Campbell Scientific SkyVUE 8 User Manual

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Revision:01/2021

Campbell Scientific, Inc.

1. General information 1

1.1 Packing list 1

1.2 General safety 1

1.3 Sensor unit safety 2

1.4 Laser safety 2

1.5 Electrical safety 4

2. Product overview 5

2.1 Introduction 6

2.1.1 Cloud height detection 6

2.1.2 Sky condition 7

2.1.3 Backscatter profile reporting 7

2.2 Optical measurement 8

2.2.1 Optical arrangement 8

2.3 Internal monitoring 8

2.4 Specifications 9

2.4.1 Measurement specifications 9

2.4.2 Mechanical specifications 9

2.4.3 Electrical specifications 10

2.4.4 Optical specifications 12

2.4.5 Environmental specifications 12

2.4.6 Communications specifications 12

2.4.7 Compliance and testing 13

3. Initial preparation and checks 14

4. Installation 15

4.1 Location and orientation 15

4.2 Grounding 15

4.3 Mounting the SkyVUE 8 16

4.4 Tilt angle 17

4.5 Connectors and wiring 18

4.5.1 Base connectors 18

4.5.2 Wiring using supplied Campbell Scientific cables 19

Table of Contents - i

4.5.2.1 Power connections 20

4.5.2.2 Communications connections 21

4.5.3 USB connection 21

4.5.4 I/O connection 22

4.6 Connecting the back-up battery 22

4.7 Bird spike kit 23

4.8 Storage information 24

5. Operation 25

5.1 Terminal mode 25

5.1.1 Entering/exiting the SkyVUE 8 terminal mode 26

5.1.2 Terminal mode commands general 26

5.1.3 Terminal mode command examples 27

5.1.4 Application command message types 41

5.1.5 MCFG command message types 43

5.1.6 Measurement and message intervals 44

5.1.7 Status command 46

5.1.8 Message polling 54

5.1.9 Loading a new operating system (OS) 55

5.1.10 Stratocumulus backscatter calibration 56

5.1.11 CRC-16 codes on terminal commands 58

5.1.12 Service command 58

5.1.13 Locked features 60

5.2 Restoring factory defaults 60

5.3 LED indicator 61

6. Messages 62

6.1 Data messages general 62

6.2 Checksums used in SkyVUE 8 messages 62

6.3 CS messages 63

6.3.1 MESSAGE 001 (no profile, no sky condition) 63

6.3.2 MESSAGE 002 (Profile, no sky condition) 67

6.3.3 MESSAGE 003 (no profile, sky condition) 70

6.3.4 MESSAGE 004 (profile, sky condition) — default message 72

6.4 CL31 messages 76

6.4.1 MESSAGES 101 - 106, (CL31 MESSAGE 1) 76

6.4.2 MESSAGE 005 (no profile, sky condition, mixing layer heights) 77

6.4.3 MESSAGES 107 - 112, CL31 Message 2 81

Table of Contents - ii

6.5 CT25K messages 85

6.5.1 MESSAGE 113, CT25K Data Message No. 1 85

6.5.2 MESSAGE 114, CT25K Data Message No. 6 88

7. Maintenance 90

7.1 General 90

7.2 Cleaning 90

7.3 Diagnostic LED indicators within the enclosure 91

7.4 Electrical safety testing 92

Appendix A. Measurement of the attenuated backscatter profile 93

A.1 Initial measurement 93 A.2 Backscatter onset height detection 93 A.3 Produce attenuated backscatter output message 94

Appendix B. Cloud height calculation 95

Appendix C. Sky condition algorithm description 96

Appendix D. Replacing the SkyVUE 8 PSU 98

Appendix E. SkyVUE 8 Laser/APD module replacement 100

List of figures

FIGURE 1-1. Location of laser warning label 4 FIGURE 2-1. Principle of operation 8 FIGURE 2-2. SkyVUE 8 dimensions 10 FIGURE 2-3. PSU types 11 FIGURE 4-1. Mounting base footprint 16 FIGURE 4-2. Setting the tilt angle 17 FIGURE 4-3. Connector layout 18 FIGURE 4-4. Cable connections 21 FIGURE 4-5. USB port 22 FIGURE 4-6. Connecting battery 22 FIGURE 4-7. Ceilometer bird spike kit installed 23 FIGURE 4-8. Preparing the SkyVUE 8 for installing the bird spikes 23 FIGURE 4-9. Attaching bird spikes to the SkyVUE 8 cowl 24 FIGURE 5-1. Restoring factory defaults 61 FIGURE 5-2. LED indicator 61 FIGURE 7-1. Diagnostic LED indicators 92

Table of Contents - iii

List of tables

Table 1-1: Packing list 1 Table 4-1: Function of the connector pins for the mains connector 18 Table 4-2: Function of the connector pins for the blower/heater connector 19 Table 4-3: Function of the connector pins for the communications connector 19 Table 5-1: Summary of the terminal mode commands available 28 Table 5-2: Summary of applications and applied settings for SkyVUE 8 42 Table 5-3: Summary of message ID and descriptions 43 Table 6-1: Most significant alarm word for CS messages 64 Table 6-2: Middle alarm word for CS messages 65 Table 6-3: Least significant alarm word for CS messages 66 Table 6-4: Most significant alarm word for CS31 messages 78 Table 6-5: Middle alarm word for CS31 messages 79 Table 6-6: Least significant alarm word for CS31 messages 79 Table 6-7: Most significant alarm word for CT25K messages 86 Table 6-8: Second alarm word for CT25K messages 87

Table of Contents - iv

1. General information

1.1 Packing list 1

1.2 General safety 1

1.3 Sensor unit safety 2

1.4 Laser safety 2

1.5 Electrical safety 4

1.1 Packing list

The following table lists the products shipped with the SkyVUE 8.

Table 1-1: Packing list

Description Quantity

Ceilometer 1

Power supply cable 1

Data cable 1

Bolt, sleeve anchor 4

Cable, USB type A plug to type B plug, 2 m 1

Triangle key 1

Calibration plate 1

1.2 General safety

This manual provides important safety considerations for the installation, operation and maintenance of the SkyVUE™8. These safety considerations are classified into three levels:

WARNING: 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.

SkyVUE™8 (CS136) LIDAR Ceilometer 1

CAUTION: Cautions warn of potential hazards. Ignoring these cautions could result in the sensor being damaged and data being lost.

NOTE: 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.

1.3 Sensor unit safety

The SkyVUE 8 sensor has been checked for safety before leaving the factory and contains no internally replaceable or modifiable parts.

WARNING: Do not modify the SkyVUE 8 unit. Such modifications will lead to damage of the unit and could expose users to dangerous light levels and voltages.

WARNING: Do not attempt to repair the SkyVUE 8 unit without consulting Campbell Scientific.

CAUTION: Ensure that the correct voltage supply is provided to the sensor.

1.4 Laser safety

The SkyVUE 8 sensor incorporates an InGaAs laser diode which is rated as a class 3B device. This is an embedded laser where the output from the sensor unit, through the optics, is minimized to class 1M. This classification indicates that viewing of the beam with the naked eye is safe but looking directly into the beam with optical instruments, e.g. binoculars can be dangerous.

From the laser head the output has the following characteristics:

Maximum average power: 15.0 mW (through 50 mm)

Maximum pulse energy: 1500 nJ (through 50 mm)

Pulse duration: 100 ns

Pulse frequency: 10 kHz

Wavelength: 912 nm ± 5 nm

Tested to: EN 60825-1:2014

SkyVUE™8 (CS136) LIDAR Ceilometer 2

Half angle divergence: 0.44 mrad

The sensor is marked with the following warning information:

INVISIBLE LASER RADIATION

DO NOT VIEW DIRECTLY WITH OPTICAL INSTRUMENTS

CLASS 1M LASER PRODUCT

IEC/EN 60825-1:2014

WARNING: Removing the laser module with the power applied to the SkyVUE 8 or battery connected may expose the user to hazardous class 3B laser radiation.

No attempt should be made to operate the laser module outside of the housing.

WARNING: Annually, check that the laser warning label on the sensor is still visible and can be clearly read.

When installing the sensor, avoid pointing the laser housing towards areas where binoculars are in common use.

WARNING: Use of controls or adjustments or performance of procedures other than those specified herein may result in hazardous radiation exposure.

SkyVUE™8 (CS136) LIDAR Ceilometer 3

FIGURE 1-1. Location of laser warning label

Before removing the laser module, the sensor must be disconnected from both the mains supply and the battery to ensure that the laser is turned off.

1.5 Electrical safety

Because the sensor is powered from potentially hazardous mains voltages, the power-supply should be wired only by personnel qualified to install electrical equipment. For permanent outside installations, this usually requires a certified electrician who is also familiar with local electrical and safety legislation. Some general guidance is given in Connectors and wiring (p. 18), but the responsibility for the installation lies with the installer.

The unit is tested for electrical safety before dispatch but may need subsequent testing according to local practice.

NOTE: The unit should only be serviced by trained personnel.

SkyVUE™8 (CS136) LIDAR Ceilometer 4

WARNING: Removal of electronic module covers or connectors while the unit is powered will expose the operator to potentially hazardous voltages and risk damage to the sensor.

The SkyVUE 8 has electrical and laser warning labels on the exterior and interior of the unit.

It is fitted with a hex-key access panel. It is recommended that the hood and access panel door are not opened in conditions of rain, hail or snow.

Isolate the sensor before removing internal components, including the cover to the avalanche photodiode (APD) module. Only trained personnel should disassemble the instrument.

Mains connectors are shrouded to prevent touching of the contacts. The mains supply should be isolated when connecting and disconnecting the cables to the sensor.

Where an isolator switch is fitted, this shall be a two-pole isolator, located as near to the sensor as possible.

The SkyVUE 8 must be properly grounded by a licensed and qualified electrician to protect against voltage leakage shock risk (Grounding (p. 15)).

Campbell Scientific recommends that RCD protection units be used with all sensors. See Power

connections (p. 20) for further information.

Mains powered heaters are enclosed to prevent contact.

CAUTION: When powered, the heaters may operate automatically and without warning. They may remain hot when not powered. Follow the isolation precautions, to avoid shock and burn hazards.

The sealed battery has cables and protected connectors to prevent shorts. Avoid shorting the battery to protect it from damage and to avoid burns to personnel through contact with hot surfaces.

2. Product overview

2.1 Introduction 6

2.2 Optical measurement 8

2.3 Internal monitoring 8

2.4 Specifications 9

SkyVUE™8 (CS136) LIDAR Ceilometer 5

2.1 Introduction

The SkyVUE 8 is a light detection and ranging (LIDAR) ceilometer that emits short pulses of near infrared light into the atmosphere from a semiconductor laser. The pulses of infrared light are scattered back by aerosols including cloud droplets. The time between transmission of the pulse and the return signal gives the range, and therefore height, of the scattering aerosols. The variation in the strength of the back-scattered light signal with height gives a profile of scatter coefficients and allows identification of cloud bases. If significant scattering is detected without a defined cloud base, then a vertical visibility can be calculated.

The control system of the SkyVUE 8 is divided into three modules, DSP, TOP and PSU as follows:

DSP (Digital Signal Processor) is the main data processing and communications unit of the SkyVUE 8. It hosts two separate time keeping circuits that are cross checked. An alarm is triggered if the circuits disagree.

TOP (top of the unit) provides safety shutdown features such as over and under laser output level. It also contains the calibration circuitry and dirty windows system.

