Weather Station
P03/3-Modbus
for Modbus
Technical specifications
and installation instructions
Elsner Elektronik GmbH Control and Automation Engineering
Herdweg 7 • D-75391 Gechingen • Germany
Phone: +49 (0) 70 56/93 97-0 • Fax: +49 (0) 70 56/93 97-20
[email protected] • www.elsner-elektronik.de
Description
The P03/3-Modbus weather station measures temperature, wind speed and brightness
(eastern, southern and western sun) and recognizes precipitation.
Data are usually output after a request made by the Modbus master via a 2-wire RS485
connection. Furthermore, the weather station can communicate with a PC, an SPS or an
MC.
The P03/3-Modbus has four ports; the data output is made via the terminals A and B.
Here, an IC is used that can operate with up to 128 participants on one bus
(TI SN65LBC184D). Terminals 1 and 2 are provided for the power supply (24 V DC). The
ports are not protected against reverse polarity. If they are wrongly connected, the
interface modules will be destroyed.
Functions:
•
Brightness measurement with three separate sensors for east, south and west.
Recognition of twilight/dawn with special filters
•
Wind speed measurement by means of a nonwearing electronic sensor. No
damage from storm or hail as with mechanical anemometers
•
Temperature measurement
•
Heated precipitation sensor (1.2 watts): No false reports as a result of fog or
dew. Dries quickly after precipitation has stopped
Technical data
Housing:
Plastic material
Colour:
White / translucent
Mounting:
On-wall
Protection category:
IP 44
Dimensions:
approx. 96 x 77 x 118 (W x H x D, mm)
Weight:
approx. 160 g
Ambient temperature:
Operation -30…+50°C, Storage -30…+70°C
Operating voltage:
24 V DC
Current:
max. 105 mA, residual ripple 10%
Data output:
RS485 2-wire
Protocol:
Modbus RTU
Heating rain sensor:
approx. 1.2 W
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Weather Station P03/3-Modbus • Version: 26 October 2009 • Subject to technical alterations. Errors excepted.
Measurement range temperature:
-40…+80°C
Resolution: 0.1°C
Accuracy:
±0.5°C at +10…+50°C
±1.5°C at -25…+80°C
Measurement range wind:
0…70 m/s
Resolution: <10% of the measured value
Accuracy: ± 25% at 0…15 m/s,
at an angle of attack of 45°, pole mounting
Measurement range brightness:
0…99 000 lux
Resolution:
1 lux at 0…120 lux
2 lux at 121…1 046 lux
63 lux at 1 047…52 363 lux
423 lux at 52 364…99 000 lux
Accuracy: ± 35%
The following standards were referenced with regard to evaluating electromagnetic
compatibility of the product:
EN 60730-1:2000-11 + A11:2002
The product has been tested by an accredited EMC laboratory according to the
standards mentioned above.
Weather Station P03/3-Modbus • Version: 26 October 2009 • Subject to technical alterations. Errors excepted.
3
PCB layout
Fig. 1 PCB
1
2
3
4
4
Connecting plug
1: +24 V CC
A: data
2: GND
B: data
DIP switch for interface parameters (see detailed view)
DIP switch for slave address (see detailed view)
LED “Com”, “Error” and “Power” (see detailed view)
LED “Power”: operating voltage
LED “Error”: sensor error or erroneous data
LED “Com”: bus communication
Weather Station P03/3-Modbus • Version: 26 October 2009 • Subject to technical alterations. Errors excepted.
Fig. 2: Detailed view: DIP switch and LEDs
If all DIP switches are in the OFF position (default setting), the following parameters are
active:
Address:
1
Baud rate:
19,200
Parity:
Even
Termination:
Disabled
Setting of the slave’s address:
The slave address is set with the help of the 8-bit DIP switch “Address”. If all switches
are in the OFF position, Address 1 is active. Address 0 is reserved for broadcast
messages; addresses greater than 247 are not valid.
