tions to a WSN802G not expressly approved by RFM may void the user’s authority to operate the
module.

©2009 by RF Monolithics, Inc. E-mail:

Technical support +1.678.684.2000 Page 3 of 51

tech [e-mail]

WSN802G - 04/30/09

www.RFM.com

Table of Contents

1.0 WSN802G Introduction ......................................................................... 5

1.1 Features............................................................................................. 6

1.2 Applications ....................................................................................... 6

2.0 WSN802G Operation ............................................................................ 7

2.1 Active and Sleep Modes .................................................................... 7

2.2 Automatic I/O Reporting ................................................................... 8

2.3 Data Serial Port ................................................................................. 8

2.4 Diagnostic Serial Port ........................................................................ 8

2.5 Analog I/O.......................................................................................... 8

2.6 Digital I/O ........................................................................................... 8

3.0 WSN802G Hardware ............................................................................ 9

3.1 Absolute Maximum Ratings............................................................... 9

3.2 Specifications .................................................................................... 10

3.3 Module Interface ................................................................................ 11

3.4 WSN802G Antenna Connector ......................................................... 12

3.5 Input Voltage ..................................................................................... 13

3.6 ESD and Transient Protection........................................................... 13

3.7 Interfacing to 5 V Logic Systems....................................................... 13

3.8 Power-On Reset Requirements ........................................................ 13

3.9 Mounting and Enclosures ..................................................................... 13

3.10 Labeling and Notices ......................................................................... 14

4.0 Application Protocol .............................................................................. 15

4.1 I/O Report Request............................................................................ 16

4.2 I/O Report .......................................................................................... 16

4.3 I/O Write GPIO .................................................................................. 17

4.4 I/O Write PWM................................................................................... 17

4.5 I/O Write Reply .................................................................................. 18

4.6 Serial Data ......................................................................................... 18

5.0 IP Address Discovery Protocol ............................................................ 19

5.1 IP Hunt Query .................................................................................... 19

5.2 IP Hunt Reply .................................................................................... 20

6.0 SSID and Security Keys ....................................................................... 21

6.1 Router Scanning ................................................................................ 21

7.0 Module Configuration............................................................................ 22

7.1 SNMP Traps ...................................................................................... 22

7.2 SNMP Management Information Blocks ........................................... 23

7.3 System Configuration Parameters .................................................... 23

7.4 Application Configuration Parameters............................................... 27

©2009 by RF Monolithics, Inc. E-mail:

Technical support +1.678.684.2000 Page 4 of 51

tech [e-mail]

WSN802G - 04/30/09

www.RFM.com

8.0 WSN802GDK Developer’s Kit............................................................................................................ 29

8.1 WSN802GDK Kit Contents ............................................................................................................ 29

8.2 Additional Items Needed ............................................................................................................... 29

8.3 Developer Kit Assembly and Testing............................................................................................. 30

8.4 Developer Board Features ............................................................................................................ 32

8.5 WSNConfig Program Operation ................................................................................................... 34

9.0 Troubleshooting ................................................................................................................................ 44

10.0 Appendices ....................................................................................................................................... 45

10.1 Ordering Information...................................................................................................................... 45

10.2 Technical Support.......................................................................................................................... 45

10.3 WSN802G Mechanical Specifications........................................................................................... 46

10.4 WSN802G Developer Board Schematic ...................................................................................... 48

11.0 Warranty............................................................................................................................................. 51

©2009 by RF Monolithics, Inc. E-mail:

Technical support +1.678.684.2000 Page 5 of 51

tech [e-mail]

WSN802G - 04/30/09

www.RFM.com

WSN802G Sensor Node with

Direct Sens or Interface

ADC _REF

PWN0

DOUT1

1

Seria

I/O

RADIO_RXD

RADIO_TXD

Seria

WSN802G Sensor Node with

Host Mi croc on tr ol le r

RADIO_RXD

Inputs

RADIO_TXD

WAKE _ I N

DOUT1

Host

I/O

1.0 WSN802G Introduction

The WSN802G transceiver module is a low cost, robust solution for 802.11 b/g sensor networks. The
WSN802G is unique in that it is able to sleep while still remaining a member of an 802.11 b/g network.
The WSN802G's low active current and very low sleep current makes long life battery operation practical.
The W SN802G module includes analog, digital and serial I/O, providing the flexibility and versatility
needed to serve a wide range of sensor network applications. The WSN802G module is easy to integrate
and is compatible with standard 802.11 b/g routers.