PSU (Power Supply Unit) controls the power supply including battery charging and deep discharge protection.

The SkyVUE 8 has a rugged environmental enclosure that protects the instrument from the harshest conditions and will measure the atmosphere with high stability and repeatability.

2.1.1 Cloud height detection

A scatter profile is measured as described in Measurement of the attenuated backscatter profile (p. 93).

Cloud height detection is carried out as described in Cloud height calculation (p. 95). Up to four cloud heights can be detected.

If clouds are not detected, the SkyVUE 8 will give one of these reports:

l No significant backscatter.

l Full obscuration determined but no cloud base detected. This is reported if the criteria for

detecting cloud base is not met but the integrated scattering coefficient reaches the limit of vertical visibility below a set height limit. The default value is 2000m (6560ft) but can be changed by the user. The height at which this occurs is given as vertical visibility.

l Some obscuration detected but determined to be transparent is reported if scattering is

detected but no cloud is detected and the calculated vertical visibility exceeds a set height limit.

SkyVUE™8 (CS136) LIDAR Ceilometer 6

If no cloud is detected but significant scattering is detected below 50m (160ft), then vertical visibility is set to 0.

2.1.2 Sky condition

Sky condition is an assessment of cloud cover measured in units of eighths known as oktas. The number of oktas is the density of cloud in eighths of that layer. The SkyVUE 8 can report up to five layers of cloud when reporting sky condition. The algorithm used in the SkyVUE 8 follows guidance in the ICAO 9837, Manual on Automatic Meteorological Observing Systems at Aerodromes.

Sky condition is not an instantaneous measurement. It is based on cloud data for the previous 30 minutes, with cloud detection in the previous 10 minutes given an extra weighting. Therefore, sky condition is not available until sufficient data has been collected. See Sky condition algorithm

description (p. 96) for more detail.

2.1.3 Backscatter profile reporting

Several possible data messages give the two-way attenuated backscatter profile. This consists of 2048 groups of five-character values (10,240 characters in total). Each character is 8 bits long and therefore each 5 figure group is 40 bits. They are given as signed two complement integers and numbers greater than 239–1 represent negative integers.

NOTE: After 1600, the remaining groups are all of 00000.

Therefore, each group actually represents negative, a value between –239to +(239–1), rather than 0 to (240–1), which would be the case for unsigned, positive, 40-bit integers.

Apply the following two-stage process to correct the decimal value:

1. Convert the hexidecimal characters to a decimal number.

2. If the number resulting from this conversion is greater than 1048575, subtract 1,099,511,627,776, which is 240.

To use this backscatter coefficient in units of sr-1m-1, the sensor multiplies the calculated decimal number by a factor of 10-8. The values are scaled by the Attenuated_SCALE parameter, see

Table 5-1 (p. 28).

NOTE: The profile is not corrected for tilt angle even if cloud heights are corrected.

SkyVUE™8 (CS136) LIDAR Ceilometer 7

2.2 Optical measurement

FIGURE 2-1. Principle of operation

2.2.1 Optical arrangement

The SkyVUE 8 uses a single biaxial lens design that increases optical signal-to-noise ratio, while maintaining Class 1M eye safety by integrating larger optics into a compact package (see FIGURE

2-1 (p. 8)). Half of the lens is used by the transmitter, and the other half is used by the receiver.

This design provides an alternative to traditional two lens or common-optics designs. The optical isolation of traditional biaxial systems is maintained to increase detector sensitivity, while the low overlap onset height of common-optics systems is incorporated to allow measurements at close ranges.

2.3 Internal monitoring

The SkyVUE 8 monitors window contamination, key voltages and currents, internal temperature and relative humidity, and other parameters relevant to its performance. Data messages (see

Operation (p. 25)) include this information allowing remote diagnosis of the SkyVUE 8 condition.

In addition, a special status message can be polled.

SkyVUE™8 (CS136) LIDAR Ceilometer 8

2.4 Specifications

2.4.1 Measurement specifications 9

2.4.2 Mechanical specifications 9

2.4.3 Electrical specifications 10

2.4.4 Optical specifications 12

2.4.5 Environmental specifications 12

2.4.6 Communications specifications 12

2.4.7 Compliance and testing 13

2.4.1 Measurement specifications

Maximum reporting range: 8 km (26,250 ft)

Minimum reporting resolution:

Hard target range accuracy:

Reporting cycle:

Cloud layers reported:

5 m (15 ft)

± 0.25% ± 4.6 m (15 ft)

2 to 600 s

Up to four layers reported reported in Sky Condition.

2.4.2 Mechanical specifications

Height: 737 mm (29 in)

Width: 294 mm (11.6 in)

Depth: 240 mm (9.5 in)

Total weight: 18 kg (40 lb)

Shipping weight: 24.6 kg (54 lb)

Base plate:

316 x 316 mm (12.4 in x 12.4 in)

, excluding cables

, instantaneously. Up to five layers

SkyVUE™8 (CS136) LIDAR Ceilometer 9

FIGURE 2-2. SkyVUE 8 dimensions

2.4.3 Electrical specifications

Power required: Nominal 115 VAC (106 to 137 VAC) or nominal 230 VAC (216

to 253 VAC) (automatic selection), 47 to 63 Hz, 380 maximum

W total

DSP:

12V OUT: 12 VDC /

Heater: Input not used with AC heaters.

Hood heater: 220

Internal heater: 110

Fuses:

DSP fuse:

10 to 40 VDC input;1A at 12 VDC;

1.7 A for optional or external equipment (if the SkyVUE 8 14VDC for this to be available

W, maximum

HBC 5A (T)

is using a DC supply,

W, maximum

(not available in DC operation)

SkyVUE™8 (CS136) LIDAR Ceilometer 10

0.5

A at 24 VDC

this must be greater than

PSU fuse:

HBC5A(T)

All fuses are 5 x 20 mm slow blow (T) and are the same for both 115VAC and 230VAC.

Battery:

The heaters are resistive, which is advantageous when connected to generators or when current consumption is important.

Internal 12V, 7Ah sealed lead-acid battery. The power supply is equipped with a system to prevent deep discharge of the battery.

FIGURE 2-3. PSU types

SkyVUE™8 (CS136) LIDAR Ceilometer 11

2.4.4 Optical specifications

Pulse duration:

Pulse frequency:

Wavelength:

Half-angle laser divergence: 0.44

Field of view: 2.0

Laser lifetime:

Eye safety class:

100 ns

10 kHz

912 ± 5 nm

mrad

10 years typical

2.4.5 Environmental specifications

Standard operating temperature range:

Battery temperature range:

Relative humidity range:

IP rating:

–40 to 60 °C

–20 to 50 °C (alternative battery types available)

0 to 100%

IP 66

(excluding battery)

Maximum wind speed:

55 m/s

2.4.6 Communications specifications

Supported serial settings:

Supported data rates: 300 baud 19200 baud

Supported standards:

8 bits, no parity, 1 stop bit (default)

7 bits, even parity, 1 stop bit

7 bits, odd parity, 1 stop bit

600 baud 38400 baud

1200 baud 57600 baud

2400 baud 76800 baud

4800 baud 115200 baud (default)

9600 baud

RS-232 (default)

RS-485 full duplex

RS-485 half duplex

SkyVUE™8 (CS136) LIDAR Ceilometer 12

Signal voltage levels:

Minimum value Nominal value Maximum value

RS-232 communications

RS-232 input threshold low 0.8 V 1.5 V –

RS-232 input threshold high – 2.0 V 2.4 V

RS-232 input absolute maximum –15 V – +15 V

RS-232 input resistance 12 KΩ – –

RS-232 output voltage low – – 0.4 V

RS-232 output voltage high (into 3 KΩ) 4.4 V – –

RS-485/422 communications

RS-485/422 input threshold voltage –0.2 V – +0.2 V

RS-485/422 output (unloaded) – – 5V

RS-485/422 output (load 50 Ω) 2 V – –

Maximum voltage at any terminal –7 V – +7 V

USB Service Port USB1.1 and 2.0 compatible, fixed 115200 baud.

2.4.7 Compliance and testing

NOTE: Further details regarding compliance and testing are available upon request.

EMC compliance:

Electrical safety compliance:

Laser safety compliance:

Eye safety standard:

Vibration:

Frequency range:

EN 61326-1:2013

EN 61010-1:2010

EN 60825-1:2014

Class 1M

BS EN 60068-2-6:2008 Test Fc: Vibration (Sinusoidal)

5 to 150 Hz (exceeds Lloyd's Register test levels)

SkyVUE™8 (CS136) LIDAR Ceilometer 13

3. Initial preparation and checks

The following steps will provide basic familiarization with the SkyVUE 8 and perform basic functionality checks. To do these, open the door and connect the battery (see Connecting the

back-up battery (p. 22)).

WARNING: The laser begins operating as soon as the battery is connected. Do not point the laser in any direction where it could be viewed with magnifying optics.

The green LED visible from above should flash once every 10 seconds (see FIGURE 5-2 (p. 61)).

Connect the SkyVUE 8 USB port (see FIGURE 4-5 (p. 22)) to a computer and use a terminal emulation program to set to 115200 baud, 8N1 bits/parity settings.

The computer should identify the USB connection and allocate a port number. Enter the port setting in the terminal emulator program. Older computer operating systems may need upgrading or additional software.

The SkyVUE 8 will output message type 004 (default) every 30 seconds (see CS messages (p. 63)).

Use the open 0 command to open the terminal mode. You should now see the prompt CS136>. Type Status to see the sensor status information described in Status command (p. 46). If using date/time information, checked it since the date/time can drift up to ±14 seconds per day.

If the unit has been in storage or transit for more than a few months, the clock battery may be discharged. However, it will charge from the back-up battery or mains power.

Use the Close command to exit the terminal mode. It will close automatically after 10 minutes of inactivity.

If you are not installing the unit and connecting mains power, you should disconnect the battery to avoid it being discharged.

SkyVUE™8 (CS136) LIDAR Ceilometer 14

4. Installation

4.1 Location and orientation 15

4.2 Grounding 15

4.3 Mounting the SkyVUE 8 16

4.4 Tilt angle 17

4.5 Connectors and wiring 18

4.6 Connecting the back-up battery 22

4.7 Bird spike kit 23

4.8 Storage information 24

4.1 Location and orientation

The SkyVUE 8 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.

To reduce the service frequency with the unit, place the SkyVUE 8 away from sources of contamination. More regular maintenance will be required when the instrument is placed in areas where contamination is unavoidable or where measurements may be safety related.

Take care that the orientation allows tilting in whatever direction is desired.

WARNING: If installing at an airport, check and follow local guidance for allowed locations for a nonfrangible object 1 m (3.2 ft) tall. Please contact Campbell Scientific if frangible fittings are required.

4.2 Grounding

The SkyVUE 8 must be properly grounded by taking a ground wire with a minimum cross sectional area of 16mm2(0.62in) and maximum length of 10m (32.8ft) from the brass grounding boss to an adequate grounding point. FIGURE 2-2 (p. 10)) shows the location of the grounding boss.

SkyVUE™8 (CS136) LIDAR Ceilometer 15

4.3 Mounting the SkyVUE 8

Mount the SkyVUE 8 by bolting to a firm, level foundation. When bolting down, ensure the SkyVUE 8 can tilt in all desired directions. FIGURE 4-1 (p. 16) shows the mounting footprint. If a suitable surface does not already exist, construct a concrete foundation, at least 600mm (23.6in) square and 600mm (23.6in) deep, by using the following procedure:

1. Drill four 12mm (0.47in) diameter holes using the mount base as a template (see FIGURE

4-1 (p. 16)) to a depth of 77mm (3.03in).

