Campbell Scientific CS125 User Manual

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USER GUIDE

CS125

Present Weather Sensor

Issued: 3.6.14

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:

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

) = 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

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

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

CS125 Present Weather Sensor

WARNING

CAUTION

NOTE

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. Technical specification

Minimum

Value

Nominal

Value

Maximum

Value

Main power supply for DSP and dew heaters

Power supply, +12V connection (DC only)

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

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

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

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.

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.

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

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.

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

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.

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.

8. CS125 internal connectors’ description

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.

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

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

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 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 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 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

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.

User Guide

8.1 CS125 recommended wiring using Campbell Scientific cables

(this cable is supplied already connected as standard)

The CS125 is provided pre-wired with a default 5 m power and communications cable which is terminated at one end with a 9 pin D-connector (DB9). The Dconnector can be connected directly to a PC or to a datalogger such as the Campbell Scientific CR1000 using a suitable interconnecting cable such as the SC110. If another type of connection is required then the D-connector should be removed.

CS125 Present Weather Sensor

9. CS215 T/RH Sensor

A CS215 temperature and RH sensor can be connected to the CS125. This is recommended as it will improve the performance of the CS125 in identifying precipitation and allows it to, for example, distinguish between mist and haze. Precipitation identification at temperatures close to freezing will be much improved by a CS215 and its use is highly recommended in regions where temperatures close to 0°C are common if information on precipitation type is important. It also allows RH information to be included in data messages.

If a CS215 is connected then the temperature used for assessment of precipitation type and included in data messages will come from the CS215 instead of the temperature sensor mounted in the cross arm.

The connections for the CS215 are shown below. The CS215 itself can be mounted in a Met20 screen on the same mast as the CS125. The screen can be mounted on the top section of an OSM1 optical mast below a CS125.

WMO – No. 8, 2.1.4.1 recommends temperature measurement at a height of between 1.2 and 2.0 m above ground. The screen should be below the height of the CS125 electronics box.

User Guide

IMPORTANT

10. Functions of the internal switches

The CS125 is equipped with four switches located within the main enclosure. These switches perform certain functions at power up, their functions are detailed below.

The switches are only read during the power up sequence of the CS125. This means that if the switches are pressed whilst the CS125 is running nothing will happen, the sensor will need to be power cycled leaving at least 10 seconds with the sensor off for any of their functions to be performed.

CS125 Present Weather Sensor

Internal switch functions

Switch number

Function

Reserved for future use

When switched to the ON position this switch temporarily sets the CS125 communications port to a default RS232 communication state (38400 bps). This is useful during field tests or maintenance when the CS125 has been remotely configured for RS485 mode or a baud rate your PC does not support. This change is temporary and will not be stored to flash. Once this switch is returned to its OFF position and the CS125 is power cycled the CS125 will return to its previous communications settings.

Reserved for future use, set to OFF.

When switched to the ON position this switch will reset the CS125 to its factory default values. This reset will affect all communication setting and will replace the user calibration settings with the factory defaults. This will take immediate effect upon power up.

NOTE

11. Message Formats: A breakdown of the different default outputs of the CS125 – Basic/Partial/Full

The CS125 has three different standard message formats available to the user. These three outputs are named Basic, Partial and Full. All parameters are space delimited with a unique start and end character allowing easy storage into any logger (see Section 15 on how to set default outputs). The SYNOP Full Format message is the default message.

STX and ETX are hexadecimal command characters.

STX

Message

Sensor ID

System

status

Visibility

distance

Visibility

units

Checksum

(CCITT)

EXT

Carriage

return

Line feed

0x02

0 M or F

XXXX

0x03

0x0D

0x0A STX

Message ID

Sensor ID

System status

Message

interval

Visibility

distance

Visibility

units

User alarms

Checksum

(CCITT)

EXT

Carriage

return

Line feed

0x02

1 M or F

0 0 XXXX

0x03

0x0D

0x0A STX

Message

Sensor ID

System

status

Message

interval

Visibility

distance

Visibility

units Averaging

duration

User

alarms System

alarms

10 characters

Checksum

(CCITT)

EXT

Carriage

return

Line feed

0x02

2 M or F

0 0 0 0 0 0 0…

XXXX

0x03

0x0D

0x0A

NOTE

11.1 Visibility Only messages (CS120 emulation)

Basic Format, Visibility Only

Partial Format, Visibility Only

User Guide

Refer to Appendix B for the checksum algorithm.

Full Format, Visibility Only

CS125 Present Weather Sensor

STX

Message ID

Sensor ID

System status

Visibility

distance

Visibility

units

SYNOP Code

Checksum

(CCITT)

EXT

Carriage

return

Line feed

0x02

M or F

00-99

XXXX

0x03

0x0D

0x0A

STX

Message ID

Sensor ID

System status

Message

interval

Visibility

distance

Visibility

units

User alarms

Particle count (minute)

Intensity (mm/h)

SYNOP Code

Temperature (deg C)

Relative humidity*

Checksum

(CCITT)

EXT

Carriage

return

Line feed

0x02

M or F

0 0

00-99

XXXX

0x03

0x0D

0x0A

STX

Message ID

Sensor ID

System status

Message interval

Visibility distance

Visibility units Averaging duration

User alarms System alarms

12 characters Particle count (minute)

Intensity (mm/h)

SYNOP Code

Temperature (deg C)

Relative humidity*

Checksum

(CCITT)

EXT

Carriage Return

Line feed

0x02

5 M or F

0 0 0 0 0 0 0…

00-99

XXXX

0x03

0x0D

0x0A

11.2 Messages with SYNOP Present Weather Codes

SYNOP Present Weather Basic Format

SYNOP Present Weather Partial Format

SYNOP Present Weather Full Format

11.3 Messages with METAR Present Weather Codes

STX

Message ID

Sensor ID

System status

Visibility

distance

Visibility

units

METAR Code

Checksum

(CCITT)

EXT

Carriage

return

Line feed

0x02

6 M or F

XXXX

0x03

0x0D

0x0A

STX

Message ID

Sensor ID

System status

Message interval

Visibility distance

Visibility units

User alarms

Particle count (minute)

Intensity (mm/h)

SYNOP Code

METAR Code

Temperature (deg C)

Relative humidity*

Checksum

(CCITT)

EXT

Carriage return

Line feed

0x02

7 M or F

0 0 XXXX

0x03

0x0D

0x0A

STX

Message ID

Sensor ID

System status

Message interval

Visibility distance

Visibility units Averaging duration

User alarms System alarms

12 characters

Particle count (minute)

Intensity (mm/h)

SYNOP Code

METAR Code

Temperature (deg C)

Relative humidity*

Checksum (CCITT)

EXT

Carriage Return

Line feed

0x02

8 M or F

0 0 0 0 0 0 0…

XXXX

0x03

0x0D

0x0A

METAR Present Weather Basic Format

METAR Present Weather Partial Format

User Guide

METAR Present Weather Full format

*Note: relative humidity is only available if a CS215 temperature and RH sensor is attached. If not this field is “-99”.

CS125 Present Weather Sensor

Message ID break down

Definition

Basic format. Contains only distance and system information

Partial format. Contains user alarm outputs

Full format. Contains all system alarms codes

Basic SYNOP present weather format

Partial SYNOP present weather format

Full SYNOP present weather format

Basic METAR present weather format

Partial METAR present weather format

Full METAR present weather format

Sensor ID break down

Definition

0-9

Unit number defined by the user to aid identification of data. Zero by default. Useful for RS485 networks. Operates as an address in RS485 mode

System status break down

(1)

Status level

Definition

No fault

Possible degraded performance

Degraded performance

Maintenance required

Message interval

Time

Definition

1-3600

The amount of time, in seconds, between outputs in continuous mode

Visibility distance break down

Definition

0-32,000 metres

Current visibility distance being detected by the sensor

Visibility units break down

Definition

Metres

Feet

Averaging duration break down (see note below)

Definition

One minute average

Ten minute average

(1) System status break down reflects the highest level of severity of any active alarm.

