Campbell NL241 Instruction Manual

INSTRUCTION MANUAL

NL241 Wireless

Copyright © 2011- 2017

Campbell Scientific, Inc.

Network Link Interface

8/17

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) number, contact
CAMPBELL SCIENTIFIC, INC., phone [phone]. Please write the
issued RMA 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 website 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.

Safety

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. Precautions ................................................................. 1

3. QuickStart .................................................................... 2

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

3.2 Configuring the NL241 ........................................................................ 3

3.3 LoggerLink Setup ................................................................................. 4

3.4 Connect ................................................................................................ 7

4. Overview ...................................................................... 7

5. Specifications ........................................................... 11

6. Wi-Fi ........................................................................... 13

6.1 Introduction to Wi-Fi for WLANs ..................................................... 13

6.2 Wireless Network Modes ................................................................... 13

6.3 RSSI ................................................................................................... 14

6.4 Antennas ............................................................................................ 15

6.5 Power ................................................................................................. 15

6.6 LED .................................................................................................... 15

6.7 Mode Button ...................................................................................... 16

7. Configuring the NL241 ............................................. 17

7.1 Configuring the NL241 with DevConfig via USB ............................. 17

7.2 Configuring the NL241 with DevConfig via Wi-Fi WLAN .............. 18

7.3 Configuring the NL241 with Telnet via Wi-Fi WLAN ...................... 19

7.4 Configuring the NL241 via RS-232 ................................................... 19

8. Operation ................................................................... 20

8.1 Wi-Fi Connection ............................................................................... 20

8.1.1 Join an Existing Network ............................................................ 20

8.1.2 Create a Network ........................................................................ 21

8.2 Operational Mode .............................................................................. 21

8.2.1 PakBus® Router ......................................................................... 21

8.2.1.1 Physical Setup .................................................................. 22

8.2.1.2 Configuring the NL241 .................................................... 22

8.2.1.3 LoggerNet Setup ............................................................... 23

8.2.1.4 Connect ............................................................................ 24

8.2.2 Bridge Mode ............................................................................... 24

8.2.2.1 Physical Setup .................................................................. 24

8.2.2.2 Configuring the NL241 .................................................... 24

8.2.2.3 Configuring the Datalogger .............................................. 24

i

Table of Contents

8.2.2.4

LoggerNet Setup .............................................................. 25

8.2.2.5 Connect ............................................................................ 26

8.2.3 TCP Serial Server ....................................................................... 26

8.2.3.1 Physical Setup ................................................................. 26

8.2.3.2 Configuring the NL241 ................................................... 26

8.2.3.3 LoggerNet Setup .............................................................. 27

8.2.3.4 Connect ............................................................................ 28

8.2.3.5 Serial Sensors .................................................................. 28

8.2.4 TCP Serial Client ....................................................................... 28

8.2.5 Modbus TCP/IP to RTU Gateway.............................................. 29

8.2.6 TLS ............................................................................................ 29

8.2.6.1 TLS Proxy Server ............................................................ 30

8.2.6.2 DevConfig TCP Encrypted Communication to the

NL241 .......................................................................... 32

9. Applications............................................................... 33

9.1 Working Around Firewalls ................................................................ 33

9.1.1 Configuring the NL241 .............................................................. 33

9.1.2 Configuring the Datalogger ........................................................ 34

10. Troubleshooting ........................................................ 34

11. Attributions ................................................................ 37

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 LED ................................................................................................. B-2

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

C. NL241 Settings ........................................................ C-1

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

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

C.3 RS-232 Tab ..................................................................................... C-7

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 NL241 ............................ 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. NL241 with CR800 (powered through CS I/O port) ............................ 2

4-1. NL241 .................................................................................................. 8

4-2. Bridge mode enabled ........................................................................... 8

4-3. Bridge mode disabled ........................................................................... 9

5-1. NL241 dimensions ............................................................................. 11

6-1. Infrastructure network ........................................................................ 14

8-1. PakBus® router LoggerNet setup ...................................................... 23

8-2. Bridge mode LoggerNet setup ........................................................... 26

8-3. CS I/O serial server LoggerNet setup ................................................. 28

8-4. TLS proxy server configurations ....................................................... 31

9-1. Working around firewalls .................................................................. 33

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. LED .................................................................................................. B-2

iii

Table of Contents

iv

NL241 Wireless Network Link Interface

1. Introduction

The NL241 is a WLAN (wireless local area network) interface that allows
Campbell Scientific dataloggers and peripherals to communicate with a Wi-Fi
network. The NL241 can either join an existing network or create a network.
This WLAN interface can be connected to a datalogger CS I/O port or RS-232
port.

2. Precautions

• READ AND UNDERSTAND the Safety section at the front of this

manual.

• The first time an NL241 is attached to a datalogger and bridge mode is

enabled, the datalogger 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. Note that once the NL241 is attached, it
can take up to 10 seconds for the datalogger to recognize it.

• 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,
Radio Frequency Emission
installations should be performed by a professional. It is very important
that the transmit power level selected and the gain of the attached antenna
do not exceed the maximum allowed ERP permitted by local regulations.
Regulations vary by country and region. As the equipment owner, you are
responsible for making sure that your installation and maintenance of the
radio equipment ensure local regulations are met.

• Device Configuration Utility (DevConfig) 2.15 or higher is required to

communicate with the NL241. The latest version of DevConfig can be
downloaded from our website at www.campbellsci.com/downloads.

• The device driver for the NL241 must be installed on your computer

before you can connect to the NL241 via USB. To install the device driver,
verify you have the latest version of DevConfig (see previous bullet).
Under Device Type, select Network Peripheral | NL241. Click the
Install USB Driver link and follow the prompts.

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

version 25 or higher in order to operate with the NL241 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 at

www.campbellsci.com/downloads.

(p. E-1), for more information. Radio

• 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 NL241, do not remove

power until the LED stops rapidly blinking red and green.

1

NL241 Wireless Network Link Interface

3. QuickStart

Out of the box, the NL241 is configured for operation as a PakBus® router and
to create an open Wi-Fi network called “NL241_SerialNumber”. In this mode,
the NL241 can be used to communicate with Campbell Scientific PakBus
devices using a Wi-Fi-enabled device such as a smart phone. The following
instructions indicate how to use an NL241 to connect to a datalogger using a
smart phone with Campbell Scientific’s LoggerLink Mobile App.

3.1 Physical Setup

As shown in FIGURE 3-1, attach an antenna to the NL241 Antenna connector.
Using the supplied serial cable, connect the NL241 CS I/O port to the
datalogger CS I/O port. This cable supplies communications and power from
the datalogger to the NL241. Ensure that the device is powered by inspecting
the LED. The LED will be solid red when the device is connecting to or
creating a Wi-Fi network. When the LED starts flashing green, it is ready for
Wi-Fi communication.

2

FIGURE 3-1. NL241 with CR800 (powered through CS I/O port)

3.2 Configuring the NL241

NOTE

INSTALL THE DEVICE DRIVER BEFORE plugging the
NL241 into your computer for the first time. You will need the
device driver properly installed before you can connect to the
NL241 via USB. To install the device driver, download the latest
version of DevConfig from our website. Under Device Type,
select Network Peripheral | NL241. Click the Install USB
Driver link and follow the prompts.

1. Ensure the NL241 is powered.

2. Connect the supplied USB cable between a USB port on your computer

and the USB port on the NL241.

3. Open DevConfig.

4. Under Device Type, select Network Peripheral | NL241.

5. Click the Browse button next to Communication Port.

NL241 Wireless Network Link Interface

6. Select the virtual com port labeled NL241.

7. Click OK.

8. Click Connect.

9. Click the Wi-Fi tab.

10. By default, the NL241 will create an unsecured Wi-Fi network. The name

of this network will be “NL241_SerialNumber.” If you wish to change the
name of this network, type a new name in the Network Name (SSID)
field. If you wish to enable encryption, type a password in the Password
field.

11. Click the NL241 tab.

12. The default IP address of the NL241 is shown in the Status field and will

be 192.168.67.1. If you desire to change the address, select disable in the

DHCP Enabled field. Then type the IP Address, Network Mask, and
Default Gateway.

13. Click Apply to save your changes.

3

NL241 Wireless Network Link Interface

NOTE

3.3 LoggerLink Setup

The next step is to download LoggerLink and configure it to connect to the
datalogger via the NL241.

1. LoggerLink is a free app downloadable from Google Play and the Apple

App Store. Download and install the app.

2. Connect your iOS or Android device to the Wi-Fi network created by the

NL241 (“NL241_SerialNumber,” by default).

For Android users, you may get a message saying there is no
internet access and asking if you want to stay connected. Select
the Don’t ask again for this network check box and press YES.

3. In the LoggerLink Getting Started screen, press the + key to add a

datalogger.

4

NL241 Wireless Network Link Interface

4. With TCP selected, press the UDP icon next to the Address field to

automatically discover IP devices on the network.

5. Select the NL241 (address 192.168.67.1 by default).

5

NL241 Wireless Network Link Interface

NOTE

6. The following screen appears. Press the PB icon to cause LoggerLink to

search for attached PakBus devices.

For the PakBus search to work with the NL241, you must have
LoggerLink version 1.6 or later.

7. The datalogger should be discovered automatically. Select the datalogger,

and all necessary fields in the Logger Setup screen will be filled in
automatically. To enter the information by hand, manually type the IP
address of the NL241 in the Address field under TCP Settings. Leave the
Port at 6785. Select the datalogger Type. Type the PakBus address of the
datalogger (default is 1) in the Address field under PakBus Settings.
Type the NL241 PakBus address (default is 678) in the Neighbor field.
The following screen shows the correct information filled in for a CR1000
with PakBus address of 2.

6

NL241 Wireless Network Link Interface

3.4 Connect

4. Overview

8. Type a name for your datalogger in the Name field. If your datalogger has

a Security Code, TCP Password, or Encryption Key, type those in the
corresponding field.

9. Press SAVE to save the changes.

You are now ready to connect to your datalogger using LoggerLink. Select the
datalogger from the LoggerLink home screen and LoggerLink will connect to
the datalogger. From there, you can view and collect data, or manage
datalogger settings.

The NL241 Wireless Network Link Interface is designed for communication
with Campbell Scientific dataloggers and peripherals over a Wi-Fi network.

The NL241 includes a CS I/O port and an RS-232 port for communication. A
USB port is used for configuring the NL241 device.

7

NL241 Wireless Network Link Interface

FIGURE 4-1. NL241

Bridge Mode Enabled

The NL241 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 CR6, CR800/850, CR1000, and CR3000 (for example,
webpage access, email, FTP, etc.). Bridge mode does not use PPP. Instead, raw
IP packets are transferred between the WLAN and CS I/O connections.

8

FIGURE 4-2. Bridge mode enabled

Bridge Mode Disabled

With bridge mode disabled (see FIGURE 4-3), the NL241 can provide multiple
services simultaneously including TCP Serial Server, TCP Serial Client,
Modbus TCP/IP Gateway, and PakBus® router. The NL241 can act as a serial
server and PakBus router simultaneously. However, each physical port
(RS-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 NL241
can act as TLS proxy server. The TLS proxy server is independent of other
modes.

NL241 Wireless Network Link Interface

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 NL241

20)

, for information on setting up your NL241 for each mode.

(p. 17), and Section 8, Operation (p.

Campbell Scientific’s LoggerNet software is used to communicate with the
dataloggers once the NL241 is configured properly and connected to a
network.

9

NL241 Wireless Network Link Interface

Bridge Mode

• Allows access to datalogger 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.

10

5. Specifications

NOTE

General

180.35 g (6.36 oz)
16 x 7.3 x 2.54 cm (6.3 x 2.9 x 1 in)

NL241 Wireless Network Link Interface

FIGURE 5-1. NL241 dimensions

Power

CS I/O or DC Barrel Connector (not USB)
9 to 16 Vdc

If you wish to prevent the NL241 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

information.