2. Clean the holes of all debris.

3. Place washers and nuts on the ends of the wedge anchors supplied (to protect the threads during installation).

4. Hammer the wedge anchors into the holes until the start of the threads are below the surface.

5. Tighten the nuts until about 25mm (0.98in) of thread protrudes above the surface.

6. Remove the washers and nuts from the protruding length screw, then lower the SkyVUE 8 into place.

7. Secure the SkyVUE 8 with the washers and nuts.

8. If the surface is not level and flat, add washers under the base on one or more of the foundation screws.

FIGURE 4-1. Mounting base footprint

SkyVUE™8 (CS136) LIDAR Ceilometer 16

4.4 Tilt angle

The SkyVUE 8 can be tilted 6°, 12°, 18° or 24° from vertical. In tropical regions, tilting the sensor north in the northern hemisphere and south in the southern hemisphere can prevent the sun from shining directly into the sensor. The tilt angle also can reduce problems caused by direct specular reflections from ice crystals, and prevent rain or snow from falling onto the window. To adjust the tilt angle, remove the bolts shown in FIGURE 4-2 (p. 17), move the SkyVUE 8 to the required tilt angle, and replace the bolts.

The SkyVUE 8 has tilt sensors in both axes to compensate the cloud height when the base is not level. Set or disable cloud height compensation by using the UNITS command (Terminal mode

command examples (p. 27)). This feature is useful for mobile or marine applications. Profile data

is NOT compensated but tilt angles are included in data messages.

NOTE: Increasing the tilt angle beyond 24° can cause significant errors in vertical visibility measurements if scatter coefficients vary significantly with height.

FIGURE 4-2. Setting the tilt angle

SkyVUE™8 (CS136) LIDAR Ceilometer 17

4.5 Connectors and wiring

4.5.1 Base connectors 18

4.5.2 Wiring using supplied Campbell Scientific cables 19

4.5.3 USB connection 21

4.5.4 I/O connection 22

4.5.1 Base connectors

The SkyVUE 8 has two connectors on its base. One connector (6 pins) is for communications; another connector (4 pins) provides power to the unit.

NOTE: Tilting the unit provides better access to these connectors.

FIGURE 4-3. Connector layout

The function of the connector pins is shown in Table 4-1 (p. 18), Table 4-2 (p. 19), and Table 4-3 (p. 19).

Table 4-1: Function of the connector pins for the mains connector

Pin Function Color of supplied cable cores

1 Live Brown

2 Not connected NA

3 Neutral Blue

4 Earth Green/yellow

SkyVUE™8 (CS136) LIDAR Ceilometer 18

Table 4-2: Function of the connector pins for the blower/heater connector

Pin Function Color of supplied cable cores

1 Neutral Black (1)

2 Fan + 12 VDC Black (2)

3 Thermistor Black (3)

4 Thermistor (0 V) Black (4)

E Earth Green/yellow

Table 4-3: Function of the connector pins for the communications connector

Pin on

connector on

SkyVUE 8

1 Red 8

2 Yellow 7

3 Green 5 Gnd

Color of

supplied cable

cores

Switched 230/115 VAC

high voltage heater

Switched 230/115 VAC

low voltage heater

9-pin D

connector

Black (5)

Black (6)

RS-485 half

RS-232

duplex

CTS (DCE)

B/D+

output

RTS (DCE)

input

RS-485 full

duplex/

RS-422

Y/TXD

non-inverting

B/RXD

non-inverting

4 Black Gnd Gnd

5 White 2

6 Blue 3

E Screen

RXD (DCE)

A/D–

output

TXD (DCE)

input

Z/TXD

inverting

A/RXD

inverting

4.5.2 Wiring using supplied Campbell Scientific cables

Two cables are supplied, each 10m (32.8ft) long. One is for the mains power supply and the other is for communications.

SkyVUE™8 (CS136) LIDAR Ceilometer 19

WARNING: Incorrectly wiring the power cable can cause irrevocable damage to the unit and can cause serious injury or death.

WARNING: The power cable must not be carrying mains voltage when it is being connected or disconnected.

4.5.2.1 Power connections

The following is a guide for wiring and installing a permanent power supply.

As the sensor is used outside, a qualified electrician should install the power cables. Please check local safety regulations.

Ensure that the termination type, cable type, and cable run of the mains power source complies with local regulations and fits the installationrequirements.

The power source needs to provide the correct voltage, frequency, and current in excess of the power requirement of the system.

Voltage requirements: 106 to 137 VAC or 216 to 253 VAC (auto select)

Power requirements: 380 W

Input frequency: 47 to 63 Hz

The power source needs fuses with ratings of 5A or larger and a slow-blow design. Cable extensions or replacement cables should be capable of carrying current in excess of that fuse rating.

Include a two-pole isolator as close to the sensor as is possible.

The power cable needs three conductors (live, neutral, and a protective earth), normally with IEC wiring colors to match those used.

The equipment requires the connection of earth ground using the earth wire of the power connector/cable or via the earth stud on the sensor base. Ensure the earth connection at the power source is suitable for this purpose.

This equipment also requires correct connection of the live and neutral conductors — make sure these are identified and wired correctly at the power source.

Normally, fit the power source with its own or system wide earth leakage breaker (also known as an RCD).

For short term testing of the sensor, fit the power cable with a suitable plug can be fitted to the end of the power cable and the sensor plugged into a standard mains supply capable of

SkyVUE™8 (CS136) LIDAR Ceilometer 20

providing 5A at the rated voltage. If this is done, the earth wire of the sensor must be connected to a suitable protective earth point.

For DC operation, the SkyVUE 8 requires a 10 to 40VDC supply capable of 1A at 12VDC or 0.5A at 24VDC.

4.5.2.2 Communications connections

The communications cable terminates at one end with a removable 9-pin, D-connector (DB9). The D-connector connects directly to a computer or data logger such as the Campbell Scientific CR1000X using a suitable interconnecting cable such as the SC110. FIGURE 4-4 (p. 21). The connector can easily be removed for direct connection to screw terminals.

See www.campbellsci.com/downloads/skyvue-example-programs for CRBasic programs that connect the SkyVUE 8 to a Campbell Scientific data logger.

CAUTION: The supplied cable is not recommended for lengths greater than 10m (32.8ft). Longer RS-485 cables should incorporate twisted pairs. Contact Campbell Scientific if needing longer cable lengths.

FIGURE 4-4. Cable connections

4.5.3 USB connection

The USB port provided inside the enclosure is for on-site maintenance. It supports communication of commands to the SkyVUE 8 and responses in the same form as the main serial port, except the baud rate is fixed at 115200 (see FIGURE 4-5 (p. 22)).

SkyVUE™8 (CS136) LIDAR Ceilometer 21

FIGURE 4-5. USB port

4.5.4 I/O connection

The I/O port is only used for factory setting of the instrument.

4.6 Connecting the back-up battery

The SkyVUE 8 is shipped with the back-up battery disconnected and includes desiccant used for transport. Before using the unit, open the door, connect the internal battery (FIGURE 4-6 (p. 22), remove the desiccant, and close the door.

FIGURE 4-6. Connecting battery

SkyVUE™8 (CS136) LIDAR Ceilometer 22

4.7 Bird spike kit

The optional bird spike kit deters birds from sitting on the SkyVUE 8. It includes four stainlesssteel spikes with rounded ends and a small reel of stainless-steel wire. The following figure shows installed bird spikes.

FIGURE 4-7. Ceilometer bird spike kit installed

To install the bird spikes, remove the cowl and blanking plugs from the cowl (FIGURE 4-8 (p. 23). If the SkyVUE 8 is an older unit without pre-existing holes, then drill four holes each 4.5mm (0.17in) diameter, evenly spaced around the aperture and 10mm (0.39in) in from the edge. For each hole, place a nut and washer then thread the spike into the hole. Tighten the nuts and washers (see FIGURE 4-9 (p. 24)). Replace the cowl on the SkyVUE 8.

FIGURE 4-8. Preparing the SkyVUE 8 for installing the bird spikes

SkyVUE™8 (CS136) LIDAR Ceilometer 23

FIGURE 4-9. Attaching bird spikes to the SkyVUE 8 cowl

Wrap the stainless steel wire around each spike using the grooves in the spike then wrap it back on itself.

CAUTION: Do not tighten the wire too much as it may pull the spikes inwards and obscure the field of view of the SkyVUE 8 optics.

Only use one strand of wire to reduce the possibility of water drops being collected.

Check the wire during maintenance and replace if necessary.

4.8 Storage information

Store the SkyVUE 8 in a dry place at –40 to 70 °C, preferably with the enclosures securely fastened. Protect the optics from possible accidental damage. Disconnect the back-up battery when storing the SkyVUE 8.

NOTE: If the battery remains connected during storage, the unit will be powered until the battery voltage falls below a shut-down threshold.

SkyVUE™8 (CS136) LIDAR Ceilometer 24

NOTE: Storing the SkyVUE 8 below 0.0 °C will increase the start-up time by up to ten minutes. At –20 °C, the SkyVUE 8 will not achieve full accuracy for an hour.

NOTE: Remove the battery if the SkyVUE 8 is to be stored outside the –20 to 50 °C temperature range.

5. Operation

5.1 Terminal mode 25

5.2 Restoring factory defaults 60

5.3 LED indicator 61

5.1 Terminal mode

5.1.1 Entering/exiting the SkyVUE 8 terminal mode 26

5.1.2 Terminal mode commands general 26

5.1.3 Terminal mode command examples 27

5.1.4 Application command message types 41

5.1.5 MCFG command message types 43

5.1.6 Measurement and message intervals 44

5.1.7 Status command 46

5.1.8 Message polling 54

5.1.9 Loading a new operating system (OS) 55

5.1.10 Stratocumulus backscatter calibration 56

5.1.11 CRC-16 codes on terminal commands 58

5.1.12 Service command 58

5.1.13 Locked features 60

SkyVUE™8 (CS136) LIDAR Ceilometer 25

5.1.1 Entering/exiting the SkyVUE 8 terminal mode

Use the OPEN Sensor_ID Password command to enter the menu system. The menu will time out and close automatically if not used for ten minutes.

Sensor_ID is the SkyVUE 8 identification, a single character 0-9, a-f, A-F case sensitive. Default is 0. Enter the password if using one. The following text should be displayed:

CS136>. The SkyVUE 8 is now ready for terminal mode commands.

The SkyVUE 8 commands are not case sensitive, but the parameters and password are case sensitive.

Example of the open command followed by the 0 parameter:

OPEN 0

Example of the open command with the password Secret:

OPEN 0 Secret

5.1.2 Terminal mode commands general

Table 5-1 (p. 28) provides a summary of the terminal mode commands.

To send commands that setup and control the SkyVUE 8, use the terminal interface, data logger, or terminal emulators built into many Campbell Scientific software products.

NOTE: To load an operating system (OS), you need a terminal emulator with XMODEM protocol such as Tera Term.

Use the following settings:

Setting RS-232/422/485 interface (default) USB service port

RS-232

Baud rate 115200 115200

Data bits 8 8

Parity none none

Stop bits 1 1

Flow control none none

The baud rate of the SkyVUE 8 must match the port setting baud rate in the terminal emulator. The SkyVUE 8 should now be ready to accept commands.