Note: In accordance with WMO requirements the CS125 produces visibility measurement that are either one or ten minute rolling averages that are updated at the chosen output interval or when the sensor is polled. Those averages are not direct averages of MOR measurements but are averages of extinction coefficient and that average is then used to calculate the MOR for that period. As the relationship between extinction coefficient and MOR is not linear it is possible to see quite rapid changes in MOR that might not be expected if the result was a rolling average of MOR. Please consider this, especially when testing the sensor with artificial obscurants or using the calibration disc.

User Guide

User alarms

Range

Definition

0-1

Visibility either less or greater than a user specified threshold

0-1

Visibility either less or greater than a user specified threshold

System alarms break down

Alarm

Range

Severity

(2)

Definition

Emitter failure

0-2

(1)

The emitter hoods main LED output power level. 0 = Everything is within normal parameters 1 = Light output level too low 2 = Light output level too high

Emitter lens dirty

0-3

0 = OK. The reported attenuation is below 10%. 1 = Reported window signal value is too low (Possible sensor fault) 2 = Slight dirt build up (10% signal attenuation or higher) 3 = High level of dirt build up (The hood could be blocked)

Emitter temperature

0-3

1 or 2

0 = Temperature is within operating conditions 1 = Too low. Less than -40°C. 2 = Too high. Over 80°C. 3 = No sensor detected or below -54°C (Severity 2)

Detector lens dirty

0-3

Detector temperature

0-3

1 or 2

0 = Temperature is within operating conditions. 1 = Too low. Less than -40°C. 2 = Too high. Over 80°C. 3 = No sensor detected or below -54°C (Severity 2)

Detector DC saturation level

0-1

The amount of background light as seen by the detector hood. 0 = Within limits 1 = Saturated. The CS125 no longer has enough head room to perform visibility readings in most circumstances.

Hood temperature

0-3

1 or 2

0 = Temperature is within operating conditions. 1 = Too low. Less than -40°C. 2 = Too high. Over 80°C. 3 = No sensor detected or below -56°C (Severity 2)

External temperature

0-3

1 or 2

0 = Temperature is within operating conditions. 1 = Too low. Less than -40°C. 2 = Too high. Over 80°C. 3 = No sensor detected or below -54°C (Severity 2)

Signature error

0-1

0 = Signature of entire flash matches the stored version 1 = Signature does not match previous readings

Flash read error

0-1

0 = No errors 1 = One or more errors reading user variables from flash occurred

Flash write error

0-1

0 = No errors 1 = One or more errors writing user variables to flash occurred

Particle limit

0-1

0 = No errors 1 = More particles detected than can be processed.

(1)

The emitter power level reporting too high will cause the CS125 to shut down and go into low power mode.

(2)

The severity of the alarm. The higher the number the more serious the error is considered to be.

CS125 Present Weather Sensor

Particle count

Range

Definition

0-7200

Value represented by an integer number of the current number of particle per minute. (-99 indicates either an error or that the sensor has been powered less than one minute)

Intensity value

Range

Definition

0-100.0

Value represented by a single precision value of the last hours rainfall intensity in millimetres (-99 indicates either an error or that the sensor has been powered up less than minute)

SYNOP code

Range

Definition

See section 10.2

SYNOP weather code for the last minute as defined by the WMO code table 4680. (-1 indicates either an error or that the sensor has been powered up less than a minute)

METAR code

Range

Definition

See section 10.3

METAR weather code for the last minute as defined by the WMO code table 4678.

External temperature

Range

Definition

-40.0 - +80.0°C

External temperature in degrees Celsius

Relative humidity

Range

Definition

0 - 100

External relative humidity in %RH (-99 indicates either a fault or no CS215 T/RH sensor is connected)

11.4 Example CS125 message outputs

Basic format (visibility only)

0 9 0 6682 M ABCD

SYNOP present weather partial format

4 9 0 60 6682 M 0 0 54 4.5 63 20.2 91 ABCD

METAR present weather full format

8 9 0 60 6682 M 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 54 4.5 63 +RA 20.2 91 ABCD

Where: 9 is the sensor id

60 is the message interval (60 seconds) 6682 is the visibility in metres M is the visibility units (metres) 54 is particle count

4.5 is intensity (4.5 mm/hr) 63 is the SYNOP code (heavy rain) +RA is the METAR code (heavy rain)

20.2 is the temperature (20.2 deg. C) 91 is the RH (91%) ABCD is the checksum

11.5 SYNOP Codes produced by the CS125

The following SYNOP codes from WMO table 4680 can be output by the CS125.

00 No significant weather observed 04 Haze or smoke, or dust in suspension in the air, visibility equal to, or greater

than, 1 km

05 Haze or smoke, or dust in suspension in the air, visibility less than 1 km

Note: Codes 04 and 05 will only be returned if a CS215 is present to provide relative humidity, otherwise they will default to mist (10) or fog (20, 30 or 35).

10 Mist

Code figures 20–26 are used to report precipitation, fog (or ice fog) or thunderstorm at the station during the preceding hour but not at the time of observation.

20 Fog 21 PRECIPITATION 22 Drizzle (not freezing) or snow grains 23 Rain (not freezing) 24 Snow 25 Freezing drizzle or freezing rain

30 FOG 35 Fog, depositing rime

40 PRECIPITATION

51 Drizzle, not freezing, slight 52 Drizzle, not freezing, moderate 53 Drizzle, not freezing, heavy 54 Drizzle, freezing, slight 55 Drizzle, freezing, moderate 56 Drizzle, freezing, heavy 57 Drizzle and rain, slight 58 Drizzle and rain, moderate or heavy

61 Rain, not freezing, slight 62 Rain, not freezing, moderate 63 Rain, not freezing, heavy 64 Rain, freezing, slight 65 Rain, freezing, moderate 66 Rain, freezing, heavy 67 Rain (or drizzle) and snow, slight 68 Rain (or drizzle) and snow, moderate or heavy

71 Snow, slight 72 Snow, moderate 73 Snow, heavy

User Guide

CS125 Present Weather Sensor

11.6 METAR Codes produced by the CS125

The following METAR codes from WMO table 4678 can be output by the CS125.

UP Unidentified precipitation HZ Haze BR Mist FG Fog DZ Drizzle RA Rain SN Snow SG Snow grains PL Ice pellets

Notes:

HZ will only be reported if a CS215 is connected to allow relative humidity information to be available.

FZ (freezing) may be added as a descriptor in front of BR, FG, DZ and RZ

Intensity qualifiers, ‘-‘ for light, ‘+’ for heavy, may be added in front of DZ, RA, SN, SG and PL

Combinations, for example RASN for rain and snow can be reported.

12. Interface methods – Device Configuration Utility/Command line/Menu

The CS125 can be setup and controlled in one of three ways.

The first method is by using Campbell Scientific’s Device Configuration Utility Software (DevConfig) which is included with each delivery on the manuals/ resource disk. This software allows an easy menu driven interface for configuring the CS125 on any Microsoft™ based personal computer. All settings can be accessed using this program.

The program includes online help instructions that describe its general use with the CS125 and also how to load an operating system.

The Device Configurator can also be used as a terminal emulator to use the builtin menu system of the CS125 and to access its calibration menu.

The second method is by using the command line interface where discrete commands are sent without response from the sensor. This would be the preferred method of setting up a CS125 if it was connected to a logger for instance. The configuration setting commands can be sent via a logger to the CS125 removing the need for a local PC to set up the unit.

The third method is by using the simple menu interface built into the CS125 communicating via RS232 or RS485, using a terminal emulator program. This menu system gives access to the more common settings.

All three of these methods use the CS125s serial port A to communicate with the sensor. Configuration cable part number 010817, described in section 8.1 can be used.

12.1 Configuring a PC for talking to the CS125

Described below is the procedure for setting up communications using a terminal emulator program. The terminal emulators built into many Campbell Scientific software products can also be used.

The following settings should then be used by default:

Bits per second: 38400 Data bits: 8 Parity: none Stop bits: 1 Flow control: none

Ensure that if the baud rate of the unit has been adjusted and then the corresponding bits per second value is entered in the port settings of the terminal emulator. The CS125 should now be ready to accept commands.