Typical Power Consumption (@ 12Vdc)

Client Mode: 7.5 to 8 mA idle, 65 to 75 mA communicating
Access Point Mode: 67 mA idle, 70 mA communicating
Standby: less than 1.5 mA

(p. B-1), for more

11

NL241 Wireless Network Link Interface

NOTE

Standby power is when the NL241 Wi-Fi power has been turned
off. This state can be enabled by configuration of the Mode button
or by using the IPNetPower() datalogger instruction. See the
CRBasic help for an example of using the IPNetPower()
instruction. Note that the IPNetPower() instruction is only
applicable when the NL241 is configured with bridge mode
enabled. See Section
the Mode button configuration.

Operating Temperature

Standard: –40 to 70 °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

6.7, Mode Button (p. 16), for information on

RS-232 Port

DTE
1200 bps to 115.2 kbps

WLAN

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

WPA/WPA2-Enterprise Security, WEP
Client Mode: WPA/WPA2-Personal and Enterprise, WEP
Access Point Mode: WPA2-Personal
Communication Rate

• 802.11b: up to 11Mbps

• 802.11g: up to 54 Mbps

• 802.11n: up to 72 Mbps

Frequency: 2.4 GHz
Transmit Power: 7 to 18 dBm (5 to 63 mW)
Rx Sensitivity: –97 dBm

Supported Protocols

IPv4, IPv6, ICMP/Ping, ICMPv6/Ping, TCP/IP, DHCP Client, DHCP
Server (in Access Point Mode only), SLAAC, DNS Client, HTTPS Proxy,
TLS, Telnet Server, PakBus®, Modbus

Miscellaneous

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

12

Compliance

CE Compliant

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

of the FCC Rules.

6. Wi-Fi

6.1 Introduction to Wi-Fi for WLANs

NL241 Wireless Network Link Interface

Contains an embedded radio transmitter with the following approvals:
FCC Identifier: XF6-RS9113SB
Industry Canada: 8407A-RS9113SB
View the EU Declaration of Conformity at www.campbellsci.com/nl241

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 NL241, 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 NL241 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 NL241 supports the 802.11b, 802.11g, and 802.11n wireless network
standards.

The NL241 also supports several wireless security protocols. These include
WEP (Wired Equivalent Privacy), WPA (Wi-Fi Protected Access) (personal),
WPA2 (Wi-Fi Protected Access II) (personal), and WPA/WPA2-Enterprise.
These security protocols allow network traffic to be encrypted and help protect
data transmitted over the Wi-Fi network.

6.2 Wireless Network Modes

Join a Network:

The NL241 can be configured to join an already established infrastructure
wireless network (WLAN) (see FIGURE 6-1). An infrastructure wireless
network is one in which all devices or stations (STA) communicate through an
access point (AP). This AP will typically connect the wireless network (and the
NL241) to a larger wired company or home network and/or the internet. The
AP device also controls and routes all the traffic on the wireless network. Once
the NL241 has successfully joined the existing wireless network, it can
communicate with other devices on the network.

The AP, 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. The SSID (or network name) and
password/key (if required) can be obtained from your network administrator.

13

NL241 Wireless Network Link Interface

FIGURE 6-1. Infrastructure network

Create a Network:

The NL241 can be configured to create a network. In this mode, it acts as the
access point which other Wi-Fi enabled devices can join. If this configuration
is enabled, the user may set an SSID (network name) and password. If a
password is supplied, the network created will be secured by WPA2
encryption. If no password is supplied, the network created will be an open
network with no encryption.

If this mode is selected, the channel may be specified manually using the
Channel setting in the Settings Editor. If the Channel setting is left at the
default setting Auto, the device will select a channel on which to operate that
has minimal interference from other networks detected in the area. A network
created by the NL241 supports up to 8 joinees.

6.3 RSSI

DHCP Server in a Created Network

When configured to Create a Network, the device will run a DHCP server to
assign addresses to joinees of the network. The beginning address of the DHCP
server pool is the address of the device plus 100. In the case that the device
address ends in 135 or above, the beginning address of the DHCP server pool
is the address of the device minus 100. There are 20 entries in the DHCP server
pool, thus the ending address in the pool is the beginning address plus 20. By
default, the device uses a server address of 192.168.67.1. In this case, the pool
of addresses is 192.168.67.101 – 192.168.67.120. If the device address is

192.168.67.135, the pool of addresses would be 192.168.67.35 –

192.168.67.55. Any connecting devices running a DHCP client will be
assigned an address in this range. If static IP addressing is desired, assign
addresses outside of the range of the DHCP address pool (while observing the
network mask).

If an IP address is supplied in the IP Address user setting, that address will be
used as the DHCP server address. The beginning address in the DHCP server
pool will still be the address of the server plus or minus 100. The ending
address in the pool will be the beginning address plus 20.

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 case of the NL241, RSSI is the measurement between
the NL241 and a wireless access point. The strength of this link is recorded in
dBm (power ratio in decibels) and can be found on the Wi-Fi tab in the
Settings Editor of DevConfig.

14

6.4 Antennas

NL241 Wireless Network Link Interface

RSSI in the NL241 is measured in a scale between –100 dBm and 0 dBm. The
higher the number (for example, –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 NL241 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 NL241 is receiving twice
as much signal (radiated power). For every 3 dBm lost, the NL241 is receiving
50% less signal.

To improve your RSSI readings, shorten antenna cable lengths and use
frequency-matched antennas with higher gain. An NL241 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 NL241 and/or the wireless access point. Remember that RSSI can
also be affected by weather, vegetation, terrain, interference, and antenna cable
length and type.

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 NL241 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 NL241 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 NL241. The NL241
antenna connector is RPSMA male. When connecting directly to the NL241,
select a coaxial cable or antenna with a mating RPSMA female connector.

6.5 Power

6.6 LED

One advantage of using the NL241 in your application is its low power
consumption capabilities. With careful planning, you can reduce your station
power needs while still meeting your critical communication needs. See
Section 5, Specifications

C.2, Wi-Fi Tab

There is a bi-color LED on the NL241 that serves as an indicator as described
below.

Normal Operation

After power-up, the LED turns solid red while the NL241 is searching for and
trying to join a Wi-Fi network (or while creating a network).

After successfully joining or creating a network, the LED will flicker green
with network activity. Note that the LED may only blink green once every few
seconds on the created network or networks that aren’t very busy.

If the device is unsuccessful at joining or creating a network, the LED will
periodically double-strobe red. The device will attempt to connect to the
network again after approximately one minute.

(p. C-4), for more details.

(p. 11) (Typical Power Consumption), and Appendix

15

NL241 Wireless Network Link Interface

If the Wi-Fi has been disabled via the Mode button configuration, or via an
IPNetPower() instruction from the datalogger, the LED will be off. See

Section 6.7, Mode Button
configuration.

Operating System Upgrade

When a new operating system is sent to the NL241, the LED will blink
repeatedly while the NL241 copies the operating system into its internal flash
memory. This process takes about 10 seconds. While the LED is blinking, the
NL241 is in a vulnerable state where removal of power could leave the NL241
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 firmware, after the typical re-flashing and blinking of the LED, the
device will power up and start copying the new firmware to the Wi-Fi module.
The 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 up
to two minutes. Again, do not remove power until the LED stops blinking.

6.7 Mode Button

(p. 16), for information on the Mode button

The behavior of the Mode button is determined by the Mode Button
Configuration setting on the DevConfig Wi-Fi tab:

Disable Button

If this configuration is selected, pressing the button will have no effect on
the operation of the device. The Wi-Fi network will continue to work as
configured.

Temporarily Enable Wi-Fi

If this configuration is selected, the configured Wi-Fi network will
normally be disabled, and it will be activated temporarily when the button
is pressed.

Temporarily Create a Network

If this configuration is selected, the device will temporarily create a
network when the button is pressed. If the Wi-Fi Configuration is set to
Join a Network, the temporarily created network will be an open network
with the name “NL241_SerialNumber.” If the Wi-Fi Configuration is set
to Create a Network, the configured Wi-Fi network will normally be
disabled and it will be temporarily activated when the button is pressed.

Note that when the Wi-Fi Configuration is set to Create a Network, the
device behavior is the same for both button configurations.

16

Temporary Network Duration

When the Mode button is used to temporarily enable or create the Wi-Fi
network, it will stay powered for at least 5 minutes. There is a 5-minute

NL241 Wireless Network Link Interface

NOTE

timeout that is refreshed every time communications are detected. Once the
timeout has expired, the device will power off the network.

If the Mode button is pressed again while the temporary network is active, the
device will power off the network.

The following graphic illustrates the possible Wi-Fi and Mode button
configurations.

7. Configuring the NL241

The NL241 is configured using DevConfig 2.15 or greater. You can connect
your NL241 to DevConfig using either a Wi-Fi connection or USB.

7.1 Configuring the NL241 with DevConfig via USB

INSTALL the DEVICE DRIVER BEFORE plugging the NL241
into your computer for the first time. You will need the device
driver properly installed before you can connect to the NL241 via
USB. To install the device driver, download the latest version of

DevConfig from our website. Under Device Type, select Network
Peripheral | NL241. Click the Install USB Driver link and

follow the prompts.

1. Ensure the NL241 is powered.

2. Connect the supplied USB cable between a USB port on your computer

and the USB port on the NL241.

17

NL241 Wireless Network Link Interface

NOTE

3. Open DevConfig.

4. Under Device Type, select Network Peripheral | NL241.

5. Click the Browse button next to Communication Port.

6. Select the port labeled NL241.

7. Click OK.

8. Click Connect.

9. Configure the NL241 as needed for your application.

10. Click Apply to save your changes.

7.2 Configuring the NL241 with DevConfig via Wi-Fi WLAN

The NL241 is configured by default to host an open Wi-Fi network
and have an IP address of 192.168.67.1. The network name will
follow the pattern “NL241_SerialNumber.”

1. Apply power to the NL241.

2. The NL241 will power up and either create or join a Wi-Fi network. After

successfully joining or creating a network, the LED will flicker green with
network activity. Note that the LED may only blink green once every few
seconds on the created network or an idle network.

3. If the device is configured to create a network, the computer must join the

NL241-created network. If the NL241 has been previously configured to
join a network, join the same network with your computer.

4. Launch DevConfig.

5. Under Device Type, select Network Peripheral | NL241.

6. Select Use IP Connection.

7. Type the IP address of the device in the Communication Port field. (If

you do not know the address of the device and the device is connected to
your local area network, you may be able to use the browse button to the
right of Communication Port to discover the devices on the network.) The
IP address must be followed by :6786 (for example, 192.168.10.55:6786)
in order to connect the device configuration service.

8. Type NL241 in the Administrative Password box. (NL241 is the default

administrative password. It can be changed via the DevConfig
Deployment | NL241 tab.)

18

9. Click OK.

10. Click Connect.

NL241 Wireless Network Link Interface

NOTE
NOTE

11. Configure the NL241 as needed for your application.

12. Click Apply to save your changes.

7.3 Configuring the NL241 with Telnet via Wi-Fi WLAN

For security reasons, Telnet is disabled by default. It must be
enabled from the Network Services tab in DevConfig.

The NL241 must have an IP address before connecting via Telnet.
Configuration via Telnet is not available in bridge mode.

1. Ensure the NL241 is powered and connected to your network.

2. Create a telnet session with the device over port 23.

3. Type the NL241 admin password (default password is NL241).

4. Type help to see a list of the functionality available when connected to the

NL241 through Telnet.

5. Type edit and press Enter to edit the settings of the NL241.

6. As each NL241 setting is shown, press Enter to accept the current value

shown in parenthesis. Type a new value and press Enter to change the
value. The up and down arrow keys on your keyboard can also be used to
navigate through the settings.

7. After progressing through all of the NL241 settings, type save to accept

the changes or cancel to discard the changes.

8. Type bye to exit the telnet session.

7.4 Configuring the NL241 via RS-232

Accessing the configuration terminal menu via RS-232 requires
the NL241 to be power cycled, so physical access to the device
will be required. A null modem serial cable will be needed; one is
not provided with the NL241.

1. Using a null modem serial cable, connect your computer’s serial port to

the RS-232 port on the NL241.