802.11b/g Network with WSN802G Sensor Nodes

WSN802G

Se nso r
Node 1

Ap pli catio n
Serv er (PC)

802. 11b/g
Rou ter

802. 11b/g
Pri nter

Figure 1.0.1

An example 802.11 b/g network with WSN802G sensor nodes is shown in Figure 1.0.1. A sensor network
application running on a server or PC communicates with one or more WSN802G sensor nodes through
a commercial 802.11b/g router. WSN802G sensor nodes can be used with 802.11b/g routers that are
also serving other applications.

ADC0

ADC1

PWM1

DIN0

DIN1

DOUT0

WAKE _ IN

WSN802G

WSN802G

802. 11b/g

WSN802G

Se nso r
Node 2

WAKE_OUT

DIN0

DIN1

DOUT0

Lap top

Microcontroller

and

Sensor

Analog
and/ or
Digi tal

Analog
and/or
Digital
Outputs

A WSN802G module is integrated with other components to create a complete sensor node. These com­ponents include a host circuit board, a power supply (battery), sensor I/O electronics and/or a host micro­controller, an antenna and a housing. Two common configurations are show in Figure 1.0.2. Serial data
communication between a WSN802G and its host microcontroller requires no protocol formatting. The
WSN802G formats data received from its host into UDP packets for RF transmission, and delivers the
payload data from received UDP packets to its host. The sensor network application on the server or PC
uses a simple protocol to send and receive data from WSN802G sensor nodes, as detailed in Section 4.

©2009 by RF Monolithics, Inc. E-mail:

Conv ert er

RS232

RS232

Con verte r

I/O

Figure 1.0.2

Technical support +1.678.684.2000 Page 6 of 51

tech [e-mail]

WSN802G - 04/30/09

www.RFM.com

1.1 Features

WSN802G modules provide a unique set of features for wireless sensor network applications:

• Compatibility with commercial and industrial 802.1 1b/g routers

• Low power consumption for long life battery operation including sleep mode

• Full -40 to +85 ºC industrial temperature range operation

• Analog and digital I/O plus data and diagnostic UART ports

• Separate data and diagnostic ports

• System/application set up using just two Management Information Blocks (MIBs)

• Full 14 channel 802.11 b/g coverage for world wide operation

• FCC, Canadian IC and European ETSI certifications

• Choice of plug-in or solder reflow configurations

• Automatic or manual I/O data reporting

1.2 Applications

WSN802G sensor networks are well suited to applications where IEEE 802.1 1b/g router compatibility,
industrial temperature range operation and long battery life are important. Many applications match these
criteria, including:

• Energy Monitoring and Management

• Physical Asset Management

• Cold Chain Data Logging and Food Safety

• Security and Access Control Systems

• Environmental Monitorin g

• Man y More

©2009 by RF Monolithics, Inc. E-mail:

Technical support +1.678.684.2000 Page 7 of 51

tech [e-mail]

WSN802G - 04/30/09

www.RFM.com

2.0 WSN802G Operation

WSN802G operation is designed to support long battery life by allowing the module to stay in sleep mode
to the maximum extent possible. Compared to 802.11 b/g cards used in notebook and handheld com­puters, the WSN802G’s active current is also very low.

2.1 Active and Sleep Modes

Once the SNMP Server IP address has been set, the default state of the WSN802G is sleep mode. The
WSN802G has a dedicated input to switch it from sleep to active mode, WAKE_IN (Pin 26). There are five
events that will wake the WSN802G from sleep mode:

•

Applying a logic high signal on the WAKE_IN pin

•

Expiration of the AutoReport timer

•

Expiration of Linkup trap timer

•

Expiration of the Config trap timer

•

Module’s SNMP Server IP address has not been set (this will not wake it, it prevents it from

sleeping)

The WAKE_IN and AutoReport can be enabled/disabled. The Linkup timer sends a keep alive packet to
the router every 60 seconds by default. The Config timer cannot be disabled and will generate a Config
trap every 10 seconds by default.

