Lambrecht sun[e] 00.16130.501030 User manual

Manual
sun[e]
00.16130.501030
Next level digital secondary standard pyranometer
compliant with IEC
61724-1:2017 Class A

2
Safety instructions and Warranty
Putting more than 30 Volt across the sensor wiring of the main power
supply can lead to permanent damage to the sensor.
For proper instrument grounding: use sun[e] with its original factory-
made cable.
Using the same Modbus address for more than one device will lead to
irregular behaviour of the entire network.
Do not operate with heater [ON] and ventilator [OFF]: secondary
standard specifications may not be met.
Disconnect power while performing service or maintenance.
This system is designed according to the state-of-the-art accepted safety regulations. However,
please note the following rules:
1. Before putting into operation please read all respective manuals!
2. Please observe all internal and state-specific guidelines and/or rules for the prevention of
accidents. If necessary ask your responsible safety representative.
3. Use the system only as described in the manual.
4. Always have the manual at hand at the installation site.
5. Use the system within the specified operating condition. Eliminate influences, which might
impair the safety.
6. Prevent the ingress of unwanted liquids into the devices.
Please note the loss that unauthorised manipulation of the system shall result in the loss of
warranty and non-liability. Changes to system components require express written permission
from LAMBRECHT meteo GmbH. These activities must be performed by a qualified technician.
The warranty does not cover:
1. Mechanical damage caused by external impacts (e. g. icefall, rockfall, vandalism).
2. Impacts or damage caused by over-voltage or electromagnetic fields which are beyond the
standards and specifications of the device.
3. Damage caused by improper handling, e. g. by using the wrong tools, incorrect installation,
incorrect electrical installation (incorrect polarity) etc.
4. Damage caused by using the device outside the specified operation conditions.
Modbus®is a registered trademark of Schneider Electric, licensed to the Modbus Organization, Inc.

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Contents
Safety instructions and Warranty 2
Contents 3
Introduction 4
1Ordering and checking at delivery 6
1.1 Ordering sun[e] 6
1.2 Included items 6
1.3 Quick instrument check 6
2Instrument schematic 7
3Specifications of sun[e] 8
3.1 Specifications of sun[e] 8
3.2 Dimensions of sun[e] 11
4Installation of sun[e] 12
4.1 Site selection and installation 12
4.2 Installation of the sun screen 13
4.3 Installation of pyranometer 14
4.4 Electrical connection of sun[e]: wiring diagram 15
4.5 Grounding and use of the shield 15
4.6 Connecting to an RS-485 network 15
5Communication with sun[e] 17
5.1 Modbus-protocol 17
5.2 Data encoding 17
5.3 Device-address 17
5.4 Standard configuration - default 17
5.5 Modbus command set 18
5.6 Measured value and parameter register 18
5.7 Sensor parameters / configuration-parameters 19
5.8 Network communication: getting started 20
5.9 Adapting the Modbus address and communication settings 20
6Maintenance and trouble shooting 21
6.1 Recommended maintenance and quality assurance 21
6.2 Trouble shooting 22
7Appendices 23
7.1 LAMBRECHT meteo – Auto-configuration 23
7.2 EU declaration of conformity 26

4
Introduction
Welcome to the next level in solar radiation monitoring!
The all-digital sun[e] pyranometer offers the highest accuracy and highest data availability: using new
Recirculating Ventilation and Heating (RVHTM) technology, sun[e] outperforms all pyranometers
equipped with traditional ventilation systems. sun[e] is the ideal instrument for use in PV system
performance monitoring and meteorological networks.
The sun[e] measures the solar radiation received by a plane surface, in W/m2, from a 180 ofield of
view angle. The sun[e] is an ISO 9060 secondary standard pyranometer. It is employed where the
highest measurement accuracy is required. The sun[e] offers several advantages over competing
pyranometers:
•Heated for best data availability: new RVHTM technology outperforms traditional pyranometer
ventilation
•The first pyranometer compliant in its standard configuration with the requirements for Class A
monitoring systems of the new IEC 61724-1:2017 standard
•Low cost of ownership: remote diagnostics and supported by an efficient worldwide calibration and
service organisation
•The right paperwork: instruments are supplied with the ISO 9060 required test certificates
Figure 0.1 Recirculating ventilation and heating between the inner- and outer dome is much more
power-efficient than traditional ventilation systems.
Suggested use
Suggested use for sun[e]:
•PV system performance monitoring
•scientific meteorological observations

