Microhard Systems NBG30 2.4GHz 802.11bg 1W OEM Module User Manual
Microhard Systems Inc 2.4GHz 802.11bg 1W OEM Module
User Manual
Operating Manual
n802.11bg-30
2.4GHz 802.11bg 1W OEM Module
Revision 0.50, June 5, 2012
Phone: (403) 248-0028
Fax: (403) 248-2762
www.microhardcorp.com
Model: n802.11bg-
30
Microhard S
y
stems Inc.
ii N2420B Operating Manual
Warranty
Microhard Systems Inc. warrants that each product will be free of defects in material and workmanship for a period of one (1)
year for its products. The warranty commences on the date the product is shipped by Microhard Systems Inc. Microhard Systems
Inc.’s sole liability and responsibility under this warranty is to repair or replace any product which is returned to it by the Buyer
and which Microhard Systems Inc. determines does not conform to the warranty. Product returned to Microhard Systems Inc. for
warranty service will be shipped to Microhard Systems Inc. at Buyer’s expense and will be returned to Buyer at Microhard
Systems Inc.’s expense. In no event shall Microhard Systems Inc. be responsible under this warranty for any defect which is
caused by negligence, misuse or mistreatment of a product or for any unit which has been altered or modified in any way. The
warranty of replacement shall terminate with the warranty of the product.
Warranty Disclaims
Microhard Systems Inc. makes no warranties of any nature of kind, expressed or implied, with respect to the hardware, software,
and/or products and hereby disclaims any and all such warranties, including but not limited to warranty of non-infringement,
implied warranties of merchantability for a particular purpose, any interruption or loss of the hardware, software, and/or product,
any delay in providing the hardware, software, and/or product or correcting any defect in the hardware, software, and/or product,
or any other warranty. The Purchaser represents and warrants that Microhard Systems Inc. has not made any such warranties to
the Purchaser or its agents MICROHARD SYSTEMS INC. EXPRESS WARRANTY TO BUYER CONSTITUTES
MICROHARD SYSTEMS INC. SOLE LIABILITY AND THE BUYER’S SOLE REMEDIES. EXCEPT AS THUS
PROVIDED, MICROHARD SYSTEMS INC. DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PROMISE.
MICROHARD SYSTEMS INC. PRODUCTS ARE NOT DESIGNED OR INTENDED TO BE USED IN
ANY LIFE SUPPORT RELATED DEVICE OR SYSTEM RELATED FUNCTIONS NOR AS PART OF
ANY OTHER CRITICAL SYSTEM AND ARE GRANTED NO FUNCTIONAL WARRANTY.
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and assigns including any subsidiaries, related corporations, or affiliates, shall be released and discharged from any
and all manner of action, causes of action, liability, losses, damages, suits, dues, sums of money, expenses
(including legal fees), general damages, special damages, including without limitation, claims for personal injuries,
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nature whatsoever at law.
IN NO EVENT WILL MICROHARD SYSTEMS INC. BE LIABLE FOR ANY INDIRECT, SPECIAL,
CONSEQUENTIAL, INCIDENTAL, BUSINESS INTERRUPTION, CATASTROPHIC, PUNITIVE OR OTHER
DAMAGES WHICH MAY BE CLAIMED TO ARISE IN CONNECTION WITH THE HARDWARE,
REGARDLESS OF THE LEGAL THEORY BEHIND SUCH CLAIMS, WHETHER IN TORT, CONTRACT OR
UNDER ANY APPLICABLE STATUTORY OR REGULATORY LAWS, RULES, REGULATIONS,
EXECUTIVE OR ADMINISTRATIVE ORDERS OR DECLARATIONS OR OTHERWISE, EVEN IF
MICROHARD SYSTEMS INC. HAS BEEN ADVISED OR OTHERWISE HAS KNOWLEDGE OF THE
POSSIBILITY OF SUCH DAMAGES AND TAKES NO ACTION TO PREVENT OR MINIMIZE SUCH
DAMAGES. IN THE EVENT THAT REGARDLESS OF THE WARRANTY DISCLAIMERS AND HOLD
HARMLESS PROVISIONS INCLUDED ABOVE MICROHARD SYSTEMS INC. IS SOMEHOW HELD
LIABLE OR RESPONSIBLE FOR ANY DAMAGE OR INJURY, MICROHARD SYSTEMS INC.'S LIABILITY
FOR ANYDAMAGES SHALL NOT EXCEED THE PROFIT REALIZED BY MICROHARD SYSTEMS INC.