It is possible to set the CS125 into the default communication state via one of the internal switches on the CS125 main board. See section 9.

User Guide

13. Definition of the variables that can be set by the user on the CS125

Both DevConfig and the command line interface can access all the user configurable variables within the CS125. The acceptable range and the identification number for these variables are listed below along with a short description.

CS125 Present Weather Sensor

Name

Range

Description

Factory default

Sensor ID

0-9

Separate ID used as an extra identifier for a particular CS125 on a network.

User Alarm 1 Enabled

0-1

User alarm one activation state 0 = Alarm one disabled 1 = Alarm one enabled

User Alarm 1 Active

0-1

0 = Check if distance is less than ‘User alarm 1 Distance’ 1 = Check if distance is greater than ‘User alarm 1 Distance’

User alarm 1 Distance

060000

Distance value that alarm one will trigger against. This value will correspond to metres or feet

depending upon which is selected in ‘Visibility

Unit’

10000

User Alarm 2 Enabled

0-1

User alarm two activation state 0 = Alarm two disabled 1 = Alarm two enabled

User Alarm 2 Active

0-1

0 = Check if distance is less than ‘User alarm 2 Distance’ 1 = Check if distance is greater than ‘User alarm 2 Distance’

User alarm 2 Distance

060000

Distance value that alarm one will trigger against. This value will correspond to metres or feet

depending upon which is selected in ‘Visibility

Unit’

10000

Baud rate

0-6

Baud rate for the main RS232/RS485 interface 0 = 115200 bps 1 = 57600 bps 2 = 38400 bps 3 = 19200 bps 4 = 9600 bps 5 = 2400 bps 6 = 1200 bps

Serial Number

032000

Internal serial number for the CS125. (Read only)

Visibility Unit

M or F

Unit the visibility value will be presented as. M = metres F = feet

Message Interval

1-3600

Interval in seconds between outputs in continuous mode. This value has no effect if polled mode has been selected in ‘Measurement mode’

Measurement mode

0-1

Selects polled or continuous modes. In continuous mode the sensor will output a string

in the format as set by ‘Message Format’ at regular

intervals as defined by ‘Continuous Interval’.

0 = Continuous mode 1 = Polled mode

Message Format

0-8

Level of detail outputted by polled or continuous modes 0, 1 and 2 = Basic, partial or full visibility messages 3, 4 and 5 = Basic, partial or full SYNOP messages 6, 7 and 8 = Basic, partial or full METAR messages

User Guide

Serial port protocol

0-1

Selects the physical serial interface 0 = RS232 mode 1 = RS485 mode

Averaging period

1 or 10

The period of time that the visibility value should be averaged over. Either one minute or ten.

Sample timing

1-60

Used to define the time interval between sampling the volume. It is recommended that this value is left at one except when very low power demands are needed. For example: 1 = Sample every second 2 = Sample one second in every two 3 = Sample one second in every three etc.

Dew heater override

0-1

0 = Allow the CS125 to automatically control the dew heaters 1 = Turn the dew heaters off

Hood heater override

(1)

0-1

0 = Allow the CS125 to automatically control the hood heaters 1 = Turn the hood heaters off

Dirty window compensation

0-1

0 = No compensation applied 1 = Compensation for dirt on lenses applied. The CS125 will compensate for up to 10% signal loss due to dirt per lens.

Use CRC

0-1

0 = Disable command line CRC checking

(2)

1 = Enable command line CRC checking Note: this does not affect communications via DevConfig or terminal emulator.

Sensor power down voltage

7-30

PSU Input voltage level below which the CS125 will enter low power mode. This is usually used to protect batteries.

7.0

Relative humidity threshold

1-99

Threshold at which the CS125 will define obscuration as liquid or dry if a CS215 is fitted.

80%

(1) Hood heater override needs to be set to `1’ (off) when either no hood heaters are installed or the hood heaters have no power connected to them. This will save power as the relay is not enabled at low temperatures in this mode.

(2) If disabled the sensor does not check the validity of received data against the checksum sent. It is, however, recommended that checksum checking is enabled to remove any chance of the CS125 being configured incorrectly by accident.

14. Command line mode

The command line interface is broken down into three major commands. These are GET, SET and POLL. The GET command is used to request all current user settable values from the CS125. The SET commands sets user settable values and the POLL command is used to request the current visibility and/or alarm conditions from the sensor.

The CS125 can be configured to expect any commands sent to it to include a valid checksum. For simple commands, e.g. GET and POLL, fixed value checksums can be used (see the example programs). For more complex SET commands the checksum needs to be calculated (see Appendix B). The use of the checksum is disabled by default. It is recommended that the checksum functionality is enabled where possible, especially when long cable runs are used, or in electronically noisy environments.

CS125 Present Weather Sensor

SET transmitted data

Example

Description

0x02

(1)

STX ^B

(2)

Delimiting character

SET

Delimiting character

Address based on Sensor ID

Delimiting character

Sensor ID

User Alarm 1 Set

User Alarm 1 Active

User Alarm 1 Distance

User Alarm 2 Set

User Alarm 2 Active

User Alarm 2 Distance

Serial Baud Rate

Sensor serial number (read only)

Visibility Units

Message interval

Polling Or Continuous modes

Message Format (Basic/Partial/Full)

RS232 or RS485 serial communications enabled

Averaging Period

Sample timing

Dew heater override

Hood heater override

Dirty window compensation

CRC checking on received commands

Sensor power down voltage

Relative humidity threshold

Delimiting character

XXXX

Checksum (use the valid CCITT checksum)

Delimiting character

0x03

(1)

ETX ^C

(2)

0x0D

(1)

Carriage return

0x0A

Line feed

14.1 The SET command

The set command is used to configure the CS125 via the command line. The SET command is a single space delimited string that can be sent from any data logger or PC equipped with an RS232 or RS485 port. The SET command and the ‘Device Configuration Utility’ software access identical settings within the CS125, please refer to the ‘Device Configuration Utility’ section of this document for a more detailed breakdown of the setting available here. This command is used to change the default power up state of the sensor. See Section 14.2 if a setting is going to be changed on a regular basis e.g. heater controls.

See Section 12 for more information on the values used by the `SET’ command.

(1) These values are shown in hexadecimal format not ASCII. (2) As entered on a keypad.

14.1.1 Example of a SET Command

GET transmitted data

Example

Description

0x02

(1)

STX (^B)

(2)

GET

Delimiting character

Address based on Sensor ID

Delimiting character

Reserved for future use, zero default

Delimiting character

XXXX

Checksum

Delimiting character

0x03

(1)

ETX (^C)

(2)

0x0D

(1)

Carriage return

0x0A

Line feed

SETNC:0:0 1 1 1000 1 0 15000 2 0 M 60 1 2 0 1 1 0 0 0 1 7 80 :XXXX: 

SET:0:0 1 1 1000 1 0 15000 2 0 M 60 1 2 0 1 1 0 0 0 1 7 :68A3: 

GET:0:0:XXXX:

14.2 The SETNC Command

The format of the SETNC command is nearly exactly the same as the SET command. The only functional difference is that the SETNC command does not commit the values set into flash memory. This means that the next time the CS125 is power cycled it will revert back to its previous settings. This command should be used when a setting in the sensor is changed regularly, e.g. heater functions, as this command avoids the risk of wearing out the flash storage memory. Note: this includes communication data rates as well.

14.2.1 Example of a SETNC Command

User Guide

14.3 The GET Command

The GET command retrieves settings data from the CS125, including message format data and user alarm settings amongst others. This command does not retrieve visibility or environmental information from the CS125. To retrieve visibility data refer to the POLL command.

