Campbell Scientific NL240 User Manual

INSTRUCTION MANUAL

NL240 Wireless

Copyright © 2011- 2014

Campbell Scientific, Inc.

Network Link Interface

Revision: 9/14

Limited Warranty

“Products manufactured by CSI are warranted by CSI to be free from defects in
materials and workmanship under normal use and service for twelve months
from the date of shipment unless otherwise specified in the corresponding
product manual. (Product manuals are available for review online at

www.campbellsci.com.) Products not manufactured by CSI, but that are resold

by CSI, are warranted only to the limits extended by the original manufacturer.
Batteries, fine-wire thermocouples, desiccant, and other consumables have no
warranty. CSI’s obligation under this warranty is limited to repairing or
replacing (at CSI’s option) defective Products, which shall be the sole and
exclusive remedy under this warranty. The Customer assumes all costs of
removing, reinstalling, and shipping defective Products to CSI. CSI will return
such Products by surface carrier prepaid within the continental United States of
America. To all other locations, CSI will return such Products best way CIP
(port of entry) per Incoterms ® 2010. This warranty shall not apply to any
Products which have been subjected to modification, misuse, neglect, improper
service, accidents of nature, or shipping damage. This warranty is in lieu of all
other warranties, expressed or implied. The warranty for installation services
performed by CSI such as programming to customer specifications, electrical
connections to Products manufactured by CSI, and Product specific training, is
part of CSI's product warranty. CSI EXPRESSLY DISCLAIMS AND

EXCLUDES ANY IMPLIED WARRANTIES OF MERCHANTABILITY
OR FITNESS FOR A PARTICULAR PURPOSE. CSI hereby disclaims,
to the fullest extent allowed by applicable law, any and all warranties and
conditions with respect to the Products, whether express, implied or
statutory, other than those expressly provided herein.”

Assistance

Products may not be returned without prior authorization. The following
contact information is for US and international customers residing in countries
served by Campbell Scientific, Inc. directly. Affiliate companies handle
repairs for customers within their territories. Please visit

www.campbellsci.com to determine which Campbell Scientific company serves

your country.

To obtain a Returned Materials Authorization (RMA), contact CAMPBELL
SCIENTIFIC, INC., phone [phone]. After an application engineer
determines the nature of the problem, an RMA number will be issued. Please
write this number clearly on the outside of the shipping container. Campbell
Scientific’s shipping address is:

CAMPBELL SCIENTIFIC, INC.
RMA#_____
815 West 1800 North
Logan, Utah 84321-1784

For all returns, the customer must fill out a “Statement of Product Cleanliness
and Decontamination” form and comply with the requirements specified in it.
The form is available from our web site at www.campbellsci.com/repair. A
completed form must be either emailed to [e-mail] or faxed to
[phone]. Campbell Scientific is unable to process any returns until we
receive this form. If the form is not received within three days of product
receipt or is incomplete, the product will be returned to the customer at the
customer’s expense. Campbell Scientific reserves the right to refuse service on
products that were exposed to contaminants that may cause health or safety
concerns for our employees.

Precautions

DANGER — MANY HAZARDS ARE ASSOCIATED WITH INSTALLING, USING, MAINTAINING, AND WORKING ON OR AROUND

TRIPODS, TOWERS, AND ANY ATTACHMENTS TO TRIPODS AND TOWERS SUCH AS SENSORS, CROSSARMS, ENCLOSURES,
ANTENNAS, ETC. FAILURE TO PROPERLY AND COMPLETELY ASSEMBLE, INSTALL, OPERATE, USE, AND MAINTAIN TRIPODS,

TOWERS, AND ATTACHMENTS, AND FAILURE TO HEED WARNINGS, INCREASES THE RISK OF DEATH, ACCIDENT, SERIOUS
INJURY, PROPERTY DAMAGE, AND PRODUCT FAILURE. TAKE ALL REASONABLE PRECAUTIONS TO AVOID THESE HAZARDS.
CHECK WITH YOUR ORGANIZATION'S SAFETY COORDINATOR (OR POLICY) FOR PROCEDURES AND REQUIRED PROTECTIVE
EQUIPMENT PRIOR TO PERFORMING ANY WORK.