2. Connect to the NL241 using a terminal emulator. The DevConfig

“Unknown” device type or HyperTerminal are examples of simple
terminal emulators. The default settings for this interface are 115200 baud,
8 data bits, no parity, 1 stop bit, no flow control.

3. Power cycle the NL241 and repeatedly press Enter at the terminal.

4. Type help to see a list of the functionality available when connected to the

NL241 through Telnet.

19

NL241 Wireless Network Link Interface

NOTE

5. Type edit and press Enter to edit the settings of the NL241.

6. As each NL241 setting is shown, press Enter to accept the current value

shown in parenthesis. Type a new value and press Enter to change the
value.

7. After progressing through all of the NL241 settings, type save to accept

the changes or cancel to discard the changes.

8. Disconnect your computer and power cycle the NL241.

8. Operation

This section describes how to configure the Wi-Fi connection and operational
mode of your NL241. See Section 6, Wi-Fi
the types of Wi-Fi connections available. See Section 4, Overview
in determining which operational mode to use.

8.1 Wi-Fi Connection

8.1.1 Join an Existing Network

(p. 13), for more information about

(p. 7), for help

In this configuration, the device will scan for available networks and attempt to
join the network (infrastructure or ad hoc) specified by the SSID setting.

1. Connect to the NL241 in DevConfig (see Section 7, Configuring the

NL241

2. Click the Wi-Fi tab.

3. Set Configuration to Join a Network.

4. Press the browse button next to the Network Name (SSID) field to see a

list of the available networks in the area. Select the network you wish to
connect to and click OK. If the Network Name (SSID) field is left blank,
the device will attempt to join the strongest unsecured network it finds.

5. If this is a secured network, enter the password in the Password field.

6. Click Apply to save your changes.

If for some reason the device cannot join the desired network (for
example, out of range or incorrect parameters), it will go to a low­power state and periodically retry to join the network
approximately once every minute. If the device has successfully
joined a network and then detects a loss of connectivity with the
network, it will begin periodically searching for the network at
approximately the one-minute interval.

(p. 17)).

20

8.1.2 Create a Network

NOTE

In this configuration, the device will be the creator of a network. A network
created by the module supports up to 8 joinees.

Please remember when joining a network with Windows or iOS,
it can take some time to successfully join the network.

1. Connect to the NL241 in DevConfig (see Section 7, Configuring the

NL241

2. Click the Wi-Fi tab.

3. Set Configuration to Create a Network.

4. By default, the name of the network will be “NL241_SerialNumber.” If

you wish to change the name of this network, type a new name in the
Network Name (SSID) field.

5. If you want your network to be encrypted, type the password to be used for

the network in the Password field. (See Appendix C, NL241 Settings
for details on the password requirements.)

NL241 Wireless Network Link Interface

(p. 17)).

(p. C-1),

6. Other Wi-Fi settings are available from the Settings Editor, but can often

be left at their default values. See Appendix C.2, Wi-Fi Tab
more information on these settings.

7. Click Apply to save your changes.

8.2 Operational Mode

8.2.1 PakBus® Router

When the RS-232 or CS I/O port is configured as a PakBus® router, the
NL241 can route packets to other devices in the network that it has in its
routing table. These are devices that the NL241 has learned about through
beaconing or allowed-neighbor lists.

Beacon Interval – Devices in a PakBus® network may broadcast a hello
message to other devices in order to determine neighbor devices. Neighbor
devices are devices that can be communicated with directly by the current
device without being routed through an intermediate device. A beacon in a
PakBus network helps ensure that all devices in the network are aware of other
viable devices in the network. The beacon interval determines how often a
beacon will be sent out. Set the Beacon Interval to 0 to disable beacons.

Verify Interval – This interval, in seconds, determines the rate at which the
NL241 will attempt to start a hello transaction with a neighbor if no other
communication has taken place within the interval. If Verify Interval is set to

0, the verify interval becomes 2.5 times the Beacon Interval. If both the
Beacon Interval and Verify Interval are set to 0, the verify interval becomes

300 seconds. Generally, the Verify Interval should be set greater than or equal
to the interval at which you will be talking to the attached PakBus devices. For
example, if you are using the NL241 as a PakBus router to allow scheduled

(p. C-4), for

21

NL241 Wireless Network Link Interface

collection of a network of dataloggers every 15 minutes, consider setting the

Verify Interval to 30 minutes.

Neighbors Allowed (RS-232 port only) – You can set a list of “acceptable

neighbors” which the NL241 expects to hear from within set intervals (the
verify interval). If the NL241 does not hear from neighbors in this list within
the verify interval, it will attempt to contact them on its own. It will ignore all
devices it hears that are not on the Neighbors Allowed list except if the
PakBus® address is ≥4000. Hello messages from devices with PakBus address
≥4000 are automatically accepted as neighbors.

8.2.1.1 Physical Setup

Using the supplied serial cable, connect the NL241 CS I/O port or RS-232 port
to the datalogger CS I/O or RS-232 port, respectively. The NL241 will be
powered if connected via CS I/O. Alternatively, power the NL241 through the
barrel-connector jack located on the edge of the device. Connect the NL241 to
your local wireless network by attaching an antenna to the NL241 antenna
connector. Ensure that the device is powered up by inspecting the LED.

8.2.1.2 Configuring the NL241

RS-232 PakBus® Router

• Connect to the NL241 in DevConfig (see Section 7, Configuring the

NL241

(p. 17)).

• On the NL241 tab:

o Set Bridge Mode to disable.

• On the RS-232 tab:

o Set Configuration to PakBus.

o Set Baud Rate to baud rate of attached device.

o Set Beacon Interval, Verify Interval, and PakBus Neighbors

Allowed as described above. Often, the default values can be used.
However, an allowed neighbors list can be useful in restricting
communication paths.

• On the Network Services tab:

o Make note of the PakBus/TCP Service Port. (The default

PakBus/TCP Service Port is 6785. Unless firewall issues exist, it is

not necessary to change the port from its default value.)

CS I/O PakBus® Router

22

• Connect to the NL241 in DevConfig (see Section 7, Configuring the

NL241

(p. 17)).

o Set Bridge Mode to disable.

• On the CS I/O tab:

• On the Network Services tab:

8.2.1.3 LoggerNet Setup

1. In the LoggerNet Setup Screen, click Add Root and select IPPort. Enter

2. Add a PakBus® Port (PakBusPort).

NL241 Wireless Network Link Interface

o Set Configuration to PakBus.

o Set SDC address. (Note that if multiple peripherals are connected to a

datalogger CS I/O port, each must have a unique SDC address.)

o Set Beacon Interval and Verify Interval as described above. Often,

the default values can be used.

o Make note of the PakBus/TCP Service Port. (The default

PakBus/TCP Service Port is 6785. Unless firewall issues exist, it is

not necessary to change the port from its default value.)

the NL241 IP address and port number. The IP address and port number
are input on the same line separated by a colon.

3. Add a PakBus® Router (pbRouter). Type the PakBus address of the

NL241. The NL241 default PakBus address is 678.

4. Add the datalogger and type the PakBus® address of the datalogger.

5. Press Apply to save the changes.

FIGURE 8-1. PakBus® router LoggerNet setup

23

NL241 Wireless Network Link Interface

NOTE

8.2.1.4 Connect

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

8.2.2 Bridge Mode

With bridge mode enabled, the device will act as a bridge from WLAN to CS
I/O. All IP packets that come into the device via WLAN will be communicated
as a complete Ethernet/TCP packet to the datalogger over the CS I/O port. This
enables the datalogger to use its TCP/IP stack to interpret the packet and,
therefore, all of the datalogger TCP services are available. In bridge mode, only
the Wi-Fi settings are valid. All other functionality is disabled. All settings
(that is, IP, netmask, gateway) are configured in the datalogger. However, in
bridge mode, the device will intercept any TCP traffic on the TCP
Configuration Port Number. This allows the device to still be configured
remotely by IP connection using DevConfig. The TCP Configuration Port
Number is a user setting with a default value of 6786.

8.2.2.1 Physical Setup

Attach an antenna to the NL241 antenna connector. Using the supplied serial
cable, connect the NL241 CS I/O port to the datalogger CS I/O port. Ensure
that the device is powered up by inspecting the LED.

8.2.2.2 Configuring the NL241

Connect to the NL241 in DevConfig (see Section 7, Configuring the NL241

17)

). In the NL241 tab, set Bridge Mode to enable.

In bridge mode, the IP address, subnet mask, and IP gateway to be
used by the NL241 are configured in the datalogger.

8.2.2.3 Configuring the Datalogger

1. Connect a serial cable from the computer COM port to the datalogger

RS-232 port.

2. Open DevConfig. Select the device type of the datalogger (CR800,

CR1000, or CR3000), the appropriate Communication Port, and the
Baud Rate. Click Connect to connect to the datalogger.

3. If using a static IP address, select the CS I/O IP tab and input the IP

address, subnet mask, and IP gateway for the correct CS I/O Interface. The
default for the NL241 is CS I/O IP Interface #2 (SDC1). DNS server
settings are shared by all active IP interfaces and can be entered on the
Ethernet tab. These values can be provided by your network
administrator. If using DHCP, leave the CS I/O IP address settings as

0.0.0.0. You will find the information acquired by DHCP in the info box
on the Ethernet and CS I/O IP tabs.

(p.

24

4. Press Apply to save the changes and then close DevConfig.

The NL241 must be connected to the datalogger before

NOTES

configuring the datalogger with DevConfig. If it is not connected,
the Ethernet settings will not be displayed.

By default, the NL241 uses the datalogger CS I/O Interface #2. If
connecting more than one NL241 to a datalogger, one NL241 can
be configured to use CS I/O Interface #1. This is done by
connecting to the NL241 in DevConfig, going to the Settings

Editor tab, and changing the CS I/O IP Interface Identifier from
2 to 1. If this setting is changed, the IP address, subnet mask, and

IP gateway should be input under CS I/O IP #1 on the datalogger
CS I/O IP tab. CS I/O Interface #2 communicates over SDC
address 1. CS I/O Interface #1 communicates over SDC address 3.

8.2.2.4 LoggerNet Setup

The next step is to run LoggerNet and configure it to connect to the datalogger
via the Wi-Fi port. (See example in FIGURE 8-2 below.) Note that your
LoggerNet computer must be part of the same network that the NL241 has
joined or created.

1. In the LoggerNet Setup Screen, click Add Root and select IPPort. Type

NL241 Wireless Network Link Interface

the datalogger IP address and port number. The IP address and port
number are input on the same line separated by a colon. (The datalogger
default port number is 6785. It can be changed using DevConfig. Unless
firewall issues exist, the port number does not need to be changed from its
default value.)

2. Add a PakBus® Port.

3. Add the datalogger (CR6, CR800, CR1000, or CR3000) and input the

PakBus® address of the datalogger.

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

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

25

NL241 Wireless Network Link Interface

FIGURE 8-2. Bridge mode LoggerNet setup

8.2.2.5 Connect

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

8.2.3 TCP Serial Server

The NL241 can tunnel RS-232 and CS I/O serial communications over Wi-Fi.
Any packet sent to the configured IP port will have the IP layer removed, and
the data is then directed to the serial connection.

8.2.3.1 Physical Setup

Using the supplied serial cable, connect the NL241 CS I/O port or RS-232 port
to the datalogger CS I/O or RS-232 port, respectively. The NL241 will be
powered if connected via CS I/O. Alternatively, power the NL241 through the
barrel-connector jack located on the edge of the device. Connect the NL241 to
your local wireless network by attaching an antenna to the NL241 Antenna
connector. Ensure that the device is powered up by inspecting the Power LED.

8.2.3.2 Configuring the NL241

RS-232 Serial Server

26

Connect to the NL241 in DevConfig (see Section 7, Configuring the NL241

(p. 17)).

NL241 Wireless Network Link Interface

• On the NL241 tab:

o Set Bridge Mode to disable.

• On the RS-232 tab:

o Set Configuration to TCP Serial Server.

o Set Baud Rate to baud rate of attached device.

o Make note of the Serial Service Port. (The default RS-232 Serial

Service Port is 6784. Typically, it is not necessary to change this
entry from its default.)