The coding of the address is binary. For the address 47, you must e.g. set the switches
1, 2, 3, 4 and 6 to ON.
Interface parameters:
The interface parameters are set with the help of the second 8-bit DIP switch. If the first
4 switches are in the OFF position, the transfer rate amounts to 19,200 bauds. If one of
these switches is set to ON, the corresponding baud rate is applicable.
Parity: If the two switches “ODD” and “NONE” are set to OFF, the parity is EVEN. Only
“ODD” or “NONE” activates the corresponding parity control.
Switch “Mobu EE”: no function.
Switch “Term.”: bus termination 124 ohms
Weather Station P03/3-Modbus • Version: 26 October 2009 • Subject to technical alterations. Errors excepted.
5
Transfer protocol
P03-Modbus request string from the master
Byte
No.
0
1
2
3
4
5
6
7
Variable
Meaning
Slave address
Command
Start address, high byte
Start address, low byte
Number of words, high byte
Number of words, low byte
CRC, low byte
CRC, high byte
xx
04H
xx
xx
xx
xx
xx
xx
Read input registers
P03-Modbus output string to the master
6
Byte
No.
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Start
Variable
address
Slave address
Command
Number of bytes
0
Outdoor temperature
1
Outdoor temperature
2
Sun sensor, south
3
Sun sensor, south
4
Sun sensor, west
5
Sun sensor, west
6
Sun sensor, east
7
Sun sensor, east
8
Light
9
Light
10
Wind
11
Wind
12
GPS / RTC
xx
04H
xx
H
L
H
L
H
L
H
L
H
L
H
L
H
16
17
18
19
20
13
14
15
16
17
L
H
L
H
L
Rain
Day
Day
Month
Month
Meaning
Read input registers
Master request * 2
with sign, value/10 =
temperature xx.x °C
1…99 Kilolux
1...99 Kilolux
1...99 Kilolux
0...999 Lux
0...999 Lux
Value/10 gives wind speed in
m/s (metres per second)
1 = GPS 0 = quartz clock
50 ppm
1 = rain; 0 = no rain
Date Day*
Date Month*
Weather Station P03/3-Modbus • Version: 26 October 2009 • Subject to technical alterations. Errors excepted.
Byte
No.
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
Start
address
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
CRC
CRC
Variable
Year
Year
Hour
Hour
Minute
Minute
Second
Second
Azimuth
Azimuth
Elevation
Elevation
Degree of longitude
Degree of longitude
Degree of latitude
Degree of latitude
Meaning
H
L
H
L
H
L
H
L
H
L
H
L
H
L
H
L
L
H
Date Year*
Time Hour*
Time Minute*
Time Second*
Value/10 = sun position
angle 0.0 ... 359.9 degrees*
Value/10 = sun position
height range +/-90.0 degrees*
Value/100
+/- xxx.xx°
+ = east / - = west *
Value/100 +/- xxx.xx°
+ = north / - = south *
* Only available with version P03/3-Modbus-GPS (with GPS module)
Negative values are represented in the two’s complement notation.
Weather Station P03/3-Modbus • Version: 26 October 2009 • Subject to technical alterations. Errors excepted.
7
Installation and first use
The weather station may only be installed, tested, put
into operation and troubleshot by a person qualified to do so.
When connecting the weather station, do not connect any live wires (switch off the
mains fuse first) and take precautionary measures to prevent them from being
accidentally switched back on. Make sure all connections are correct. An incorrect
connection could destroy the weather station or any electronic devices connected to it.
The weather station must be used for its intended purpose only. Any improper
modification or failure to observe the operation instructions will void all guarantees or
claims to warranty.
When unpacking, check the unit immediately for any mechanical damage. The supplier
must be informed immediately of any damage caused during transport.
The weather station must not be put into use if
damaged.
If there is any cause to believe that safe operation is no longer guaranteed, the system
must be rendered inoperative and secured against being switched on unintentionally.