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Features
•Heated for high data availability, featuring new RVH TM technology, 3 operating modes possible
•standard operating mode with heater and ventilator both [ON];
•operation in medium power mode; heater is switched [OFF]; most accurate
measurement (if no danger of deposition of dew or frost)
•operation in low power mode; both the ventilator and heater switched [OFF].
•Compliant with IEC 61724-1: 2017, Class A and B
•Low cost of ownership
•low demand on infrastructure, sun[e]’s RVH TM requires only 2 W power, compared to
10 W for traditional ventilation systems
•reduction of unnecessary on-site inspection by remote diagnostics
•designed for efficient servicing; easy local diagnostics
•supported by an efficient calibration and maintenance organisation. LAMBRECHT meteo
and Hukseflux offers local support in the main global economies: USA, EU, China, India,
Japan and Brazil. Recalibration is recommended every 2 years, which is good practice in
the industry.
•Liabilities covered: test certificates as required by ISO 9060 for secondary standard
classification
•outstanding zero offset specifications, sun[e] also is the instrument of choice for high-accuracy
diffuse radiation measurement.

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1 Ordering and checking at delivery
1.1 Ordering sun[e]
Id-No. for standard configurations sun[e]:
Version 00.16130.501030:
digital ISO 9060 secondary standard pyranometer sensor with Modbus over RS-485
Common options / accessories are:
•cable 5m, M12 plug connector Id-No. 32.14567.060030
•cable 12m, M12 plug connector Id-No. 32.14567.060000
•cable 15m, M12 plug connector Id-No. 32.14567.060010
•cable 20m, M12 plug connector Id-No. 32.14567.060040
Suitable data loggers:
•met[LOG] Id-No. 00.95800.010000
•Ser[LOG] Id-No. 00.95770.000000
1.2 Included items
Arriving at the customer, the delivery should include:
•pyranometer sun[e]
•sun screen
•cable of the length as ordered
•product certificate matching the instrument serial number, including:
ocalibration certificate
otemperature response test report
odirectional response test report
otilt sensor test report
•any other options as ordered
Please store the certificates in a safe place.
1.3 Quick instrument check
1. At power–ON the signal may have a temporary output level different from zero; an offset. Let
this offset settle down; it is a normal part of the power-ON procedure.
2. Check if the sensor reacts to light: expose the sensor to a strong light source, for instance a
100 W light bulb at 0.1 m distance. The signal should read > 100 W/m2now. Darken the
sensor either by putting something over it or switching off the light. The instrument irradiance
output should go down and within one minute approach 0 W/m2.
3. Inspect the instrument for any damage.
4. Check the instrument serial number as indicated by the label on the instrument against the
certificates provided with the instrument.

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2 Instrument schematic
sun[e]’s scientific name is pyranometer. A pyranometer measures the solar radiation received by a
plane surface from a 180 ° field of view angle. This quantity, expressed in W/m2, is called
“hemispherical” solar radiation.
The solar radiation spectrum extends roughly from 285 to 3000 x 10-9 m. By definition a pyranometer
should cover that spectral range with a spectral selectivity that is as “flat” as possible.
Figure 2.0.1 Overview of sun[e]:
(1) cable (standard length 5 metres, optional longer cable)
(2) connector
(3) sun screen
(4) bubble level
(5) bubble level window
(6) outer dome
(7) inner dome
(8) thermal sensor with black coating
(9) internal ventilation vents
(10) quick release system of sun screen
(11) instrument body
(12) levelling feet
sun[e] pyranometer employs a state-of-the-art thermopile sensor with black coated surface, two
domes and an anodised aluminium body. sun[e] offers a digital output via Modbus RTU over 2-wire
RS-485. The pyranometer dome is heated by ventilating the area between the inner and outer dome
using RVH TM - Recirculating Ventilation and Heating - technology.
12
3
6789105
4
11
12