SkyVUE™8 (CS136) LIDAR Ceilometer 26

NOTE: Commands will always output all parameters on a new line after a CR LF (carriage return and line feed) and then the SkyVUE 8 prompt CS136>. If you only want to see parameter values without changing them, then enter the command without parameters. If a particular parameter did not need changing, then the parameter can be replaced with a comma (,). Back space will abort the command.

5.1.3 Terminal mode command examples

How to enter a command

Example 1

The following text shows an example of setting up the SkyVUE 8 serial port. This example sets the serial port to RS-232 hand shaking at 115200 bps, 8 data bits, no parity and if it was in RS-485 mode, then a 100ms turn around delay.

serial 0 10 0 100

You could also type the following to obtain the same results as the RS-485 turn around delay is not needed:

serial 0 10 0

To change only the data baud rate, you can replace mode parameter, with a comma (,) as shown below.

serial , 10

Alternatively if you just wished to change the parity to 8-bits no parity, then type the following:

serial , , 0

You do not need to replace the remaining parameters with a comma (,); you only need to replace the ones up to the parameter you wish to edit.

NOTE: Leave a space character between the command and the parameters as shown in the examples.

Example 2

Entering the MCFG command, as shown below, will set the sensor to send messages at 10 second intervals and to send one message only with the message number 112.

MCFG 10 112 0 0 0 0 (return)

The four zeros indicate that no other message outputs have been set. The MCFG command is described in Table 5-1 (p. 28).

SkyVUE™8 (CS136) LIDAR Ceilometer 27

Table 5-1: Summary of the terminal mode commands available

Command

ALARMS Angle

APPLICATION

parameter block

Application_n Application_n selects pre-configured user

Parameter/

Description

Angle is the threshold tilt angle of the sensor beyond which an alarm will be flagged. The settable range is 0 to 90.0 degrees tilt and the default is 45.0 degrees.

settings optimized for a specific application. For the following values of n:

0 = Help

10 = Aviation

20 = Research

40 = Meteorology

225 = User defaults

The default application for the SkyVUE 8 is 10, Aviation. Settings adjusted by the APPLICATION command include settings in BS, MCFG, and UNITS.

(see

Measurement and message intervals (p. 44)

for more information on compatibility of different parameters)

Attenuated_ SCALE,

BS_Av_Time,

Noise_Gate,

Measurement_ Period,

Rolling_

Average,

Message_ Interval

BS_Temporal_ Filter_Mode

Rules for BS command are:

BS_Av_Time <= Measurement_Period-1s.

Message_Interval must be a multiple of Measurement_Period.

Attenuated_SCALE is the scalar for the

attenuated backscatter percent. 0.001 to 100% (default 100%)

BS_Av_Time is the backscatter average time in seconds. 1 to 30 (default 7).

Note: Must not be greater than Measurement_

Period – 1.0

Noise_Gate controls the noise threshold applied

to back-scatter.

Noise_Gate = -1000, all backscatter range is corrected.

SkyVUE™8 (CS136) LIDAR Ceilometer 28

Table 5-1: Summary of the terminal mode commands available

Command

Parameter/

Description

parameter block

Noise_Gate = 0.0 to 1000.0, standard deviation (default 2) for noise threshold. Only backscatter above this is range corrected.

Measurement_Period = 0 or 2 to 600 seconds (default 10). If set to 0 and the SkyVUE 8 is polled, it will output the last measurement made. If between 2 and 600 seconds, the SkyVUE 8 continually outputs messages. For sky condition output, Campbell Scientific recommends setting the measurement_

Period ≤ 30 seconds. If a measurement_ Period is greater than 30 seconds, the sky condition

algorithm will be less able to resolve coverage for higher layers.

Note: Must be a sub multiple of Message_

Interval

Rolling_Average = 1 to 29 (default 3). This is the

number of measurement_periods to use in a rolling average of the backscatter.

Message_Interval is the message interval in seconds. Range is 2 to 600 seconds (default 10 s); 0 gives polled messages.

Note: Must be a multiple of Measurement_

Period

BS_Temporal_ Filter_Mode allows the

selection of backscatter filtering modes.

0 = Averaging

1 = Median signal processing

Default setting is 1, the median mode for aviation.

CLOSE No parameters Closes the terminal interface to allow normal

message output and saves new settings to flash nonvolatile storage.

SkyVUE™8 (CS136) LIDAR Ceilometer 29

Table 5-1: Summary of the terminal mode commands available

Command

CLOUDMODE CloudMode_A

DEFAULTS

GETUSER

Parameter/

parameter block

No parameters Loads factory defaults

Description

CloudMode_A turns on a filter that reports the highest cloud during precipitation to avoid precipitation from being reported as low cloud.

0 = Filter Off

1 = Filter On (default). Reports the highest cloud during precipitation

Reads all user settings as a string of text. Parameters are read in the following order:

user = text user

volVer = user volume version

OS_VER = DSP OS version

PsuOsVer = PSU OS version

TopOsVer = TOP OS version

Id = SkyVUE 8 ID

Pw = SkyVUE 8 password

terminalCrc = terminal crc mode

terminalTimeout = terminal timeout

unitsTiltMode = units and tilt mode

hoodHBMode = hood heater / fan heater mode

hoodHBTestInt = hood heater / blower test

interval in hours

battBoost_mV = boost voltage used for battery charging mV

battCharge_mA = battery charge current mA

psuPresent = PSU present switch

hoodHBNormSpeed = fan voltage for normal

speed mV

SkyVUE™8 (CS136) LIDAR Ceilometer 30

Table 5-1: Summary of the terminal mode commands available

Command

Parameter/

Description

parameter block

hoodHBHighSpeed = fan voltage for high speed mV

hoodHBLowSpeed = fan voltage for low speed mV

intHMode = internal heater mode

message[0] = fields for message 0

message[1] = fields for message 1

message[2] = fields for message 2

message[3] = fields for message 3

message[4] = fields for message 4

messagePeriod = output message period in

seconds

heightOffset= height offset meters

bsAvTime= backscatter average time in seconds

laserMode = laser operation mode

laserPower = laser power

laserHeater = laser heater mode

attenuatedSCALE = attenuated backscatter

scaling factor

logInterval = debug logging interval

measurementPeriod = measurement interval in

seconds

serMode = serial port mode

baudSel = serial port baud rate mode

dataParityStop = serial port parity mode

rx2txTimeout = serial port RX to TX turnaround

time

snrMarginBoundary = onset of backscatter detection threshold

SkyVUE™8 (CS136) LIDAR Ceilometer 31

Table 5-1: Summary of the terminal mode commands available

Command

Parameter/

Description

parameter block

snrMarginDetector = cloud detection threshold

alphaGuessEnd = cloud alpha guess at boundary

alphaMin = cloud detection alpha minimum

Vcld_D = cloud detection

delta_Vcld_D = cloud detection

vis_Av_T = cloud detection

alphaGuess = visibility initial alpha guess

ratioLevel = visibility ratio

alphaMin = visibility alpha minimum

cap = visibility cap in meters

tiltLimit = tilt limit in degrees used by alarms

noiseGate = attenuated backscatter noise gate

mode

vvLimit_percent = sky condition report vertical visibility %

alphaGuessStart= cloud detection alpha guess at lowest height bin

reserved

cloudMode = cloud detector mode parameter (03072019a)

CRC = 4-digit character. CRC calculated from the u up to but not including the CRC using the standard CRC-16.

SkyVUE™8 (CS136) LIDAR Ceilometer 32

Table 5-1: Summary of the terminal mode commands available

Command

Parameter/

Description

parameter block

Note: Many parameters are not adjusted. This command allows a reliable technique for copying full settings from one SkyVUE 8 to another with the SETUSER command.

A typical response to the GETUSER command is:

>>>>> COPY FROM START OF NEXT LINE >>>>>

user 7 007638-6da 106 510 0 , 0 10 2 0 1 14520 400 1 1000 1000 2000 0 1 0 0 0 0 10 0.000E+00 2.000E+00 1

1.000E+00 0 1.000E+00 0 10 1 0 10 0 100 4.000E+00

6.000E+00 2.000E-03 2.500E-04 1.000E+03 2.200E+01

4.800E+03 1.000E-01 9.000E-01 2.500E-04 2.000E+03

4.500E+01 2.000E+00 50 2.00E-03 3.000E+01

1.500E+02 1.800E+00 5.000E+00 1.000E+01 150 98b2

<<<<< TO START OF THIS LINE <<<<<

HEATERS Hood

Internal

Laser

Test_interval

HELP

No parameters Calls up a list of user commands with brief

Sets or reads heater settings as follows:

Hood = 0, Hood blower and heater OFF

Hood = 1, Hood blower ON and heater OFF

Hood = 2, Hood blower ON and heater ON

Hood = 3, Hood blower and heater AUTO (default)

– (see note (1) below).

Internal = 0, Internal heater OFF

Internal = 1, Internal heater ON

Internal = 2, Internal heater AUTO (default)

Laser = 0, laser heater off

Laser = 1, laser heater on (default)

Test_interval = 1 to 168 hours (default 24

hours). Heater/Blower test interval

descriptions

SkyVUE™8 (CS136) LIDAR Ceilometer 33

Table 5-1: Summary of the terminal mode commands available

Command

HOFFSET Height_offset

ID Sensor_ID

LASER Laser

LASEROFF

Parameter/

parameter block

Laser_Power

No parameters Instructs the SkyVUE 8 to turn the laser off until either

Description

Height_offset is the offset to be added or subtracted in the range of ±1000 m (±3281 ft). Positive values are added to measured height and negative values are subtracted from measured height. The default is 0.

Reads or sets the sensor ID, a single character, 0-9, a z or A - Z, case sensitive. Default ID = 0.

Note: Lower case letters are not allowed if using a CT25K message.

Laser = 0, laser off after power up (user must switch laser on)

Laser = 1, laser on after power up (default)

Laser_Power = 20% to 100%, default 100%

a power cycle or the sensor is instructed to turn the laser back on.

LASERON

LOADOS Module

MCFG Message_

No parameters Instructs the SkyVUE 8 to try and turn the laser on

Interval

Message_ID_A

Message_ID_B

Message_ID_C

Message_ID_D

Message_ID_E

Loads new operating system.

This command must be sent using XMODEM protocol. Refer to Loading a new operating system

(OS) (p. 55) for more information.

Set or read message configuration

Message_Interval is the message interval in seconds. Range is 2 to 600 s (default 10); 0 gives polled messages.

Note: This command may affect measurement parameters within the BS command. See

Measurement and message intervals (p. 44).

Message_ID is the message type to output between 0 and 999 (default 001). If Message_ID =

SkyVUE™8 (CS136) LIDAR Ceilometer 34

Table 5-1: Summary of the terminal mode commands available

Command

Parameter/

parameter block

OPEN ID

Password

PASSWORD Password

Description

0, no message type is output. Up to five messages can be set (refer to MCFG command message types (p.

43)).

Opens the SkyVUE 8 terminal mode

ID = Sensor ID as per the terminal ID command.

AnySkyVUE 8 with firmware OS2 or newer will respond to global ID = 99, regardless of its own ID number.

Password = The sensors user password as per the terminal PASSWORD command. The default is no password.

Sets or clears a password from 1 to 10 characters in length. Valid characters, 0-9, a - z or A – Z, and letters are case sensitive. Typing the PASSWORD command without any parameters clears the password. The default is no password.

