USER GUIDE
CS125
Present Weather Sensor
Issued: 3.6.14
Copyright © 2013-14 Campbell Scientific Ltd.
CSL 1000
Guarantee
This equipment is guaranteed against defects in materials and workmanship.
This guarantee applies for twelve months from date of delivery. We will
repair or replace products which prove to be defective during the guarantee
period provided they are returned to us prepaid. T he guarantee will not apply
to:
• Equipment which has been modified or altered in any way without the
written permission of Campbell Scientific
• Batteries
• Any product which has been subjected to misuse, neglect, acts of God or
damage in transit.
Campbell Scientific will return guaranteed equipment by surface carrier
prepaid. Campbell Scientific will not reimburse the claimant for costs incurred
in removing and/or reinstalling equipment. This guarantee and the Company’s
obligation thereunder is in lieu of all other guarantees, expressed or implied,
including those of suitability and fitness for a particular purpose. Campbell
Scientific is not liable for consequential damage.
Please inform us before returning equipment and obtain a Repair Reference
Number whether the repair is under guarantee or not. Please state the faults as
clearly as possible, and if the product is out of the guarantee period it should
be accompanied by a purchase order. Quotations for repairs can be given on
request. It is the policy of Campbell Scientific to protect the health of its
employees and provide a safe working environment, in support of this policy a
“Declaration of Hazardous Material and Decontamination” form will be
issued for completion.
When returning equipment, the Repair Reference Num ber must be clearly
marked on the outside of the package. Complete the “Declaration of
Hazardous Material and Decontamination” form and ensure a completed copy
is returned with your goods. Please note your Repair may not be processed if
you do not include a copy of this form and Campbell Scientific Ltd reserves
the right to return goods at the customers’ expense.
Note that goods sent air freight are subject to Customs clearance fees which
Campbell Scientific will charge to customers. In many cases, these charges are
greater than the cost of the repair.
Campbell Scientific Ltd,
Campbell Park, 80 Hathern Road,
Shepshed, Loughborough, LE12 9GX, UK
Tel: +44 (0) 1509 601141
Fax: +44 (0) 1509 601091
Email: support@campbellsci.co.uk
www.campbellsci.co.uk
PLEASE READ FIRST
About this manual
Some useful conversion factors:
2
Area: 1 in
Length: 1 in. (inch) = 25.4 mm
1 ft (foot) = 304.8 mm
1 yard = 0.914 m
1 mile = 1.609 km
(square inch) = 645 mm2
Mass: 1 oz. (ounce) = 28.35 g
1 lb (pound weight) = 0.454 kg
Pressure: 1 psi (lb/in
Volume: 1 UK pint = 568.3 ml
1 UK gallon = 4.546 litres
1 US gallon = 3.785 litres
2
) = 68.95 mb
Recycling information
At the end of this product’s life it should not be put in commercial or domestic refuse
but sent for recycling. Any batteries contained within the product or used during the
products life should be removed from the product and also be sent to an appropriate
recycling facility.
Campbell Scientific Ltd can advise on the recycling of the equipment and in some cases
arrange collection and the correct disposal of it, although charges may apply for some
items or territories.
For further advice or support, please contact Campbell Scientific Ltd, or your local agent.
Campbell Scientific Ltd, Campbell Park, 80 Hathern Road, Shepshed, Loughborough, LE12 9GX, UK
Tel: +44 (0) 1509 601141 Fax: +44 (0) 1509 601091
Email: support@campbellsci.co.uk
www.campbellsci.co.uk
Contents
PDF viewers note: These page numbers refer to the printed version of this document. Use
the Adobe Acrobat® bookmarks tab for links to specific sections.