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3 Specifications of sun[e]
3.1 Specifications of sun[e]
sun[e] measures the solar radiation received by a plane surface from a 180 ofield of view angle. This
quantity, expressed in W/m2, is called “hemispherical” solar radiation. sun[e] offers irradiance in W/m2
as a digital output. It must be used in combination with suitable power supply and a data acquisition
system which uses the Modbus communication protocol over an RS-485 connection. When operated
with both heater and ventilator [ON] or both [OFF], or with only the ventilator [ON] the instrument is
classified as secondary standard according to ISO 9060. It should be used in accordance with the
recommended practices of ISO, IEC, WMO and ASTM.
Table 3.1.1 Specifications of sun[e] (continued on next pages)
sun[e] MEASUREMENT SPECIFICATIONS:
ISO classification (ISO 9060:1990)
secondary standard pyranometer
WMO performance level (WMO-No. 8,
seventh edition 2008)
high quality pyranometer
Response time (95 %)
3 s
Zero offset a (response to 200 W/m2net
thermal radiation)
- in standard operating mode
- in medium power mode
- in low power mode
2 W/m2
2 W/m2
5 W/m2
Zero offset b (response to 5 K/h change in
ambient temperature)
< 2 W/m2
Non-stability
< 0.5 % change per year
Non-linearity
< 0.2 % (100 to 1000 W/m2)
Directional response
< 10 W/m2
Directional response test of individual
instrument
report included
Spectral selectivity
< 3 % (0.35 to 1.5 x 10-6 m)
Temperature response
< 0.4 % (-30 to +50 °C)
Temperature response test of individual
instrument
report included
Tilt response
< 0.2 % (0 to 90 ° at 1000 W/m2)
Measurement range
-400 to 4000 W/m2
Zero offset steady state
< 1 W/m2(-40 to + 80 °C)
Spectral range
(20 % transmission points)
285 to 3000 x 10-9 m
Figure 3.1.1 Spectral response of the pyranometer compared to the solar spectrum. The
pyranometer only cuts off a negligible part of the total solar spectrum.

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sun[e] ADDITIONAL SPECIFICATIONS
Measurand
hemispherical solar radiation
Measurand in SI radiometry units
irradiance in W/m2
Optional measurand
sunshine duration
Field of view angle
180 °
Technology employed
Recirculating Ventilation and Heating(RVHTM)
Heating
included
Ventilation
included
Output definition
running average over 4 measurements, refreshed every 0.1 s
Recommended data request interval
1 s, storing 60 s averages
IEC 61724-1:2017 COMPLIANCE
IEC 61724-1:2017 compliance
meets Class A PV monitoring system requirements
meets Class B PV monitoring system requirements
Standards governing use of the instrument
IEC 61724-1; Photovoltaic system performance monitoring –
guidelines for measurement, data exchange and analysis
ISO/TR 9901:1990 Solar energy -- Field pyranometers --
Recommended practice for use
ASTM G183 - 05 Standard Practice for Field Use of
Pyranometers, Pyrheliometers and UV Radiometers
Measurand
sensor temperature
Sensor temperature measurement accuracy
0.5 °C
Rated operating temperature range
-40 to +80 °C
Measurand
sensor tilt angle
Tilt measurement uncertainty
1 ° (0 to 90 °)
Tilt sensor detection limit
< 0.1 ° (smallest meaningfully detectable change in a time
interval of < 10 min)
Tilt sensor characterisation of individual
instrument
report included
Levelling (see options)
bubble level and adjustable levelling feet are included
Levelling accuracy
< 0.1 ° bubble entirely in ring
Measurand
sensor internal relative humidity
Humidity sensor uncertainty
3 %
Measurand
sensor internal pressure
sensor uncertainty
4 mbar
Measurand
heater current
Measurand
ventilator current
Measurand
ventilator speed in RPM
Connector type
M12-A, 5-pole, IP67
Mounting
2 x M5 bolt at 46 mm distance on north-south axis
IP protection class
IP67
Net weight including 5m cable
0.64 kg
HEATING AND VENTILATION
Heater voltage
Internal 5 V (independent of supply voltage)
Rated heater current range
0.250 to 0.375 A
Rated ventilator speed
5,000 to 10,000 RPM (uncontrolled)
STANDARD OPERATING MODE
Standard operating mode
heater [ON] and ventilator [ON]
Zero offset a
< 2 W/m2
Supply voltage range
8 to 30 VDC
Power consumption
< 2.3 W at 12 VDC
MEDIUM POWER OPERATING MODE
Operating condition
heater [OFF] and ventilator [ON]
Zero offset a
2 W/m2
Supply voltage range
8 to 30 VDC
Power consumption
< 0.6 W