When the module wakes to an active state due to either the WAKE_IN pin or the AutoReport timer, it re-
mains awake for a time period controlled by the Wake Timeout timer. The module returns to sleep mode
when the Wake Timeout timer expires, subject to the conditions listed below. The Wake Timeout timer is
held in reset and the module remains in active mode when any of the following events occur:

•

A logic high signal is held on the WAKE_IN pin

•

A serial byte is received

•

An RF packet is sent or received

•

Module’s SNMP Server IP address has not been set

The Wake Timeout feature is used to support scenarios such as a server application parsing the I/O report
and sending back a serial string or I/O output change command, or a host processor sending a serial
string and waiting for a response.

As discussed in Section 5, the SNMP Server IP address can be set in a short period of time, allowing the
module to switch to sleep mode for battery conservation. The SNMP server IP address only needs to be
set one time.

A WSN802G module that has an SNMP Server IP Address but is not linked to an 802.11 b/g router will
cycle between sleep and active mode under the control of the scanning algorithm, even if none of the
wake events discussed above are present.

Whenever the module is in active mode, a logic high is asserted on WAKE_OUT (Pin 27). WAKE_OUT
can be used to signal an external processor. When the WSN802G is in sleep mode, WAKE_OUT is set
to logic low.

©2009 by RF Monolithics, Inc. E-mail:

Technical support +1.678.684.2000 Page 8 of 51

tech [e-mail]

WSN802G - 04/30/09

www.RFM.com

2.2 Automatic I/O Reporting

The WSN802G sends an I/O report when one of the following events occur:

•

A logic high signal is applied to the WAKE_IN pin

•

The AutoReport timer fires (module in either active or sleep mode)

2.3 Data Serial Port

The data serial port of the WSN802G supports baud rates from 1.2 to 921.6 kb/s. The following serial port
configurations are supported:

•

5, 6, 7 and 8-bit character lengths

•

1 o r 2 stop bits

•

Even, odd, mark, space or no parity

The default serial port configuration is 9.6 kb/s, 8, N,1. See Section 7.2 for serial port configuration de­tails. Serial port operation is full-duplex. Data is sent and received on the serial port transparently. No pro­tocol formatting is required. The WSN802G includes an acknowledgement and retry mechanism to mini­mize data loss on RF transmissions. However, the UDP/IP protocol being carried by the RF transmissions
does not provide guaranteed end-to-end delivery. The user must make provisions for detecting and re­sending data lost on an end-to-end transmission. The WSN802G is a three-wire interface; hardware flow
control will be provided in a future firmware release.

2.4 Analog I/O

The WSN802G includes two 10-bit ADC inputs. Input ADC0 is on Pin 18 and input ADC1 is on Pin 19. Pin
25 provides a full-scale reference voltage to support ratiometric ADC measurements. ADC measurements
are triggered and added to the automatic I/O report when a logic high signal is first applied to the WAKE_
IN pin or the AutoReport timer fires, as discussed in Section 2.2. An ADC reading is also made on the
internal buss voltage of the WSN802G and included in the automatic I/O report. These readings can also
be retrieved anytime the WSN802G is in active mode using the IO_REPORT application protocol com­mand as discussed in Section 4.1.

The WSN802G also includes an active 16-bit pulse width modulated output, PWM0 (Pin 9). The PWM
output is low-pass filtered to provide an analog output voltage with ripple suppressed to 7 bits. External
low-pass filtering can be added to further suppress ripple. The full-scale PWM output is referenced to the
regulated supply voltage (Pin 24). The PWM output is set using the IO_ WRITE_PWM application proto­col command, as discussed in Section 4.3.

2.5 Digital I/O

The WSN802G includes two digital inputs, DIN0 (Pin 4) and DIN1(Pin 11). The states of the DIN pins are
captured as part of the automatic I/O report when a logic high signal is applied to the WAKE_IN pin or the
AutoReport timer fires, as discussed in Section 2.2. These readings can also be retrieved anytime the
WSN802G is in active mode using the IO_REPORT application protocol command as discussed in Sec­tion 4.1. The WSN802G also includes two digital outputs, DOUT0 (Pin 10) and DOUT1 (Pin 12). The
states of the DOUT pins are set using the IO_WRITE_GPIO application protocol command as discussed
in Section 4.2.