Use tripods, towers, and attachments to tripods and towers only for purposes for which they are designed. Do not exceed design
limits. Be familiar and comply with all instructions provided in product manuals. Manuals are available at www.campbellsci.com or
by telephoning [phone] (USA). You are responsible for conformance with governing codes and regulations, including safety
regulations, and the integrity and location of structures or land to which towers, tripods, and any attachments are attached. Installation
sites should be evaluated and approved by a qualified engineer. If questions or concerns arise regarding installation, use, or
maintenance of tripods, towers, attachments, or electrical connections, consult with a licensed and qualified engineer or electrician.

General

• Prior to performing site or installation work, obtain required approvals and permits. Comply

with all governing structure-height regulations, such as those of the FAA in the USA.

• Use only qualified personnel for installation, use, and maintenance of tripods and towers, and

any attachments to tripods and towers. The use of licensed and qualified contractors is
highly recommended.

• Read all applicable instructions carefully and understand procedures thoroughly before

beginning work.

• Wear a hardhat and eye protection, and take other appropriate safety precautions while

working on or around tripods and towers.

• Do not climb tripods or towers at any time, and prohibit climbing by other persons. Take

reasonable precautions to secure tripod and tower sites from trespassers.

• Use only manufacturer recommended parts, materials, and tools.

Utility and Electrical

• You can be killed or sustain serious bodily injury if the tripod, tower, or attachments you are

installing, constructing, using, or maintaining, or a tool, stake, or anchor, come in contact
with overhead or underground utility lines.

• Maintain a distance of at least one-and-one-half times structure height, 20 feet, or the

distance required by applicable law, whichever is greater, between overhead utility lines and
the structure (tripod, tower, attachments, or tools).

• Prior to performing site or installation work, inform all utility companies and have all

underground utilities marked.

• Comply with all electrical codes. Electrical equipment and related grounding devices should

be installed by a licensed and qualified electrician.

Elevated Work and Weather

• Exercise extreme caution when performing elevated work.

• Use appropriate equipment and safety practices.

• During installation and maintenance, keep tower and tripod sites clear of un-trained or non-

essential personnel. Take precautions to prevent elevated tools and objects from dropping.

• Do not perform any work in inclement weather, including wind, rain, snow, lightning, etc.

Maintenance

• Periodically (at least yearly) check for wear and damage, including corrosion, stress cracks,

frayed cables, loose cable clamps, cable tightness, etc. and take necessary corrective actions.

• Periodically (at least yearly) check electrical ground connections.

WHILE EVERY ATTEMPT IS MADE TO EMBODY THE HIGHEST DEGREE OF SAFETY IN ALL CAMPBELL SCIENTIFIC PRODUCTS,
THE CUSTOMER ASSUMES ALL RISK FROM ANY INJURY RESULTING FROM IMPROPER INSTALLATION, USE, OR
MAINTENANCE OF TRIPODS, TOWERS, OR ATTACHMENTS TO TRIPODS AND TOWERS SUCH AS SENSORS, CROSSARMS,
ENCLOSURES, ANTENNAS, ETC.

Table of Contents

PDF viewers: These page numbers refer to the printed version of this document. Use the
PDF reader bookmarks tab for links to specific sections.