The GET request

(1) These values are shown in hexadecimal format not ASCII. (2) As entered on a keypad

Example of a GET command

CS125 Present Weather Sensor

GET returned data

Example

Description

0x02

(1)

STX

Sensor ID

User Alarm 1 Set

User Alarm 1 Active

User Alarm 1 Distance

User Alarm 2 Set

User Alarm 2 Active

User Alarm 2 Distance

Serial Baud Rate

Sensor serial number (read only)

Visibility Units

Message interval

Polling Or Continuous modes

Message Format (Basic/Partial/Full)

RS232 or RS485 serial communications enabled

Averaging Period

Sample timing

Dew heater override

Hood heater override

Dirty window compensation

CRC checking on received commands

Sensor power down voltage 7.0

Relative humidity threshold

Delimiting character

XXXX

Checksum

Delimiting character

0x04

(1)

EOT

0x0D

(1)

Carriage return

0x0A

Line feed

Example data returned by the GET command – See Section 12 for more information on values returned by the `GET’ command

(1) These values are shown in hexadecimal format not ASCII.

Example of a GET returned data

0 0 0 10000 0 0 10000 2 1009 M 30 0 2 1 1 1 0 0 0 1 11.5 D4FD

Explanation: -

Sensor ID = 0 User Alarm 1 not set User Alarm 1 not active User Alarm 1 distance = 10000 metres User Alarm 2 not set User Alarm 2 not active

User Guide

POLL transmitted data

Example

Description

0x02

(1)

STX, ^B

(2)

POLL

Delimiting character

Address based on Sensor ID

Delimiting character

Reserved for future use, zero default

Delimiting character

XXXX

Checksum

(3)

Delimiting character

0x03

(1)

ETX, ^C

(2)

0x0D

(1)

Carriage return

0x0A

Line feed

User Alarm 2 distance = 10000 metres Serial baud rate 2 (=38400Bd) Serial number = 1009 Visibility Units = M Continuous mode output interval = 30 seconds Polling mode = 0 (continuous mode) Message format = 2 (full message) RS232 or RS485 serial communications = 1 ( RS485) Averaging period = 1 minute Sample timing = 1 sample per second Dew heater override = 0 (CS125 will automatically control the dew heaters) Hood heater override = 0 (CS125 will automatically control the hood heaters) Dirty window compensation = 0 (dirty window compensation off) CRC checking on received commands = 1 (CRC checking enabled) Sensor power down voltage = 11.5V Checksum = D4FD

14.4 The POLL command – Polling the CS125

The POLL command requests the current visibility and/or alarm conditions from the CS125. The output format of this command depends on how the CS125 is configured using the SET command or the menu interfaces.

The POLL request

(1) These values are shown in hexadecimal format not ASCII. (2) As entered on a keypad. (3) Not case sensitive.

CS125 Present Weather Sensor

NOTE

POLL:0:0:XXXX:

WELCOME TO THE CAMPBELL SCIENTIFIC LTD CS125 SETUP MENU ID 0 S/N 1003 (1) Message output menu (2) User alarm menu (3) Calibrate CS125 (4) Communications setup (5) System configuration

(9) Exit and save (0) Exit and don't save

Example of a POLL request

The maximum response time to a poll command is 100 ms.

If the setting to check the checksum on received commands is enabled the checksum varies with the Sensor ID value.

15. Entering the CS125 menu system

The user can enter the menu system by typing ‘open id’ into their terminal program then pressing the return key on their keyboard. The id corresponds to the sensor ID number. The Sensor ID number can be in the range of 0 to 9. The factory default is 0.

The ‘open 0’ command is not normally echoed. The terminal menu only gives access to more common settings.

The following text should now be displayed:

The displayed options are accessed simply by typing the corresponding number then pressing return. No changes will take effect until you `save and exit’. The exception to this is the calibration menu, but you will be informed before any changes are made.

The displayed options are accessed simply by typing the corresponding number then pressing return. No changes will take effect until you `Exit and Save’. The exception to this is the calibration menu, but you will be informed before any changes are made.

Typing `1’ opens the message menu containing settings relating to the CS125’s outputs.

User Guide

CS125 ALARM - MENU 2 ID 0 S/N 1009 (1) Toggle user alarm one: DISABLED (2) Toggle alarm one threshold: LESS THAN (3) Set new user alarm one activation point: 10000 m (4) Toggle user alarm two: DISABLED

(5) Toggle alarm two threshold: LESS THAN (6) Set new user alarm two activation point: 10000 m

(9) Refresh (0) Return to main menu

CS125 CALIBRATION - MENU 3 ID 0 S/N 1003 (1) Perform calibration (2) Restore the factory calibration (3) Perform dirty windows zero offset calibration (4) Restore dirty windows factory calibration

(9) Refresh

(0) Return to main menu

CS125 MESSAGE - MENU 1 ID 0 S/N 1009 (1) Toggle message format:FULL (2) Toggle units:METRES (3) Toggle polled or continuous mode:CONTINUOUS (4) Set continuous mode output interval:6 second(s) (5) Toggle output averaging period: 1 minute(s) (6) Sampling interval:1 second(s)

(9) Refresh (0) Return to main menu

Menu 1: The message output menu

For example, typing `2’ will toggle the units through the options `METRES’ and

`FEET’ and typing `4’ will allow the message interval to be entered.

Option (2) allows the User Alarms to be set, again by toggling through options or changing values.

Menu 2: The user alarm menu

Menu 2: The user alarm menu. Sub menu 2: Alarm two activation level (Option 6)

Option (3) is the calibration menu

Menu 3: The calibration menu

CS125 Present Weather Sensor

NOTE

CS125 INFORMATION - MENU 4 ID 0 S/N 1003 OS version: 007646v1

Alarm Value

- Last visibility reading: - 3258M

- Overall system status: 0 No faults

- Emitter dirty window alarm: 0 0%

- Emitter internal temperature: 0 38.4

- Detector dirty window alarm: 0 0%

- Detector internal temperature: 0 31.0

- Detector DC light saturation: 0 -

- Hood heater temperature: 0 25.6

- CS125 Calibrator Serial No: - 1000

- CS125 Calibrator Constant: - 30.5

- Calibration value Fac offset: - -0.026

- Calibration value Fac scale: - 0.02682

- Calibration value Cal offset: - -0.026

- Calibration value Cal scale: - 0.02682

- Signature fault: 0 -

- Flash write errors: 0 0

- Flash read errors: 0 0

- Supply voltage: <7.0V 11.3V

- Aux supply voltages: +5V=5.0 -5V=-5.1 +6V=5.9

- External temperature: 0 26.4

- Present weather mode enabled

(8) Get debug (9) Refresh (0) Return to main menu

Consult the ‘calibration’ section of this manual for information on how to calibrate the CS125 present weather sensor.

Once a calibration is finished changes are immediate, but factory calibrations can be restored if needed using Option `(2)’ in the calibration menu. The disk constants however remain as the last disk used.

Option (4) gives the systems information menu containing useful information such as temperature and system alarms.

Menu 4: The system information menu

If either of the dirty window alarms are set it is recommended you follow the cleaning section of this manual (Section 18).

If there is a flash error or signature error it is recommended that you contact Campbell Scientific.

User Guide

NOTE

CS125 COMMUNICATIONS - MENU 5 ID 0 S/N 1009 (1) Set sensor ID (2) Set RS232/RS485 baud rate:38400 (3) Toggle RS232/RS485 modes:RS232

(9) Refresh

(0) Return to main menu

CS125 CONFIGURATION - MENU 6 ID 0 S/N 1003 (1) Dew heater override: AUTOMATIC (2) Hood heater override: AUTOMATIC (3) Dirty window compensation: NO COMPENSATION (4) Command line CRC Checking: DO NOT CHECK (5) Sensor power down voltage: 7.0V (6) RH threshold: 80%

(9) Refresh

(0) Return to main menu

The sensor power down voltage shown before the supply voltage is only available if the sensor is running firmware version 4 or later and only functional for sensors with serial number greater than E1029.

Menu 5: The communication menu

The communications menu is used to set baud rates and the mode of operation (RS232/RS485).

No change will take effect until you `exit and save’.

Menu 6: Configuration

This menu sets dew and hood heaters to automatic or off, dirty window compensation and CRC checking. In addition it allows the sensor power down voltage to be set. If set this will shut down the CS125 before the battery voltage has fallen low enough to damage a back-up battery. The RH threshold can also be set from this menu. This applies if a CS215 sensor is attached and defined the level of RH below which obscuration is deemed to be dry (that is haze, SYNOP 04 or 05, METAR HZ) rather than wet (mist, SYNOP 10, METAR BR or fog, SYNOP 30 etc. METAR FG).