10
LOW POWER OPERATING MODE
Operating condition
heater [OFF] and ventilator [OFF]
Zero offset a
5 W/m2
Supply voltage range
5 to 30 VDC
Power consumption
< 0.1 W
CALIBRATION
Calibration traceability
to WRR
Calibration hierarchy
from WRR through ISO 9846 and ISO 9847, applying a
correction to reference conditions
Calibration method
indoor calibration according to ISO 9847, Type IIc
Calibration uncertainty
< 1.2 % (k = 2)
Recommended recalibration interval
2 years
Reference conditions
20 °C, normal incidence solar radiation, horizontal mounting,
irradiance level 1000 W/m
2
, heater and ventilator [ON]
Validity of calibration
based on experience the instrument sensitivity will not change
during storage. During use under exposure to solar radiation
the instrument “non-stability” specification is applicable.
MEASUREMENT ACCURACY AND RESOLUTION
Uncertainty of the measurement
statements about the overall measurement uncertainty can
only be made on an individual basis.
WMO estimate on achievable accuracy for
daily sums
2 %
WMO estimate on achievable accuracy for
hourly sums
3 %
Irradiance resolution
0.05 W/m2
DIGITAL COMMUNICATION
Digital output
irradiance in W/m²
House keeping data
instrument body temperature in °C
instrument internal humidity in %r h
instrument internal pressure in Pa
instrument tilt angle in °
ventilator speed in RPM
ventilator current in A
heater current in A
Rated operating voltage range
8 to 30 VDC
Communication protocol
Modbus over 2-wire RS-485
half duplex
Transmission mode
RTU

11
3.2 Dimensions of sun[e]
Figure 3.2.1 Dimensions of sun[e] in x 10-3 m
95
Ø 92
M6
Ø 68
46
M5 (2x)

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4 Installation of sun[e]
4.1 Site selection and installation
Table 4.1.1 Recommendations for installation of pyranometers
Location
The horizon should be as free from obstacles as possible.
Ideally, there should be no objects between the course of the
sun and the instrument.
Mechanical mounting / thermal insulation
Use connection by bolts to the bottom plate of the instrument.
A pyranometer is sensitive to thermal shocks. Do not mount
the instrument with the body in direct thermal contact to the
mounting plate (so always use the levelling feet also if the
mounting is not horizontal), do not mount the instrument on
objects that become very hot (black coated metal plates).
Instrument mounting with 2 bolts
2 x M5 bolt at 46 x 10-3 m centre to centre distance on north-
south axis, connection from below under the bottom plate of
the instrument.
Instrument mounting with one bolt
1 x M6 bolt at the centre of the instrument, connection from
below under the bottom plate of the instrument.
Performing a representative measurement
The pyranometer measures the solar radiation in the plane of
the sensor. Some installations require a tilted or inverted
position. The sensor bottom plate, parallel to the black sensor
surface, should be mounted parallel to the plane of interest.
in case a pyranometer is not mounted horizontally or in case
the horizon is obstructed, the representativeness of the
location becomes an important element of the measurement.
See the chapter on uncertainty evaluation.
Levelling
In case of horizontal mounting, use the bubble level and
levelling feet. The bubble level is visible and can be inspected
at all times.
Tilted installation
For tilted installation, the tilt sensor provides a sufficiently
accurate measurement. The register “tilt angle” can be used
when mounting and levelling the sensor.
Instrument orientation
by convention: with the cable exit pointing to the nearest pole,
so the cable exit should point north in the northern
hemisphere, south in the southern hemisphere.
Installation height
in case of inverted installation, WMO recommends a distance
of 1.5 m between soil surface and sensor (reducing the effect
of shadows and in order to obtain good spatial averaging).