1. Introduction ................................................................. 1

2. Cautionary Statements ............................................... 1

3. Quickstart .................................................................... 1

3.1 Physical Setup ...................................................................................... 2

3.2 Configuring the NL240 ........................................................................ 2

3.3 LoggerNet Setup .................................................................................. 4

3.4 Connect ................................................................................................ 4

4. Overview ...................................................................... 5

5. Specifications ............................................................. 8

6. Wi-Fi ........................................................................... 10

6.1 Introduction to Wi-Fi for WLANs ..................................................... 10

6.2 Wireless Network Modes ................................................................... 10

6.3 RSSI ................................................................................................... 11

6.4 Antennas ............................................................................................ 12

6.5 Power ................................................................................................. 12

6.6 LEDs .................................................................................................. 12

7. Configuring the NL240 ............................................. 13

7.1 Configuring the NL240 with DevConfig via USB ............................. 13

7.2 Configuring the NL240 with DevConfig via Wi-Fi WLAN .............. 14

7.3 Configuring the NL240 with Telnet via Wi-Fi WLAN ...................... 14

7.4 Configuring the NL240 via RS-232 ................................................... 15

8. Operation ................................................................... 15

8.1 Wi-Fi Connection ............................................................................... 16

8.1.1 Join an Existing Network ............................................................ 16

8.1.2 Create an Ad hoc Network .......................................................... 16

8.2 Operational Mode .............................................................................. 17

8.2.1 PakBus® Router ......................................................................... 17

8.2.1.1 Physical Setup .................................................................. 17

8.2.1.2 Configuring the NL240 .................................................... 18

8.2.1.3 LoggerNet Setup ............................................................... 19

8.2.1.4 Connect ............................................................................ 20

8.2.2 Bridge Mode ............................................................................... 20

8.2.2.1 Physical Setup .................................................................. 20

8.2.2.2 Configuring the NL240 .................................................... 20

8.2.2.3 Configuring the Datalogger .............................................. 20

8.2.2.4 LoggerNet Setup ............................................................... 21

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Table of Contents

8.2.2.5 Connect ............................................................................ 22

8.2.3 TCP Serial Server ....................................................................... 22

8.2.3.1 Physical Setup ................................................................. 22

8.2.3.2 Configuring the NL240 ................................................... 22

8.2.3.3 LoggerNet Setup .............................................................. 23

8.2.3.4 Connect ............................................................................ 24

8.2.3.5 Serial Sensors .................................................................. 24

8.2.4 TCP Serial Client ....................................................................... 24

8.2.5 Modbus TCP/IP to RTU Gateway.............................................. 25

8.2.6 TLS ............................................................................................ 25

8.2.6.1 TLS Proxy Server ............................................................ 26

8.2.6.2 DevConfig TCP Encrypted Communication to the

NL240 .......................................................................... 28

9. Applications............................................................... 29

9.1 Working Around Firewalls ................................................................ 29

9.1.1 Configuring the NL240 .............................................................. 29

9.1.2 Configuring the Datalogger ........................................................ 30

10. Troubleshooting ........................................................ 30

11. Attribution .................................................................. 33

Appendices

Glossary ................................................................... A-1

A.

B. Cables, Pinouts, LED Function, and Jumper ....... B-1

B.1 CS I/O.............................................................................................. B-1

B.2 RS-232 ............................................................................................. B-1

B.3 USB ................................................................................................. B-2

B.4 Power............................................................................................... B-2

B.5 LEDs ............................................................................................... B-2

B.6 Power Jumper .................................................................................. B-3

C. NL240 Settings ........................................................ C-1

C.1 Main Tab ......................................................................................... C-1

C.2 Wi-Fi Tab ........................................................................................ C-4

C.3 RS-232 Tab ..................................................................................... C-8

C.4 CS I/O Tab .................................................................................... C-11

C.5 Net Services Tab ........................................................................... C-12

C.6 TLS Proxy Server Tab ................................................................... C-14

C.7 TLS Tab ........................................................................................ C-16

D. Sending a New OS to the NL240 ............................ D-1

D.1 Sending an OS via USB .................................................................. D-1

D.2 Sending an OS via Wi-Fi ................................................................. D-1

E. Radio Frequency Emission .................................... E-1

ii

Figures

Tables

Table of Contents

3-1. NL240 with CR800 (powered through CS I/O port) ............................ 2

3-2. LoggerNet setup ................................................................................... 4

4-1. NL240 .................................................................................................. 5

4-2. Bridge Mode enabled ........................................................................... 5

4-3. Bridge Mode disabled .......................................................................... 6

5-1. NL240 dimensions ............................................................................... 8

6-1. Infrastructure network ........................................................................ 11

6-2. Ad hoc network .................................................................................. 11

8-1. PakBus® router LoggerNet setup ...................................................... 19

8-2. Bridge mode LoggerNet setup ........................................................... 22

8-3. CS I/O Serial Server LoggerNet Setup ............................................... 24