CS125 Present Weather Sensor

CS125 CALIBRATION - MENU 3 ID 0 S/N 1009 (1) Perform calibration (2) Restore the factory calibration

(9) Refresh (0) Return to main menu

CAMPBELL SCIENTIFIC LTD CS125 menu exited.

Menu 9 and 0: Exiting the menu system

Options `9’ and `0’ exit from the menu system. Note that typing `0’ will lose all changes made including communications settings.

16. Calibrating the CS125

The CS125 can be checked and adjusted using the optional CS125 calibrator part number 010816. The calibration must be run using the onboard menu system. If

you have Campbell Scientific’s Device configuration program a terminal

emulation screen is provided in the CS125 screens to let you access this function. To perform the calibration you will need a CS125 calibrator disk and a computer with a standard serial port compatible with the CS125. If your CS125 is not currently configured for RS232 communications you can set the internal switch, switch three, to temporarily set the sensor to RS232 mode 38400bps. If the sensor is already set in RS232 mode it should not be necessary to change any internal switches. (See Section 10 for more information on the CS125 internal switches.)

The test should ideally be performed in the following conditions:

 Ambient temperature should be 20ºC +/-10ºC  The local visibility should be approximately 10,000 metres or higher.

The system is self-regulating. However, it is recommended that the CS125 is calibrated at least every two years.

The calibration is performed from menu item 3 on the main terminal screen. Please refer to the menu section (Section 13) of this manual for further information on how to access this menu.

Once you have selected menu item 3 you should be presented with the following screen.

Select option 1 to start the calibration. You will then be asked to confirm that you would like to perform a calibration. Please note, once you have entered yes at this point you will not be able to exit until the test is complete. However, power cycling the unit at this point will have no adverse effect on the sensor.

User Guide

CS120/125 calibrator serial number and coefficients will be within this area.

NOTE

Starting calibration. Input the CS125 calibrator serial number ->12345 Is 12345 correct? (Y/N)? Input the CS125 calibrator constant ->10000 Is 10000 correct? (Y/N)?

Place one calibration bung into each hood, then press any key.

Do you want to perform a calibration Y/N?

Once you have started the tests you will be asked for the CS125 calibrator serial number and coefficient with a confirmation at each step giving you the chance to correct typing mistakes.

When asked for confirmation you do not need to press return after you type ‘y’.

When you have entered the calibrator information the sensor will wait for you to place the foam bungs into the sensor hoods. The bungs are designed to block all light from the outside reaching inside the head. Place one bung into each hood. If either of the bungs are damaged or appear to have any gaps around the edge please contact Campbell Scientific.

CS125 Present Weather Sensor

NOTE

Starting dark level calibration. This test will take approximately two minutes

Dark level test complete. Please remove the bungs. Now place the CS125 calibrator into the sampling volume. Press any key once this is done.

This part of the test will take approximately two minutes. Every ten seconds a dot should appear indicating that the test is progressing as normal.

Remove the bungs once the sensor instructs you to. Place the CS125 calibrator into the volume by fastening it to the central mounting point.

At this stage it is advisable to clean the lenses. Refer to Section 18

`Cleaning’ for more information. A simple visual check may be

enough to confirm the lenses are clean.

User Guide

Starting light level calibration. This test will take approximately two minutes.

Calibration is now complete. Saving user settings Press any key to exit.

This part of the test will take approximately two minutes. Every ten seconds a dot should appear indicating that the test is progressing as normal.

Once the second stage of the test has been completed the new calibration constants will be saved automatically. All calibration constants including both the user and the factory setting can be viewed from menu item 4 from the main menu once the test is completed.

17. Performing a firmware update

Firmware updates for the CS125 present weather sensor are performed using Campbell Scientifics Device Configuration Utility (DevConfig) software. Please refer to the help built into the DevConfig software for full instructions on how to update the CS125 firmware.

CS125 Present Weather Sensor

NOTE

CAUTION

NOTE

18. Cleaning

The CS125 present weather sensor is a robust instrument that will provide years of uninterrupted weather monitoring. Calibration of the instrument is carried out at the factory and can be redone easily on site with the optional CS125 calibrator or carried out by Campbell Scientific if required. Only general cleaning of the lenses is required to keep the sensor working efficiently.

Cleaning of the CS125 will be required from time to time to ensure that the lenses are free from contaminants. The frequency of required cleaning depends on the exposure of the instrument to such contaminants. This will vary depending on the site location. The CS125 is capable of self diagnosing dirty lenses and will indicate in its output when the lenses are contaminated to such a degree that its visibility measurements may be affected.

A lower level of contamination than is detected by the dirty window alarms, can affect the visibility measurements. The sensor can be configured to attempt to make a correction for contamination although the accuracy of that correction depends on the `type of dirt’.

We suggest 6 monthly intervals for locations not prone to contaminants and monthly intervals for those prone to contamination (roadside or airport use). In some cases more frequent cleaning may be required where there are high levels of contaminants and high dependency on the instrument output.

If the lenses require cleaning, it is very important that only a proper lens cloth or lens tissue be used. The use of inappropriate materials to clean the lenses can permanently damage or reduce the effectiveness of the lenses leading to errors in measurement of precipitation and visibility.

It is advisable to use an air duster to blow any loose dust and dirt from the lenses as a first step. Using a lint free lens cloth or lens tissue impregnated with a small amount of isopropyl alcohol solvent clean the lens surface by dragging the cloth across the lens surface being careful not to apply excessive pressure.

Excessive pressure may lead to some types of contaminant scratching the lens surface. Over time such scratches can lead to reduced sensor accuracy.

Spiders webs and certain `fluffy’ seeds which get lodged in the optical path can lead to the sensor permanently giving low readings as they can emulate precipitation. Cleaning the contamination away with a duster will return the sensor to normal operation.

If spiders are a persistent problem, using some carefully applied insecticide can deter them.

19. Lubricating the enclosure screws

CAUTION

The CS125 enclosure screws should be lubricated with a suitable anti-seize grease (often copper loaded) to protect the threads from corrosion. This should be reapplied when resealing the enclosure at regular intervals, normally after replacing the desiccant. This is of particular importance if using the sensor in corrosive or salt laden atmospheres.

20. Desiccant

Two bags of desiccant are supplied. One is inside the enclosure, the other is separate and sealed in a plastic bag. Desiccant use depends on your application but for use in typical temperature conditions one bag is sufficient for a twelve month period. The desiccant should be placed inside the enclosure taking care that it is not trapped between the lid and the enclosure when the lid is replaced.

The second bag of desiccant should be kept in the plastic shipping bag as a replacement for when the initial bag needs to be dried out. The bags can be rotated in this way many times. Desiccant bags can be dried out by the following method:

1. Arrange the bags on a wire tray in a single layer to allow for adequate air flow

around the bags during the drying process. The oven’s inside temperature

should be room or ambient temperature (25°C - 30°C). A convection, circulating, forced air type oven is recommended for this regeneration process. Seal failures may occur if any other type of heating unit or appliance is used.

User Guide

2. When placed in a forced air, circulating air, or convection oven, allow a

minimum of 4 to 5 cm of air space between the top of the bags and the next metal tray above the bags. If placed in a radiating exposed infrared element type oven, shield the bags from direct exposure to the heating element, giving the closest bags a minimum of 40 cm clearance from the heat shield. Excessive surface film temperature due to infrared radiation will cause the Tyvek material to melt and/or the seals to fail. Seal failure may also occur if the temperature is allowed to increase rapidly. This is due to the fact that the water vapour is not given sufficient time to diffuse through the Tyvek material, thus creating internal pressure within the bag, resulting in a seal rupture. Temperature should not increase faster than 0.1°C to 0.3°C per minute.

3. Set the temperature of the oven to 118°C, and allow the bags of desiccant to

reach equilibrium temperature.

Tyvek has a melting temperature of 121°C - 127°C.