CS I/O Serial Server

Connect to the NL241 in DevConfig (see Section 7, Configuring the NL241

(p. 17)).

• On the NL241 tab:

o Set Bridge Mode to disable.

• On the CS I/O tab:

8.2.3.3 LoggerNet Setup

The next step is to run LoggerNet and configure it to connect to the datalogger
via the Wi-Fi port. (See example in FIGURE 8-3 below.)

1. In the LoggerNet Setup Screen, click Add Root and choose IPPort. Input

2. Add a PakBus® Port.

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

4. Press Apply to save the changes.

o Set Configuration to TCP Serial Server.

o Set SDC address. (Note that if multiple peripherals are connected to a

datalogger CS I/O port, each must have a unique SDC address.)

o Make note of the Serial Service Port. (The default CS I/O Serial

Service Port is 6783. Typically, it is not necessary to change this

entry from its default.)

the NL241 IP address and port number. The IP address and port number
are input on the same line separated by a colon.

5. You can verify your settings are correct by selecting the datalogger in the

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

27

NL241 Wireless Network Link Interface

FIGURE 8-3. CS I/O serial server LoggerNet setup

8.2.3.4 Connect

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

8.2.3.5 Serial Sensors

The NL241 configured as an RS-232 serial server as described above can be
used to communicate with a serial sensor. However, LoggerNet is not capable
of communicating with the serial sensor. You must have some other method of
communicating with the sensor.

8.2.4 TCP Serial Client

When the RS-232 port is configured as TCP Serial Client, the NL241 will
initiate and maintain a TCP socket connection to the IP address and port
number specified by the Serial Client Address and Serial Client Port
settings. Data received on the RS-232 port will be forwarded to this TCP
connection, and data received on the TCP connection will be forwarded to the
RS-232 port. This mode can be particularly useful when an RF base or serial
sensor is behind a firewall and needs to be the party responsible for initiating
the TCP socket connection to the data collection server.

28

The NL241 will attempt to open a connection with the remote server, and, if
the connection fails to open, the device will continue to retry at an interval of
60 seconds. If data arrives on the RS-232 port when no TCP connection exists,
the device will buffer the data (up to 1500 bytes) and immediately attempt to

open a connection to deliver the data. If the remote server closes the connection
due to error, the NL241 will make a best effort to save any data that was in
process and re-queue it to be sent on the next successfully-opened TCP
connection.

8.2.5 Modbus TCP/IP to RTU Gateway

The NL241 can serve as a Modbus TCP/IP to RTU Gateway. It will listen for
incoming Modbus TCP/IP connections from a Modbus TCP/IP master client.
The port number of the listening connection is specified in the RS-232 Serial
Service Port setting and is typically set to a value of 502. The NL241 will
convert incoming Modbus TCP/IP frames to Modbus RTU and forward them
to the RS-232 port. The NL241 will wait for a response from the Modbus RTU
device and forward that response back to the remote Modbus TCP/IP master
client over the established TCP connection. The Modbus RTU device is
generally a datalogger, such as a CR200(X), connected to the RS-232 port or a
datalogger located remotely over a transparent radio (for example, RF450)
connection, but can be any Modbus RTU device. When the NL241 is
connected directly to a CR800 series, CR1000, or CR3000 being polled by a
Modbus TCP/IP master client, the NL241 is most commonly configured with
bridge mode enabled instead of as a Modbus TCP/IP to RTU Gateway.

8.2.6 TLS

NL241 Wireless Network Link Interface

The NL241 supports transport layer security (TLS) for proxy functions
including HTTPS. TLS versions 1.0 and 1.1 are supported. The TLS
implementation supports symmetric algorithms AES-256, AES-128, and RC4
and RSA keys up to 4096 bits. For any TLS connection, the unit will
preferentially use AES-256, then AES-128, and finally RC4. X.509 certificates
are supported, with the exception of v3 extensions. Certificates should be PEM
(privacy-enhanced mail) format. Up to 10 certificates can be chained. 10 kB of
space is provided for certificate storage. The private key should also be in PEM
format and, if encrypted, use AES-256 or AES-128 (SHA).

The implementation of TLS in the NL241 is provided so that secure, encrypted
communications can be established between a TLS client and the NL241. With
the TLS proxy server enabled, the NL241 can act as a TLS proxy server for a
datalogger. The NL241TLS proxy server maintains a secure TLS connection
with a remote TLS client and forwards data onto a datalogger using a standard
TCP connection thus enabling communication with TLS clients. The TLS
client can be a web browser using HTTPS or another user-supplied TLS client.
This offloads from the datalogger the intensive computations that are necessary
for a TLS server to perform.

Also, with the NL241 configured for TLS, it can establish a secure TLS
configuration session with DevConfig.

In order to use TLS, the user must configure the NL241 with a user-supplied
TLS private key and TLS certificate. The key and certificate are loaded using
DevConfig.

Using DevConfig, navigate to the Settings Editor tab and then to the TLS tab.

1. Load the user-supplied, PEM-formatted TLS private key using the Set

TLS Key button. A file dialog will open. Navigate to the key file and click
Open.

29

NL241 Wireless Network Link Interface

NOTE
NOTE

2. Load the user-supplied, PEM-formatted TLS certificate using the Set TLS

Certificate button. A file dialog will open. Navigate to the certificate file

and click Open.

3. Enter the TLS Private Key Password if the TLS private key is encrypted.

Otherwise, leave the setting blank.

4. After loading the key and certificate, click the Apply button. The NL241

will reboot. Connect with DevConfig again and navigate to the Settings

Editor tab and then to the TLS tab. The TLS Status should say
Initialized.

The TLS Settings described above cannot be edited over a
standard TCP DevConfig link. The TLS Private Key, TLS
Private Key Password, and TLS Certificate can only be
edited/transmitted over a secure DevConfig link (USB or TLS).

If the status of the TLS stack is Initialized, the NL241 will
automatically negotiate a secure TLS connection with DevConfig
as long as the Use IP Connection option is selected.

8.2.6.1 TLS Proxy Server

A TLS proxy server is a device that acts as a secure intermediary for requests
from clients seeking resources from other servers. A client connects to the
proxy server, requesting some service, such as a file, connection, webpage, or
other resource, available from a different server. The proxy server evaluates the
request according to its filtering rules. For example, it may filter traffic by IP
address or protocol. If the request is validated by the filter, the proxy provides
the resource by connecting to the relevant server and requesting the service on
behalf of the client.

When the TLS proxy server function is enabled, the NL241TLS proxy server
maintains a secure TLS connection with a remote TLS client and forwards data
to a datalogger using a standard TCP connection thus enabling communication
with TLS clients. The TLS client can be a web browser using HTTPS or
another user-supplied TLS client. Any other client program that encrypts a
standard TCP connection using TLS may be used to establish a connection
with the NL241 TLS proxy server, and the NL241 will forward unencrypted
TCP data to a datalogger. In this way, a remote TLS client can establish a TLS
connection with a datalogger.

The settings found in the TLS Proxy Server and TLS tab in DevConfig are
used to configure the NL241 TLS proxy server.

Two physical configurations are possible and the required settings differ
depending on the configuration chosen. The possible configurations are shown
in FIGURE 8-4.

30

NL241 Wireless Network Link Interface

FIGURE 8-4. TLS proxy server configurations

Configuration A

In Configuration A, the NL241 decrypts TLS traffic and forwards the
unencrypted TCP traffic to the datalogger over the CS I/O port. The NL241 is
able to “learn” the IP address of the attached datalogger and will open a TCP
connection on the “learned” IP address.

Configuration B

In Configuration B, the NL241 decrypts TLS traffic and forwards the
unencrypted TCP traffic to the datalogger back out on the Wi-Fi port. The user
must specify an IP address and TCP port number for the forwarding TCP
connection.

To configure the NL241 TLS proxy server to communicate with a datalogger
attached to the CS I/O port or with a datalogger over a Wi-Fi connection, open
DevConfig and configure the following settings.

Settings Editor | TLS Proxy Server tab

• Set the TLS Proxy Server setting to enable.

• Enter the TLS Proxy Service Port. This is the TCP port number on which

the proxy server will listen for incoming connections. The TLS client also
needs to be set to communicate on this port number. When TLS
communications are received on this port number, the NL241 will decrypt
the data and attempt to open a TCP connection to the datalogger and
forward the unencrypted data. In HTTPS communications, web browsers
use port 443. The NL241 will always listen on port 443 regardless of the
value of this setting. Therefore, if HTTPS communications are desired, it
is unnecessary to configure this setting.

• Set the TLS Proxy Forward Physical Port to CS I/O Port for

Configuration A or to Wi-Fi for Configuration B.

31

NL241 Wireless Network Link Interface

• For Configuration A, leave the TLS Proxy Forward IP Address set to

0.0.0.0. For Configuration B, enter the datalogger IP address in the TLS
Proxy Forward IP Address setting. This address must be configured in

the datalogger. It must be a unique, static IP address on the same subnet as
the NL241 IP address. For example, if the NL241 IP address is

192.168.5.1 with subnet 255.255.255.0, a valid IP address for the
datalogger would be 192.168.5.2 provided there are no other devices on
the subnet with that address.

• Set the TLS Proxy Forward Port. This is the TCP port number that the

proxy server will use when it opens a TCP connection to the datalogger to
forward unencrypted data. The datalogger TCP server must be set to
communicate on this port number. The default value for the datalogger
PakBus/TCP service port is 6785, so this setting can likely be left at the
default. The datalogger listens for HTTP traffic on port 80. The NL241
will always forward TLS traffic received on port 443 (HTTPS) to port 80
(HTTP) regardless of this setting. Therefore, if HTTPS communications
are desired, it is unnecessary to configure this setting.

• It is recommended to leave the TLS Proxy Timeout set to 90 seconds,

although it can be changed if desired. This will determine how fast the
NL241 proxy server and client connections will timeout if no activity is
detected.

To configure the datalogger for Configuration A, connect to the datalogger
using DevConfig and select the CS I/O IP tab. Set the CS I/O Interface IP
Address to a static IP address. Use the datalogger CS I/O Interface that
corresponds to the NL241 CS I/O IP Interface Identifier setting. To
configure the datalogger for Configuration B, connect to the datalogger using
DevConfig and select the TCP/IP tab. Set the Ethernet Interface IP Address to
a static IP address.

For either configuration, the IP address must not be 0.0.0.0, and it must be
unique on the same subnet as the NL241 IP address. For example, if the NL241
IP address is 192.168.5.1 and subnet mask is 255.255.255.0, the datalogger
address could be set as 192.168.5.2 provided there are no other devices on the
subnet with that address. Also, set the datalogger subnet mask to match that of
the NL241.

The datalogger must be listening on the same TCP port that the NL241 is
configured to forward TCP traffic on (NL241 setting: TLS Proxy Forward
Port). The datalogger always listens on port 80 for HTTP, therefore, no TCP
port configuration is necessary for using HTTP.

8.2.6.2 DevConfig TCP Encrypted Communication to the NL241

In order to use DevConfig TCP encrypted communication with the NL241, you
will need to load your TLS private key and TLS certificate into the NL241.
This is done from the Settings Editor | TLS tab in DevConfig. Once the
private key and certificate are loaded successfully, the TLS Status field should
read Initialized.

32

To use TCP encrypted communication, select the Use IP Connection check
box in DevConfig. Input the NL241 IP address (or press the browse button to
select it from a list of NL241s connected to the network) and press Connect.

9. Applications

NOTES

9.1 Working Around Firewalls

NL241 Wireless Network Link Interface

If the status of the TLS stack is Initialized, the NL241 will
automatically negotiate a secure TLS connection with DevConfig
as long as the Use IP Connection option is selected.

Encrypted communication is required to change the TLS Private
Key and/or TLS Certificate via TCP. The private key and
certificate cannot be initialized via TCP, since the connection is
not encrypted. They must be initialized through a direct USB
connection to the NL241.

When the NL241 is in bridge mode, it cannot be configured via a
secure network connection, because in bridge mode the TLS stack
is not initialized. It can be configured via USB, RS-232, or an
unsecured network connection.