8-4. TLS proxy server configurations ....................................................... 27

9-1. Working around firewalls .................................................................. 29

B-1. CS I/O Pinout ................................................................................... B-1

B-2. RS-232 Pinout .................................................................................. B-1

B-3. USB Micro-B ................................................................................... B-2

B-4. Power In ........................................................................................... B-2

B-5. Power LED (Red) ............................................................................ B-2

B-6. Wi-Fi LED (Green) .......................................................................... B-3

iii

Table of Contents

iv

NL240 Wireless Network Link Interface

1. Introduction

The NL240 is a WLAN (Wireless Local Area Network) interface that allows
Campbell Scientific dataloggers and peripherals to communicate with a Wi-Fi
network or wireless ad hoc network. This WLAN interface can be connected
to a datalogger’s CS I/O port or RS-232 port.

2. Cautionary Statements

• The first time an NL240 is attached to a datalogger and Bridge Mode is

enabled, the datalogger’s memory has to be reorganized to allow room in
memory for the IP stack. To avoid the loss of data, collect your data
before enabling Bridge Mode.

• 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. See Appendix E for
more information.

3. Quickstart

• Device Configuration Utility (DevConfig) 2.03 or higher is required to

communicate with the NL240. The latest version of DevConfig can be
downloaded from our website at www.campbellsci.com/downloads.

• The device driver for the NL240 must be installed on your computer

before you can connect to the NL240 via USB. To install the device
driver, verify you have the latest version of DevConfig (see previous
bullet). Under Device Type, select Network Peripheral | NL240. Click the
Install the device driver for the NL240 link and follow the prompts.

• CR1000, CR3000, and CR800-series dataloggers require operating system

version 25 or higher in order to operate with the NL240 in bridge mode.
(OS version 25 or higher is not required to operate as a serial server or
PakBus router.) The latest operating systems can be downloaded from our
website at www.campbellsci.com/downloads.

• Ensure maximum protection against surges. Use coaxial surge protection.

Keep RS-232 and CS I/O connections short.

• When downloading a new operating system to the NL240, do not remove

power until the red LED stops blinking.

Out of the box, the NL240 is configured for operation as a PakBus® Router.
In this mode, the NL240 can be used to communicate with Campbell Scientific
PakBus devices over a Wi-Fi network connection.

1

NL240 Wireless Network Link Interface

NOTE

3.1 Physical Setup

Attach an antenna to the NL240’s antenna connector. Using the supplied serial
cable, connect the NL240’s CS I/O port to the datalogger’s CS I/O port.
Alternatively, power the NL240 through the barrel-connector jack located on
the edge of the device. Ensure that the device is powered up by inspecting the
Power LED.

2

FIGURE 3-1. NL240 with CR800 (powered through CS I/O port)

3.2 Configuring the NL240

INSTALL THE DEVICE DRIVER BEFORE plugging the
NL240 into your PC for the first time. You will need the device
driver properly installed before you can connect to the NL240 via
USB. To install the device driver, download the latest version of
DevConfig from our website. Under Device Type, select Network
Peripheral | NL240. Click the Install the device driver for the
NL240 link and follow the prompts.

NL240 Wireless Network Link Interface

NOTE

• Ensure the NL240 is powered.

• Connect the supplied USB cable between a USB port on your computer

and the USB port on the NL240.

• Open DevConfig.

• Under Device Type, select Network Peripheral | NL240.

• Click the Browse button next to Communication Port.

• Select the virtual com port labeled NL240.

• Click OK.

• Click Connect.

• Click on the Wi-Fi tab.

• By default, the NL240 will attempt to connect to the strongest, unsecured

network available. This network will be shown in the Status field. If this
is not the network you wish to connect to, press the browse button next to
the SSID field. A dialog box showing all of the available wireless
networks will be displayed. Select the network you wish to connect to and
click OK. If this is a secured network, enter the password in the
Password field.

• Click on the NL240 tab.

• To enter a static IP address, select disable in the Use DHCP field. Then

input the IP Address, Network Mask, and Default Gateway. These
values can be provided by your network administrator.

