Atonometrics Mars User manual

Document Number 880060 Rev. C, November 2020
www.atonometrics.com
Copyright © 2020 Atonometrics, Inc. All rights reserved.

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Table of Contents
Table of Contents..........................................................................................................................2
1Product Overview...................................................................................................................3
2Configuration..........................................................................................................................4
2.1 Getting Started ..........................................................................................................4
2.2 Configuration Kit........................................................................................................4
2.3 Accessing the Web Interface.....................................................................................6
2.4Configuration Steps...................................................................................................8
2.5 Checking Communication .......................................................................................10
3Wiring...................................................................................................................................11
3.1 Power ......................................................................................................................11
3.2 Cable Options..........................................................................................................11
3.3 Atonometrics-Supplied Cables ................................................................................12
3.4 User Assembly of Power & RS-485 Cable ..............................................................13
3.5 Protecting Unused Wires.........................................................................................14
4Mounting ..............................................................................................................................15
4.1 Mounting Requirements ..........................................................................................15
4.2 Dimensions..............................................................................................................17
4.3 Mounting Accessories .............................................................................................18
5Network Setup .....................................................................................................................20
6Modbus ................................................................................................................................21
7Troubleshooting ...................................................................................................................22
8Maintenance ........................................................................................................................23
9Theory of Operation .............................................................................................................24
10 Specifications.......................................................................................................................25

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1 Product Overview
The Atonometrics Mars™ Soiling Sensor, shown in Figure 1-1, is a revolutionary product that
provides simplified measurement of soiling losses for PV installations. Patented Mars™
technology detects accumulated soiling on a soil collection window using an internal camera. The
Mars™ unit requires no water, has no moving parts, is compact and easy to install, and does not
require site-specific dust calibration or technician service visits. It is specifically designed to be
suitable for a wide range of PV installation types, including small commercial and industrial
projects.
The Mars™ unit has two options for digital communication. An M12-connectorized Ethernet port
provides for simple setup, configuration, and status checks using a networked PC with a web
browser, as well as output data via Modbus TCP. An M12-connectorized RS-485 port is also
provided which may be used for output data via Modbus RTU.
The Mars™ unit and cable connections are IP67-rated for weather protection and the product is
built in a cast aluminum enclosure that provides for solid mounting.
Soil collection
window
M12
Ethernet port
Modbus TCP
IP67 Rated
Internal data analysis
M12
Power & RS485
Modbus RTU
Figure 1-1: Mars™ Soiling Sensor (810230)

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2 Configuration
2.1 Getting Started
Your Mars™ unit must be configured in order to work properly at your installation site. Key
configuration steps include updating software, setting the site’s physical coordinates, confirming
the unit’s clock, and setting communication parameters.
Before starting configuration, visit the Atonometrics website (www.atonometrics.com) and
download the latest version of the Mars™ firmware and the latest User Guide (this
document).
2.2 Configuration Kit
The optional Configuration Kit (810235-01, sold separately) allows you to conveniently power your
Mars™ unit while you perform configuration via Ethernet and, if desired, test communication over
the RS-485 port. The kit, shown in Figure 2-1, contains everything needed to connect your PC to
the Mars™ unit, including a power adapter (AC to 15 VDC) with slide-on worldwide receptacle
adapters, an Ethernet-to-USB adapter, an Ethernet cable, an RS-485 to USB adapter, and a cable
for connecting power and RS-485 to your Mars™ unit. (An M12 to RJ45 Ethernet cable is also
included with each Mars™ unit for connection to the M12 Ethernet port on SN15000 and higher.)
To assemble and install the kit:
•Select and install the receptacle adapter appropriate for your country
•Insert the 15 VDC plug into the Mars™ cable assembly
•Connect the Mars™ cable assembly to the Mars™ unit
•Connect the M12/RJ45 Ethernet cable to the Ethernet-to-USB adapter and to the Mars™
connector; insert the adapter into one of your PC’s USB ports; allow Windows to detect
the adapter and automatically install its driver; configure the adapter address to
10.244.69.1
•If desired, insert the RS-485-to-USB adapter into one of your PC’s USB ports; allow
Windows to detect the adapter and automatically install its driver, or install the driver from
the CD included in the kit
•Connect the power adapter to AC power
Note: The Configuration Kit is optional. You may duplicate the functions of the Configuration
Kit with user-supplied equipment, or using cables prepared for your installation site.
Note: Installing the RS-485-to-USB adapter is only needed for testing Modbus RTU over
RS-485. The configuration kit does not include software for this purpose. Use your own
or third-party Modbus software.