(NON MIL-D-3464E activation or reactivation of both silica gel and Bentonite clay can be achieved at temperatures of 104°C).

4. Desiccant bags should be allowed to remain in the oven at the assigned

temperature for 24 hours. At the end of this period, the bags should be immediately removed and placed in a desiccators jar or dry (0% relative humidity) air tight container for cooling. If this procedure is not followed precisely, any water vapour driven off during reactivation may be re-adsorbed during cooling and/or handling.

CS125 Present Weather Sensor

5. After the bags of desiccant have been allowed to cool in an airtight desiccator,

they may be removed and placed in either an appropriate type polyliner tightly sealed to prevent moisture adsorption, or a container that prevents moisture from coming into contact with the regenerated desiccant. Some care should be taken when re-activating desiccant bags. If heated in an oven which is too hot, the bags may burst. If in any doubt, we recommend purchasing new desiccant packs instead of oven drying. Failure to use or exchange the desiccant may lead to condensation inside the enclosure. Not only will this lead to corrupted data but, in the long term, can also cause corrosion which is expensive to repair.

Appendix A. CS125 block diagram

850nm

Emitter

Photo-

detector

Transimpedance

amplifier

Power level +

Driver circuitry

Emitter power

feedback

Dirty window

detector

Dirty window

detector

Amplifier

and filter

Amplifier

and filter

Second stage

amplifiers and filters

14-bit Analogue to

digital converter

MCU

(Micro controller unit)

Hood heater

drive

Low noise PSU

Two 5V user

alarm outputs

RS232 or RS485

serial

communications

24V

AC/DC

12V DC

Hood

temperature

A-1

CS125 Present Weather Sensor

A-2

Appendix B. Example C code of the CCITT CRC

The code below is provided as an example for programmers implementing their own code to communicate with the sensor. Users using Campbell loggers can use the Checksum command in CRBasic to generate a CCITT checksum. Command: Checksum/ChkSumString,1,0).

The checksum includes all characters excluding the SOT, EOT and the checksum itself.

The SET and SETNC commands also exclude the two delimiting `:’ characters, one on each side of the checksum itself.

//---------------------------------------------------------------------------// Creates a CCITT CRC16 checksum seeded with 0x0000 (XModem style) using a // fast non table based algorithm. // Pass in the data to convert into a CRC in the form of a NULL terminated // character array (a string). // Returns the CRC in the form of an unsigned 16 bit integer value // Note: This algorithm has only been tested on a native 16-bit processor with // a hardware barrel shifter // All integers are 16-bits long //---------------------------------------------------------------------------unsigned int CRC_CCITT(char LineOfData[]){

unsigned int crc; // returned CRC value unsigned int i; // counter

crc = 0x0000;

// create a check sum for the incoming data for(i=0;i < strlen(LineOfData); i++){ unsigned crc_new = (unsigned char)(crc >> 8) | (crc << 8); crc_new ^= LineOfData[i]; crc_new ^= (unsigned char)(crc_new & 0xff) >> 4; crc_new ^= crc_new << 12; crc_new ^= (crc_new & 0xff) << 5; crc = crc_new; }

return(crc); }

B-1

CS125 Present Weather Sensor

B-2

Appendix C. Example CRBasic programs

C.1 CRBasic read program

'CR800 'Demonstration program to read data from a CS125 set to continuous output 'with the full SYNOP (default) message being transmitted 'Note: The CS125 emits this message every minute by default.

Public Visibility 'These variables could be defined as DIM in a final program

Public InString As String * 100 'Incoming string Public SerialIndest(27) As String, NBytesReturned Public ChecksumOK As Boolean

Public lngCRCCalc As Long, lngCRCMsg As Long 'Define the aliases for the full message Alias SerialIndest(1)=Message_ID '0..2 Alias SerialIndest(2)=Sensor_ID '0..9 Alias SerialIndest(3)=System_status '0..3 Alias SerialIndest(4)=Interval_time '1..3600 Alias SerialIndest(5)=Visibilitystr '0..32000 metres Alias SerialIndest(6)= VisibilityUnits 'M or F for Metres or Feet Alias SerialIndest(7)=Averaging_duration '1 or 10 minutes Alias SerialIndest(8)=User_alarm_1 '0..1 - Visibility compared to Threshold One Alias SerialIndest(9)=User_alarm_2 '0..1 - Visibility compared to Threshold Two Alias SerialIndest(10)=Emitter_failure '0..2 - Emitter Failure Alias SerialIndest(11)=Emitter_lens_dirty '0..3 - Emitter Lens Dirty Alias SerialIndest(12)=Emitter_temp_error '0..3 - Emitter Temperature Alias SerialIndest(13)=Detector_lens_dirty '0..3 - Detector Lens Dirty Alias SerialIndest(14)=Detector_temp_error '0..3 - Detector Temperature Alias SerialIndest(15)=Detector_saturated '0..1 - Detector DC Saturation Level Alias SerialIndest(16)=Hood_temp_error '0..3 - Hood Temperature Alias SerialIndest(17)=External_temp_error '0..3 - External Temperature Alias SerialIndest(18)=Signature_error '0..1 - Signature Error Alias SerialIndest(19)=Flash_read_error '0..1 - Flash Read Error Alias SerialIndest(20)=Flash_write_error '0..1 - Flash Write Error Alias SerialIndest(21)=Particle_Limit_error '0 or 1 - Particle limit reached Alias SerialIndest(22)=Particle_Count Alias SerialIndest(23)=Intensity 'mm/h Alias SerialIndest(24)=SYNOP_code Alias SerialIndest(25)=Temperature 'deg C Alias SerialIndest(26)=Relative_Humidity '%, 0..100 Alias SerialIndest(27) = checksumrx 'CCITT Checksum 'Define the serial port to which the CS125 is connected - amend as needed Const CS125_Comport = COM1 'Main Program BeginProg 'Open the logger serial port to which the CS125 is connected SerialOpen (CS125_Comport,38400,3,0,1000)

Scan(10,Sec,1,0)

'Sensor emits a message every 60 seconds by default so this will fail 5

'times out of 6 with a 10 second scan

C-1

CS125 Present Weather Sensor

SerialInRecord(CS125_Comport,InString,&h02,0,&h03,NBytesReturned,01) 'Check that a message has been recieved first If NBytesReturned > 0 Then 'Split out the Data into strings SplitStr (SerialIndest(),InString," ",27,5) 'Check the received checksum is valid 'Calculate the expected checksum lngCRCCalc = CheckSum(InString,1,NBytesReturned-5) 'Extract the checksum from the message & convert it for comparison lngCRCMsg = HexToDec(checksumrx) ChecksumOK = ( lngCRCMsg = lngCRCCalc) 'In critical applications the visibility can be set to NaN if the system status 'is degraded or a critical error flag is set. If ChecksumOK Then Visibility = Visibilitystr Else Visibility =NaN EndIf 'Call data storage commands here NextScan EndProg

C-2

Appendix C. Example CRBasic programs

C.2 CRBasic POLL program

'CR800 'Demonstration program to read data from a CS125 set to polled output 'with the full SYNOP (default) message being transmitted 'Note: the sensor needs to be configured to behave like this, it is not setup by this program.