• If a dynamic address is to be used, the network information acquired via

DHCP can be seen on the NL240 tab. (Note that if you have selected a
different network than the default network, you will need to press Apply
to save this change, then press the Connect button to reconnect to the
NL240 and view the network information.)

• Click Apply to save your changes.

It is recommended that a static IP address be given to the NL240
for most applications so that the path to the device is always
known. If using a dynamic IP address acquired via DHCP, you
may wish to configure the NL240 as a PakBus/TCP client.

3

NL240 Wireless Network Link Interface

3.3 LoggerNet Setup

The next step is to run LoggerNet and configure it to connect to the datalogger
via the NL240.

• In the LoggerNet Setup screen, press Add Root and choose IPPort. Input

the NL240 IP address and port number. The IP address and port number
are input on the same line separated by a colon. IPv6 addresses will need
to be enclosed in square brackets when specifying a port number. An
IPv4 address may look like 192.168.1.100:6785. An IPv6 address may
look like [2001:db8::1234:5678]:6785. A fully qualified host name entry
may look like yourlogger.com:6785.

• Add a PakBus® Port (PakBusPort).

• Add a PakBus® Router (pbRouter). Input the PakBus address of the

NL240. The NL240 default PakBus address is 678.

• Add the datalogger and input the PakBus® address of the datalogger.

• Press Apply to save the changes.

• You can verify that your settings are correct by selecting the datalogger in

the Network Map, selecting the Clock tab, and pressing Check Clocks. If
your settings are correct, you should see the current clock of your server
and datalogger.

4

FIGURE 3-2. LoggerNet setup

3.4 Connect

You are now ready to connect to your datalogger using the LoggerNet Connect
screen.

4. Overview

NL240 Wireless Network Link Interface

The NL240 Wireless Network Link Interface is designed for communication
with Campbell Scientific dataloggers and peripherals over a Wi-Fi network.
The Wi-Fi network can be an infrastructure network or an ad hoc (point-to­point) network. See Section 6, Wi-Fi, for more information.

The NL240 includes a CS I/O port and an RS-232 port for communication. A
USB device port is used for configuring the NL240 device.

FIGURE 4-1. NL240

Bridge Mode Enabled

The NL240 can be configured to bridge WLAN and CS I/O communications
(see FIGURE 4-2). This mode is used for providing access to the internal IP
functionality of the CR800/850, CR1000, and CR3000 (e.g., web page access,
email, FTP, etc.). Bridge mode does not use PPP. Instead, raw IP packets are
transferred between the WLAN and CS I/O connections.

FIGURE 4-2. Bridge Mode enabled

Bridge Mode Disabled

With Bridge Mode disabled (see FIGURE 4-3), the NL240 can provide
multiple services simultaneously including TCP Serial Server, TCP Serial
Client, Modbus TCP/IP Gateway, and PakBus® router. The NL240 can act as
a serial server and PakBus router simultaneously. However, each physical port

5

NL240 Wireless Network Link Interface

(R2-232 and CS I/O) is only associated with one service (PakBus router, serial
server, Modbus/TCP Gateway, etc.) at a time. For example, you can have an
RS-232 serial server and a CS I/O serial server, an RS-232 serial server and a
CS I/O PakBus router, an RS-232 PakBus router and a CS I/O serial server, or
an RS-232 PakBus router and a CS I/O PakBus router. In addition, the NL240
can act as TLS proxy server. The TLS proxy server is independent of other
modes.

6

FIGURE 4-3. Bridge Mode disabled

Some reasons you might want to use each of these modes are described below.
Refer to Section 7, Configuring the NL240, and Section 8, Operation, for
information on setting up your NL240 for each mode.

NL240 Wireless Network Link Interface

Campbell Scientific’s LoggerNet software is used to communicate with the
dataloggers once the NL240 is configured properly and connected to a
network.

Bridge Mode

• Allows access to datalogger’s internal IP functionality when a peripheral

port is not accessible. For example, accessing the HTTP/webpage, email,
and FTP capabilities of a CR800/850, ET107, RAWS, or CS110.