©2009 by RF Monolithics, Inc. E-mail:

Technical support +1.678.684.2000 Page 9 of 51

tech [e-mail]

WSN802G - 04/30/09

www.RFM.com

+3.3 V

+1.8 V

GND

10

11

12

13

14

15

3

4

8

9

2

5

6

7

1

Filter

1 6 1 7 1 8 1 9 2 0 2 1 2 2 2 3 2 4 2 5 2 6 2 7

32.768 kHz

802.11g

44 M

Hz

RFIO

GND

28

29

30

3.0 WSN802G Hardware

WSN802G Block Diagram

Figure 3.0.1

GND

DIAG_TX

DIAG_RX

DIN0

RADIO_TXD

RADIO_RXD

RSVD

RSVD

PWM0

DOUT0

DIN1

DOUT1

RSVD

VCC

Reg

Reg

Low Current
Transceiver

Balun

>

BPF

RSVD

GND

The WSN802G operates in the international 2.4 GHz ISM band over the frequency range of 2401­2474 MHz, with a nominal RF output power of 10 mW. The WSN802G supports two standard 802.11g RF
data rates, 1 and 2 Mb/s. The WSN802G transceiver module provides a variety of hardware interfaces.
There are two serial interfaces, one for data and a second for diagnostics. The data port supports stan­dard serial baud rates from 1.2 to 921.6 kb/s, and the diagnostic port operates at a fixed baud rate of

9.6 kb/s. Hardware flow control is not currently implemented on either serial port. The WSN802G includes
two 10-bit ADC inputs, a 16-bit PWM (DAC) output, two digital inputs and two digital outputs to support
sensor network applications.

The WSN802G is available in two mounting configurations. The WSN802GC is designed for solder reflow
mounting, and the WSN802GP is designed for plug-in connector mounting.

3.1 Absolute Maximum Ratings

Rating

Input/Output Pins Except ADC Inputs

ADC Input Pins

Non-Operating Ambient Temperature Range

Table 3.1.1

Sym Value

-0.5 to +3.63 V

-0.5 to 1.98 V

-40 to +85

Units

o

C

Technical support +1.678.684.2000 Page 10 of 51

©2009 by RF Monolithics, Inc. E-mail:

tech [e-mail]

WSN802G - 04/30/09

www.RFM.com

5

0

1

0

3.2 Specifications

Characteristic

Operating Frequency Range

Spread Spectrum Method

RF Chip Rate

RF Data Rates

Modulation Type

Number of RF Channels

RF Channel Spacing

Receiver Sensitivity, 8% PER:

RF Transmit Power

RF Connector

Optimum Antenna Impedance

ADC Input Range

ADC Input Resolution

ADC Input Impedance

PWM Output Resolution

Data Serial Port Baud Rates

Diagnostic Serial Port Baud Rate

Digital I/O:

Power Supply Voltage Range VCC +3

Power Supply Voltage Ripple

Receive Mode Current

Transmit Mode Current

Sleep Mode Current

WSN802GC Mounting

WSN802GP Mounting

Operating Temperature Range

Operating Relative Humidity Range, Non-condensing

1 Mb/s RF Data Rate

2 Mb/s RF Data Rate

Logic Low Input Level

Logic High Input Level

Input Pull Up/Down Resistor
Logic Low Output Level

Logic High Output Level

Sym Minimum

Table 3.2.1

Typical

Maximum Units

2401

CCK Direct Sequence

11 Mc/s

1 or 2 Mb/s

BPSK at 1 Mb/s, QPSK at 2 Mb/s

11

-92

-90

10

U.FL Coaxial Connector

50

10

1.2, 2.4, 4.8, 9.6 (default), 19.2, 28.8, 38.4,

57.6, 76.8, 115.2, 230.4, 460.8, 921.6

9.6

-0.3

2.24

50

2.4

7.5

Reflow Soldering

Socket

-40

10

2474 MHz

1.8 V

16 bits

0.7 V

VCC V

1000

0.4 V

VCC V

+3.63 Vdc

10 mV

150 mA

200 mA

85

90 %

MHz

dBm

dBm

mW

Ω

bits

MΩ

kb/s

kb/s

KΩ

P-P

µA

o

C

©2009 by RF Monolithics, Inc. E-mail:

Technical support +1.678.684.2000 Page 11 of 51

tech [e-mail]