1. Introduction ................................................................. 1
1.1 Version Information .................................................................................. 1
1.2 General Safety .......................................................................................... 2
1.3 Sensor Unit Safety .................................................................................... 2
2. Technical specification .............................................. 3
3. Electrical specification ............................................... 3
4. Supported data rates for RS232 and RS485 ............. 4
5. Environmental specifications .................................... 5
6. Mechanical specifications .......................................... 5
7. Installation procedure ................................................ 5
7.1 Equipment grounding ............................................................................... 7
7.2 Mounting the CS125 ................................................................ ................. 7
7.3 Optional Campbell Scientific Mount ........................................................ 9
8. CS125 internal connectors’ description .................. 11
8.1 CS125 recommended wiring using Campbell Scientific cables ............. 13
9. CS215 T/RH Sensor .................................................. 14
10. Functions of the internal switches ........................ 15
11. Message Formats: A breakdown of the different
default outputs of the CS125 –
Basic/Partial/Full ............................................... 16
2
11.1 Visibility only messages (CS120 emulation) ........................................ 17
11.2 Messages with SYNOP Present Weather Codes ................................ ... 18
11.3 Messages with METAR Present Weather Codes .................................. 19
11.4 Example CS125 message outputs ......................................................... 22
11.5 SYNOP Codes produced by the CS125 ................................................ 23
11.6 METAR Codes produced by the CS125 ............................................... 24
12. Interface methods – Device Configuration
Utility/Command Line/Menu ................................. 24
12.1 Configuring a PC for talking to the CS125 ........................................... 25
13. Definition of the variables that can be set by
the user on the CS125 ......................................... 25
14. Command line mode .............................................. 27
14.1 The SET command ............................................................................... 28
14.1.1 Example of a SET Command .................................................... 29
14.2 The SETNC Command ......................................................................... 29
14.2.1 Example of a SETNC Command .............................................. 29
14.3 The GET command ............................................................................... 29
14.4 The POLL command – Polling the CS125 ........................................... 31
15. Entering the CS125 menu system ......................... 32
16. Calibrating the CS125 ............................................. 36
Appendices
17. Performing a firmware update ............................... 39
18. Cleaning .................................................................. 40
19. Lubricating the enclosure screws ......................... 41
20. Desiccant ................................................................. 41
A. CS125 Block Diagram ............................................ A-1
B. Example C code of the CCITT CRC ....................... B-1
C. Example CRBasic programs ................................ C -1
3
CS125 Present Weather Sensor
Manual Version
Revisions
1.0
None
1. Introduction
The CS125 is an infrared forward scatter present weather sensor for automatic
weather stations including road, marine and airport based stations. The CS125
uses the well-established forward scatter system for visibility measurement,
utilising a 42º scatter angle. The CS125 uses high speed sampling to reduce
missed events such as rain and hail and improves response to other suddenly
changing conditions. When an optional CS215 temperature and RH sensor is
connected, the CS125 can distinguish wet and dry obscuration (for example mist
and haze) and make more precise discrimination between liquid and frozen
precipitation.
1.1 Version Information
1
CS125 Present Weather Sensor
WARNING
CAUTION
NOTE
WARNING
WARNING
CAUTION
1.2 General Safety
1.3 Sensor Unit Safety
This manual provides important safety considerations for the installation,
operation and maintenance of the CS125. These safety considerations are
classified into three levels:
Warnings alert the installer or user to serious hazards.
Ignoring these warnings could result in injury or death
and/or irrevocable damage to the sensor unit.
Cautions warn of potential hazards. Ignoring these cautions
could result in the sensor being damaged and data being lost.
Notes highlight useful information in the installation, use and
maintenance of this product. These should be followed carefully in
order to gain the maximum benefit from the use of this product.
The CS125 sensor has been checked for safety before leaving the factory and
contains no internally replaceable or modifiable parts.
Do not modify the CS125 unit. Such modifications will
lead to damage of the unit and could expose users to
dangerous light levels and voltages.
In unusual failure modes and environmental conditions
the sensor hood could become hot. In normal operation
they will be at ambient temperature or slightly above.
Ensure that the correct voltage supply is provided to the
sensor.