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RS485 Adapter
To PC USB Port
DC Power Adapter
To AC Power
Slide-On
Receptacle Adapter
(Worldwide Options Included)
15 VDC
To Mars™
M12 Power/RS485
Connector
White
Purple
Orange
Pink
Black
1 2 3 4 5
+ –
Ethernet Adapter
To Mars™
M12 Ethernet
Connector
To PC USB Port
Ethernet Cable
PN 830256-004
PN 830261-002
Figure 2-1: Configuration Kit 810235-01 (sold separately)

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2.3 Accessing the Web Interface
After power up, the Mars unit’s soil collection window will light up for a short time and then will go
dark. Wait 2-5 minutes for initialization to complete.
Configuration is performed by accessing the unit’s internal web interface from your PC using a
web browser, such as Chrome, Firefox, or Internet Explorer.
Launch the web browser on your PC and enter the Mars™ IP address (default = 10.244.69.66).
You will then see the Mars™ web interface shown in Figure 2-2.
Note: If you are not using the Ethernet-to-USB adapter supplied in the Configuration Kit,
configure your PC’s Ethernet adapter to operate on the same subnet as the Mars™
unit. The unit’s default IP address upon shipment from Atonometrics is 10.244.69.66.
Therefore, set your PC’s Ethernet adapter to 10.244.69.XX, where XX is any unused
node (not .66). When configuration is complete, return your PC’s IP settings to their
previous values.
Note: If the IP address of your Mars™ unit has been changed from the factory default, use
the appropriate subnet and address corresponding to the Mars™ unit on your PC’s
Ethernet adapter.
Note: If the IP address of your Mars™ unit is unknown, visit the Atonometrics website and
download the Mars IP Address Discovery Tool from the utilities section in the
downloads area for the Mars™ product. Instructions are provided with the software
tool to help you recover the unit’s IP address.

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Figure 2-2: Web interface

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2.4 Configuration Steps
2.4.1 Updating the Firmware
Your unit’s current installed Firmware Version number is shown near the top of the web interface
(Figure 2-2). If the version you downloaded in Step 2.1 is newer, update the firmware before
proceeding.
To update the firmware, press “Select File(s)” next to “Update Configuration” near the bottom of
the web interface. Following the prompts that will appear, select the previously downloaded
firmware update .zip file and transmit it to the Mars™ unit.
Note: The .zip file is transmitted directly to the Mars™ unit and is not user-openable.
2.4.2 Setting Latitude, Longitude, and Altitude
Use the web interface (Figure 2-2) to set Latitude, Longitude, and Altitude for the unit’s operation
location. For Latitude, +/- = N/S. For Longitude, +/- = E/W. Altitude is in meters. After entering
new values, press “Update”.
Note: For the unit to operate correctly, latitude and longitude of the actual operation site
must be properly entered.
Note: If the unit is moved to a new location, change latitude and longitude to match the new
location.
Note: Latitude and longitude should be entered accurately to within 0.1 degrees or within
10 kilometers.
2.4.3 Checking the Clock
The unit’s internal clock must be set to UTC time and is set by Atonometrics prior to shipment.
To confirm the clock time, use the web interface (Figure 2-2) to check the clock against another
UTC time source, such as a UTC time website.
If your unit’s clock does not match UTC time, press the “UTC Time” button on the web interface
to update the clock. This will populate the UTC time update field with current time from your PC.
Then press “Update” to transfer this time to your Mars™ unit.
Note: The unit must be set to UTC time to operate properly. Do not use local time zones.
Note: To update the Mars™ clock, the clock on your PC must be accurately set.
Note: Check the unit’s clock at least once per year and update as needed.
2.4.4 Enabling Network Time Protocol (NTP) Services
To ensure that your unit’s clock is continuously updated, you may optionally enable the network
time protocol (NTP) service, available in firmware version 4395 and later. This service periodically
synchronizes the Mars™ clock with an internet or local time server.