The NL241 can be used to provide a connection between LoggerNet and a
datalogger when both are behind firewalls as shown in FIGURE 9-1. The
NL241 must be on a public IP address and will act as a common meeting place
for all PakBus® communications.

FIGURE 9-1. Working around firewalls

9.1.1 Configuring the NL241

Connect to the NL241 in DevConfig (see Section 7, Configuring the NL241

(p. 17)).

• On the NL241 tab:

o Set Bridge Mode to disable.

o Set DHCP Enabled to disable.

33

NL241 Wireless Network Link Interface

NOTE

o Input the IP Address, Network Mask, and Default Gateway. These

• On the Network Services tab:

o Make note of the PakBus/TCP Service Port.

9.1.2 Configuring the Datalogger

The datalogger must first be configured for internet
communication (that is, through an NL115, an NL120, a second
NL241, or a cellular modem).

1. Connect a serial cable from the computer COM port to the datalogger RS-

232 port.

2. Open DevConfig. Select the device type of the datalogger (CR800,

CR1000, or CR3000), the appropriate Communication Port, and Baud
Rate. Press Connect to connect to the datalogger.

3. On the Network Services tab:

Under PakBus TCP Clients, input the NL241 IP address and PakBus
TCP Service Port.

values can be provided by your network administrator.

4. Press Apply to save the changes and then close DevConfig.

10. Troubleshooting

This section covers some common problems that might be encountered when
using the NL241. This is not comprehensive but should provide some insight
and ability to correct simple errors without a call to Campbell Scientific
technical support.

When your Campbell Scientific software cannot establish a link to a remote
datalogger that is connected to the NL241, do the following:

1. Check all your power connections.

• Your NL241 and any wireless access point (WAP) and/or wireless

2. Check all your cables and antenna.

• Verify that your antenna is securely attached to the NL241 and

router being used must be connected to power. Check power indicator
lights to make sure your devices are powered.

oriented in the same direction as the antenna of your WAP. The
Link/Act light on the NL241 should start blinking when it is
connected to a network. Also, the WLAN activity light on your WAP
(if it has one) should be blinking with activity as well.

34

NL241 Wireless Network Link Interface

3. Power cycle the NL241 and your WAP/hub/router/computer.

• Turn off or unplug your WAP/hub/router/computer and NL241. Wait

10 seconds and then plug them back in or turn them on. A full restart
may take 30 to 60 seconds.

4. Check the settings of the NL241.

• Make sure you have entered the correct SSID and password (if

needed) for your network.

• Make sure the NL241 is connected to the right WLAN (Wi-Fi Status

in DevConfig or show | Wi-Fi settings | Wi-Fi in a telnet session).

• Make sure the wireless network you are connecting to has a RSSI

level of greater than (>) –90dBm (in DevConfig, Settings Editor |
Wi-Fi | Wireless Networks in Area).

• Make sure the assigned NL241 IP address (DHCP or static) and the IP

address of the computer you are trying to connect from are able to
communicate with each other. (Your network administrator can help
with this.)

For example, the following addresses are able to communicate:

NL241: IP address: 192.168.0.2, Network Mask: 255.255.255.0

Computer: IP address: 192.168.0.3, Network Mask: 255.255.255.0

• If you are using DHCP to assign an IP address to the NL241, use

DevConfig to read the IP address assigned to your NL241. This is
done through a USB connection to the NL241 while the NL241 is
connected to your network (if bridge mode is not being used).

• The IP address assigned to the NL241 must be unique on your

network.

• When bridge mode is enabled, the datalogger controls how the IP

address is assigned. Make sure your datalogger is connected correctly
to the NL241 via the CS I/O port and SC12 cable.

5. Try to ping the NL241 from your computer. (From the Windows Start

Menu, choose Accessories | Command Prompt. Then type ping
xxx.xxx.xxx.xxx where xxx.xxx.xxx.xxx is the IP address of your NL241.)
If no packets are returned, this indicates that there is no network
connection to that IP address.

35

NL241 Wireless Network Link Interface

6. Make sure the IP address and port number entered in

LoggerNet/PC400/RTDAQ match the settings in the NL241.

• Note that PakBus® and serial server communications use different

7. If you are unable to communicate with the NL241 via the USB cable,

verify that you have installed the latest drivers for the NL241. These can
be downloaded from our website at www.campbellsci.com.

8. If the NL241 is configured as a CS I/O serial server, verify that any other

SDC device attached to the datalogger is using a different SDC address.
For example, if the NL241 is configured for SDC7, any other device
attached to the datalogger cannot use SDC7.

port numbers. The default port number for PakBus communications is

6785. The default port number for CS I/O serial server
communications is 6783. The default port number for RS-232 serial
sever communications is 6784. The correct port number must follow
the IP address of the NL241 in LoggerNet Setup in order for
LoggerNet to communicate through the NL241. For example, if the
NL241 is configured as a CS I/O serial server, in LoggerNet Setup,
enter the correct IP address of your NL241 followed by :6783 (for
example, 192.168.0.3:6783).

9. If communicating over a slow or intermittent connection, it may be

necessary to lower the Maximum Packet Size of the datalogger in

LoggerNet Setup and/or add Extra Response Time to the PakBus Port in
LoggerNet Setup.

10. Reset the NL241 to its default settings.

• If none of the above steps correct your communication problems, reset

the NL241 to its default settings. This can be done using the Factory
Defaults button in DevConfig or by using the Defaults command in a
telnet session with the NL241.

11. Verify you are running the latest revision of firmware (operating system).

It is possible that an issue affecting your ability to communicate via the
NL241 is resolved in the latest version. The latest firmware version and its
revision history can be found at www.campbellsci.com/downloads. There
is no charge for this download. See Appendix D, Sending a New OS to the
NL241

(p. D-1), for instructions on downloading the firmware revision to the

NL241.

12. If the above steps do not resolve the issue, please call Campbell Scientific,

for help. Before calling, it would be helpful to do the following:

• Obtain a detailed description of your network setup including TCP/IP

address, port number, PakBus® settings, and other pertinent
information regarding all of the devices in the NL241 communication
network.

36

• Save a copy of the NL241 settings (in XML format) using DevConfig.

• Save a copy of the NL241 event log. This is low-level code that can

be used by Campbell Scientific’s technical support to help

11. Attributions

NL241 Wireless Network Link Interface

troubleshoot the NL241. To obtain the event log, the NL241 must not
be in bridge mode. Telnet into the NL241 using your favorite telnet
program. Once you have logged in, type “eventlog” at the prompt.
Record the date and time that you did this. Copy and paste the output
into a text file.

• Once the eventlogs have been copied, you can type “eventlog erase”

at the prompt to clear the log. If you want to add a date to indicate
when the logs were last cleared, you can enter “eventlog erase date”
where date is a string of up to 8 characters.

After calling Campbell Scientific for help, email your network description, the
newly created text files, and the saved XML settings file to the person you are
working with.

PakBus is a registered trademark of Campbell Scientific, Inc.

lwIP

Copyright (c) 2001-2004 Swedish Institute of Computer Science.
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.

3. The name of the author may not be used to endorse or promote products
derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE AUTHOR “AS IS” AND ANY

EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.

37

NL241 Wireless Network Link Interface

38

Appendix A. Glossary

Auto-IP

A method of automatically assigning IP addresses to a device without the
use of a DHCP server.

It is used in the NL241 when DHCP is enabled but the NL241 is not able
to access a DHCP server. A local IP address is assigned in the

169.254.XXX.XXX range. This process can take up to two minutes.

Beacon Interval

Devices in a PakBus® network may broadcast a hello message to other
devices in order to determine "neighbor" devices. Neighbor devices are
devices that can be communicated with directly by the current device
without being routed through an intermediate device. A beacon in a
PakBus network helps to ensure that all devices in the network are aware
of which other devices are viable in the network.

Bridge (Bridging, Network Bridge)

In the context of this manual, bridging is the act of connecting two
network interfaces at the data link layer. The NL241 acts as a semi­transparent bridge passing, without alteration, IP packets between the Wi­Fi and CS I/O ports.

DHCP (Dynamic Host Configuration Protocol)

A TCP/IP application protocol in which IP addresses are assigned
automatically by a DHCP server. Note that an IP address obtained through
DHCP is not static but is leased for a period of time set by the network
administrator. The address may change, if the NL241 is powered down.

Hello Exchange

A communication exchange that establishes two PakBus® devices as
neighbors. A hello command packet is sent by one PakBus device (A) to
another device (B). Device (B) then sends a hello response (A). The
receipt of that packet establishes the two devices as neighbors. Only a
hello exchange can establish two devices as neighbors.

Neighbor (PakBus® Neighbor)

A device in a PakBus network that can be communicated with directly
(that is, not via a router). Every PakBus device maintains its own neighbor
list.

A-1

Appendix A. Glossary

PakBus®

Campbell Scientific’s packet-switched communications protocol. Packets

of information transmitted between PakBus devices contain user data and

administrative information (a header) that routing devices use to move the

packets to their ultimate destination. PakBus devices examine the header

information and then either remove the header (at the packet’s final

destination) or forward the packet to another PakBus device.

PakBus® Node

A device in a PakBus network. Each device in a network must have a

unique PakBus address.

Port Number

A port number is a way to identify a specific process to which a network

message is to be forwarded when it arrives at the NL241.

SDC (Synchronous Device Communications)

A Campbell Scientific addressable and synchronous communications

protocol. The protocol allows multiple peripherals to be connected to the

same device as long as each peripheral has a unique SDC address.

Serial Server

A serial server (also referred to as a terminal server) allows serial

communication over an IP communications link.

Proxy (Proxy Server)

A device that acts as an intermediary for IP communications between two

clients. In the context of this manual, the NL241 acts an intermediary

between two or more clients requiring a secure connection (TLS) and one

client requiring an unsecured connection. Communications are encrypted

and decrypted as necessary for the two clients to communicate via the

proxy.

TLS (Transport Layer Security)

An encryption protocol allowing secure client/server communications. A

keyed, message-authentication code is used for message reliability.

Verify Interval

An interval of time that a PakBus device uses to determine when it is time

send a hello message to another device to verify that they can still

communicate.

A-2

TABLE B-1. CS I/O Pinout

Pin

Datalogger (DB9 Female)

Function

Peripheral (DB9 Male)

Function

TABLE B-2. RS-232 Pinout

Datalogger (DCE, DB9 Female)

Peripheral (DTE, DB9 Male)

1

DCD

DCD 2 TXD

RXD 3 RXD

TXD 4 DTR

DTR

5

SIGNAL GND

SIGNAL GND

6

DSR

DSR 7 CTS

RTS 8 RTS

CTS 9 RING

RING

Appendix B. Cables, Pinouts, LED Function, and Jumper

B.1 CS I/O

The CS I/O cable is a 9-pin, straight-through cable with all 9 pins connected.
The supplied SC12 cable (pn 16675) is recommended. Pin configuration for the
CS I/O port is shown in TABLE B-1.

1 5 Vdc N/C

2 SIGNAL GND SIGNAL GND

3 RING RING

4 RXD TXD

5 ME ME

6 SDE SDE

7 CLK/HS CLK/HS

8 12 Vdc (output) 12 Vdc (input)

9 TXD RXD

B.2 RS-232

A DB9 female to DB9 male cable (such as Campbell Scientific pn 10873) is
used to connect the NL24 RS-232 port to the datalogger RS-232 port. The
supplied SC12 cable can also be used. A DB9 female null modem cable (such
as Campbell Scientific pn 13657) is used to connect the NL241 RS-232 port to
a computer RS-232 port. The RS-232 cable should be kept short when using
high baud rates. Pin configuration for the RS-232 port is shown in TABLE B-2.

Pin

Function

Function

B-1

Appendix B. Cables, Pinouts, LED Function, and Jumper

TABLE B-3. USB Micro-B

Pin

Function

1

VBUS (Not Used)

2

Data –

3

Data +

4

N/C

5

GND

TABLE B-4. Power In

Pin

Function

Center

9 to 16 Vdc

Sleeve

Power GND

TABLE B-5. LED

State

Description

The device is powered off or the Wi-Fi has been disabled via

After power-up: scanning nearby networks and trying to join
or create a Wi-Fi network.