ON THE SALE OR PROVISION OF THE HARDWARE TO THE CUSTOMER.
Proprietary Rights
The Buyer hereby acknowledges that Microhard Systems Inc. has a proprietary interest and intellectual property rights in the
Hardware, Software and/or Products. The Purchaser shall not (i) remove any copyright, trade secret, trademark or other evidence
of Microhard Systems Inc.’s ownership or proprietary interest or confidentiality other proprietary notices contained on, or in, the
Hardware, Software or Products, (ii) reproduce or modify any Hardware, Software or Products or make any copies thereof, (iii)
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with this Agreement.
N2420B Operating Manual: Contents iii
n802.11bg-30 Regulatory Requirements
WARNING:
To satisfy FCC RF exposure requirements for both base and mobile a separation distance of 23 cm or more
should be maintained between the antenna of this device and persons during device operation. To ensure
compliance, operations at closer than this distance is not recommended. The antenna used for this transmitter
must not be co-located in conjunction with any other antenna or transmitter.
WARNING:
Changes or modifications not expressly approved by Microhard Systems Inc. could void the user’s authority to
operate the equipment. This device has been tested with MMCX and Reverse Polarity SMA connectors with the
antennas listed in Appendix A When integrated in OEM products, fixed antennas require installation preventing
end-users from replacing them with non-approved antennas. Antennas not listed in the tables must be tested to
comply with FCC Section 15.203 (unique antenna connectors) and Section 15.247 (emissions).
WARNING:
To ensure compliance with all non-transmitter functions the host manufacturer is responsible for ensuring
compliance with the module(s) installed and fully operational. For example, if a host was previously authorized as
an unintentional radiator under the Declaration of Conformity procedure without a transmitter certified module
and a module is added, the host manufacturer is responsible for ensuring that the after the module is installed and
operational the host continues to be compliant with the Part 15B unintentional radiator requirements. Since this
may depend on the details of how the module is integrated with the host, the grantee (the party responsible for the
module grant) shall provide guidance to the host manufacturer for compliance with the Part 15B requirements.
WARNING:
MAXIMUM EIRP
FCC Regulations allow up to 36 dBm equivalent isotropically radiated power (EIRP). Therefore, the sum
of the transmitted power (in dBm), the cabling loss and the antenna gain cannot exceed 36 dBm.
WARNING:
EQUIPMENT LABELING
The FCC and IC numbers depend on the model of the radio module. Do NOT use the Marketing Name of the product
but the Model to distinguish the Certifications Numbers. This device has been modularly approved. The
manufacturer, product name, and FCC and Industry Canada identifiers of this product must appear on the outside
label of the end-user equipment.
SAMPLE LABEL REQUIREMENT for Model: n802.11bg-30:
Contains:
FCCID: NS9NBG30 IC : 3143A-NBG30
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.
iv N2420B Operating Manual
Contents
Warranty ....................................................................................................................................................................... ii
Warranty Diclaims ........................................................................................................................................................ ii
Indemnification ............................................................................................................................................................. ii
Proprietary Rights ......................................................................................................................................................... ii
N2420B Regulatory Requirements .............................................................................................................................. iii
CONTENTS .............................................................................................................................................................. IV
2. GENERAL ........................................................................................................................................................... 1
2.0 PRODUCT OVERVIEW ........................................................................................................................................................ 1
2.1 OUTPUT POWER LEVEL ..................................................................................................................................................... 2
3. INSTALLATION ................................................................................................................................................. 4
3.0 OVERVIEW ....................................................................................................................................................................... 4
3.1 ESTIMATING THE GAIN MARGIN ....................................................................................................................................... 4
3.2 ANTENNAS AND CABLING ................................................................................................................................................. 6
3.2.1 ........................................................................................................................ Internal Cabling
............................................................................................................................................................................... 6
3.2.2 ............................................................ Installing External Cables, Antennas and Lightning Arrestors
............................................................................................................................................................................... 7
N2420B Operating Manual: Chapter2 General 1
2. General
2.0 Product Overview
The N2420B is a high-performance embedded wireless data transceiver.