The weather station may only be operated as a stationary installation; i.e. only when
mounted and after all installation and initialization procedures are complete, and only in
the environment it is intended for.
Elsner Elektronik is not liable for any changes to standards or defaults after publication
of the operation instructions.
Position
Choose an installation position in the building where wind, rain and sun can be
measured unhindered by the sensors. The weather station must not be installed
underneath any structural parts from which water can still drip onto the rain sensor
after it has stopped raining or snowing. The weather station must not be shaded by
anything, such as building structures or trees. There must be at least 60 cm of free
space underneath the weather station to allow it to measure the wind correctly and to
prevent it from being snowed in when it snows. Please also make sure that no shadow
is cast on the station by an extended awning and that the station is not in the sheltered
zone.
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Weather Station P03/3-Modbus • Version: 26 October 2009 • Subject to technical alterations. Errors excepted.
North
Fig. 3
Align the
direction.
weather
station
in
a
southward
South
Fig. 4
The weather station must be mounted onto a
vertical wall (or pole).
Fig. 5
The weather station must be mounted horizontally in the lateral direction.
Attaching the mount
The weather station comes with a combination wall/pole mount. The mount comes
adhered by adhesive strips to the rear side of the housing.
Fasten the mount vertically onto the wall or pole.
Fig. 6
When wall mounting: flat side on wall, crescentshaped collar upward.
Weather Station P03/3-Modbus • Version: 26 October 2009 • Subject to technical alterations. Errors excepted.
9
Fig. 7
When pole mounting: curved side on pole, collar
downward.
Fig. 8
An additional, optional accessory available
from Elsner Elektronik is an articulated arm for
flexible wall, pole or beam mounting of the
weather station.
View of rear side and drill hole plan
Fig. 9a: Dimensions of rear side of housing with bracket. Subject to change for technical
enhancement.
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Weather Station P03/3-Modbus • Version: 26 October 2009 • Subject to technical alterations. Errors excepted.
Fig. 9b
Drill hole plan
Preparing the weather station
Fig. 10
The weather station cover with the rain sensor snaps in on the left and right along the
bottom edge (see Fig. 10). Remove the weather station cover. Proceed carefully, so as
not to pull off the wire connecting the PCB in the bottom part with the rain sensor in the
cover (wire with push-connector).
Push the connecting cable through the rubber seal on the bottom of the weather station
and connect the power and bus cables to the terminals provided for this purpose. The
connection is by typical telephone cable (J-Y(ST)Y 2 × 2 × 0.8).
Weather Station P03/3-Modbus • Version: 26 October 2009 • Subject to technical alterations. Errors excepted.
11
Mounting the weather station
Close the housing by putting the cover back over the bottom part. The cover must snap
in on the left and right with a definite “click”.
Fig. 11
Make sure the cover and bottom part are properly
snapped together! This picture is looking at the
closed weather station from underneath.
Fig. 12
Push the housing from above into the fastened
mount. The bumps on the mount must snap into
the rails in the housing.
To remove it, the weather station can be simply pulled upwards out of the mount,
against the resistance of the fastening.
Notes on installation
Do not open the P03 weather station if water (rain) could get in: even a few drops could
damage the electronics inside.
When mounting, you must take care not to damage the temperature sensor (small PCB
on the bottom of the housing). Also, the wire connecting the PCB with the rain sensor
must not be pulled off or kinked at the terminal.
Remove all existing protection labels after installation.
It will take 30 seconds after applying the power before the wind measurement will be
output.
Maintenance
The weather station must be checked for dirt on a regular, twice-yearly basis and
cleaned if necessary. A dirty weather station can lead to strange results, such as the
wind sensor failing to work, the station constantly announcing rain, or failure to detect
sunlight.
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Weather Station P03/3-Modbus • Version: 26 October 2009 • Subject to technical alterations. Errors excepted.