2
2. Technical specification
Minimum
Value
Nominal
Value
Maximum
Value
Main power supply for DSP and dew heaters
Power supply, +12V connection (DC
only)
9V
12V
28V
(1)
Current consumption sampling
continuously with dew heaters active
(at 12V DC)
-
200mA
248mA
Current consumption sampling
continuously with dew heaters
disabled (at 12V DC)
-
110mA
151mA
Current consumption without any
sampling occurring and dew heaters
disabled (at 12V DC)
-
21mA
30mA
Active power consumption with dew
heaters and RS232 communications
interface active
(2,3)
(at 12V DC)
-
200mA
250mA
Hood heater power supply
Hood heater voltage (AC or DC)
-
24V
(3)
30V
(4)
Hood heater wattage (at 24V AC or
DC)
-
60W
(5)
-
RS232 Communications
RS232 input threshold Low
0.8V
1.5V
-
RS232 input threshold High
-
2.0V
2.4V
RS232 input absolute maximum
-15V
-
+15V
RS232 input resistance
12K
-
-
RS232 output voltage low
- - 0.4V
User Guide
Visibility characteristics
Reported Visibility (metric) 12 metres - 32,000
Reported Visibility (imperial) 39 feet - 104,985
Visibility accuracy up to 10,000m - +/-10%
Visibility accuracy up to 20,000m - +/-20%
Weather characteristics
Precipitation Sensitivity
Optical characteristics
LED centre wavelength - 850nm
LED spectral bandwidth - +/-35nm
Pulse characteristics
Light pulse rate - 1KHz
3. Electrical specification
Minimum
Value
-
Nominal
Value
0.05 mm/h
Maximum
Value
metres
feet
-
-
-
-
-
-
3
CS125 Present Weather Sensor
RS232 output voltage high (into
3K)
4.4V - -
RS485 Communications
RS485 input threshold voltage
-0.2V
-
+0.2V
RS485 output (Unloaded)
- - 5V
RS485 output (Load 50)
2V - -
Maximum voltage at any terminal
(6)
-7V
-
+7V
User alarm outputs
User output high level (at 85ºC)
3.8V - -
User output high level (at 25ºC )
4.13V - -
User output low (All temperatures)
0.25V
-
0.55V
User output current
- - 32mA
CAUTION
(1) If a CS215 is being used the supply voltage should not exceed 16V.
(2) The RS232 communications interface will automatically turn itself off when not transmitting.
(3) If hood heaters are not being used ensure `Hood heater override’ (details in Section 13) is set to
off.
(4) It is recommended that the hood heaters are run at 24V AC/DC. It’s possible to run the heaters at
any voltage below 24V but the heaters will generate proportionally less heat reducing their ability to
prevent ice build-up.
(5) Each hood takes 30W, 60W is the total for both hoods on the sensor together.
(6) The ground of the CS125 and the earth of any RS485 equipment cannot be further apart than this
voltage. A 100 resistor can be used to connect the CS125 RS485 earth to other equipment. This will
reduce any parasitic currents and bring the two earths closer together if a direct connection cannot be
made.
If a CS215 is being used the supply voltage should not
exceed 16V.
4. Supported data rates for RS232 and RS485
Serial setting 8N1
Supported data rates
1200 bps
2400 bps
9600 bps
19200 bps
38400 bps - default
57600 bps
115200 bps
4
Supported formats
Minimum
Value
Nominal
Value
Maximum
Value
Sensor temperature ranges
Operating temperature
-25°C
-
+60°C
Extended operating temperature
-40°C
-
+70°C
(1)
Storage temperature
-40°C
-
+85°C
Sensor humidity ranges
Operating humidity range
0%
-
100%
Sensor heater thresholds
Dew heater Turn On
-
<35°C
-
Dew heater Turn Off
-
>40°C
-
Hood heater Turn On
-
<5°C
-
Hood heater Turn Off
-
>15°C
-
RS232 (Full duplex only), default
RS485 (Half duplex)
8 bit data bytes
1 stop bit
Parity checking is not supported as most communication protocols used by
the CS125 have built in checksums as well as checks that communications
have been understood
5. Environmental specifications
User Guide
(1) Extended temperature ranges are only guaranteed if the sensor has been tested by Campbell
Scientific and verified within this temperature range. Some degradation of absolute accuracy can be
expected at the extremes of the extended ranges.