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To enable the service, use the web interface (Figure 2-2) to enter an IP address for your desired
NTP Time Server and press “Update”. The web interface will display your selected server IP and
“Attempting” or “Synchronized” to indicate status of clock synchronization. Synchronization may
take several minutes.
Note: The NTP service can only operate if your unit has a communication path to the
selected time server. The time server could be a local server within your private
network. Alternatively, set firewall and port forwarding on your network as needed to
allow the Mars™ unit’s NTP service to communicate with a remote public time server.
Note: NTP service requires IP port 123 via UDP. See page 20.
2.4.5 Setting IP Address, Subnet Mask, and Gateway
Your Mars™ unit’s default IP address upon shipment from Atonometrics is 10.244.69.66.
To change your Mars™ unit’s IP address, enter the new address, as well as any desired subnet
mask and gateway, using the web interface (Figure 2-2), then press “Update”.
After setting the new IP address:
•Adjust the subnet of the Ethernet adapter on your PC, if required, to match
•Update the Mars™ IP address entered into your web browser
•Refresh your web browser to confirm that the new address is properly set.
2.4.6 Setting Modbus RTU Settings
If you will be using Modbus RTU for communication over RS-485, configure the Modbus RTU
settings. Otherwise, you may leave these settings at their default values.
Modbus Node Address
•The unit’s default node address for Modbus RTU upon shipment from Atonometrics is 16.
•To change the node address, enter the new address using the web interface (Figure 2-2),
then press “Update”.
•Node addresses from 1 to 247 are allowed.
Baud Rate and Data Format
•From the web interface you may also select the serial communication parameters for baud
rate and data format.
•Supported baud rates are 4800, 9600, 19200, 38400, 57600, and 115200.
•Supported data formats are 8-N-1, 8-N-2, 8-E-1, and 8-O-1.
•To change the settings, select the new values and press “Update”.
2.4.7 Checking Status
Check the Status field on the web interface (Figure 2-2) and confirm it reads “Normal”. If an error
condition is shown, confirm all configuration settings. If the error persists, contact Atonometrics
for support.

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Note: Upon initial configuration, the Transmission Loss and Soiling Ratio fields could read 0,
1, NAN, or other unexpected values. These fields will update properly once the unit is
correctly configured (including latitude, longitude, and clock) and deployed outdoors in
its installation location for a period including at least two hours before and after sunset.
2.5 Checking Communication
For an example and guidance on checking Modbus communication using third-party software in
your data logger or SCADA system, see the Atonometrics application note document 880084
“Testing Modbus Communication on the Mars™ Soiling Sensor”, available via the Atonometrics
website in the downloads area for the Mars™ product.
Note: Upon initial configuration, the Transmission Loss and Soiling Ratio fields could read 0,
1, NAN, or other unexpected values. These fields will update properly once the unit is
correctly configured (including latitude, longitude, and clock) and deployed outdoors in
its installation location for a period including at least two hours before and after sunset.
Note: Reading a value of NAN for Transmission Loss and Soiling Ratio is not a
communication error condition. This value confirms that communication is correct but
indicates that a measurement value is not available yet. As noted above, the device
must be configured correctly and allowed to collect data overnight.

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3 Wiring
3.1 Power
The Mars™ unit requires 10-30 VDC and typically draws < 3 W of power in operation. However,
use at least a 6 W power supply to provide for inrush and transient currents.
3.2 Cable Options
Each Mars™ unit is supplied with the following:
•An M12 connector (160375-02) for user assembly of the power/RS-485 cable using user-
supplied wiring material.
•A two-meter RJ45 to Mars™ M12 Ethernet cable (830261-002) for configuration and
testing.
Complete cable assemblies are available from Atonometrics, sold separately. See Section 3.3.
Instructions for making user-supplied cables are provided in Section 3.4.
Note: Use only Atonometrics-supplied connectors or cable assemblies.Although other
connectors may appear to fit, use of non-approved components may result in water
penetration
Note: Atonometrics recommends using Ethernet vs. RS-485 when possible, since
Ethernet enables remote configuration and status checks via the web interface, in
addition to data acquisition via Modbus TCP.
Note: Units with serial number less than 15000 have a sealed RJ45 Ethernet connector on
the Mars™ unit instead of an M12 connector.
WARNING: Check all wiring before turning on power. Incorrect wiring may damage the
unit and/or your other equipment.