Serial Server

• Allows access to a CR10X over a Wi-Fi network (RS-232 serial server)

when used in conjunction with an RS-232 to CS I/O (ME) adapter like the
SC32B or SC105.

• Allows access to a serial sensor over a Wi-Fi network (RS-232 serial

server).

• Allows access to an RF500M Base over a Wi-Fi network (RS-232 serial

server).

PakBus® Router

• Allows access to a CR10X-PB over a Wi-Fi Network.

• Allows access to a CR200X over a Wi-Fi Network.

• Allows you to connect to a PakBus® Device on the RS-232 port and a

PakBus Device on the CS I/O port using only one TCP port.

• Allows a PakBus® device on the RS-232 port and a PakBus device on the

CS I/O port to communicate with each other without routing through the
WLAN.

• Allows multiple computers to concurrently talk to PakBus® devices

connected to the RS-232 and CS I/O ports.

TLS Proxy Server

• Adds an encrypted WLAN interface to a datalogger that supports CS I/O

IP (bridge mode) communications.

7

NL240 Wireless Network Link Interface

NOTE

2.65

5. Specifications

General

177 g (6.3 oz)
16 x 6.73 x 2.54 cm (6.3 x 2.65 x 1 in)

[6.73]

FIGURE 5-1. NL240 dimensions

Power

CS I/O or DC Barrel Connector (not USB)
7 to 20 Vdc

If you wish to prevent the NL240 from being powered over the CS
I/O port, you can do so by removing a jumper. See Appendix B,
Cables, Pinouts, LED Function, and Jumper, for more
information.

8

NL240 Wireless Network Link Interface

NOTE

Power Consumption

Maximum: 950 mW

Typical, Low Power Disabled
connected to Access Point: 600 mW idle, 670 mW communicating
searching for out of range network: 65 mW

Typical, Low Power Enabled
connected to Access Point: 73 mW idle, 480 mW communicating
searching for out of range network: 50 mW

Sleep: 16 mW

Standby power is when the IPNetPower instruction has been used
to turn off power to the Wi-Fi. See the CRBasic help for an
example of using the IPNetPower instruction. Note that the
IPNetPower instruction is only applicable when the NL240 is
configured with Bridge Mode Enabled

Operating Temperature

Standard: –25 to +50 °C
Extended: –55 to +85 °C

Configuration

DevConfig over USB or Wi-Fi
Telnet console over Wi-Fi
Terminal menu over RS-232

CS I/O Port

SDC 7, 8, 10, 11 (does not support ME)
9600 to 460.8 kbps

RS-232 Port

DTE
1200 bps to 115.2 kbps

WLAN

Antenna Connector: RPSMA
Supported Technologies: 802.11b/g/n, WPA, WPA2 (Personal

only)/TKIP or AES, WEP, WEP(open), APIPA/AutoIP, IPv4, IPv6,
ICMP/Ping, ICMPv6/Ping, TCP, DHCP Client, SLAAC, DNS Client,

HTTPS Proxy, Telnet Server, TLS, PakBus®, Modbus, TCP/IP
Topologies: infrastructure and ad hoc
Transmit Power: 5 to 50 mW, 7 dBm at low power level, 10 dBm at

medium power level, 16 to 17 dBm at high power level
Rx Sensitivity: –97 dBm (<8% PER)
Frequency: 2.4 to 2.5 GHz (2.4 GHz ISM band)

Miscellaneous

Supports 20 simultaneous TCP connections
Up to 10 of the 20 TCP connections can be used for TLS
PakBus® router supports 50 routes
Supports up to 15 concurrent Modbus server transactions

9

NL240 Wireless Network Link Interface

Compliance

RoHS Compliant

Complies with the limits for a Class B digital device, pursuant to part 15

of the FCC Rules.

Contains an embedded radio transmitter with the following approvals:
FCC Identifier: XF6-RS9110N1102
Industry Canada: 8407A-91101102
Europe ETSI EN 301 489-17 V1.2.1:2002
Europe ETSI EN 300 328 V1.7.1:2006

6. Wi-Fi

6.1 Introduction to Wi-Fi for WLANs

Wi-Fi is a technology that allows data transfer among electronic devices using
specific radio frequencies over a wireless local area network (WLAN). A
wireless network is like a wired network, except it uses radio waves just like
cell phones, televisions, and other radios. Over-the-air speeds vary depending
on protocol, distance, and network activity. When using the NL240, please
note that your total throughput to the datalogger will generally be governed by
the speed of serial communication.