Operating in the 2400 - 2483.5 MHz ISM band, this a spread-spectrum
module is capable of providing reliable wireless data transfer between
almost any type of equipment. The small-size and superior RF performance
of this module make it ideal for many applications.
While a pair of N2420B modules can link two terminal devices (“point-to-
point” operation); multiple modules can be used together to create a
network of various topologies, including “point-to-multipoint” and
“repeater” operation. Multiple independent networks can operate
concurrently, so it is possible for unrelated communications to take place in
the same or a nearby area without sacrificing privacy or reliability.
1.1 Features
Key features of the N2420B include:
transmission within a public, license-exempt band of the radio
spectrum1 – this means that it can be used without access fees
(such as those incurred by cellular airtime).
a serial I/O data port with handshaking and hardware flow
control, allowing the N2420B to interface directly to any
equipment with an asynchronous serial interface.
ease of installation and use – the N2420B module uses a
subset of standard AT style commands, very similar to those
used by traditional telephone line modems.
all units in a system are physically identical, and can be
configured as a master, repeater or slave using the AT
command set. No hardware modifications are required
128 sets of user-selectable pseudo-random hopping patterns,
intelligently designed to offer the possibility of separately
operating multiple networks while providing security,
reliability and high tolerance to interference.
encryption key with 65536 user-selectable values to maximize
security and privacy of communications.
32-bit of CRC error detection and auto re-transmit to provide
accuracy and reliability of data.
1 902-928 MHz, which is license-free within North America; may need to be factory-
configured differently for some countries.
2 N2420B Operating Manual: Chapter 2 General
TDMA (time division multiple access) support, allowing
multi-slave access in point-to-point mode.
roaming ability, allowing repeaters and slaves to re-
synchronize with a new master if the synchronization pulse
from the original master is lost.
While the typical application for the N2420B is to provide a short- to mid-
range wireless communications link between DTEs, it can be adapted to
almost any situation where an asynchronous serial interface is used and data
intercommunication is required.
2.1 Output Power Level
The Output Power Level determines at what power the N2420B transmits.
The N2420B’s sensitive receiver can operate with very low power levels, so
it is recommended that the lowest power necessary is used; using excessive
power contributes to unnecessary “RF pollution”.
Ideally, you should test the communications performance between units
starting from a low power level and working upward until the RSSI is
sufficiently high and a reliable link is established. The conditions will vary
widely between applications, the output power settings can be calculated
based on following information.
Transmitter antenna gain
Cable loss
Equivalent Isotropically Radiated Power (EIRP) requirement by FCC
Regulations
Power Setting = 36 – Antenna Gain – Cable Loss
The power setting must be no more than the above calculation value. Any
higher is a violation of FCC rules. See IMPORTANT warning below.
Table 1 Output Power
Power Setting
(dBm) Approx. Output Power
(mW)
22 160
23 200
24 250
25 320
26 400
27 500
28 630
29 800
30 1000
N2420B Operating Manual: Chapter2 General 3
4 N2420B Operating Manual: Chapter 3 Installation
3. Installation
3.0 Overview
Qualified and experienced personnel must carry out the
installation, removal or maintenance of all antenna
components.
The N2420B complies with FCC part 15 at the modular level for operation
in the license-free 2400-2483.5 MHz ISM band. This chapter provides
guidelines for installing and deploying equipment which incorporates the
N2420B module.
3.1 Estimating the Gain Margin
Successful communication between N2420B modules is dependent on three
main factors:
System Gain
Path Loss
Interference
System gain is a calculation in dB describing the performance to be
expected between a transmitter-receiver pair. The number can be calculated
based on knowledge of the equipment being deployed. The following four
factors make up a system gain calculation:
1. Transmitter power (user selectable)
2. Transmitter gain (transmitting antenna gain minus cabling loss between
the transmitting antenna and the N2420B module)
3. Receiver gain (Receiving antenna gain minus cabling loss between the
receiving antenna and the module)
4. Receiver sensitivity (Specified as -108dBm on the N2420B module)
In the following illustration, the transmitting antenna has a gain of 6 dB,
and the receiving antenna has a gain of 3 dB. The cable loss between the
module and the antenna is 2 dB on both the transmitting and receiving side.