POLL Sensor_ID

Message_ID

POWEROFF

REBOOT

No parameters Prepares the PSU to power down the SkyVUE 8 even

No parameters Forces a system reboot. This will restore previously

Requests Message_ID from Sensor_ID.

Refer to Message polling (p. 54) for more information on this command

Note: If Message_ID is omitted, the SkyVUE 8 outputs the message configured by MCFG.

if the battery is connected. As soon as the mains supply is disconnected, the SkyVUE 8 will power off and NOT run on battery back-up. The SkyVUE 8 can be re-activated with battery back-up enabled by reconnecting the mains supply. You will be asked to confirm.

saved user settings. Any unsaved changes will be lost. (Settings are saved in the terminal mode when the

SkyVUE™8 (CS136) LIDAR Ceilometer 35

Table 5-1: Summary of the terminal mode commands available

Command

SCCAL

SERIAL Mode

parameter block

No parameters but user interaction required

Baud

Bits_Parity

Delay

Parameter/

Description

CLOSE command is typed, which exits the terminal mode).

Stratocumulus backscatter calibration.

This requires a human observer to confirm a stable Stratocumulus cloud layer between 250 m to 2500 m without holes, precipitation or reduced visibility and has been stable for at least 10 minutes prior to running this command. See Stratocumulus

backscatter calibration (p. 56) for more information.

Set or read the serial port.

Mode = 0, RS-232, full duplex (default)

Mode = 1, RS-232, half duplex

Mode = 2, RS-485, full duplex

Mode = 3, RS-485, half duplex

Mode = 4, reserved

Mode = 5, RS-422, full duplex

Baud = 0, 300 baud

Baud = 1, 600 baud

Baud = 2, 1200 baud

Baud = 3, 2400 baud

Baud = 4, 4800 baud

Baud = 5, 9600 baud

Baud = 6, 19200 baud

Baud = 7, 38400 baud

Baud = 8, 57600 baud

Baud = 9, 76800 baud

Baud = 10, 115200 baud (default)

Bits_Parity = 0, 8 bits, no parity, 1 stop bit

SkyVUE™8 (CS136) LIDAR Ceilometer 36

Table 5-1: Summary of the terminal mode commands available

Command

SERVICE

SETUSER

Parameter/

parameter block

(default)

Bits_Parity = 1, 7 bits, even parity, 1 stop bit

Bits_Parity = 2, 7 bits, odd parity, 1 stop bit

Delay = delay time, in milliseconds, before

transmitting (RS-485 half-duplex mode only). Range: 0 to 100 ms (default 100 ms).

No parameters but user intervention required

String Load all user settings as a string of text.

Performs a service procedure

(not changed) = parameter will not be updated and the previously set value will persist.

String = user (not changed)

Description

volVer = user volume version (not changed)

OS_VER = DSP OS version (not changed)

PsuOsVer = PSU OS version (not changed)

TopOsVer = TOP OS version (not changed)

Id = SkyVUE 8 ID (not changed)

Pw = SkyVUE 8 password (not changed)

terminalCrc = terminal crc mode

terminalTimeout = terminal timeout

unitsTiltMode = units and tilt mode

hoodHBMode = hood heater / fan heater mode

hoodHBTestInt = hood heater / blower test

interval in hours

battBoost_mV = boost voltage used for battery charging mV

battCharge_mA = battery charge current mA

SkyVUE™8 (CS136) LIDAR Ceilometer 37

Table 5-1: Summary of the terminal mode commands available

Command

Parameter/

Description

parameter block

psuPresent = PSU present switch

hoodHBNormSpeed = Fan voltage for normal

speed, mV

hoodHBHighSpeed = Fan voltage for high speed, mV

hoodHBLowSpeed = Fan voltage for low speed, mV

intHMode = internal heater mode

message[0] = fields for message 0

message[1] = fields for message 1

message[2] = fields for message 2

message[3] = fields for message 3

message[4] = fields for message 4

messagePeriod = output message period in

seconds

heightOffset = height offset meters

bsAvTime = backscatter average time in seconds

laserMode = laser operation mode

laserPower = laser power

laserHeater = laser heater mode

attenuatedSCALE = attenuated backscatter

scaling factor

logInterval = debug logging interval

measurementPeriod = measurement interval in

seconds

serMode = serial port mode

baudSel = serial port baud rate mode

dataParityStop = serial port parity mode

SkyVUE™8 (CS136) LIDAR Ceilometer 38

Table 5-1: Summary of the terminal mode commands available

Command

Parameter/

Description

parameter block

rx2txTimeout = serial port RX to TX turnaround time

snrMarginBoundary = onset of back-scatter detection threshold

snrMarginDetector = cloud detection threshold

alphaGuessEnd = cloud alpha guess at boundary

alphaMin = cloud detection alpha minimum

Vcld_D = cloud detection

delta_Vcld_D = cloud detection

vis_Av_T = cloud detection

alphaGuess = visibility initial alpha guess

ratioLevel = visibility ratio

alphaMin = visibility alpha minimum

cap = visibility cap in meters

tiltLimit = tilt limit in degrees used by alarms

noiseGate = attenuated backscatter noise gate

mode

vvLimit_percent = sky condition report vertical visibility %

alphaGuessStart = cloud detection alpha guess at lowest height bin

Reserved

cloudMode = cloud detector mode parameter

SkyVUE™8 (CS136) LIDAR Ceilometer 39

Table 5-1: Summary of the terminal mode commands available

Command

STATUS

Parameter/

Description

parameter block

(03072019a)

CRC = 4-digit character. CRC calculated from the u up to but not including the CRC using the standard CRC-16.

Note: String is added as text and should be cut and pasted from a stored file.

No parameters Outputs SkyVUE 8, serial number, ID, DSP OS version,

Time and Date, DSP version, TOP OS version, PSU OS version, watch dog counts, serial parameters, blower heater mode, internal heater mode, message parameters, tilt angle, units, temperature/humidity, temperatures, supply voltages, height offset, visibility cap, laser run days, window parameters, backscatter parameters, features, alarms, warnings, and status.

TERMINAL Terminal

Timeout

TIME

UNITS

Date_Time Date is in the format yyyy/mm/dd

Units Sets measurement units and tilt correction

Note: Refer to Status command (p. 46) for more information on this command

Sets the user terminal time out.

Timeout is the delay in minutes from 1 to 15 where the terminal will automatically close if no characters are sent to the SkyVUE 8. The default is 10 minutes.

Time is in the format hh:mm:ss

yyyy=year, mm=month, dd=day

hh=hours, mm=minutes, ss=seconds

For example: time 2013/05/25 10:00:00, sets the date and time to May 25, 2013 at 10:00:00)

Note: The set time could drift by up to ±14 seconds a day.

Units = 0, meters corrected by tilt

SkyVUE™8 (CS136) LIDAR Ceilometer 40

Table 5-1: Summary of the terminal mode commands available

Command

UNLOCK

VIS

NOTE: If AUTO is set, then the heater / blower will heat to 80 °C if (sky condition > 1 okta coverage) or (cloud height <3km (9842ft) AND sky condition > 1 okta coverage) OR window Tx <80% OR precipitation detected. When the event has passed, the blower/heater will remain active at 80°C for a further 15 minutes before going into a fan-off state and the heater temperature drops to an average of approximately 40°C, ready to be activated again.

Parameter/

Description

parameter block

Units = 1, meters not corrected by tilt

Units = 2, feet corrected by tilt (default)

Units = 3, feet not corrected by tilt

Key Key = a 12 digit key purchased from Campbell

Scientific. The key unlocks features such as Mixing Layer Height assessment.

The key is specific to the individual SkyVUE 8 and only has to be entered once.

Cap Cap is the vertical visibility maximum range 100 to

10000 in meters or 328 to 32808 in feet (default 2000 m or 6561 ft).

5.1.4 Application command message types

The Application_n parameter for the APPLICATION command defines settings to optimize the ceilometer for a range of applications, Aviation, Research and Meteorology. The default application setting for the SkyVUE 8 is Aviation, but this can be changed, or returned to, using the Application_n command.

Users can adjust any element of these settings once an application has been applied through the following individual commands:ALARMS, BS, CLOUDMODE, MCFG and UNITS.

SkyVUE™8 (CS136) LIDAR Ceilometer 41

Table 5-2: Summary of applications and applied settings for SkyVUE 8

Application modes for SkyVUE 8

using OS2 and newer

Aviation

Settings

(default)

ALARMS (tilt degs) 30 45 45 45

APPLICATION: Application n (sets user application settings)

BS: Attenuated scale (%) 100 100 100 100

BS: Backscatter averaging time (s) 2 7 7 7

BS: Noise Gate 2 (ON) -1000 (OFF) -1000 (OFF) -1000 (OFF)

BS: Measurement Period (s)

BS: Rolling Averages (sets the number of readings for averaging. Alternative description: Backscatter temperal filter rolling samples

Application10Application20Application

10 10 10 10

3 6 3

Research Meteorology

Defaults using

OS1

General

application

N/A

BS: Message Interval (s) 30 30 30 30

BS: BS_Temporal_ Filter_Mode (Sets Averaging or Median Mode.)

CLOUDMODE: CloudMode_A (Reports highest cloud only during precipitation)

MCFG: Message ID

UNITS

1 (Median) 0 (Average) 0 (Average)

ON OFF ON N/A

(CB,SC,BS)

2 (Feet, tilt

corrected)

(CB,SC,

(CB,SC,BS)

MLH,BS)

0 (Meters,

0 (Meters, tilt

tilt

corrected)

N/A

(Average)

CB,SC,BS)

0 (Meters, tilt

corrected)

SkyVUE™8 (CS136) LIDAR Ceilometer 42

5.1.5 MCFG command message types

The Message_ID_x parameter for the MCFG commands defines the output types. Refer to

Messages (p. 62) for further information on message output types.

Table 5-3: Summary of message ID and descriptions

Message_

ID_x type

000 No message

001 Campbell Scientific Message 1, no sky condition, no profile data

Campbell Scientific Message 2, no sky condition, profile data, 1600 range bins, 5 m

002

003 Campbell Scientific Message 3, sky condition, no profile data

004

(default)

101 CL31 Message 1, 770 range bins, 10 m resolution

102 CL31 Message 1, 385 range bins, 20 m resolution

103 CL31 Message 1, 1500 range bins, 5 m resolution

104 CL31 Message 1, 770 range bins, 5 m resolution

resolution. 2048 bins in total are output. However, after bin 1600, the bins only contain zeros.

Campbell Scientific Message 4, sky condition and profile data, 1600 range bins, 5 m resolution. 2048 bins in total are output. However, after bin 1600, the bins only contain zeros.

Description

105 CL31 Message 1, No profile data

106

107 CL31 Message 2, 770 range bins, 10 m resolution

108 CL31 Message 2, 385 range bins, 20 m resolution

109 CL31 Message 2, 1500 range bins, 5 m resolution

110 CL31 Message 2, 770 range bins, 5 m resolution

111 CL31 Message 2, No profile data

112

113 CT25K Message 1

114 CT25K Message 6

CL31 Message 1, Full SkyVUE 8 output, 1600 range bins, 5 m resolution. 2048 bins in total are output. However, after bin 1600, the bins only contain zeros.

CL31 Message 2, Full SkyVUE 8 output, 1600 range bins, 5 m resolution. 2048 bins in total are output. However, after bin 1600, the bins only contain zeros.