13
4.2 Installation of the sun screen
The quick release system of sun[e]’s sun screen allows for easy and secure mounting of the sun
screen on the sensor. Installation and removal of the connector can be done after removal of the sun
screen.
Release sun screen: The system consists of a spring loaded lever opposite the bubble level window of
the sun[e] sun screen. The bottom of the handle can be pulled out gently. Once the handle is pulled
out and fully released, as shown in the figure below, the sun screen can be lifted off manually for
removal.
Installing the sun screen: pull out the bottom of the quick release system handle so it is fully released,
place the screen on sun[e] and, once it is positioned properly, press the handle of the quick release
system until it is locked.
Figure 4.2.1 sun[e]’s sun screen with its quick release system and bubble level window
Figure 4.2.2 Installation of sun[e]’s sun screen

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4.3 Installation of pyranometer
LAMBRECHT meteo provides several mounting set for the sun[e] pyranometer.
Id-No. 32.14627.003010 Set for inclined mounting on traverse system 14627
Id-No. 32.14627.003000 Set for horizontal mounting on traverse system 14627
Id-No. 33.14627.012000 Set for wall mounting
The picture below shows the installation of the sun[e] on the “Set for inclined mounting”
as an example. The whole pattern for mounting the sun[e] is the same for all the sets
mentioned above.
Figure 4.3.1 Mounting of sun[e] on Set for inclined mounting on traverse system 14627
(1) sun[e] pyranometer
(2 mounting plate for pyranometer*
(3) fixation for mounting on traverse system 14627*
(4) TORX M4 x 16 TX20 DIN 7985 TX A2
(5) washer 4.3 DIN 125 A A2
(6) washer 5.3 DIN 125 A A2
(7) hexagon screw M8 x 16 DIN 933 A2
(8) nut M5 DIN 934 A2
(9) nut M8 DIN 985 A2
(10) nut M4 DIN 985 A4
(11) setscrew M4 DIN 985 A4
* Parts of the “Set for inclined mounting on traverse system 14627”

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4.4 Electrical connection of sun[e]: wiring diagram
The instrument must be powered by an external power supply, providing an operating voltage in the
range from 8 to 30 VDC. This is the main power supply for the sensor, using the brown and white
wires. Do not put more than 30 Volt across these wires, this will damage the sensor.
Table 4.4.1 Wiring diagram of sun[e]
PIN WIRE
00.16130.501030
Modbus over RS-485
1 Brown VDC [+]
2 White VDC [−]
3 Blue RS-485 B / B’ [+]
4 Black RS-485 A / A’[−]
5 Grey not connected
Shield mesh shield
Note 1: At the connector-end of the cable, the shield is connected to the connector housing.
Figure 4.4.1: Connector layout of sun[e], indicating PIN numbers (viewed from cable side)
4.5 Grounding and use of the shield
Grounding and shield use are the responsibility of the user. The cable shield (called shield in the
wiring diagram) is connected to the aluminium instrument body via the connector. In most situations,
the instrument will be screwed on a mounting platform that is locally grounded. In these cases the
shield at the cable end should not be connected at all. When a ground connection is not obtained
through the instrument body, for instance in laboratory experiments, the shield should be connected to
the local ground at the cable end. This is typically the ground or low voltage of the power supply or the
common of the network. In exceptional cases, for instance when both the instrument and a datalogger
are connected to a small size mast, the local ground at the mounting platform is the same as the
network ground. In such cases ground connection may be made both to the instrument body and to
the shield at the cable end.
4.6 Connecting to an RS-485 network
sun[e] is designed for a two-wire (half-duplex) RS-485 network. In such a network, sun[e] acts as a
slave, receiving data requests from the master. An example of the connection to an RS-485 two-wire
network is shown in the figure below. sun[e] is powered from 8 to 30 VDC. The power supply is not
shown in the figure. The VDC [-] power supply ground must be connected to the common line of the
network. [Modbus over serial line specification and implementation guide V1.02 (www.modbus.org).]
After the last nodes in the network, on both sides, line termination resistors (LT) are required to
eliminate reflections in the network. According to the RS-485 standard, these LT have a typical value
of 120 to 150 Ω. Never place more than two LT on the network and never place the LT on a derivation