WSN802G - 04/30/09

www.RFM.com

3.3 Module Interface

Pin Name I/O Description

1 GND - Power supply and signal ground. Connect to the host circuit board ground.

2 DIAG_TX O Diagnostic serial port output.

3 DIAG_RX I Diagnostic serial port input.

4 DIN0 I Digital input port 0.

5 RADIO_TXD O Serial data output from the radio.

6 RADIO_RXD I Serial data input to the radio.

7 RSVD - Reserved pin. Leave unconnected.

8 RSVD - Reserved pin. Leave unconnected.

9 PWM0 O

10 DOUT0 O Digital output port 0.

11 DIN1 I Digital input port 1.

12 DOUT1 O Digital output port 1.

13 RSVD - Reserved pin. Leave unconnected.

14 VCC I Power supply input, +3.0 to +3.63 Vdc.

15 GND - Power supply and signal ground. Connect to the host circuit board ground.

16 GND - Power supply and signal ground. Connect to the host circuit board ground.

17 /RESET I Active low module hardware reset.

18 ADC0 I 10-bit ADC input 0. ADC full scale reading can be referenced to the module’s +1.8 V regulated supply.

19 ADC1 I 10-bit ADC input 1. ADC full scale reading can be referenced to the module’s +1.8 V regulated supply.

20 RSVD - Reserved pin. Leave unconnected.

21 RSVD - Reserved pin. Leave unconnected.

22 RSVD - Reserved pin. Leave unconnected.

23 RSVD - Reserved pin. Leave unconnected.

24 3.3V _ OUT O

25 ADC _ REF O

26 WAKE _ IN I

27 WAKE _ OUT O

28 GND - RF ground for the WSN802GC only. Connect to the host circuit board ground plane.

29 RSVD - Reserved pin. Leave unconnected.

30 GND - RF ground for the WSN802GC only. Connect to the host circuit board ground plane.

16-bit pulse-width modulated output 0 with internal low-pass filter. Filter is first-order, with a 159

Hz 3 dB bandwidth, 10K output resistance.

Module’s +3.3 V regulated supply, available to power external sensor circuits. Current drain on this

output should be no greater than 50 mA.

Module’s +1.8 V regulated supply, used for ratiometric ADC readings. Current drain on this output

should be no greater than 5 mA.

Active high interrupt input to wake the module from timer sleep. Can be used to wake module on

event, etc.

Active high output asserted when module wakes from timer sleep. Can be used to wake an

external device.

Table 3.3.1

©2009 by RF Monolithics, Inc. E-mail:

Technical support +1.678.684.2000 Page 12 of 51

tech [e-mail]

WSN802G - 04/30/09

www.RFM.com

Trace Separation from

Length of Trace Run

Copper

FR-4 PCB

Copper

3.4 WSN802G Antenna Connector

A U.FL miniature coaxial connector is provided on both WSN802G configurations for connection to the
RFIO port. A short U.FL coaxial cable can be used to connect the RFIO port directly to an antenna. In this
case the antenna should be mounted firmly to avoid stressing the U.FL coaxial cable due to antenna
mounting flexure. Alternately, a U.FL coaxial jumper cable can be used to connect the WSN802G module
to a U.FL connector on the host circuit board. The connection between the host circuit board U.FL con­nector and the antenna or antenna connector on the host circuit board should be implemented as a
50 ohm stripline. Referring to Figure 3.4.1, the width of this stripline depends on the thickness of the cir­cuit board between the stripline and the groundplane. For FR-4 type circuit board materials (dielectric
constant of 4.7), the width of the stripline is equal to 1.75 times the thickness of the circuit board. Note
that other circuit board traces should be spaced away from the stripline to prevent signal coupling, as
shown in Table 3.4.1. The stripline trace should be kept short to minimize its insertion loss.

Circuit Board Stripline Trace Detai

Ground
Plane

Material

For 50 ohm impedance W = 1.75 * H

50 ohm Microstrip

100 mil 125 mill

150 mil 200 mil

200 mil 290 mil

250 mil 450 mil

300 mil 650 mil

Stripline
Trace

Figure 3.4.1

Parallel to Microstrip

Table 3.4.1

©2009 by RF Monolithics, Inc. E-mail:

Technical support +1.678.684.2000 Page 13 of 51

tech [e-mail]

WSN802G - 04/30/09

www.RFM.com

3.5 Input Voltage

WSN802G radio modules can operated from an unregulated DC input (Pin 14) in the range of 3.0 V
(trough) to 3.63 V (peak) over the temperature range of -40 to 85° C.