6. Mechanical specifications
Main body including base mount
Height: 447 mm
Width: 640 mm
Depth: 245 mm
Sensor weight: 3 Kg
Sensor mounting: Bracket mounts on a vertical pole 32-52.5 mm diameter. The
mounting bracket has cut-outs for band clamps for larger
diameter masts.
Shipping weight: 6 Kg (including packing box)
7. Installation procedure
The CS125 measures environmental variables and is designed to be located in
harsh weather conditions. However there are a few considerations to take into
account if accurate and representative data from a site are to be obtained.
5
CS125 Present Weather Sensor
NOTE
Receiver
Transmitter
The descriptions in this section are not exhaustive. Please refer to
meteorological publications for further information on locating
weather instruments
The CS125 should be sited in a position representative of local weather conditions
and not of a specific microclimate (unless the analysis of microclimate weather is
being sought).
The CS125 has good resistance to background light but it is a good idea to avoid
locations where the transmitter is pointing at a light scattering or reflecting
surface. Ideally the receiver should point north in the northern hemisphere and
south in the southern hemisphere but this is not critical if the field of view does
not include a bright and scattering surface.
To give non-microclimatic measurements the CS125 should be sited away from
possible physical obstructions that could affect the fall of precipitation. The
CS125 should also be positioned away from sources of heat, electrical interference
and in such a position as to not have direct light on the sensor lenses. Whenever
possible, the CS125 should be located away from windbreaks.
Several zones have been identified upwind and downwind of a windbreak in
which the airflow is unrepresentative of the general speed and direction. Eddies
are generated in the lee of the windbreak and air is displaced upwind of it. The
height and depth of these affected zones varies with the height and to some extent
the density of the obstacle.
Generally, a structure disturbs the airflow in an upwind direction for a distance of
about twice the height of the structure, and in a downwind direction for a distance
of about six times the height. The airflow is also affected to a vertical distance of
about twice the height of the structure. Ideally, therefore, the CS125 should be
located outside this zone of influence in order to obtain representative values for
the region.
In order to reduce the service frequency with the unit, the CS125 should be placed
away from sources of contamination, in the case of roadside monitoring; larger
mounting poles can be used. More regular maintenance will be required when the
instrument is placed in areas where contamination is unavoidable or where
measurements may be safety critical.
The WMO recommend a sample volume height of 1.5 m. However, for
applications such as aviation or road visibility other heights may be appropriate.
6
NOTE
NOTE
If operating a CS125 indoors it is likely that there will be sources of
light and/or reflections that will create false readings and erratic
results.
If carrying out simple checks, blocking a lens or the sample volume
will simulate an INCREASE in visibility not a decrease.
7.1 Equipment grounding
User Guide
The CS125 must be properly grounded by taking a ground wire with a minimum
cross sectional area of 6 mm2 and maximum length of 5 m from the brass
grounding lug in the lower face of the electronics enclosure to an adequate
grounding point. The pole and foundations of a pole mounted installation will
provide some basic lightning protection and protection against radio frequency
interference and should also be correctly grounded.
7.2 Mounting the CS125
A pole mounting kit is supplied with the CS125. To mount the CS125 onto a pole:
1. Offer up the DSP plate to the pole and present the `V’ bolts from the other side
as shown.
2. Clamp the pole between the DSP plate and brackets by tightening using the
nuts and washers provided.
3. If a power supply enclosure has been supplied with the sensor it can be
mounted on the pole, near its base using the brackets supplied with the
enclosure. Alternatively the power supply can be mounted elsewhere, e.g. on a
wall at some distance from the sensor. The power supply enclosure should be
7
CS125 Present Weather Sensor
CAUTION
CAUTION
mounted away from the sensor head to avoid wind flow disturbance or rain
drops bouncing back up into the sensor’s sensing volume.
Take care not to overtighten the nuts on the bolts, as it may
be possible to distort and/or damage the brackets or DSP
plate by doing so, and/or the nuts may seize up. Only tighten
the nuts to a degree necessary to hold the CS125 firmly in
place.
Where the CS125 is to be mounted onto another type of mast, please refer to
the manual for that mast for mounting details.