Transmitter
30 dBm
Output Power
Receiver
Sensitivity =
-105 dBm
Cable Loss = 2 dBCable Loss = 2 dB
Antenna Gain = 6 dB Antenna Gain = 3 dB
N2420B Operating Manual:Glossary 5
Figure 1 Gain Calculation
The power level has been set to 30dBm (1W) on the transmitter, and the
receiver sensitivity for the N2420B is -108dBm.
System gain would be calculated to be:
30 - 2 + 6 + 3 - 2 + 108 = 143 dB.
Figure 2 System Deploying
When deploying your system, care must be taken to ensure the path loss
(reduction of signal strength from transmitter to receiver in dB) between
equipment does not exceed the system gain (140 dB in the above example).
It is recommended to design for a gain margin of at least 20 dB to ensure
reliable communication. Gain margin is the difference between system gain
and path loss. Referring to the same example, suppose the path loss is 100
dB, the gain margin would be 40 dB, which is more than adequate for
reliable communication.
Path loss is a very complicated calculation which mainly depends on the
terrain profile, and the height of the antennas off the ground.
The following table provides path loss numbers for varying antenna heights
and antenna separation: These numbers are real averages taken from rural
environments. They do not apply to urban, non-line-of-sight environments.
Table 2 Path Loss
Distance
(km) Base Height
(m) Mobile Height
(m) Path Loss
(dB)
5 15 2.5 116.5
5 30 2.5 110.9
8 15 2.5 124.1
8 15 5 117.7
8 15 10 105
16 15 2.5 135.3
16 15 5 128.9
16 15 10 116.2
16 30 10 109.6
16 30 5 122.4
16 30 2.5 128.8
Base Height (m)
Mobile
Heigh
t
(m)
Distance (km)
6 N2420B Operating Manual: Glossary
Once the equipment is deployed, you can verify the signal strength by
entering into Command Mode and reading Register S123. This register
provides the average signal strength in dBm. The minimum strength for
communication is roughly -108dBm. For consistent reliable
communication, you should try to deploy the equipment such that signal
strength exceeds -95dBm.
3.2 Antennas and Cabling
This section describes the recommended procedure for installing cabling
and antennas for use with the N2420B module.
3.2.1 Internal Cabling
The most common method for installing the module is to run a cable from
the module’s MCX connector to a reverse TNC bulkhead connector on the
chassis of the equipment as shown in Figure 3. This cable can be purchased
from Microhard Systems.
Figure 3 Suggested Internal Cabling
Cable losses are negligible for the short piece used within the chassis.
Additional losses up to 0.5 dB may be present in the MCX and Reverse
TNC connections.
RG316 Cable
with MCX male
connecto
r
and Reverse TNC
b
ulkhea
d
connecto
r
Reverse TNC Connecto
r
MCX female connector
n802.11BG-30
N2420B Operating Manual:Glossary 7
WARNING:
To satisfy FCC RF exposure
requirements for mobile
transmitting devices, a separation
distance of 23 cm or more should
be maintained between the
antenna of this device and
persons during device operation.
To ensure compliance, operations
at closer than this distance is not
recommended. The antenna used
for this transmitter must not be
co-located in conjunction with
any other antenna or transmitter.
WARNING:
Direct human contact with the
antenna is potentially unhealthy
when the N2420B is generating
RF energy. Always ensure that
the N2420B equipment is
powered down during
installation.
WARNING:
Never work on an antenna
system when there is lightning in
the area.
3.2.2 Installing External Cables, Antennas and Lightning
Arrestors
Never work on an antenna system when there is lightning in the area.
Direct human contact with the antenna is potentially unhealthy when the
N2420B is generating RF energy. Always ensure that the N2420B
equipment is powered down during installation. At all times a distance of
23 cm must be maintained between the antenna and any person when the
device is in operation.