SkyVUE™8 (CS136) LIDAR Ceilometer 43

5.1.6 Measurement and message intervals

The message interval is the time, in seconds, between the automatic message transmissions. It can be set between 2 to 600s (0 gives polled messages). The default is 10, meaning a message will be sent automatically every 10 seconds. The message interval must be a multiple of the measurement period.

The backscatter average time, BS_Av_Time, is the period over which the laser is firing and taking measurements.

The measurement period is the time interval between the start of backscatter average time (BS_ Av_Time), during which the laser fires, and the start of the next measurement period. The measurement period must be long enough to include the backscatter average time and some processing time. The minimum measurement period is 2 seconds, which assumes the backscatter average time is 1 second. The measurement period can be set between 2 to 600 s (default is 10s). If it is set to 0, then measurements must be polled.

The rolling average (1 to 29, default 3) is the number of periods used to calculate each scatter value that is either used in a profile message or in a calculation of cloud height.

The message interval chosen may affect measurement parameters allowed within the BS command, which can be used to set non-standard measurement parameters) as follows:

If message interval = measurement period = 2 (the lowest values allowed), then the backscatter average time (BS_Av_Time) must equal 1 and the rolling average must equal 1.

If the message interval is between 3 and 9s, then the measurement period must be the same as the message interval.

In the following examples, yellow means laser firing.

To comply with the requirements for Sky Condition the total measurement period for rolling averages should not exceed 30 seconds.

In this case, the SkyVUE 8 sends a message every 2 seconds based on one measurement averaged over 1 second. Therefore, each message is based on a single 1 second period of backscatter average data.

Laser firing (yellow)

(BS_AV_Time) = 1 s 1s

Measurement Period = 2 s 2 s

Message Interval = 2 s 2 s

In this case, with the rolling average set to 1, the SkyVUE 8 sends a message every 30 seconds. It takes three, 2 second, measurements at 10 second intervals. Only the last measurement is used in

SkyVUE™8 (CS136) LIDAR Ceilometer 44

the output message but all three are used for calculating sky condition. Therefore, each message is based on a single 2 second period of backscatter average data.

Laser firing (yellow)

(BS_AV_Time) = 2 s 2s

Measurement Period = 10 s 10 s 10 s 10 s

Message Interval = 30 s 30 s

In this case, with the rolling average set to 3 (default), the SkyVUE 8 sends a message every 30 seconds that contains the average of the latest three measurements. Therefore, each message is based on three, 10 second measurement periods, with each containing 2 seconds of backscatter average data.

Laser firing (yellow)

(BS_AV_Time) = 2 s 2s

Measurement Period = 10 s 10 s 10 s 10 s

Message Interval = 30 s 30 s

In this case, with the rolling average set to 3 (default), the SkyVUE 8 sends a message every 10 seconds that contains the average of the latest three measurements. Therefore, each message is based on three, 10 second measurement periods, with each containing 2 seconds of backscatter average data.

Laser firing (yellow)

(BS_AV_Time) = 2 s 2s

Measurement Period = 10 s 10 s 10 s 10 s

Message Interval = 10 s 10 s 10 s 10 s

In this case, the SkyVUE 8 sends a message every 14 seconds based on one measurement taking 4 seconds over a 14 second interval. Therefore, each message is based on a single 4 second period of average data.

Laser firing (yellow)

(BS_AV_Time) = 4 s

Measurement Period = 14 s 14 s 14 s 14 s 14 s

Message Interval = 14 s 14 s 14 s 14 s 14 s

This message cannot be set up using the MCFG command alone.

SkyVUE™8 (CS136) LIDAR Ceilometer 45

The BS command has to be used as follows:

BS_Av_Time (averaging period) has to be set to 4, not the default value.

5.1.7 Status command

The STATUS command returns the following information:

Line Example line output

1 Identification CS136 SN1000 ID 0

Description of the line sections

Section Description

CS136 Product name

SN1000 Sensor serial number

ID 0 Sensor identification number

Line Example line output

2 Date Time 2012/01/10 11:39:46

Description of the line sections

Section Description

2012/01/10 Date in the format yyyy/mm/dd

11:39:46 Time in the format hh:mm:ss

Line Example line output

3 DSP_OS A

Description of the line sections

Section Description

A DSP OS revision number

SkyVUE™8 (CS136) LIDAR Ceilometer 46

Line Example line output

4 TOP_OS_HW 8 2

Description of the line sections

Section Description

A TOP board OS revision number and hardware revision

Line Example line output

5 PSU_OS 1 PS136

Description of the line sections

Section Description

A PSU board OS revision number

Line Example line output

6 Watchdog A

Description of the line sections

Section Description

A Watchdog counter for unscheduled system resets

Line Example line output

7 Serial A B C D

Description of the line sections

Section Description

A Serial mode (Note: Refer to the SERIAL command)

B Serial baud rate (Note: Refer to the SERIAL command)

C Parity and stop bits (Note: Refer to the SERIAL command)

Receive to transmit delay time in RS-485 mode (Note: Refer to the SERIAL command)

SkyVUE™8 (CS136) LIDAR Ceilometer 47

Line Example line output

8 Heaters A B C D

Description of the line sections

Section Description

A Hood blower mode

B Internal heater mode

C Laser heater mode

D Heater/blower test interval in hours

Line Example line output

9 MCFGX A B C D E

Description of the line sections

Section Description

X Message interval (Note: Refer to the MCFG command)

A Message ID A (Note: Refer to the MCFG command)

B Message ID B (Note: Refer to the MCFG command)

C Message ID C (Note: Refer to the MCFG command)

D Message ID D (Note: Refer to the MCFG command)

E Message ID E (Note: Refer to the MCFG command)

Line Example line output

10 AngleA B C

Description of the line sections

Section Description

A X axis tilt

B Y axis tilt

C Beam angle from vertical

SkyVUE™8 (CS136) LIDAR Ceilometer 48

Line Example line output

11 Units A

Description of the line sections

Section Description

Line Example line output

12 TRHA B C

Description of the line sections

Section Description

A Sensor internal temperature reading in degrees Celsius

B Sensor internal humidity reading as a percentage

C Sensors internal dew point value in degrees Celsius

Line Example line output

13 TA B C D E F G

Measurement units and tilt correction. (Note: Refer to the UNITS command)

Description of the line sections

Section Description

A External fan blower assembly temperature in degrees Celsius

B PSU internal temperature in degrees Celsius

C TOP board laser monitor temperature in degrees Celsius

D TOP board calibration LED temperature in degrees Celsius

E Laser module temperature in degrees Celsius

F Photo diode module temperature in degrees Celsius

G Internal heater temperature in degrees Celsius

SkyVUE™8 (CS136) LIDAR Ceilometer 49

Line Example line output

14 SupplyVoltage A B C D E

Description of the line sections

Section Description

A DSP board supply voltage

B PS136E internal supply voltage

C Cyclic power cycle counter. Resets after 31 cycles

D Hood heater voltage

E Internal heater voltage

Line Example line output

15 HOffset A

Description of the line sections

Section Description

Line Example line output

16 Visibility Cap A

Description of the line sections

Section Description

A Vertical visibility maximum range

Height offset reported in feet or meters dependent upon the UNITS command

SkyVUE™8 (CS136) LIDAR Ceilometer 50

Line Example line output

17 LaserRunDaysA

Description of the line sections

Section Description

A Number of days that the laser module has been active for

Line Example line output

18 WindowTX A

Description of the line sections

Section Description

A Window transmittance %

Line Example line output

19 BS A B C D E F (Note: refer to the BS command)

Description of the line sections

Section Description

A Attenuated scale

B Averaging time

C Noise Gate

D Measurement period

E Rolling average

F Message interval

SkyVUE™8 (CS136) LIDAR Ceilometer 51

Line Example line output

21 Features A

Description of the line sections

Section Description

A List of features enabled

Line Example line output

22 Flags 0000 0000 0000

Description of the most significant alarm word (left side, bits going left to right). Each alarm word is a hexadecimal sum of all the error bits.

Bit Description

8000 XXXX XXXX Units. feet = 0, meters = 8

4000 XXXX XXXX Reserved for future use

2000 XXXX XXXX Reserved for future use

1000 XXXX XXXX Reserved for future use

0800 XXXX XXXX DSP clock out of specification

0400 XXXX XXXX Laser shut down due to operating temperature out of range

0200 XXXX XXXX The lead acid battery voltage is reading low

0100 XXXX XXXX Mains supply has failed (requires a PSU to be present)

0080 XXXX XXXX The external heater blower assembly temperature is out of bounds

0040 XXXX XXXX External heater blower failure

0020 XXXX XXXX The PSUs internal temperature is high

0010 XXXX XXXX PSU OS has failed its signature check

0008 XXXX XXXX No communications between DSP and PSU

0004 XXXX XXXX

0002 XXXX XXXX Tilt beyond limit set by user, default 45 degrees

Photo diode and Laser windows are dirty. This can only be set if the laser is on

0001 XXXX XXXX No communications between DSP and inclinometer board

SkyVUE™8 (CS136) LIDAR Ceilometer 52

Description of the middle alarm word (middle word, bits going left to right)

Bit Description

XXXX 8000 XXXX The sensors internal humidity is high

XXXX 4000 XXXX

XXXX 2000 XXXX DSP input supply voltage is low

XXXX 1000 XXXX Self-test active

XXXX 0800 XXXX Watch dog counter updated

XXXX 0400 XXXX User setting stored in flash failed their signature checks

XXXX 0200 XXXX DSP factory calibration stored in flash has failed its signature check

XXXX 0100 XXXX DSP board OS signature test failed

XXXX 0080 XXXX DSP board RAM test failed

XXXX 0040 XXXX DSP boards on board PSUs are out of bounds

XXXX 0020 XXXX TOP board non-volatile storage is corrupt

XXXX 0010 XXXX TOP board OS signature test has failed

XXXX 0008 XXXX TOP boards ADC and DAC are not within specifications

XXXX 0004 XXXX TOP boards on board PSUs are out of bounds

Communications to the DSP boards temperature and humidity chip have failed

XXXX 0002 XXXX Communications have failed between TOP board and the DSP

XXXX 0001 XXXX Photo diode background radiance is out of range

SkyVUE™8 (CS136) LIDAR Ceilometer 53

Description of the least significant alarm word (right side, bits going left to right)

Bit Description

XXXX XXXX 8000 Photo diode temperature is out of range

XXXX XXXX 4000 Photo diode is saturated

XXXX XXXX 2000 Photo diode calibrator temperature is out of range

XXXX XXXX 1000 Photo diode calibrator has failed

XXXX XXXX 0800 The sensor could not reach the desired gain levels

XXXX XXXX 0400 Laser run time has been exceeded

XXXX XXXX 0200 Laser temperature out of range

XXXX XXXX 0100 Laser thermistor failure

XXXX XXXX 0080 Laser is obscured. This can only be set if the laser is on

XXXX XXXX 0040 Laser did not achieve significant output power

XXXX XXXX 0020 Laser max power exceeded

XXXX XXXX 0010 Laser max drive current exceeded

XXXX XXXX 0008 Laser power monitor temperature out of range

XXXX XXXX 0004 Laser power monitor test fail

XXXX XXXX 0002 Laser shutdown by top board

XXXX XXXX 0001 Laser is off

5.1.8 Message polling

The POLL Sensor_ID Message_ID command requests the Message_ID from the Sensor_ID. Where Message_ID is a SkyVUE 8 message type as defined in MCFG command

message types (p. 43).