Wi-Fi transmits at frequencies around 2.4 and 5 GHz (the NL240 only uses 2.4
GHz). The high frequency allows fast rates but reduced communication
distance. These frequencies can be used by anyone and do not require a license
from the FCC to use or transmit (unlike most UHF and VHF frequencies) as
long as certain power levels are maintained.

The NL240 supports the 802.11b, 802.11g, and 802.11n wireless network
standards.

The NL240 Wi-Fi device also supports several wireless security protocols.
These include WEP (Wired Equivalent Privacy), WPA (Wi-Fi Protected
Access)(personal) with TKIP (Temporal Key Integrity Protocol),
WPA(personal) with AES (Advanced Encryption Standard), WPA(personal)
with TKIP+AES, WPA2(Wi-Fi Protected Access II)(personal) with TKIP,
WPA2(Wi-Fi Protected Access II)(personal) with AES, and WPA2(Wi-Fi
Protected Access II)(personal) with TKIP+AES. These security protocols
allow network traffic to be encrypted and help protect data transmitted over the
Wi-Fi network.

6.2 Wireless Network Modes

The NL240 works in two types of wireless modes, infrastructure and ad hoc.
In infrastructure mode (see FIGURE 6-1, Infrastructure network), the NL240
connects to an already established wireless network (WLAN). This wireless
network is usually controlled by a single Wireless Access Point (WAP). This
WAP will typically connect the wireless network (and the NL240) to a larger
wired company or home network and/or the internet. The WAP device also
controls and routes all the traffic on the wireless network. The WAP,
furthermore, controls security for network access, the wireless frequency
(channel) to use, and has the pre-established Service Set Identifier (SSID) for
the wireless network. Infrastructure mode wireless networks are usually the

10

NL240 Wireless Network Link Interface

easiest wireless network to connect the NL240 to. (See Section 8.1, Wi-Fi
Connection, for details.) The network password/key (if required) and SSID

can be obtained from your network administrator.

FIGURE 6-1. Infrastructure network

Unlike infrastructure networks, ad hoc or peer-to-peer networks do not have a
single device (like a WAP) that controls access to the wireless network (see
FIGURE 6-2, Ad hoc network). Instead, network management and access is
decentralized. Ad hoc networks are created on the fly and all network devices
communicate directly with each other. Usually the first device on the network
(a NL240, PC, or iOS smart phone) establishes the security type, the SSID, and
the channel (frequency) that the wireless network will operate on. IP addresses
can be set statically or via AutoIP. It can take up to two minutes to find a
usable IP address using AutoIP.

6.3 RSSI

FIGURE 6-2. Ad hoc network

Once the network is established by the first wireless device, subsequent
wireless devices can connect to the ad hoc network if the correct SSID and
password (if needed) are specified in the configuration settings. Ad hoc
networks are usually small with up to five wireless devices connecting to the
wireless network. Also, ad hoc networks can only use WEP security or no
security (open). WPA security is not available in ad hoc networks.

RSSI is Received Signal Strength Indication. It is a generic radio receiver
technology metric used to determine the strength of the link between a receiver
and a transmitter. In the NL240’s case, RSSI is the measurement between the
NL240 and a wireless access point, a computer in ad hoc or another NL240 in
ad hoc. The strength of this link is recorded in dBm (power ratio in decibels)
and can be found under the Wi-Fi tab under the Settings Editor in DevConfig.

11

NL240 Wireless Network Link Interface

RSSI in the NL240 is measured in a scale between –100 dBm and 0 dBm. The
higher the number (i.e. –12 dBm as compared to –72 dBm), the better the
connection between Wi-Fi devices. A reliable connection will be maintained if
the RSSI reading in the NL240 stays between –85 dBm and –15 dBm. A
weak, and thus intermittent, connection will have readings between –85 dBm
and –95 dBm. For every 3 dBm increase, the NL240 is receiving twice as
much signal (radiated power). For every 3 dBm lost, the NL240 is receiving
50% less signal.