Applying AC, reverse DC, or a DC
voltage outside the range given above can cause damage and/or create a fire and safety hazard. Further,
care must be taken so logic inputs applied to the radio stay within the voltage range of 0 to 3.3 V. Signals
applied to the analog inputs must be in the range of 0 to ADC_REF (Pin 25). Applying a voltage to a logic
or analog input outside of its operating range can damage the WSN802G module.

3.6 ESD and Transient Protection

WSN802G circuit boards are electrostatic discharge (ESD) sensitive. ESD precautions must be observed
when handling and installing these components. Installations must be protected from electrical transients
on the power supply and I/O lines. This is especially important in outdoor installations, and/or where con­nections are made to sensors with long leads.

and/or create a fire and safety hazard.

Inadequate transient protection can result in damage

3.7 Interfacing to 5 V Logic System

All logic signals including the serial ports on the WSN802G are 3.3 V signals. To interface to 5 V signals,
the resistor divider network shown in Figure 3.7.1 below must be placed between the 5 V signal outputs
and the WSN802G signal inputs. The output voltage swing of the WSN802G 3.3 V signals is sufficient to
drive 5 V logic inputs. Figure 3.7.1 refers to the DNT500

5V

Logic

2.2K

WSN802G

4.3K

Figure 3.7.1

3.8 Power-On Reset Requirements

When applying power to the WSN802G, the /RESET pin should be held low until the power supply volt­age reaches 3.3 volts for 100 milliseconds.

3.9 Mounting and Enclosures

WSN802GC radio modules are mounted by reflow soldering them to a host circuit board. WSN802GP
modules are mounted by plugging their pins into a set of mating connectors on the host circuit board.
Refer to Section 10.3 and/or the WSN802G Data Sheet for mounting details.

WSN802G enclosures must be made of plastics or other materials with low RF attenuation to avoid com­promising antenna performance where antennas are internal to the enclosure. Metal enclosures are not
suitable for use with internal antennas as they will block antenna radiation and reception. Outdoor enclo­sures must be water tight, such as a NEMA 4X enclosure.

©2009 by RF Monolithics, Inc. E-mail:

Technical support +1.678.684.2000 Page 14 of 51

tech [e-mail]

WSN802G - 04/30/09

www.RFM.com

3.10 Labeling and Notices

WSN802G FCC Certification - The WSN802G hardware has been certified for operation under FCC Part
15 Rules, Section 15.247.

tion distance of at least 20 cm from all persons and must not be co-located or operating in conjunction
with any other antenna or transmitter.

The antenna(s) used for this transmitter must be installed to provide a separa-

WSN802G FCC Notices and Labels -

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.

A clearly visible label is required on the outside of the user’s (OEM) enclosure stating ”Contains FCC ID:
HSW-WSN802G.”

WARNING: This device operates under Part 15 of the FCC rules. Any modification to this device, not
expressly authorized by RFM, Inc., may void the user’s authority to operate this device. Canadian De­partment of Communications Industry Notice - IC: 4492A-WSN802G

This apparatus complies with Health Canada’s Safety Code 6 / IC RSS 210.

ICES-003

This digital apparatus does not exceed the Class B limits for radio noise emissions from digital apparatus
as set out in the radio interference regulations of Industry Canada.

Le present appareil numerique n’emet pas de bruits radioelectriques depassant les limites applicables
aux appareils numeriques de Classe B prescrites dans le reglement sur le brouillage radioelectrique
edicte par Industrie Canada.

ETSI EN 300 328

The WSN802G module has passed ETSI EN 300 328 testing conducted by an independent test
laboratory.