Ensure that the CS125 is mounted according to the figure
below. Do not reposition, once fixings are tightened, by
forcing the arms of the unit as this can cause damage.
Slots are provided to allow band clamps to be used with larger diameter masts.
8
7.3 Optional Campbell Scientific Mount
A Campbell Scientific `optical sensor mount’, part number 009354, is available.
This will put the sample volume at about 1.5 m in compliance with the WMO
`Guide to Meteorological Instruments and Methods of Observation’, 7
Section 9.3.4.
User Guide
th
Edition,
If one is to be used, follow the installation instructions below.
The mount should be installed on a concrete foundation. If one does not already
exist then a concrete foundation should be constructed at least 600 mm square and
600 mm deep. Ensure the ground consistency is not too loose and will be able to
support the mount and concrete foundation.
9
CS125 Present Weather Sensor
Drill four 12 mm diameter holes using the mount base as a template or following
the drawing below to a depth of 77 mm.
Clean the holes of all debris.
Place washers and nuts on the ends of the wedge anchors supplied (to protect the
threads during installation).
Hammer the wedge anchors into the holes until the start of the threads are below
the surface.
Tighten the nuts until about 25 mm of thread protrudes above the surface.
Remove the washers and nuts from the protruding length screw. Then lower the
mount into place.
Finally secure the mount with the washers and nuts.
If the surface is not level and flat it may be necessary to add washers under the
base on one or more of the foundation screws.
10
8. CS125 internal connectors’ description
CAUTION
CAUTION
The CS125 has three standard IP66 rated glands. The first gland is by default used
by the power/communications line. This comprises the +12V/24V for the main
electronics, and the serial communications wires. The CS125 is supplied with 5 m
cable already connected.
The second gland is used for the 24 V feeds for the hood heaters fitted with a 5 m
cable.
The third gland is spare.
If the power cable is incorrectly wired to the CS125 then
irrevocable damage can be done to the unit.
10 m is the longest length of the cable type supplied
recommended. In particular, additional RS485 communication
should be twisted pair. Please contact Campbell Scientific if
you wish to use a longer length of cable.
User Guide
A configuration cable, part number 010817, is available from Campbell Scientific
that plugs directly into connector B, in place of the normal connector and cable.
The configuration cable is fitted with a 9-way D connector for use with a PC serial
port or USB to serial adaptor.
11
CS125 Present Weather Sensor
Connector A
Five way connector
Pin number
Description
Notes
Pin 1
+12V
Main electronics 12V supply input (also supports 24V DC)
Pin 2
0V
Auxiliary Electronics 0V. Common with the main electronics 0V.
Pin 3
Hood low
Hood heater –V input, this input is totally separate to the main
electronics 0V within the sensor so can be connected to a separate
power supply. However, this pin should not be more than 5V
different from the main electronics 0V.
Pin 4
0V
Auxiliary Electronics 0V. Common with the main electronics 0V.
Pin 5
Hood high
Hood heater +V input (Normally 24V)
Connector B
Three way connector
Pin number
Description
Notes
Pin 1
0V
0V connection for serial communications. This connection is
common with the main electronics 0V (Connector A, pin 2).
Pin 2
Receive
RS232 receive line. Also, acts as the Y transmit line in RS485 half
duplex mode and the A receive line
Pin 3
Transmit
RS232 transmit line. Also, acts as the Z transmit line in RS485 half
duplex mode and the B receive line
Connector C – USER ALARMS
Four way connector
Pin number
Description
Notes
Pin 1
0V
0V connection for user alarms. This connection is common with the
main electronics 0V (Connector A, Pin 2).
Pin 2
User 2
Output for user alarm 2
Pin 3
0V
0V connection for user alarms. This connection is common with the
main electronics 0V (Connector A, Pin 2).
Pin 4
User 1
Output for user alarm 1
CS215 Connector
Three way connector
Pin number
Description
Pin 1
+12V
Pin 2
SDI-12
Pin 3
0V
NOTE
To use these connections it is necessary to either use the cable gland
taking the hood heater power or, if the hood heater is also required,
to use different cables to those supplied. Please contact Campbell
Scientific if you need any advice on choice of cable.
12
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