The following example uses the SkyVUE 8 POLL command to request preconfigured message outputs.

First configure the SkyVUE 8 to use polling mode from the terminal interface via the MCFG command as follows:

CS136> MCFG 0

0 1 0 0 0 0

SkyVUE™8 (CS136) LIDAR Ceilometer 54

This configures the SkyVUE 8 into polling mode leaving your message output configurations unchanged. Exit the terminal by typing the CLOSE command. This will save the changes you just made.

CS136> CLOSE

COMMAND CLOSED

Automatic message outputs should continue. Type the POLL command as shown below to verify that the system is working as expected.

NOTE: Once exited, the terminal characters will not be automatically echoed back to you.

POLL 0

This should return all messages you have set via the MCFG command. In this example, only default message output was set. Therefore, the POLL command returns text similar to the following.

NOTE: If you have no message configured, the MCFG command returns 0 0 0 0 0, then nothing will be returned from the command you just typed.

CS0100001

10 100 12345 ///// ///// ///// 000000000000

abcd

The following example shows how to use the POLL command to request a specific message output type.

To poll the SkyVUE 8 for a particular message type, enter the following.

POLL 0 113

This command requests CT25K Message 1 and should look similar to the following.

CT00010

10 12345 ///// ///// 00000f80

5.1.9 Loading a new operating system (OS)

A new OS can be entered with the LOADOS command.

SkyVUE™8 (CS136) LIDAR Ceilometer 55

NOTE: The new OS must be sent using xmodem protocol using Tera Term. See Terminal mode

commands general (p. 26).

To load a new operating system:

Enter terminal mode by typing Open 0 (for a sensor with the default ID 0)

This will return the prompt: CS136>

Type the command: LOADOS

The SkyVUE 8 will respond:

Load OS into DSP

DO NOT REMOVE POWER DURING OS UPDATE!!!

Waiting for xmodem

At this point, use your terminal emulator to send the appropriate file. Loading the OS could take a few minutes.

When the process is complete the SkyVUE 8 will return the message:

Updating DSP OS, please wait....PASS

Updating TOP OS, please wait....PASS

Updating PSU OS, please wait....PASS

Wait 40 sec for OS to restart

Afterwards, the SkyVUE 8 will resume operation according to the previously set operating parameters. It will no longer be in terminal mode.

5.1.10 Stratocumulus backscatter calibration

The SCCAL command allows a simple stratocumulus backscatter calibration of the scatter coefficient measurements. This requires a human observer to confirm a stable Stratocumulus cloud layer between 250m (820ft) to 2500m (8202ft) without holes, precipitation or reduced visibility, and has been stable for at least 10 minutes prior to running this command.

Set the Measurement_Period to 10 (see Table 5-1 (p. 28)).

A detailed description of this technique is given in: Ewan J. O’Connor, Anthony J. Illingworth, and Robin J. Hogan, 2004: A Technique for Autocalibration of Cloud Lidar. Journal of Atmospheric and Ocean Technology, 21, pp 777 – 786.

Enter terminal mode by typing Open 0 (for a sensor with an ID of 0)

This will return the prompt: CS136>

SkyVUE™8 (CS136) LIDAR Ceilometer 56

Type SCCAL

The SkyVUE 8 will respond:

Stratocumulus calibration.

Enter height above sea level (m)? Press enter to continue:

Enter the sensor height above sea level, for example 70 m then type return.

The SkyVUE 8 will respond: 70 m entered, is this correct? “Y”, “N” or “Q”

Type Y to confirm. If you have entered an incorrect number, type N and you will be able to replace it. Type Q to quit the calibration and return to the terminal command prompt.

The SkyVUE 8 will respond:

For correct calibration a trained human observer must confirm that the layer is between 250 m (820 ft) to 2500 m (8200 ft) and has been stable for at least 10 minutes without drizzle. Has the Stratocumulus been stable for at least 10 minutes? “Y” or “N”

To confirm, type Y and the SkyVUE 8 will respond:

Old Stratocumulus calibration = 0.0282

New Stratocumulus calibration parameters = 0.0258 70 1328

Do you want to apply this calibration? “Y” or “N”

In this example, 70 is the height of the sensor above sea level previously entered and 1210 is the cloud base in meters above the sensor.

As a rough guide, if the calibration factor has changed by less than 20%, there is no need to change. If it has changed by a factor of 2, it is wise to run the service routine on the sensor (see

Service command (p. 58)).

Type Y to confirm and the SkyVUE 8 will respond:

Calibration saved.

The following error messages may appear during the process.

l Error ... Time out

l Error ... Cloud not detected or height not within limits

(250 m to 2500 m / 820 ft to 8200 ft)

l Try again when layer is stable

l Error ... Not enough data available try again in 10 minutes.

SkyVUE™8 (CS136) LIDAR Ceilometer 57

5.1.11 CRC-16 codes on terminal commands

If CRC-16 on mode is set using the Terminal command, all terminal commands need a CRC-16. A semi-colon is used to indicate start of the CRC-16 in 4-byte character, for example open 0;233A. The CRC-16 is calculated either from the start of a new line or after a [STX] up to but not including the semi-colon. ETX can follow the CRC-16 if required.

To find the valid CRC-16 for a command, type the command and then type: ;????. For example, typing open 0;???? gives the response [CRLF]CRC>233A<CRC[CRLF] so 233A is the CRC-16.

The CRC-16 is not case sensitive.

NOTE: Make sure the terminal software sends [CR] and not [CRLF] for the command-line termination.

The table below gives some commonly used CRC-16 codes.

Terminal command CRC-16

open 0 233A

close D94E

status 7CE5

password EB85

terminal 0 (this command will

B576

remove CRC-16 checking)

defaults 7D8E

serial 7FCE

5.1.12 Service command

The service command triggers the SkyVUE 8 to go through a series of tests including tests that require the white test surface (ceilometer calibration plate supplied) to be placed on the SkyVUE 8 windows.

The service command results in the following procedures:

l System noise level including noise spike test l Detector maximum gain test l Simulates a clear night sky for calibration offset l Window contamination functionality test l Laser function and monitoring alarm check

SkyVUE™8 (CS136) LIDAR Ceilometer 58

l Thermistor fault alarm check l Calibrator LED alarm check l PSU supply alarm check l Temperature RH% sensor alarm check l Inclinometer alarm check l Heater/blower alarm check l Internal clocks alarm check l Top board and PSU communications alarm check.

If any test or check has failed, then full instrument status and debug information is output with a fault summary at the end.

The response is similar to the following:

Initially the SkyVUE 8 outputs a STATUS message, then goes through various self-test routines before requesting a white test surface to be placed over each of the windows in turn. This process is as follows:

self test, please wait

wait for new measurement..................

Place white test surface onto detector window (left side fan at the top)

Press Enter to continue

Cover the detector window and press Enter . The computer will respond:

wait for new measurement.............

Place white test surface onto laser window (right side fan at the top)

Press Enter to continue

Cover the laser window and press Enter . The computer will respond:

wait for new measurement.......................

Remove white test surface from laser window. Press Enter to continue.

When this is complete, the SkyVUE 8 will output a string of diagnostic data similar. This is useful for a Campbell Scientific engineer investigating problems with the SkyVUE 8.

Finally, the SkyVUE 8 will list any faults found as shown below:

******** CS136 FAULT list ********

FAULT - external heater/blower thermistor

FAULT - detector dirty windows with white test surface

FAULT - max APD gain not achieved

SkyVUE™8 (CS136) LIDAR Ceilometer 59

Otherwise it will report the following message:

******** CS136 has PASSED all tests ********

5.1.13 Locked features

Optional features are protected by a key. They are enabled by typing UNLOCK followed by entering the key. This is specific to the individual SkyVUE 8 and only has to be entered once.

5.2 Restoring factory defaults

Restore factory defaults by using the DEFAULTS command in the terminal mode.

Hard Reset

Alternatively, use the RESET push switch on the DSP to restore factory defaults (FIGURE 5-1 (p.

61).

First open the access door.

WARNING: Opening the access door MUST be carried out by a competent person, who has sufficient training, experience and knowledge both in electrical safety and the detail and operation of the sensor.

WARNING: Opening the access door may expose hot surfaces.

Use a narrow tool such as a screw driver to reach the reset switch.

If the reset switch is pushed for four seconds, the SkyVUE 8 will reboot in exactly the same way as the REBOOT terminal command. If it is held closed while the SkyVUE 8 is powered off and on again, it will return to factory defaults. To power cycle the SkyVUE 8, disconnect the battery and switch the main power off and on.

SkyVUE™8 (CS136) LIDAR Ceilometer 60

FIGURE 5-1. Restoring factory defaults

5.3 LED indicator

FIGURE 5-2. LED indicator

A green LED is visible through the window, see FIGURE 5-2 (p. 61). It will give 0.5 second flashes as follows:

Permanently on = top board firmware fault

1 flash every 10 seconds = OK, no fault

2 flashes every 10 seconds = warning (possible degraded performance)

3 flashes every 10 seconds = alarm (measurements not possible)

SkyVUE™8 (CS136) LIDAR Ceilometer 61

6. Messages

6.1 Data messages general 62

6.2 Checksums used in SkyVUE 8 messages 62

6.3 CS messages 63

6.4 CL31 messages 76

6.5 CT25K messages 85

6.1 Data messages general

The SkyVUE 8 can provide a variety of data message types to allow efficient output of data. Not all messages provide the full information available, but these messages may be more efficient in terms of data storage and transmission.

CL31 and CT25K messages follow formats used by common existing CL31 and CT25K sensors allowing easier replacement or network expansion.

6.2 Checksums used in SkyVUE 8 messages

This is based on the CRC-16 with the output XOR’d with Hex 0xFFFF and outputs a two-byte CRC-16 character. The CRC-16 is calculated on all characters after the SOH character up to and including the ETX character.

The following example uses the C code to calculate the SkyVUE 8 checksum.

NOTE: Shorts are 16 bits long and ints are 32 bits long.