After successfully joining or creating a network, the LED

If the device is unsuccessful at joining or creating a network,

one minute.

Fast red and

OS Download in progress – DO NOT DISCONNECT

B.3 USB

The USB cable is the supplied USB A to micro B style cable (Campbell
Scientific pn 27555). This is used only for device configuration. Pin
configuration for the USB port is shown in TABLE B-3.

B.4 Power

Pin configuration for the Power connector is shown in TABLE B-4.

B.5 LED

The color and light pattern of the LED indicate the state of the device as
described in TABLE B-5.

the Mode button configuration or via an IPNetPower()

Off

On red solid

Green flicker

Red double-

strobe

instruction from the datalogger. See Section

(p. 16), for information on the Mode button

Button
configuration.

will flicker green with network activity. Note that the LED
may only blink green once every few seconds on the created
network or networks that aren’t very busy.

the LED will periodically double-strobe red. The device will
attempt to connect to the network again after approximately

6.7, Mode

green blink

B-2

POWER

B.6 Power Jumper

If you wish to prevent the NL241 from being powered over the CS I/O port,
remove the two screws on the top of the NL241, remove the NL241top cover,
remove the jumper above the red LED and place it so that it is connected to
only one post. With the jumper connected to only one post, the NL241 can only
be powered from the barrel connector. With the jumper connected to both
posts, the NL241 can be powered from the CS I/O port or from the barrel
connector.

Appendix B. Cables, Pinouts, LED Function, and Jumper

B-3

Appendix B. Cables, Pinouts, LED Function, and Jumper

B-4

NOTE

Appendix C. NL241 Settings

All of the NL241 settings available from the Settings Editor in DevConfig are
described below.

C.1 Main Tab

Model (read only)

Model name.

Serial Number (read only)

Specifies the NL241 serial number assigned by the factory.

OS Version (read only)

Operating system version currently in the NL241.

Compile Date (read only)

Operating system compile date.

Bridge Mode

This setting is used to configure the device's mode of operation.

Bridge Mode Disabled

With Bridge Mode set to disable, the serial server (RS-232 or CS I/O),
PakBus®, and secure proxy server functionalities are available. Refer to
the respective device settings for the configuration of these functionalities.

Bridge Mode Enabled

With Bridge Mode set to enable, the device will act as a bridge from
Ethernet to CS I/O. All IP packets that come in to the device via Ethernet
will be communicated to a datalogger over the CS I/O port. Some
filtering is done in order to minimize the amount of traffic on the CS I/O
port, but every packet that is transmitted to the datalogger is sent intact as
a complete Ethernet/TCP packet. This enables the datalogger to use its
TCP/IP stack to interpret the packet, and, therefore, all of the datalogger
TCP services are available. In bridge mode, none of the other device
settings are valid and all other functionality is disabled. All settings (that
is, IP address, subnet mask, and default gateway) are configured in the
datalogger. However, in bridge mode, the device will intercept any TCP
traffic on the TCP configuration port number. This allows the device to
still be configured remotely by IP connection using DevConfig. The TCP

Configuration Port Number is a user setting with a default value of

6786.

When the device is configured in bridge mode, it is not possible to
open a telnet session with it.

C-1

Appendix C. NL241 Settings

CS I/O IP Interface Identifier

When the device is configured to operate in bridge mode, the datalogger will
address the device using this identifier. The datalogger can address up to two
CS I/O IP devices. The corresponding CS I/O IP Address settings in the
datalogger will control the interface. CS I/O IP Interface 1 uses SDC channel 3.
CS I/O IP Interface 2 uses SDC channel 1.

Bridge Mode Forward Code

When the device is configured for bridge mode, it forwards Ethernet packets to
the datalogger. Because the device is aware of the MAC address and IP address
being used by the datalogger, it is able to do some filtering on incoming
packets and only forward relevant packets. This decreases the amount of traffic
on the relatively bandwidth-limited CS I/O port and minimizes the amount of
Ethernet processing the datalogger needs to perform.

It may be desired to further reduce the amount of CS I/O traffic. This setting
allows the filtering by the device to be customized to some degree. The default
value of this setting is 65535 (0xFFFF hex) and will forward all packets that
have been determined to be relevant for proper datalogger IP communication.
If desired, other codes may be entered to filter out certain packet types.

A packet is forwarded to the datalogger if its corresponding bit is set in the
Bridge Mode Forward Code. It will not be forwarded if its corresponding bit
is cleared. Single bits or multiple bits may be cleared to accomplish custom
filtering. The following are example values of this code.

Forward Code Values

65535 (0xFFFF): Leave all bits set to forward all relevant packets.

65531 (0xFFFB): Clear bit 2 to forward all relevant packets except UDP

Broadcast packets. Filtering UDP broadcasts will disable the datalogger’s

ability to respond to DevConfig discovery packets but, in many cases, will

greatly reduce the total number of forwarded packets.

65279 (0xFEFF): Clear bit 8 to forward all relevant packets except IPv6

packets. Filtering these packets may be desired if the datalogger is on an

IPv6-enabled network but not required to respond to any IPv6-related

traffic.

DHCP

When DHCP (Dynamic Host Configuration Protocol) is set to enable, the
device will automatically acquire an IP address, subnet mask, and gateway
from the local DHCP server. After DHCP is enabled, the device will reboot
and it may take a few moments to acquire the IP settings. In order to see the
acquired settings, you may have to refresh by pressing F5.

C-2

Appendix C. NL241 Settings

NOTE

NOTE

NOTE

IP Address

The IP address uniquely identifies this node on an internet. If DHCP is
disabled, a static IP address must be obtained from your network administrator
for use with this device. If DHCP is enabled, the IP address obtained from the
local DHCP server will be displayed in the Status box on the Deployment |
NL241 tab. (It is recommended to configure a static IP address.)

In bridge mode, this setting is obtained from the datalogger and
cannot be edited here. It must be edited in the datalogger settings.
The setting obtained from the datalogger will be displayed in the

Status box on the Deployment | NL241 tab.

Subnet Mask

The subnet mask is used to select that portion of the IP address which identifies
the network. It is used to facilitate routing and should be obtained from the
network administrator along with the IP address. If DHCP is enabled, the
subnet mask obtained from the local DHCP server will be displayed in the
Status box on the Deployment | NL241 tab.

In bridge mode, this setting is obtained from the datalogger and
cannot be edited here. It must be edited in the datalogger settings.
The setting obtained from the datalogger will be displayed in the

Status box on the Deployment | NL241 tab.

Default Gateway

Packets being sent to an unknown network are routed via the default gateway.
This entry specifies the Internet address of the default gateway. If no default
gateway exists, set this entry to 0.0.0.0. If DHCP is enabled, the default
gateway obtained from the local DHCP server will be displayed in the Status
box on the Deployment | NL241 tab.

In bridge mode, this setting is obtained from the datalogger and
cannot be edited here. It must be edited in the datalogger settings.
The setting obtained from the datalogger will be displayed in the

Status box on the Deployment | NL241 tab.

DNS Servers

This setting specifies the addresses of up to three domain name servers that the
device can use to resolve domain names to IP addresses. Note that if DHCP is
used to resolve IP information, DNS addresses obtained via DHCP will
override this list.

IP Info

Reports the IP address, network mask, and default gateway of the network
interface. If DHCP is used, this setting will report the values configured by the
DHCP server.

C-3

Appendix C. NL241 Settings

C.2 Wi-Fi Tab

Admin Password

To help guard against unauthorized access to the NL241, it is password­protected by the admin password. This password will be required to gain
access to the NL241 via DevConfig over TCP and Telnet. If the password
setting is left blank, no password is required to access the NL241. After
settings are saved, the new password will be in effect.

TCP Configuration Port Number

The default TCP port number for configuration via TCP is 6786. This entry
makes it possible for the user to change the port number used in TCP
configuration. Typically, it is not necessary to change this entry from its default
(range 1 to 65535).

Wi-Fi Status

Status of the Wi-Fi Module.

Configuration

This setting controls whether the device is configured to join an existing
network or create a network.

Join a Network

If this mode is selected, the device will scan for available networks and

attempt to join the network specified by the SSID setting. If the SSID is

left blank, the device will attempt to join the first open network it finds. If

for some reason the device cannot join the desired SSID (that is, network

out of range or incorrect parameters), it will go to a low power state and

periodically (approximately every 1 minute) retry.

Create a Network

If this mode is selected the device will be the creator of a network. Enter

the desired name of the network in the SSID setting. A network created by

the module supports up to 8 joinees. If a password is supplied, the

network that is created will be secured by WPA2 encryption. If no

password is supplied, the network that is created will be an open network

with no encryption. If this mode is selected, the channel may be specified

manually using the Channel setting in the Settings Editor. If the

Channel setting is left at the default setting of Auto, the device will select

a channel on which to operate that has minimal interference from other

networks detected in the area

C-4

Network Name (SSID)

The Network Name (SSID) setting is the name that identifies a wireless
network (31- character maximum). The SSID differentiates one wireless
network from another, so all devices attempting to connect to the same network
must use the same SSID. If the device is configured to Join a Network, enter
the SSID of the network to join here. If no SSID is specified, the device will

Appendix C. NL241 Settings

NOTE

join the first open network it finds. If the device is configured to Create a
Network, the SSID entered here will be the SSID of the network created.

To see a list of the available networks detected in the area click on the ... button
or view the Wireless Networks in Area list.

When the Browse button is clicked or the Refresh button inside
the resulting dialog is clicked, if the device is currently connected
to a network, the connection will be temporarily interrupted. The
device will disconnect, scan for available networks, then
reconnect.

Password

If joining a WPA or WPA2 security enabled network, this is where the
password is entered. If joining a WEP security enabled network, this is where
the WEP key is entered.

If creating a network and a password is supplied, the network will be created
using WPA2 encryption. The password must be at least 8 characters. If a
password is not supplied, an open (unencrypted) network will be created.

When joining a network, the device supports 64-bit WEP and 128-bit WEP.
For 64-bit WEP, enter a 40-bit key in the form of 5 ASCII characters or 10
hexadecimal digits (0-9, A-F). For 128-bit WEP, enter a 104-bit key in the
form of 13 ASCII characters or 26 hexadecimal digits (0-9, A-F).

EAP User

If joining an Enterprise Security enabled network, enter the user name here.

EAP Password

If joining an Enterprise Security enabled network, enter the password here.

EAP Method

The EAP Method must be set to match the EAP method being used by the
Enterprise Security Network. The inner EAP Methods supported are
MSCHAPv2, MSCHAP, CHAP, and PAP.

Button Configuration

This setting controls how the device acts when the Mode button is pressed.

Disable Button

If this configuration is selected, pressing the button will have no effect on
the operation of the device. The Wi-Fi network will continue to work as
configured.

C-5

Appendix C. NL241 Settings

NOTE

Temporarily Enable Wi-Fi

If this configuration is selected, the configured Wi-Fi network will

normally be disabled and it will be activated temporarily when the button

is pressed.

Temporarily Create a Network

If this configuration is selected, the device will temporarily create a

network when the button is pressed. If the Wi-Fi Configuration is set to

Join a Network, the temporarily created network will be an open network

with the name “NL241_SerialNumber.” If the Wi-Fi Configuration is set

to Create a Network, the configured Wi-Fi network will normally be

disabled and it will be temporarily activated when the button is pressed.

Note that when the Wi-Fi Configuration is set to Create a Network, the
device behavior is the same for both button configurations.

Channel

Applicable only when the device is configured to create a network. This setting
specifies on which channel the network should be created. If Auto is selected,
the device will select a channel on which to operate that has minimal
interference from other networks detected in the area. When manually selecting
a channel, it should be noted that two Wi-Fi networks operating on the same
channel will interfere with each other and will have to compete for bandwidth.
The center frequencies of adjacent channels are 5 MHz apart and the
bandwidth of each channel is 20 MHz which means that adjacent channels
overlap. To completely avoid interference there must be a spacing of at least 5
channels between each Wi-Fi network. It is therefore recommended to use
channels 1, 6, and 11. For a list of all the wireless networks in the area and the
associated channels on which they operate, see the Settings Editor | Wi-Fi
Wireless Networks in Area box.