Surge Arrestors
The most effective protection against lightning is to install two lightning
(surge) arrestors, one at the antenna, the other one at the interface with the
equipment. The surge arrestor grounding system should be fully
interconnected with the transmission tower and power grounding systems to
form a single, fully integrated ground circuit. Typically, both ports on surge
arrestors are N-female.
External Filter
Although the N2420B is capable of filtering out RF noise in most
environments, there are circumstances that require external filtering.
Paging towers and cellular base stations in close proximity to the N2420B
antenna can desensitize the receiver. Microhard Systems’ external cavity
filter eliminates this problem. The filter has two N-female ports and should
be connected in line at the interface to the RF equipment.
Weatherproofing
Type N and RTNC connectors are not weatherproof. All connectors should
be taped with rubber splicing tape (weatherproofing tape), and then coated
with a sealant.
Cabling
The following coax cables are recommended:
Table 3 Cable Loss
Cable Loss (dB/100ft)
LMR 195 10.7
LMR 400 3.9
LMR 600 2.5
Factors to take into consideration when choosing a cable are:
price;
bend radius limitations (the lower performance cables generally can
bend more sharply)
performance requirements; and,
distance between the equipment and the antenna.
8 N2420B Operating Manual: Glossary
WARNING:
MAXIMUM EIRP
FCC and IC Regulations allow
up to 36dBm equivalent
isotropically radiated power
(EIRP). Therefore, the sum of
the transmitted power (in dBm),
the cabling loss and the antenna
gain cannot exceed
36 dBm with respect to the
isotropic radiator.
WARNING:
The N2420B can only be used
with any antennas listed in
Appendix A.
WARNING:
Be careful with dBi vs dBd gains
on antenna specifications.
Antenna manufactures may not
clearly indicate the gain on the
antenna if it is dBd or dBi. Note
1dBd = 2.15dBi.
When installing the cable, always begin fastening at the top near the
antenna connector/surge arrestor. The cable must be supported at the top
with a hose clamp or wrap lock, and at 5 ft intervals down the length of the
tower. Over-tightening the fasteners will dent the cable and reduce
performance. If properly grounded surge arrestors are not installed at both
the top and the bottom of the cable, then the cable should be grounded to
the tower at these locations using a cable grounding kit. If the tower is non-
conductive, then a separate conductor, physically separate from the cable,
should be run down the tower.
Antenna
Before choosing an antenna, you should have some knowledge of the path
loss and the topology of the equipment. If the equipment is in a fixed
location and is to communicate with only one other unit also in a fixed
location, then a Yagi antenna is suitable. Choose a Yagi with enough gain
to ensure adequate gain margin. When deploying the Yagi, point the
antenna towards the intended target, ensuring the antenna elements are
perpendicular to the ground for vertical polarization.
In applications where there are multiple units that you must communicate
with or units, which are in motion, you may select an Omni-directional
antenna with appropriate gain.
See appendix A for a list of approved antennas that can be used with
the N2420B radio modem. If you require another type of antenna
please contact Microhard Systems Inc. The N2420B CANNOT be used
with any antenna that does not appear in Appendix A.
Microhard Systems Inc. can provide you with approved antennas to ensure
FCC and Industry Canada compliance.
FCC Regulations allow up to 36dBm effective radiated power (EIRP).
Therefore, the sum of the transmitted power (in dBm), the cabling loss
and the antenna gain cannot exceed 36dBm with respect to the isotropic
radiator.
EIRP is calculated as follows:
EIRP = Tx Power(dBm) - Cable/Connector Loss(dB) + Ant Gain(dBi)
Antenna Gains must be in dBi when calculating the 36dBm EIRP limit.
1dBd = 2.15dBi
Use the guidelines in the previous section for calculating cable and
connector losses. If cabling and connector losses are 2 dB, then the
maximum allowable gain of the antenna will be 8 dB.
N2420B Operating Manual:Glossary 9
Examples:
FCC and Industry Canada Regulations allow up to 36dBm equivalent
isotropically radiated power (EIRP). Therefore, the sum of the
transmitted power (in dBm), the cabling loss and the antenna gain
cannot exceed 36dBm with respect to the isotropic radiator.