©2009 by RF Monolithics, Inc. E-mail:

Technical support +1.678.684.2000 Page 15 of 51

tech [e-mail]

WSN802G - 04/30/09

www.RFM.com

4.0 Application Protocol

In most applications, the auto-reporting functions of the WSN802G will be used to send data from nodes
to the application removing the need for the application to poll nodes. However, applications can read and
write data to and from WSN802G nodes if desired. WSN802G modules only accept commands over the
air; commands cannot be entered through either the data or diagnostic serial ports. Obviously, WSN802G
modules must be in active mode (awake) to receive commands. The WSN802G supports this type of op­eration through use of the auto-reporting function and the AutoReport and Wake Timeout timers. For ex-
ample, a WSN802G module has been configured to wake up once every minute. When the module
wakes up, it will send its I/O report. While the data may not be of interest, it will serve as a notification to
the application that the module is awake. Setting the Wake Timeout timer to 2 seconds will keep the mod-
ule awake giving the application 2 seconds to send any application commands to the module. The mod­ule will remain awake past the 2 seconds if commands are being received or processed. Once the appli­cation commands are completed the module will return to sleep immediately if the Wake Timeout time has
elapsed. Typically, this mode will be used when the application needs to write data to the WSN802G
module.

All commands and responses between a server and its WSN802G clients are formatted as UDP/IP pack­ets. The IPv4 UDP/IP packet format is shown in Figure 4.0.1 below. WSN802G commands and re­sponses are carried in the UDP datagram payload area. In the text below, commands and responses will
be referred to as datagrams with the understanding they are the payload of a UDP datagram. Automati­cally generated I/O reports from the WSN802G module due to timeouts or event interrupts take the form
of the I/O_Report application command.

Byte 0 Byte 1 Byte 2 Byte 3

IP

Version

Time to Live Protocol

Header

Length

Source Port

UDP Length

Type of

Service

ID Flags Fragment Offset

Source IP Address

Destination IP Address

Payload (Application Command)

Header Checksum

Destination Port

Checksum

Total

Length

Figure 4.0.1

WSN802G modules only accept application commands from and send application command data/replies
to the IP address of the server running their sensor application. As shown in Figure 4.0.2 below,
WSN802G application protocol datagrams use a standard header beginning with a protocol identifier to
discriminate WSN802G protocol messages from other message types. Datagrams are in 32-bit, big­endian format. The standard header fields are:

Protocol Identifier:

Opcode:

Code indicating the type of command or response

Transaction ID:

Unique identifier for all WSN messages, 0x52464D49

This is an incrementing transaction reference counter. Each end of the

link must keep its own counter for transactions that it originates. The
most significant bit of the transaction ID will be set for all transactions
that the server originates.

©2009 by RF Monolithics, Inc. E-mail:

Technical support +1.678.684.2000 Page 16 of 51

tech [e-mail]

WSN802G - 04/30/09

www.RFM.com

Byte 0 Byte 1 Byte 2 Byte 3

WSN802G Protocol Identifier = 0x52464D49

Opcode

Data (variable length)

Figure 4.0.2

The WSN802G application protocol commands are listed in Table 4.0.1 below. The port number that the
module sends and receives application messages on is defined by the SensorS erverPortNum parameter,
as discussed in Section 7.2. A WSN802G module will accept messages specifically addressed to it, or
that are broadcast (addressed to all modules). If a command is received through a broadcast, the WSN
will reply with a broadcast.

Opcode Direction Description

0x0000 Server-to-Module IO_REPORT_REQUEST

0x0001 Module-to-Server IO_REPORT

0x0002 Server-to-Module IO_WRITE_GPIO

0x0003 Server-to-Module IO_WRITE_PWM

0x0004 Module-to-Server IO_WRITE_REPLY

0x0005 Bidirectional SERIAL_DATA

Table 4.0.1

Transaction ID

4.1 I/O Report Request

The IO_REPORT_REQUEST datagram is used to request current I/O values, as shown in Figure 4.1.1.

Byte 0

Opcode = 0x0000

Byte 1

WSN802G Protocol Identifier = 0x52464D49

Byte 2

Transaction ID = varies

Byte 3

Figure 4.1.1

The module responds to an IO_REPORT_REQUEST with an IO_REPORT

4.2 I/O Report

The IO_REPORT datagram is used to report current I/O values, as shown in Figure 4.2.1.

Byte 0 Byte 1 Byte 2 Byte 3

WSN802G Protocol Identifier = 0x52464D49

Timestamp High Bytes

Timestamp Low Bytes

Opcode = 0x0001

ADC0

VOLT

DIN

Transaction ID = varies

ADC1

RSSI

©2009 by RF Monolithics, Inc. E-mail:

Technical support +1.678.684.2000 Page 17 of 51

Figure 4.2.1

tech [e-mail]

WSN802G - 04/30/09