16
cable. To minimise noise on the network when no transmission is occurring, a pull up and pull down
resistor are required. Typical values for both resistors are in the range from 650 to 850 Ω.
Figure 4.6.1 Connecting sun[e] to a typical RS-485 network
not connected
[+] 8 to 30 VDC
[-]8 to 30 VDC
common
[+] data
[-
]data, RS-485 A /A’
sun[e] wire
white
black
blue
grey
brown
,RS-485 B / B’
RS-485 network
shield
shield

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5 Communication with sun[e]
5.1 Modbus-protocol
The Lambrecht meteo Modbus sensors and the met[LOG] follow the specification of the Modbus
organization: "MODBUS APPLICATION PROTOCOL SPECIFICATION
V1.1b3". (See www.modbus.org).
5.2 Data encoding
MODBUS uses the "big-endian" format for addresses and data. This means that if a value is
transmitted with a number format that is larger than a single byte, the "most significant byte" is sent
first. For values that go beyond one register (e.g. 32 bit) this is not clearly specified for the Modbus. In
these cases (32 bit or 64 bit) the LAMBRECHT Modbus sensors follow the big-endian number format.
Example Big-Endian:
Register size value
16 - Bits 0x1234 is transmitted in the order: 0x12 0x34.
Example big-endian (32bit or 64bit):
Register size value
32 - Bits 0x12345678 is transmitted in the order: 0x12 0x34 0x56 0x78.
5.3 Device-address
The addresses 1...247 are permitted for Modbus.
Warning: Using the same Modbus address for more than one device will lead to irregular behaviour of
the entire network.
5.4 Standard configuration - default
Baud rate: 19200 Baud
Address: Each sensor type (or family) has its own default address.
Table 5.4.1 Default addresses of the LAMBRECHT sensors
Address
Sensor
1
Wind speed
2
Wind direction
3
Precipitation rain[e]
4
THP
5
EOLOS IND
6
com[b]
7
PREOS
8
ARCO
9
u[sonic]
10
Pyranometer 2nd Class
11
Secondary standard Pyranometer
12
PT100 to Modbus converter (temperature)
Byte frame according to MODBUS standard for RTU mode:
8E1 (1 start bit, 8 data bits, 1 parity bit (even parity), 1 stop bit)

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5.5 Modbus command set
The Lambrecht Modbus sensors support the following commands:
•Read Input Register" command: 0x04 (Read measured data)
•Write Multiple Register" command: 0x10 (Write sensor data)
5.6 Measured value and parameter register
The Lambrecht meteo Modbus provide in the register range 30001 to the measured values. The
registers Addresses 30001 to 35000 apply to all Lambrecht meteo Modbus sensors, but are only
available or valid if the respective sensor supports the corresponding values (e.g. a pure wind sensor
does not provide any air humidity).
Table 5.6.1 Measured values provided by sun[e]
Register
address
Parameter name
Unit
Factor
Description
31401
Global radiation instantaneous
values
W/m²
10
1 decimal
INT
31402
Global radiation - average value
since last retrieval
W/m²
10
1 decimal
INT
31403
Global radiation - maximum
value since last retrieval
W/m²
10
1 decimal
INT
31404
Global radiation - minimum
value since last retrieval
W/m²
10
1 decimal
INT
31501
Global radiation instantaneous
values (High-WORD)
(temperature compensated)
W/m²
100
2 decimal
The register 31501 +
31502 should be
read in one
sequence. (function
code 0x04)
LONG
31502
Global radiation instantaneous
values (Low-WORD)
(temperature compensated)
31591
Global radiation instantaneous
values (High-WORD)
(uncompensated)
W/m²
100
2 decimal
The register 31591 +
31592 should be
read I none
sequence. (function
code 0x04)
LONG
31592
Global radiation instantaneous
values (Low-WORD)
(uncompensated)
Register 31501 + 31502, Global radiation instantaneous values (Irradiance), provides the solar
radiation output in 0.01 W/m². The value given must be divided by 100 to get the value in W/m². MSW
and LSW should be read together in one request.
Note: The values from the registers with the maximum values (31403) and minimum values (31404)
are automatically reset as soon as the register (31402) with the mean values has been read out.
The Lambrecht sensors give 0xD8F1=-9999(16bit) or 0xFF676981=-9999999 (32bit) as error code or
invalid value.
Note: Individual readout of related registers (e.g. 31501 and 31502) is not permitted.