Example 1)
What is the maximum power the N2420B can be set to comply with
FCC and IC given the following equipment given a Rubber Ducky Ant
Gain 2dBi and no cable or connectors in the system?
Max EIRP 36dBm
Max TX power = EIRP – Ant Gain(dBi) + Cable/Connector loss (dB)
Ant Gain dBi = 2dBi
Max TX power = 36dBm – 2dBi + 0dB = 34dBm
We can set the modem to the maximum power setting of 30dBm.
Example 2)
What is the maximum power the N2420B can be set to comply with
FCC and IC given the following equipment given a Yagi Ant Gain
12dBd and cable and connector loss of 4.5 dB?
Max EIRP 36dBm
Max TX power = EIRP – Ant Gain(dBi) + Cable/Connector loss (dB)
Ant Gain dBi = Ant Gain dBd + 2.15 dB
Yagi Gain (dBi) = 12 + 2.15 = 14.15dBi
Max TX power = 36dBm – 14.15dB + 4.5dB = 26.35dBm
We must round down
Hence Max TX power = 26dBm
Example 3)
What is the maximum power the N2420B can be set to comply with
FCC and IC given the following equipment given a Omni Ant Gain
6dBd and cable and connector loss of 2.5 dB?
Max EIRP 36dBm
Max TX power = EIRP – Ant Gain(dBi) + Cable/Connector loss (dB)
Ant Gain dBi = Ant Gain dBd + 2.15 dB
Omni Gain (dBi) = 6 + 2.15 = 8.15dBi
Max TX power = 36dBm – 8.15dB + 2.5dB = 30.35dBm
Hence Max TX power = 30dBm
10 N2420B Operating Manual: Glossary
A. Approved Antennas
Group Part Number Description
Rubber Ducky
MHS031100 2dBi, 2.4GHz Rubber Ducky Antenna RPTNC Swivel
MHS031110 2dBi, 2.4GHz Rubber Ducky Antenna Reverse SMA Swivel
MHS031120 2dBi, 2.4GHz Rubber Ducky Antenna Reverse SMA Straight
Patch Antennas
MHS034200 8 dBi, 2.4GHz Mini Flat Patch Directional Antenna RPTNC Pigtail
MHS034210 14 dBi, 2.4GHz Flat Patch Directional Antenna RPTNC Pigtail
Yagi Antennas
MHS034100 9 dBi, 2.4GHz Yagi Directional Antenna RPTNC Pigtail
MHS034110 12 dBi, 2.4GHz Yagi Directional Antenna RPTNC Pigtail
MHS034120 14 dBi, 2.4GHz Yagi Directional Antenna RPTNC Pigtail
MHS034150 14.5 dBi, 2.4GHz Yagi Directional Antenna RPTNC Pigtail
Omni Directional
MHS031260 5 dBi, Omni Directional Antenna RPTNC Pigtail
MHS034000 6 dBi, 2.4GHz Omni Directional Antenna RPTNC Pigtail
MHS031340 8 dBi, Omni Directional Antenna RPTNC Pigtail
MHS034020 10.5 dBi, 2.4GHz Omni Directional Antenna RPTNC Pigtail
MHS034030 12 dBi, 2.4GHz Omni Directional Antenna RPTNC Pigtail
MHS034040 15 dBi, 2.4GHz Omni Directional Antenna RPTNC Pigtail
WARNING:
Changes or modifications not expressly approved by Microhard Systems Inc. could void the user’s authority to operate
the equipment. This device has been tested with MMCX and Reverse Polarity SMA connectors with the antennas listed
in Appendix A When integrated in OEM products, fixed antennas require installation preventing end-users from
replacing them with non-approved antennas. Antennas not listed in the tables must be tested to comply with FCC
Section 15.203 (unique antenna connectors) and Section 15.247 (emissions). Please Contact Microhard Systems Inc. if
you need more information.
Industry Canada: This device has been designed to operate with the antennas listed below, and having a maximum gain
of 15 dBi. Antennas not included in this list or having a gain greater than 15 dBi are strictly prohibited for use with this
device. The required antenna impedance is 50 ohms. To reduce potential radio interference to other users, the antenna
type and its gain should be so chosen that the equivalent isotropically radiated power (EIRP) is not more than that
required for successful communication.