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3.3 Atonometrics-Supplied Cables
Options for Atonometrics-supplied cable assemblies are listed in Table 3-2, with wire colors for
the 830256 M12 power and RS-485 cable shown in Figure 3-1.
Note: Atonometrics-supplied 830256 M12 power and RS-485 cables include additional wires
that are not used for the Mars™ product. See Section 3.5.
Note: Atonometrics-supplied 830261 Ethernet cables will have one sealed M12 connector
for connection to the Mars™ unit. The other end of the cable will include a non-sealed
RJ45 for cable testing purposes. Remove this and use a user-supplied cable gland or
sealed connector for installation to your outdoor equipment cabinet.
Length M12 Cable
Power & RS485
M12 Cable
Ethernet
4 m 830256-004 830261-004
10 m 830256-010 830261-010
25 m 830256-025 830261-025
50 m 830256-050 830261-050
100 m 830256-100 830261-100
❶Pink: 10-30 VDC
❷Black: Ground
❸Orange: No connect
❹Gray: No connect
❺Green: No connect
❻Brown: No connect
❼White: RS-485 A
❽Purple: RS-485 B
4 m (830256-004)
10 m (830256-010)
25 m (830256-025)
50 m (830256-050)
100 m (830256-100)
Ø 6 mm
Table 3-1: Atonometrics-supplied cables (sold separately)
Figure 3-1: Wire colors for 830256 M12 power & RS485 cable

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3.4 User Assembly of Power & RS-485 Cable
In place of purchasing a complete power & RS485 cable from Atonometrics, you may optionally
assemble this cable using user-provided wiring materials as listed in Table 3-2 and Figure 3-2.
Note that each Mars unit is shipped with a 160377 connector for user wiring.
Item
Atonometrics
Part Number Cable Requirements
Power & RS485 M12
Connector
8 pins
(Sealed, IP67)
160375-02
2 conductors (power only) or 4 conductors
(power & RS485)
Outer diameter 6-8 mm
20-24 AWG / 0.20-0.52 mm2
Example: Belden 5502G1
For wiring the power & RS-485 M12 connector, use the pinout shown in Figure 3-2. Note that the
view is facing the connector on the Mars™ unit from the outside.
❶Power (10-30 VDC) ❷Ground
❼RS-485 A
❽RS-485 B
Table 3-2: Materials for user-assembled power & RS485 cable
Figure 3-2: Pinout of Power & RS-485 M12 connector

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3.5 Protecting Unused Wires
Protect any unused wires from accidental contact by cutting to unequal lengths, folding back, and
insulating, as shown in Figure 3-3.
Cut
Insulate
Figure 3-3: Protecting unused wires from accidental contact

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4 Mounting
4.1 Mounting Requirements
Mount the Mars™ unit in the plane of array of your PV modules, choosing a location where the
unit will have a clear view of the sky within a cone at least ±30°from the normal, as shown in
Figure 4-1
To mount the Mars™ unit, use the four mounting holes on the flange of the unit shown in Figure
4-2.
To minimize the potential for water entry to the sealed housings, always mount the Mars™ unit
with the cables facing down or to the side, as shown in Figure 4-3, and never with the cables
facing up.
See Figure 4-4 for dimensions.
Note: Do not remove the screws on the top cover of the unit, as this may compromise the
weather-proof seal. Removing the screws will void the warranty.
Figure 4-1: Mounting requirements and view of sky

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Mounting holes
(x4)
Figure 4-2: Mounting holes
Figure 4-3: Mount with cables down or to the side

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4.2 Dimensions
Figure 4-4: Mars™ dimensions

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4.3 Mounting Accessories
Optional flat plate, right-angle, and pole-mountable adjustable-angle mounting accessories are
shown in Figure 4-5, Figure 4-6, and Figure 4-7.
Figure 4-5: Optional flat mounting plate 610449 (sold separately)

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Figure 4-6: Optional right-angle mounting bracket 610451 (sold separately)
Figure 4-7: Optional adjustable bracket kit 810241 for pole mounting (sold separately)

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5 Network Setup
To configure your Mars™ unit for use on an Ethernet network, set IP addresses and related
communication parameters as directed in section 2.4.5.
In addition, you may need to open ports in your network firewall, or set port forwarding on your
cellular modem. See Table 5-1.
Port
Number
Protocol Function
22 TCP Atonometrics technical support, if needed
80 TCP Access to web interface for configuration and status
123 UDP Network Time Protocol (NTP) service
2018 UDP IP address recovery using Atonometrics Mars™ IP discovery tool
Table 5-1: Mars IP ports