To improve your RSSI readings, shorten antenna cable lengths and use
frequency matched antennas with higher gain. An NL240 with a 0 db gain
antenna can achieve ranges of up to 32 meters (120 feet) indoors and 95 meters
(300 feet) outdoors. Ranges can be improved by installing higher gain
antennas on both the NL240 and/or the wireless access point. Remember that
RSSI can also be affected by weather, vegetation, terrain, interference, and
antenna cable length and type.

6.4 Antennas

Antenna selection and placement can greatly affect the strength of the signal
you transmit and receive and therefore can impact the quality of
communications with your device. The NL240 should be paired with an
antenna designed for Wi-Fi communications at 2.4 GHz (2.401 to 2.483 GHz).
Ideally the antenna will be connected directly to the NL240 or positioned in
such a way as to minimize coaxial cable length. Note that coaxial cables
attenuate signals more as frequency increases; care should be taken when
selecting the type and length of coaxial cable used with the NL240. The
NL240 antenna connector is RPSMA male. When connecting directly to the
NL240, select a coaxial cable or antenna with a mating RPSMA female
connector.

6.5 Power

6.6 LEDs

One advantage of using the NL240 in your application is its low power
consumption capabilities. With careful planning, you can reduce your station’s
power needs while still meeting your critical communication needs. See
Section 5, Specifications (Power Consumption), and Appendix C.2, Wi-Fi Tab,
for more details.

There are two LEDs on the NL240 that serve as indicators as described below.

Normal Operation

After power-up, the red LED stays solid while the NL240 is searching for and
trying to join a Wi-Fi network (or while creating an ad hoc network).

After joining the network (or failing to join the network) the red LED will
indicate the power mode of the NL240. A double strobe indicates that the
NL240 is in low-power mode. If the red LED stays solid, low-power mode is
not enabled. If the NL240 is in Bridge Mode and the datalogger executes the
IPNetPower instruction, the NL240 will power down and the red LED will
single strobe approximately every four seconds.

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After the NL240 has joined a network, the green LED will flash with network

NOTE

activity. If the NL240 is configured for DHCP, the green LED will blink once
a second while it is attempting to acquire a network address from DHCP.

Operating System Upgrade

When a new operating system is sent to the NL240, the red LED will blink
repeatedly while the NL240 copies the operating system into its internal flash.
This process takes about 10 seconds. While the LED is blinking, the NL240 is
in a vulnerable state where a removal of power will leave the NL240 without a
valid operating system. Do not remove power until the LED stops blinking.

If an operating system upgrade includes an upgrade to the internal Wi-Fi
module’s firmware, after the typical re-flashing and blinking of the red LED,
the device will power up and start copying the new firmware to the Wi-Fi
module. The red LED will also blink during this process. It will start out as a
slow blink and get faster and faster as the process nears completion. This
process can take around 1.5 minutes. Again, do not remove power until the
LED stops blinking.

7. Configuring the NL240

NL240 Wireless Network Link Interface

The NL240 is configured using DevConfig version 2.03 or greater. You can
connect your NL240 to DevConfig using either a Wi-Fi connection or USB.

7.1 Configuring the NL240 with DevConfig via USB

INSTALL the DEVICE DRIVER BEFORE plugging the NL240
into your PC for the first time. You will need the device driver
properly installed before you can connect to the NL240 via USB.
To install the device driver, download the latest version of
DevConfig from our website. Under Device Type, select Network
Peripheral | NL240. Click the Install the device driver for the
NL240 link and follow the prompts.

• Ensure the NL240 is powered.

• Connect the supplied USB cable between a USB port on your computer

and the USB port on the NL240.

• Open DevConfig.

• Under Device Type, select Network Peripheral | NL240.

• Click the Browse button next to Communication Port.

• Select the port labeled NL240.

• Click OK.

• Click Connect.

• Configure the NL240 as needed for your application.

• Click Apply to save your changes.

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