Public Visibility 'These variables could be defined as DIM in a final program

Public InString As String * 100 'Incoming string Public SerialIndest(27) As String, NBytesReturned Public ChecksumOK As Boolean

'Preload the poll command for a sensor for address 0, in this example 'If the sensor has a different address uncomment the relevant line Const CS125_Poll = CHR(2)&"POLL:0:0:3A3B:"&CHR(3)&CHR(13) 'address 0 'Const CS125_Poll = CHR(2)&"POLL:1:0:0D0B:"&CHR(3)&CHR(13) 'address 1 'Const CS125_Poll = CHR(2)&"POLL:2:0:545B:"&CHR(3)&CHR(13) 'address 2 'Const CS125_Poll = CHR(2)&"POLL:3:0:636B:"&CHR(3)&CHR(13) 'address 3 'Const CS125_Poll = CHR(2)&"POLL:4:0:E6FB:"&CHR(3)&CHR(13) 'address 4 'Const CS125_Poll = CHR(2)&"POLL:5:0:D1CB:"&CHR(3)&CHR(13) 'address 5 'Const CS125_Poll = CHR(2)&"POLL:6:0:889B:"&CHR(3)&CHR(13) 'address 6 'Const CS125_Poll = CHR(2)&"POLL:7:0:BFAB:"&CHR(3)&CHR(13) 'address 7

C-3

CS125 Present Weather Sensor

'Const CS125_Poll = CHR(2)&"POLL:8:0:939A:"&CHR(3)&CHR(13) 'address 8 'Const CS125_Poll = CHR(2)&"POLL:9:0:A4AA:"&CHR(3)&CHR(13) 'address 9

'Main Program BeginProg 'Open the logger serial port to which the CS125 is connected SerialOpen (CS125_Comport,38400,3,0,1000) Scan(10,Sec,1,0) 'The sensor is polled every 10 seconds SerialOut(CS125_Comport,CS125_Poll,"",0,100) SerialInRecord(CS125_Comport,InString,&h02,0,&h03,NBytesReturned,01) 'Check that a message has been recieved first If NBytesReturned > 0 Then SplitStr (SerialIndest(),InString," ",27,5) 'Check the received checksum is valid 'Calculate the expected checksum lngCRCCalc = CheckSum(InString,1,NBytesReturned-5) 'Extract the checksum from the message & convert it for comparison lngCRCMsg = HexToDec(checksumrx) ChecksumOK = ( lngCRCMsg = lngCRCCalc) 'In critical applications the visibility can be set to NaN if the system status 'is degraded or a critical error flag is set. If ChecksumOK Then Visibility = Visibilitystr Else Visibility =NaN EndIf 'Call data storage commands here NextScan EndProg

C-4

Appendix C. Example CRBasic programs

C.3 Example CRBasic SET program

'------------------------------------------------------------------------------' CS125 Visibility ' ' Program to test the SET command part of the command line interface on the CS125 ' Do not run this script for extended periods of time (days!) as it writes ' to flash over and over and will eventually wear the flash out ' Logger:CR1000 '-------------------------------------------------------------------------------

Public InString As String * 200 Public TempString As String *100

' Variables for the SET command subroutine Dim CS125CArray(21) As String * 6 ' CS125 Command Array

'------------------------------------------------------' This function creates a SET command string for the ' CS125 visibility sensor. Including all delimiting ' characters and checksums ' then returns the string in "CS125CommandString" ' Array variable order is as follows: ' 1. Sensor ID ' 2. User Alarm 1 Set ' 3. User Alarm 1 Active ' 4. User Alarm 1 Distance ' 5. User Alarm 2 ' 6. User Alarm 2 Active ' 7. User Alarm 2 Distance ' 8. Serial BaudRate ' 9. Serial number (Read only so not used) ' 10. Visibility Units ' 11. Continuous mode output interval ' 12. Polling Or Continuous modes ' 13. Message Format (Basic/Partial/Full) ' 14. RS232 or RS485 serial communications enabled ' 15. Averaging Period ' 16. Sample timing ' 17. Dew heater override ' 18. Hood Heater override ' 19. Dirty window compensation ' 20. Use CRC checking ' 21. PSU input voltage shutdown level Function CS125_SETCommand As String *100 Dim TempStringFunc As String * 100 Dim CS125CommandString As String * 100 Dim i As Long Dim CheckVal As Long

' Create a string containing the values going out to the CS125 TempStringFunc = "SET:0:" For i = 1 To 21 TempStringFunc = TempStringFunc + CS125CArray(i) + " " Next ' Create a check sum of the values going out

C-5

CS125 Present Weather Sensor

CheckVal = CheckSum (TempStringFunc,1,0) ' Use the CCITT CRC16 checksum ' Create final string going out to CS125 including start characters and end characters CS125CommandString = CHR(2) + TempStringFunc + ":" + FormatLong (CheckVal,"%04X") + ":" + CHR(3) + CHR(13) + CHR(10) 'CS125CommandString = CHR(2) + TempStringFunc + CHR(3) + CHR(13) + CHR(10) ' Use this line if no checksum is desired Return(CS125CommandString) EndFunction '-------------------------------------------------------

'Main Program BeginProg

' open port to the visibility sensor using Com1 SerialOpen (Com1,38400,3,0,10000)

' Note: Change the following array variable to suit your own application ' load example/dummy values into the array CS125CArray(1) = 0 ' Set ID to 0 CS125CArray(2) = 1 ' Enable alarm 1 CS125CArray(3) = 1 ' Set alarm 1 to if greater than CS125CArray(4) = 1000 ' Set alarm 1 trigger distance to 1000 CS125CArray(5) = 1 ' Enable alarm 2 CS125CArray(6) = 0 ' Set alarm 2 to if less than CS125CArray(7) = 15000 ' Set alarm 2 trigger distance to 15000 CS125CArray(8) = 2 ' Set serial baud rate to 38400bps CS125CArray(9) = 0 ' Read only so dummy value added here, but not needed CS125CArray(10) = "M" ' Set unit type to metres (use upper case) CS125CArray(11) = 60 ' Set output period to 60 seconds CS125CArray(12) = 1 ' Polling mode CS125CArray(13) = 2 ' Set FULL output message format CS125CArray(14) = 0 ' Set RS232 serial mode CS125CArray(15) = 1 ' Set averaging over one minute CS125CArray(16) = 1 ' Set sample timing to one second CS125CArray(17) = 0 ' Set dew heaters to automatic CS125CArray(18) = 0 ' Set hood heaters to automatic CS125CArray(19) = 0 ' Don't use dirty window compensation CS125CArray(20) = 1 ' Use CRC checking on incoming command line data CS125CArray(21) = 7.0 ' Set Low voltage battery shutdown to a very low value so it doesn't trigger

' Send information once every 10 seconds Scan (10,Sec,0,0)

TempString = CS125_SETCommand() ' Create the outgoing string SerialOut (Com1,TempString,"",0,100) ' Send SET command to the CS125

Delay (1,1,Sec)

SerialIn (InString,Com1,100,0,1000) ' Grab retuned data from the CS125 ' Returned data is identical to the ' data a GET command would return NextScan EndProg

C-6

Appendix C. Example CRBasic programs

C.4 Example CRBasic SETNC Command

'------------------------------------------------------------------------------' CS125 Visibility ' ' Program to test the SETNC command part of the command line interface on the CS125 ' This command does not commit the settings to flash so settings will be lost if ' the sensor is power cycled ' This example uses a CS215 temperature and humidity probe to determine dew point. ' The CS125s hood heaters are then turned on only when needed, this is to save power. ' Logger:CR1000 '-------------------------------------------------------------------------------

'Declare Public Variables Public InStringSETNC As String * 200 Public InStringGET As String * 200 Public TRHData(2) Public OutString As String * 40, CheckVal

Dim CS125CArray(21) As String * 6 ' CS125 Command Array Dim TempDewPoint Dim StatusDewHeater Dim TempString As String * 100

Alias TRHData(1)=AirTC Alias TRHData(2)=RH

'------------------------------------------------------' This function creates a SETNC command string for the ' CS125 visibility sensor. Including all delimiting ' characters and checksums then returns the string ' in "CS125CommandString" ' Array variable order is as follows: ' 1. Sensor ID ' 2. User Alarm 1 Set ' 3. User Alarm 1 Active ' 4. User Alarm 1 Distance ' 5. User Alarm 2 ' 6. User Alarm 2 Active ' 7. User Alarm 2 Distance ' 8. Serial BaudRate ' 9. Serial number (Read only so not used) ' 10. Visibility Units ' 11. Continuous mode output interval ' 12. Polling Or Continuous modes ' 13. Message Format (Basic/Partial/Full) ' 14. RS232 or RS485 serial communications enabled ' 15. Averaging Period ' 16. Sample timing ' 17. Dew heater override ' 18. Hood Heater override ' 19. Dirty window compensation ' 20. Use CRC checking ' 21. PSU input voltage shutdown level Function CS125_SETNCCommand As String *100 Dim TempStringFunc As String * 100