C-6

Tx Power Level

This fixes the Transmit Power level of the module. This value can be set as
follows: Low (7 +/– 1 dBm), Medium (10 +/– 1 dBm), High (15 +/– 2 dBm).

This setting affects the transmission power level of the NL241,
which may affect the transmission range of the device. This setting
does not affect the overall power consumption of the device.

Power Mode

This setting controls the power saving mode of the device. Regardless of the
Power Mode, the device enables the power-save mode when communications
are not active. The Power Mode determines how the device acts when
communications are ongoing.

This setting only applies when the Wi-Fi Configuration is set to Join a
Network.

Appendix C. NL241 Settings

Mode 0

If this mode is selected, the device will attempt to determine automatically
when high throughput communications are desired and temporarily
disable the Wi-Fi module's power-save mode while the high throughput
communications are ongoing. The power-save mode will be re-enabled
when the high throughput communications are finished. Use this mode for
a good balance between communication speed and low power
consumption.

Mode 1

If this mode is selected, the device will disable the Wi-Fi module's power­save mode at the first sign of any type of communications and re-enable
the power-save when communications are finished. Use this mode when
throughput is of more concern than power consumption and
communications seem too slow using Mode 0.

Mode 2

If this mode is selected, the device will leave the Wi-Fi module's power­save mode enabled at all times even during communications. This lessens
throughput a great deal but saves more power overall. Use this mode if
power consumption is of greater concern than throughput.

C.3 RS-232 Tab

WLAN Domain Name

This setting is only relevant when the Wi-Fi Configuration is set to Create a
Network. When attempting to communicate with the device, attached Wi-Fi

client devices can use the domain name specified here which will be resolved
to the device's IP address. For example, the datalogger's webpage can be
accessed by entering the domain name specified here into a web browser.

Wireless Networks in Area

This is a read-only field that lists the networks available in the area.
Information listed for each network is: SSID, RSSI / Signal Strength, Channel,
and Security. Sometimes areas are covered by multiple access points
configured with the same network name (SSID). In that case, multiple unique
access points possessing the same network name (SSID) may be listed here.

RS-232 Configuration

This setting controls which process will be associated with the RS-232 port.
The following values are defined:

TCP Serial Server

The device will listen for an incoming TCP connection from a remote
client. The port number of the listening connection is specified in the RS-
232 Service Port setting. Data received on the TCP connection will be
forwarded to the RS-232 port, and data received on the RS-232 port will
be forwarded to this TCP connection.

C-7

Appendix C. NL241 Settings

TCP Serial Client

The device will maintain a TCP client connection with a remote server.

The IP address and port number of the remote server are configured in the

settings RS-232 TCP Serial Client IP Address and RS-232 TCP Serial

Client Port. Data received on the RS-232 port will be forwarded to this

TCP connection, and data received on the TCP connection will be

forwarded to the RS-232 port. The device will attempt to open a

connection with the remote server and if the connection fails to open, the

device will continue to retry at an interval of 60 seconds. If data arrives on

the RS-232 port when no TCP connection exists, the device will buffer the

data (up to 1500 bytes) and immediately attempt to open a connection to

deliver the data. If the remote server closes the connection due to error,

the device will make a best effort to save any data that was in process and

re-queue it to be sent on the next successfully-opened TCP connection.

PakBus

This port uses the PakBus® protocol.

MODBUS/TCP gateway

The device will listen for incoming Modbus/TCP connections from a

remote client. The port number of the listening connection is specified in

the RS-232 Service Port setting. The device will convert incoming

Modbus/TCP frames to Modbus/RTU and forward them to the RS-232

port. The device will wait for a response from the Modbus/RTU device

and forward the response back to the remote Modbus/TCP client over the

established TCP connection.

Disabled

This port will not be used.

RS-232 Service Port

This setting is used when the RS-232 Configuration is set to Serial Server or
MODBUS/TCP gateway. To communicate with a TCP/IP server, the client

application must open a socket to that server. The socket of a specific server is
uniquely identified by an IP address of the host where the server is running and
a port number associated with the server application on that host. This entry is
where the port number of the server is set. Ensure that the client application is
set to use the same port number as configured here. Most MODBUS/TCP
applications use port 502 (range 1 to 65535).

RS-232 Baud Rate

C-8

This setting specifies the baud rate of the RS-232 port. The connected device
must be set to communicate at the same baud rate.

RS-232 RTS

The NL241 asserts the RTS and DTR lines when doing RS-232
communications. This setting allows the user to disable the RTS line if needed
so that it will not be asserted. Some hardware will not function if the RTS line

Appendix C. NL241 Settings

is asserted, but typically it is not necessary to change this setting from its
default (enable).

RS-232 TCP Timeout

This setting will determine how fast the device will time out on the open TCP
connection. For Serial Server and MODBUS/TCP gateway configurations,
the device will close the TCP connection if no activity is detected for the
timeout period. For the TCP Client configuration, the device will close the
TCP client connection if no activity is detected and then immediately open
another connection with the remote server. This behavior helps to ensure that
the connection is functional as the device does not know the frequency or
nature of the expected data. Set to 0 for no timeout (not recommended) (range
0 to 999 seconds).

RS-232 Always On

This setting controls whether the device is allowed to shut down the RS-232
port when it is not in use in order to conserve power. Typically, it is not
necessary to change this setting from its default (Auto).

Auto

Based on the RS-232 port configuration, the device will decide which of
the following two modes is more likely to be desired and will operate in
the according manner. If the port is configured to TCP Serial Client, the
device will choose RS-232 Always On. Otherwise, the device will choose
Power Down Port When Inactive, and it will allow the RS-232 port to
power down when not in use in order to conserve power.

Always On

The device will not power down the RS-232 port. The port will remain
active always. As a result, the processor cannot enter its lowest power
state. Keeping the port Always On may be necessary because when the
RS-232 port is powered down, there is a wake-up latency and the first few
bytes that come in on the port will be missed. If this behavior is
unacceptable, set this setting to Always On to keep the RS-232 port
always on.

Power Down Port when Inactive

The device will power down RS-232 when the port is inactive. If the
device is configured for Serial Server mode, the inactivity timeout is 40
seconds. If configured for PakBus, the device can use the PakBus
protocol’s link-state to do a more intelligent and effective inactivity
timeout. If communications are received on the port after it has been
powered down, there is a wake-up latency and the first few bytes will be
missed. PakBus has a built-in mechanism to deal with this, but if the
device is not configured for PakBus communications, the user must
decide if the application can accept this behavior. If this behavior is
unacceptable, set this setting to Always On. The power savings that the
device is able to achieve by powering down the RS-232 port are
significant as the processor is also able to go to a deeper sleep mode. In an
idle state with Low Power Mode enabled, an additional ~0.12W savings

C-9

Appendix C. NL241 Settings

are observed by setting RS-232 Always On to Power Down Port when

Inactive.

RS-232 PakBus Beacon Interval

This setting, in units of seconds, governs the rate at which the NL241 will
broadcast PakBus® messages on the RS-232 port in order to discover any new
PakBus neighboring nodes. It will also govern the default verification interval
if the value of the RS -232 PakBus Verify Interval setting for the associated
port is 0.

RS-232 PakBus Verify Interval

This setting specifies the interval, in units of seconds, that will be reported as
the link verification interval in the PakBus® hello-transaction messages. It will
indirectly govern the rate at which the NL241 will attempt to start a hello
transaction with a neighbor if no other communication has taken place within
the interval.

Neighbors Allowed RS-232

This setting specifies the explicit list of PakBus node addresses that the NL241
will accept as neighbors on the RS-232 port. If the list is empty (the default
value), any node will be accepted as a neighbor. This setting will not affect the
acceptance of a neighbor if that neighbor's address is greater than 3999. The
formal syntax for this setting follows:

neighbor : = { "(" range-begin "," range-end ")" }.
range-begin : = pakbus-address. ;
range-end : = pakbus-address.
pakbus-address : = number. ; 0 < number < 4000

Example: (129,129) (1084,1084)

In the example above, nodes 129 and 1084 are assigned as neighbors to the
NL241.

RS-232 Modbus Timeout

This setting determines how long, in milliseconds, the MODBUS/TCP to
MODBUS/RTU gateway will wait for an answer from the MODBUS slave
device(s) attached to the RS-232 port. If no answer is received within the
timeout period, the MODBUS/TCP server will reply to the MODBUS/TCP
client with error code 0x0B (Target Device Failed to Respond).

RS-232 TCP Serial Client IP Address

This setting specifies the IP address of the outgoing TCP Serial Client
connection that the device should maintain. If the connection fails, the device
will retry until the connection succeeds. No entry specifies that no client
connection will be made.

C-10

C.4 CS I/O Tab

Appendix C. NL241 Settings

RS-232 TCP Serial Client Port

This setting specifies the TCP port of the outgoing TCP Serial Client
connection (range 1 to 65535).

CS I/O Configuration

This setting controls which process will be associated with the CS I/O port.
The following values are defined:

TCP Serial Server

The device will listen for an incoming TCP connection from a remote
client. The port number of the listening connection is specified in the CS
I/O Service Port setting. Data received on the TCP connection will be
forwarded to the CS I/O port, and data received on the CS I/O port will be
forwarded to this TCP connection.

PakBus

This port uses the PakBus® protocol.

Modbus/TCP gateway

The device will listen for incoming MODBUS/TCP connections from a
remote client. The port number of the listening connection is specified in
the CS I/O Service Port setting. The device will convert incoming
MODBUS/TCP frames to MODBUS/RTU and forward them to the CS
I/O port. The device will wait for a response from the MODBUS/RTU
device and forward the response back to the remote MODBUS/TCP client
over the established TCP connection.

Disabled

This port will not be used.

CS I/O Service Port

This setting is used when the CS I/O Configuration is set to Serial Server or
MODBUS/TCP gateway. To communicate with a TCP/IP server, the client

application must open a socket to that server. The socket of a specific server is
uniquely identified by an IP address of the host where the server is running and
a port number associated with the server application on that host. This entry is
where the port number of the serial server is set. Typically, it is not necessary
to change this entry from its default (range 1 to 65535).

SDC Address

Communication with the datalogger via the CS I/O port is done using SDC
(Synchronous Device Communication). The datalogger will address the
devices with which it wishes to communicate using an SDC address. The CS
I/O port can be configured to respond to SDC address 7, 8, 10, or 11.

C-11

Appendix C. NL241 Settings

CS I/O TCP Timeout

This setting, in units of seconds, will determine how fast the CS I/O serial
server will time out if no activity is detected. Set to 0 for no time-out (not
recommended) (range 0 to 999).

CS I/O PakBus Beacon Interval

This setting, in units of seconds, governs the rate at which the NL241 will
broadcast PakBus® messages on the CS I/O port in order to discover any new
PakBus neighboring nodes. It will also govern the default verification interval
if the value of the CS I/O Verify Interval setting is set to 0.

CS I/O PakBus Verify Interval

This setting specifies the interval, in units of seconds, that will be reported as
the link verification interval in the PakBus® hello-transaction messages. It will
indirectly govern the rate at which the NL241 will attempt to start a hello
transaction with a neighbor if no other communication has taken place within
the interval.

CS I/O Modbus Timeout

This setting determines how long, in milliseconds, the MODBUS/TCP to
MODBUS/RTU gateway will wait for an answer from the MODBUS slave
device(s) attached to the CS I/O port. If no answer is received within the
timeout period, the MODBUS/TCP server will reply to the MODBUS/TCP
client with error code 0x0B (Target Device Failed to Respond).

C.5 Net Services Tab

Telnet

Enables/Disables the telnet service.

Telnet Port Number

The default TCP port number for the configuration monitor telnet session is 23.
This entry makes it possible for the user to change the telnet session port
number if desired. Typically, it is not necessary to change this entry from its
default (range 1 to 65535).

Telnet Timeout

This setting, in units of seconds, will determine how fast the configuration
monitor telnet session will time out if no activity is detected. Set to 0 for no
time-out (not recommended) (range 0 to 999).