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5.7 Sensor parameters / configuration-parameters
Table 5.7.1 Configuration registers
Register
address
Parameter name
Unit
Divisor
Description
40001
Modbus device address
1
The addresses
1...247 are allowed.
INT
40200
Baud rate
0,01
96=9600
192=19200
384=38400
INT
46000
Number of mapping-registers*
1
Contains the number
of occupied mapping
registers for the auto-
configuration
sun[e] = 8
INT
* For more information about the registers for auto-configuration see Appendix.
Register 40001, Modbus device address, contains the Modbus address of the sensor. This allows the
Modbus master to detect the slave, sun[e], in its network. The address can be changed; the value of
the address must be between 1 and 247. The default Modbus address is 11.
Note: The sensor needs to be restarted before changes become effective.
Register 40200, Baud rate, is used to enter the settings for the baud rate. The framing of the serial
data transfer is 8 data bits, even parity and 1 stop bit. Default setting is 19200 baud.
Note: The sensor needs to be restarted before changes become effective.
Table 5.7.2 Format of data
FORMAT OF DATA
DESCRIPTION
uINT
Unsigned 16 bit integer
INT
Signed 16 bit integer
uLONG
Unsigned 32 bit integer
LONG
Signed 32 bit integer
The data format includes signed and unsigned integers. The difference between these types is that a
signed integer passes on negative values, which reduces the range of the integer by half. Up to five
16 bit registers can be requested in one request; if requesting six or more registers, multiple requests
should be used.
If the format of data is a signed or an unsigned 32 bit integer, the first register received is the most
significant word (MSW) and the second register is the least significant word (LSW). This way two
16 bit registers are reserved for a 32 bit integer. MSW and LSW have to be read together in one
request. This is necessary to make sure both registers contain the data of one internal measurement.

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5.8 Network communication: getting started
Once it has the correct Modbus address and communication settings, sun[e] can be connected directly
to an RS-485 network and a power supply.
Installing a sun[e] in the network also requires configuring the communication for this new Modbus
device. This usually consists of defining a request that can be broadcast by the master.
Typical operation requires the master to make a request of irradiance data in registers 31501 + 31502
every 1 second, and store the 60 second averages. The data format of register 31501 + 31502 is a
signed 32 bit integer.
Note: Up to five 16 bit registers can be requested in one request. In case six or more registers are
requested in just one request, sun[e] will not respond. If requesting six or more registers, multiple
requests should be used: sun[e] will respond as expected.
5.9 Adapting the Modbus address and communication settings
Setting the instrument address and baud rate can be done in different ways:
•by connecting the sensor to the PC and using a Modbus testing tool. There are links to
different solutions available at www.modbus.org;
•by using the available network user interface software.
The Modbus address is stored in register 40001 and has a default value of 11. A user may change the
address to a value in the range of 1 to 247. The address value must be unique in the network. The
baud rate is stored in register 40200.
The default communication frame is 19200 baud, with even parity bit, 8 data bits and 1 stop bit. After a
new address or communication setting is written the sensor must be restarted.