C-7

CS125 Present Weather Sensor

Dim CS125CommandString As String * 100 Dim i As Long

Dim CheckVal As Long

' Create a string containing the values going out to the CS125 TempStringFunc = "SETNC:0:" For i = 1 To 21 TempStringFunc = TempStringFunc + CS125CArray(i) + " " Next ' Create a check sum of the values going out CheckVal = CheckSum (TempStringFunc,1,0) ' Use the CCITT CRC16 checksum ' Create final string going out to CS125 including start characters and end characters CS125CommandString = CHR(2) + TempStringFunc + ":" + FormatLong (CheckVal,"%04X") + ":" + CHR(3) + CHR(13) + CHR(10)

'CS125CommandString = CHR(2) + TempStringFunc + CHR(3) + CHR(13) + CHR(10) ' Use this line if no checksum is desired Return(CS125CommandString) EndFunction '-------------------------------------------------------

'Main Program BeginProg

' Open port to the visibility sensor using Com1 SerialOpen (Com1,115200,3,0,10000)

' Note: Change the following array variable to suit your own application ' load example/dummy values into the array ' Loading the array is not strictly necessary, but is done as a fail safe in ' case the GET command does not return data CS125CArray(1) = 0 ' Set ID to 0 CS125CArray(2) = 0 ' Disable alarm 1 CS125CArray(3) = 1 ' Set alarm 1 to if greater than CS125CArray(4) = 10000 ' Set alarm 1 trigger distance to 10000 CS125CArray(5) = 0 ' Disable alarm 2 CS125CArray(6) = 0 ' Set alarm 2 to if less than CS125CArray(7) = 10000 ' Set alarm 2 trigger distance to 10000 CS125CArray(8) = 0 ' Set serial baud rate to 115200bps CS125CArray(9) = 0 ' Read only so dummy value added here, but not needed CS125CArray(10) = "M" ' Set unit type to metres (use upper case)

CS125CArray(11) = 60 ' Set output period to 60 seconds

CS125CArray(12) = 1 ' Polling mode CS125CArray(13) = 2 ' Set FULL output message format CS125CArray(14) = 0 ' Set RS232 serial mode CS125CArray(15) = 1 ' Set averaging over one minute CS125CArray(16) = 1 ' Set sample timing to one second CS125CArray(17) = 0 ' Set dew heaters to automatic CS125CArray(18) = 0 ' Set hood heaters to automatic CS125CArray(19) = 0 ' Don't use dirty window compensation CS125CArray(20) = 1 ' Use CRC checking on incoming command line data CS125CArray(21) = 7.0 ' Set Low voltage battery shutdown to a very low value so it

doesn't trigger

StatusDewHeater=False

Scan (10,Sec,0,0)

C-8

Appendix C. Example CRBasic programs

'CS215 Temperature & Relative Humidity Sensor measurements AirTC and RH SDI12Recorder(TRHData(),5,"0","M!",1,0)

'Calculate DewPoint DewPoint(TempDewPoint,AirTC,RH)

' Gather the current settings from the CS125 SerialFlush (Com1) TempString = "GET:0:0" CheckVal = CheckSum (TempString,1,0) ' Use the CCITT CRC16 checksum OutString = CHR(2) + TempString + ":" + FormatLong (CheckVal,"%04X") + ":" + CHR(3) + CHR(13) + CHR(10) SerialOut (Com1,OutString,"",0,100) ' Send GET command to the CS125 Delay (1,1,Sec) SerialIn (InStringGET,Com1,100,0,200) ' Save the data returned from the GET command If Len(InStringGET) > 1 Then ' Check data was returned SplitStr (CS125CArray(1),InStringGET, " ",21,5) ' Strip the settings from the returned data string CS125CArray(1) = Right (CS125CArray(1),1)' Trim the SOT from the first data point EndIf

'Enable Dew Heaters if AirTC < DewPoint If AirTC <= TempDewPoint AND StatusDewHeater=False Then CS125CArray(17)=0 SerialFlush (Com1) TempString = CS125_SETNCCommand() SerialOut (Com1,TempString,"",0,100) Delay (1,1,Sec) SerialIn (InStringSETNC,Com1,100,0,1000) StatusDewHeater=True EndIf

'Disable Dew Heaters if AirTC > DewPoint+3 If AirTC > TempDewPoint+3 AND StatusDewHeater=True Then CS125CArray(17)=1 SerialFlush (Com1) TempString = CS125_SETNCCommand() SerialOut (Com1,TempString,"",0,100) Delay (1,1,Sec) SerialIn (InStringSETNC,Com1,100,0,1000)

StatusDewHeater=False EndIf

NextScan EndProg

C-9

CS125 Present Weather Sensor

'------------------------------------------------------------------------------' CS125 Visibility ' ' Program to test the GET command part of the command line interface on the CS125 ' Connecting to serial port one on a CR1000 logger ' Logger:CR1000 ' ' Example outputs including checksums (varies with sensor ID) ' GET:0:0:2C67: ' GET:1:0:1B57: ' GET:2:0:4207: ' GET:3:0:7537: ' GET:4:0:F0A7: ' GET:5:0:C797: ' GET:6:0:9EC7: ' GET:7:0:A9F7: ' GET:8:0:85C6: ' GET:9:0:B2F6: '------------------------------------------------------------------------------Public OutString As String * 40 ' Outgoing string Dim CheckVal As Long ' Checksum value Public InString As String * 200 ' Incomming string Dim TempString As String * 16

'Main Program BeginProg

SerialOpen (Com1,38400,3,0,10000) ' open port to the visibility sensor

' Send a request for information once every 10 seconds Scan (10,Sec,0,0)

' Create the basic GET string for the CS125 TempString = "GET:0:0" CheckVal = CheckSum (TempString,1,0) ' Use the CCITT CRC16 checksum OutString = CHR(2) + TempString + ":" + FormatLong (CheckVal,"%04X") + ":" + CHR(3) + CHR(13) + CHR(10)

SerialOut (Com1,OutString,"",0,100) ' Send GET command to the CS125

Delay (1,1,Sec)

SerialIn (InString,Com1,100,0,200) ' Save the data returned from the GET command

NextScan EndProg

C.5 Example CRBasic GET program

C-10

Appendix C. Example CRBasic programs

C-11

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

Campbell Scientific CS125 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Guarantee

PLEASE READ FIRST

1. Introduction

1.1 Version Information

1.2 General Safety

1.3 Sensor Unit Safety

2. Technical specification

3. Electrical specification

4. Supported data rates for RS232 and RS485

5. Environmental specifications

6. Mechanical specifications

7. Installation procedure

7.1 Equipment grounding

7.2 Mounting the CS125

7.3 Optional Campbell Scientific Mount

8. CS125 internal connectors’ description

8.1 CS125 recommended wiring using Campbell Scientific cables

9. CS215 T/RH Sensor

10. Functions of the internal switches

11. Message Formats: A breakdown of the different default outputs of the CS125 – Basic/Partial/Full

11.1 Visibility Only messages (CS120 emulation)

11.2 Messages with SYNOP Present Weather Codes

11.3 Messages with METAR Present Weather Codes

11.4 Example CS125 message outputs

11.5 SYNOP Codes produced by the CS125

11.6 METAR Codes produced by the CS125

12. Interface methods – Device Configuration Utility/Command line/Menu

12.1 Configuring a PC for talking to the CS125

13. Definition of the variables that can be set by the user on the CS125

14. Command line mode

14.1 The SET command

14.2 The SETNC Command

14.3 The GET Command

14.4 The POLL command – Polling the CS125

15. Entering the CS125 menu system

16. Calibrating the CS125

17. Performing a firmware update

18. Cleaning

19. Lubricating the enclosure screws

20. Desiccant

Appendix A. CS125 block diagram

Appendix B. Example C code of the CCITT CRC

Appendix C. Example CRBasic programs

C.1 CRBasic read program

C.2 CRBasic POLL program

C.3 Example CRBasic SET program

C.4 Example CRBasic SETNC Command

C.5 Example CRBasic GET program

CAMPBELL SCIENTIFIC COMPANIES