C-12

Ping (ICMP)

The NL241 will not respond to Ping requests if this setting is disabled.

Appendix C. NL241 Settings

PakBus Address

This setting specifies the PakBus® address for this device. The value for this
setting must be chosen such that the address of the device will be unique in the
datalogger network. Duplication of PakBus addresses in two or more devices
can lead to failures and unpredictable behavior in the PakBus network. When a
device has a neighbor list or neighbor filter setting filled in for a port, any
device that has an address greater than or equal to 4000 will be allowed to
connect to that device regardless of the neighbor filter.

PakBus/TCP Service Port

This setting specifies the TCP service port for PakBus® communications with
the datalogger. Unless firewall issues exist, this setting probably does not need
to be changed from its default value.

PakBus/TCP Password

Specifies the password that will be used to authenticate any incoming (server)
or outgoing (client) PakBus/TCP sessions. This password is used by the server
to generate a challenge to any client that connects to the PakBus/TCP service
port. If the client fails to respond appropriately, the connection will be
terminated. If this password is blank (the default value), no authentication will
take place.

PakBus/TCP Client Address (1-4)

This setting specifies the IP address of an outgoing PakBus®/TCP client
connection that the NL241 should maintain. If the connection fails, the NL241
will retry that connection periodically until a connection is made. No entry or a
setting of 0.0.0.0 specifies that no client connection will be made.

PakBus/TCP Client Port (1-4)

This setting specifies the TCP port of the outgoing PakBus®/TCP client
connection. Typically, it is not necessary to change this entry from its default
(range 1 to 65535).

PakBus Routes (read only)

This setting lists the routes that are known to the NL241. Each route known to
the NL241 will be represented by the following four components separated by
commas and enclosed in parentheses. The description of each component
follows:

Port Number

Specifies a numeric code for the port that the router will use. It will
correspond with one of the following:

0 CS I/O

1 RS-232

100 PakBus/TCP Connection — If the value of the port number is

100 or greater, the connection is made through PakBus/TCP.

C-13

Appendix C. NL241 Settings

NOTE

Via Neighbor Address

Specifies the address of the neighbor/router that will be used to send

messages for this route. If the route is for a neighbor, this value will be the

same as the address.

PakBus Address

Specifies the address that the route will reach.

Response Time

Specifies the amount of time, in milliseconds, that will be allowed for the

route.

Central Routers

This setting specifies a list of up to eight PakBus® addresses for routers that
are able to work as central routers. By specifying a non-empty list for this
setting, the device will be configured as a branch router meaning that it will not
be required to keep track of neighbors of any routers except those in its own
branch. Configured in this fashion, the device will ignore any neighbor lists
received from addresses in the central routers setting and will forward any
messages that it receives to the nearest default router, if it does not have the
destination address for those messages in its routing table.

C.6 TLS Proxy Server Tab

TLS Proxy Server

Enable/disable the TLS Proxy Server. When doing TLS proxy communications,
the device’s TLS server maintains a secure TLS connection with a remote TLS
client and forwards information onto a datalogger using a standard TCP
connection. TCP ports and physical connections are configured below.

If the TLS Proxy Server is enabled and a datalogger is connected
to the CS I/O port, the datalogger will load its TCP stack in case
it is required to do TCP communications. Running the TCP stack
causes the datalogger to use more memory, leaving less for final
storage, etc. So, if TCP/TLS server capability is not required, the
TLS Proxy Server should be left disabled.

TLS Proxy Service Port

When doing TLS Proxy communications, the NL241 TLS server maintains a
secure connection with a remote client. If the TLS Proxy Forward Physical
Port is set to CS I/O Port, the NL241 will open a TCP connection with the
datalogger over the CS I/O port and do unencrypted data transfer with the
datalogger. If the TLS Proxy Forward Physical Port is set to Wi-Fi, the
NL241 will open the TCP connection over Wi-Fi on the TLS Proxy Forward
IP Address.

C-14

In order to communicate with the NL241 TLS server, the client application
must open a socket to that server. The socket of the NL241 TLS server is

Appendix C. NL241 Settings

uniquely identified by the IP address and a port number. This entry is where
the port number of the NL241 TLS server is set.

The TLS client needs to be set to communicate on this port number. If secure
communications come in on the TLS Proxy Service Port, the NL241 will
attempt to open a TCP connection to the datalogger on the TLS Proxy
Forward Port. Also, regardless of this setting, the NL241 Secure Proxy Server
will always listen on the secure HTTP (HTTPS) port number 443. If a secure
connection is established on this port, the NL241 will attempt to communicate
to the datalogger on the HTTP port 80 (range 1 to 65535).

TLS Proxy Forward Physical Port

When doing TLS Proxy communications, the NL241 TLS server maintains a
secure connection with a remote client. If the TLS Proxy Forward Physical
Port is specified to be the CS I/O Port, the NL241 will open a TCP
connection with the datalogger over the CS I/O port and do unencrypted data
transfer with the datalogger. If the TLS Proxy Forward Physical Port is
specified to be Wi-Fi, the NL241 will open the TCP connection over Wi-Fi on
the TLS Proxy Forward IP Address.

TLS Proxy Forward IP Address

Secure communications received on the NL241 TLS server will be forwarded
on a non-secure TCP connection to this IP address. If the TLS Proxy Forward
Physical Port is specified to be the CS I/O Port, this setting does not need to
be set by the user since the NL241 will obtain the IP address of the datalogger
automatically. The datalogger must be configured with a static IP address that is
unique and that exists on the same subnet as the NL241's IP address. If the TLS
Proxy Forward Physical Port is specified to be Wi-Fi, the forward IP address
must be specified. Enter the IP address of the destination datalogger here.

TLS Proxy Forward Port

When doing TLS Proxy communications, the NL241 TLS server maintains a
secure connection with a remote client. If the TLS Proxy Forward Physical
Port is specified to be the CS I/O Port, the NL241 will open a TCP
connection with the datalogger over the CS I/O port and do unencrypted data
transfer with the datalogger. If the TLS Proxy Forward Physical Port is
specified to be Wi-Fi, the NL241 will open the TCP connection over Wi-Fi on
the TLS Proxy Forward IP Address.

In order to communicate with the connected datalogger’s TCP server, the
NL241’s TCP client application must open a socket to that server. The socket
of the datalogger’s TCP server is uniquely identified by an IP address and a
port number. This entry is where the port number of the NL241’s TCP client is
set. The datalogger TCP service port must be set to communicate on this port
number.

If secure communications come in on the TLS Proxy Service Port, the NL241
will attempt to open a TCP connection to the datalogger on the TLS Proxy
Forward Port. Also, regardless of this setting, the NL241 TLS Proxy Server
will always listen on the secure HTTP (HTTPS) port number 443. If a secure
connection is established on this port, the NL241 will attempt to communicate
to the datalogger on the HTTP port 80.

C-15

Appendix C. NL241 Settings

NOTE

NOTE

NOTE

NOTE

C.7 TLS Tab

Leave this setting at its default unless the datalogger is expecting
communications on a different port (range 1 to 65535).

TLS Proxy Timeout

This setting, in units of seconds, will determine how fast the proxy server/client
sessions will time out if no activity is detected. Set to 0 for no time-out (not
recommended) (range 0 to 999).

TLS Status (read only)

Specifies the current status of the TLS network stack.

If the status of the TLS stack is Initialized, the device will
automatically negotiate a secure TLS connection with DevConfig
if the Use TCP option is selected. The TLS Private Key, Private
Key Password, and TLS Certificate can only be
edited/transmitted over a secure DevConfig link (USB or TLS).
These settings cannot be edited over a standard TCP DevConfig
link.

TLS Private Key Password

Specifies the password that is used to decrypt the TLS Private Key.

This setting can only be edited/transmitted if the DevConfig link
is considered secure (USB or TLS). If the TLS stack has been
initialized, the device will automatically negotiate a secure TLS
connection with DevConfig if the Use TCP option is selected.

TLS Private Key

Specifies the private key (in PEM format) for the encryption stack.

This setting can only be edited/transmitted if the DevConfig link
is considered secure (USB or TLS). If the TLS stack has been
initialized, the device will automatically negotiate a secure TLS
connection with DevConfig if the Use TCP option is selected.

TLS Certificate

Specifies the public certificate (in PEM format) for the encryption stack.

This setting can only be edited/transmitted if the DevConfig link
is considered secure (USB or TLS). If the TLS stack has been
initialized, the device will automatically negotiate a secure TLS
connection with DevConfig if the Use TCP option is selected.

C-16

Appendix D. Sending a New OS to the NL241

Whenever a new operating system is released for the NL241, it will be
available from our website, www.campbellsci.com/downloads.

D.1 Sending an OS via USB

Follow these steps to send the new OS to the NL241 via USB:

1. Plug the wall charger into an AC outlet and the barrel connector into the

NL241 power jack.

2. Connect a USB cable between one of your computer USB ports and the

USB port on the NL241.

3. Open DevConfig.

4. Select the NL241 under Device Type.

5. Select the appropriate Communication Port.

6. Go to the Send OS tab.

7. Press the Start button.

8. In the resulting dialog box, select the file that should be sent to the device

as an operating system (this file should have an .obj extension) and press
the OK button.

9. The operating system will be sent to the NL241.

10. After the file has been sent, the LED on the NL241 will blink repeatedly

while the NL241 copies the OS into its internal flash. Depending upon the
operating system that was previously installed, it may take up to 2 minutes
for the NL241 to finish updating the operating system. While the LED is
blinking, the NL241 is in a vulnerable state where a removal of power
could leave the NL241 without a valid operating system to run. Do not
remove power until the LED stops blinking.

D.2 Sending an OS via Wi-Fi

Follow these steps to send the new OS to the NL241 via Wi-Fi:

1. Using the supplied serial cable, connect the NL241 CS I/O port to the
datalogger CS I/O port. Alternatively, power the NL241 through the
barrel-connector jack located on the edge of the device.

2. The NL241 will power up and either create or join a Wi-Fi network. After
successfully joining or creating a network, the LED will flicker green with
network activity. Note that the LED may only blink green once every few
seconds on the created network or an idle network.

D-1

Appendix D. Sending a New OS to the NL241

3. If the device is configured to create a network, the computer must join the
NL241 created network. If the NL241 has been previously configured to
join a network, join the same network with your computer.

4. Open DevConfig.

5. Select the NL241 under Device Type.

6. Ensure that the Use IP Connection box is checked on the left-hand panel.

7. If the Admin Password of the device has been set, you will need to enter
that password in the Administrative Password control on the left panel in
order for the connection to succeed.

8. Enter the IP address or domain name address of the device in the
Communication Port control on the left panel. If you do not know the
address of the device and the device is connected to your local area
network, you may be able to use the … button to the right of
Communication Port to discover the list of devices on the network.
Whatever address is entered, it must end with :6786 in order to connect the
device configuration service.

9. Go to the Send OS tab.

10. Click the Start button.

11. In the resulting dialog box, select the file that should be sent to the device
as an operating system (this file should have an .obj extension) and press
the OK button.

12. The operating system will be sent to the NL241.

13. After the file has been sent, the power LED on the NL241 will blink
repeatedly while the NL241 copies the OS into its internal flash.
Depending upon the operating system that was previously installed, it may
take up to 2 minutes for the NL241 to finish updating the operating
system. While the LED is blinking, the NL241 is in a vulnerable state
where a removal of power could leave the NL241 without a valid
operating system to run. Do not remove power until the LED stops
blinking

D-2

NOTE

Appendix E. Radio Frequency Emission

Changes or modifications to the NL241 not expressly approved by Campbell
Scientific, Inc. could void the user’s authority to operate this product.

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 the equipment into an outlet on a circuit different from that to

which the receiver is connected.

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

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.

The embedded radio transmitter approval:

FCC Identifier: XF6-RS9113SB

Industry Canada: 8407A-RS9113SB

View the EU Declaration of Conformity at www.campbellsci.com/nl241

E-1

Campbell Scientific Companies

Campbell Scientific, Inc.

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BRASIL

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Please visit www.campbellsci.com to obtain contact information for your local US or international representative.

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