// ---------------------------------------------------------------// Calculate CRC-16 // buf is a pointer to the input string // len is the length of the input string // ---------------------------------------------------------------unsigned short crc16(char *buffer, int length) { unsigned short crc; unsigned short m; int i, j;

crc = 0xFFFF; for (i=0; i < length; ++i)

{

SkyVUE™8 (CS136) LIDAR Ceilometer 62

crc ^= buffer[i] << 8;

for (j=0; j<8; ++j){ m = (crc & 0x8000) ? 0x1021 : 0; crc <<= 1; crc ^= m; } } crc ^= 0xFFFF; return crc; }

6.3 CS messages

6.3.1 MESSAGE 001 (no profile, no sky condition)

Example message line outputs

CS0001001

10 087 00139 ///// ///// ///// 800000000000

942f

LINE 1

SOH CS ID OS N STX CR LF

where

SOH = Start-of-Heading character

CS = Always "CS"

ID (1 character) = A single character, 0 to 9, a to z or A to Z, case sensitive. Default ID = 0

OS (3 characters) = Operating system, 001 to 999

N (3 characters) = Message number

STX = Start-of-Text Character

CR LF = Carriage Return + Line Feed

LINE 2

S WAV trVh1Vh2Vh3Vh4Vflags CR LF

SkyVUE™8 (CS136) LIDAR Ceilometer 63

where

S (1 character) = detection status:

0 = No significant backscatter 1 = One cloud base detected 2 = Two cloud bases detected 3 = Three cloud bases detected 4 = Four cloud bases detected 5 = Full obscuration determined but no cloud base detected 6 = Some obscuration detected but determined to be transparent / = Raw data input to algorithm missing or suspect

WA (1 character) = Warning or alarm status:

0 = No alarm or warning W = Warning A = Alarm

tr (3 characters) = Window transmission, %

h1 (5 characters) = 1st Height If detection status is 1, 2, 3, or 4 h1 = Lowest cloud base reported If detection status is 5 h1 = Vertical visibility as calculated If detection status is 0 or 6 h1 = /////

h2 (5 characters) = 2nd Height If detection status is 2, 3, or 4 h2 = Second cloud base reported If detection status is 5 h2 = Highest signal received If detection status is 0, 1, or 6 h2 = /////

h3 (5 characters) = 3rd Height If detection status is 3 or 4 h3 = Third cloud base reported If detection status is 0, 1, 2, 5, or 6 h3 = /////

h4 (5 characters) = 4th Height If detection status is 4 h4 = Fourth cloud base reported If detection status is 0, 1, 2, 3, or 5 h4 = /////

flags (12 characters in 3 groups of 4) = Alarm or warning information

Table 6-1: Most significant alarm word for CS messages

Bit

Description

8000 XXXX XXXX Units. Feet = 0, meter = 1.

4000 XXXX XXXX Reserved for future use

SkyVUE™8 (CS136) LIDAR Ceilometer 64

Table 6-1: Most significant alarm word for CS messages

Bit

Description

2000 XXXX XXXX Reserved for future use

1000 XXXX XXXX Reserved for future use

0800 XXXX XXXX DSP clock out of specification

0400 XXXX XXXX Laser shut down due to operating temperature out of range

0200 XXXX XXXX The lead acid battery voltage is reading low

0100 XXXX XXXX Mains supply has failed (requires a PSU to be present)

0080 XXXX XXXX The external heater blower assembly temperature is out of bounds

0040 XXXX XXXX External heater blower failure

0020 XXXX XXXX The PSUs internal temperature is high

0010 XXXX XXXX PSU OS has failed its signature check

0008 XXXX XXXX No communications between DSP and PSU

0004 XXXX XXXX

Photo diode and Laser windows are dirty. This can only be set if the laser is on

0002 XXXX XXXX Tilt beyond limit set by user, default 45 degrees

0001 XXXX XXXX No communications between DSP and inclinometer board

Alarm words are sum of error bits.

Table 6-2: Middle alarm word for CS messages

Bit

Description

XXXX 8000 XXXX The sensors internal humidity is high

Communications to the DSP board temperature and humidity chip

XXXX 4000 XXXX

have failed

XXXX 2000 XXXX DSP input supply voltage is low

XXXX 1000 XXXX Self-test active

XXXX 0800 XXXX Watch dog counter updated

XXXX 0400 XXXX User setting stored in flash failed their signature checks

SkyVUE™8 (CS136) LIDAR Ceilometer 65

Table 6-2: Middle alarm word for CS messages

Bit

Description

XXXX 0200 XXXX DSP factory calibration stored in flash has failed its signature check

XXXX 0100 XXXX DSP board OS signature test failed

XXXX 0080 XXXX DSP board RAM test failed

XXXX 0040 XXXX DSP boards on board PSUs are out of bounds

XXXX 0020 XXXX TOP board non-volatile storage is corrupt

XXXX 0010 XXXX TOP board OS signature test has failed

XXXX 0008 XXXX TOP boards ADC and DAC are not within specifications

XXXX 0004 XXXX TOP boards on board PSUs are out of bounds

XXXX 0002 XXXX Communications have failed between TOP board and the DSP

XXXX 0001 XXXX Photo diode background radiance is out of range

Alarm words are sum of error bits.

Table 6-3: Least significant alarm word for CS messages

Bit

Description

XXXX XXXX 8000 Photo diode temperature is out of range

XXXX XXXX 4000 Photo diode is saturated

XXXX XXXX 2000 Photo diode calibrator temperature is out of range

XXXX XXXX 1000 Photo diode calibrator has failed

XXXX XXXX 0800 The sensor could not reach the desired gain levels

XXXX XXXX 0400 Laser run time or maximum laser drive current has been exceeded

XXXX XXXX 0200 Laser temperature out of range

XXXX XXXX 0100 Laser thermistor failure

XXXX XXXX 0080 Laser is obscured. This can only be set if the laser is on

XXXX XXXX 0040 Laser did not achieve significant output power

XXXX XXXX 0020 Laser max power exceeded

XXXX XXXX 0010 Laser max drive current exceeded

SkyVUE™8 (CS136) LIDAR Ceilometer 66

Table 6-3: Least significant alarm word for CS messages

Bit

XXXX XXXX 0008 Laser power monitor temperature out of range

XXXX XXXX 0004 Laser power monitor test fail

XXXX XXXX 0002 Laser shutdown by top board

XXXX XXXX 0001 Laser is off

Alarm words are sum of error bits.

CR LF = Carriage Return and Line Feed

LINE 3

ETX CRC-16 EOT CR LF

where

ETX = End-of-Text character CRC-16 (4 characters) = CRC-16 Checksum EOT = End-of-Transmission character CRLF = Carriage Return + Line Feed

Description

6.3.2 MESSAGE 002 (Profile, no sky condition)

Example message line outputs

CS0001002

10 085 01123 ///// ///// ///// 800000000000

00100 05 2048 100 +40 02 0074 0070 30 000

0c5df047……………………00000(Line output cropped for clarity)

9f68

LINE 1

SOH CS ID OS N STX CR LF

where

SOH = Start-of-Heading character

CS = Always CS

ID (1 character) = A single character, 0 to 9, a to z or A to Z, case sensitive. Default ID = 0

OS (3 characters) = Operating system, 001 to 999

SkyVUE™8 (CS136) LIDAR Ceilometer 67

N (3 characters) = Message number

STX = Start-of-Text Character

CR LF = Carriage Return + Line Feed

LINE 2

S WAVtrVh1Vh2Vh3Vh4Vflags CR LF

where

S (1 character) = detection status:

WA (1 character) = Warning or alarm status:

0 = No alarm or warning W = Warning A = Alarm

tr (3 characters) = Window transmission, %

h2 (5 characters) = 2nd Height If detection status is 2, 3, or 4 h2 = Second cloud base reported If detection status is 5 h2 = Highest signal received If detection status is 0, 1, or 6 h2 = /////

h3 (5 characters) = 3rd Height If detection status is 3 or 4 h3 = Third cloud base reported If detection status is 0, 1, 2, 5, or 6 h3 = /////

h4 (5 characters) = 4th Height If detection status is 4 h4 = Fourth cloud base reported If detection status is 0, 1, 2, 3, or 5 h4 = /////

SkyVUE™8 (CS136) LIDAR Ceilometer 68

flags (12 characters in 3 groups of 4) = Alarm or warning information.

Refer to Message 001 for a breakdown of the flags.

CR LF = Carriage Return and Line Feed

LINE 3

scaleVresVnV energyVltVti_blVpulseVrateVsum CR LF

where

scale (5 characters) = Attenuated_SCALE parameter, %, 0 to 99999. 100% is default

res (2 characters) = Backscatter profile resolution in meters

n (4 characters) = Profile length

energy (3 characters) = Laser pulse energy, %.

lt (3 characters including leading +/-) = Laser temperature, degrees C

ti (2 characters) = Total tilt angle, degrees

bl (4 characters) = Background light, millivolts at internal ADC input (0 to 2500)

pulse (4 characters) = Pulse quantity x 1000 (0000 to 9999)

rate (2 characters) = Sample rate, MHz, (00 to 99)

sum (3 characters) = Sum of detected and normalized backscatter, 0 to 999. Multiplied by scaling factor times 104. At scaling factor 100 the SUM range 0 to 999 corresponds to integrated backscatter 0 to 0. srad-1.

CR LF = Carriage Return + Line Feed

LINE 4

SSSSSSSSSSSSSSSSSSSSSSSSSSSSS........(2048 x 5 bytes) CR LF

The two-way attenuated normalized backscatter profile (Backscatter profile reporting (p. 7)

CR LF = Carriage Return + Line Feed

LINE 5

ETX CRC-16 EOT CR LF

where

ETX = End-of-Text character CRC-16 (4 characters) = CRC-16 Checksum EOT = End-of-Transmission character CR LF = Carriage Return + Line Feed

SkyVUE™8 (CS136) LIDAR Ceilometer 69

6.3.3 MESSAGE 003 (no profile, sky condition)

Example message line outputs

CS0001003

10 091 00828 ///// ///// ///// 800000000000

99 //// 0 //// 0 //// 0 //// 0 ////

f62a

LINE 1

SOH CS ID OS N STX CR LF

where

SOH = Start-of-Heading character

CS = Always CS

ID (1 character) = A single character, 0 to 9, a to z or A to Z, case sensitive. Default ID = 0

OS (3 characters) = Operating system, 001 to 999

N (3 characters) = Message number

STX = Start-of-Text Character

CR LF = Carriage Return + Line Feed

LINE 2

S WAVtrVh1Vh2Vh3Vh4Vflags CR LF

where

S (1 character) = detection status:

SkyVUE™8 (CS136) LIDAR Ceilometer 70

WA (1 character) = Warning or alarm status:

0 = No alarm or warning W = Warning A = Alarm

tr (3 characters) = Window transmission, %

h2 (5 characters) = 2nd Height If detection status is 2, 3, or 4 h2 = Second cloud base reported If detection status is 5 h2 = Highest signal received If detection status is 0, 1, 5, or 6 h2 = /////

h3 (5 characters) = 3rd Height If detection status is 3 or 4 h3 = Third cloud base reported If detection status is 0, 1, 2, 5, or 6 h3 = /////

h4 (5 characters) = 4th Height If detection status is 4 h4 = Fourth cloud base reported If detection status is 0, 1, 2, 3, or 5 h4 = /////

flags (12 characters in 3 groups of 4) = Alarm or warning information.

Refer to Message 001 for a breakdown of the flags.

CR LF = Carriage Return and Line Feed

LINE 3

_d_h1__d2_h2__d3_h3__d4_h4__d5_h5 CR LF

(note spaces)

where

d (2 characters) = Data available _0 to _8Amount of lowest layer in oktas _9Vertical visibility only available

-1No sky condition data available 99Insufficient data

h1 (4 characters) = Height of the lowest cloud layer in 10 s of meters or 100 s of feet

d2 (1 character) = Cloud amount of the 2nd layer in oktas

SkyVUE™8 (CS136) LIDAR Ceilometer 71

h2 (4 characters) = Height of the 2nd cloud layer in 10 s of meters or 100 s of feet, if no 2nd layer is reported h2 = ////.

d3 (1 character) = Cloud amount of the 3rd layer in oktas

h3 (4 characters) = Height of the 3rd cloud layer in 10 s of meters or 100 s of feet, if no 3rd layer is reported h3 = ////.

d4 (1 character) = Cloud amount of the 4th layer in oktas

h4 (4 characters) = Height of the 4th cloud layer in 10 s of meters or 100 s of feet, if no 4th layer is reported h4 = ////.

d5 (1 character) = Cloud amount of the 5th layer in oktas

h5 (4 characters) = Height of the 5th cloud layer in 10 s of meters or 100 s of feet, if no 5th layer is reported h5 = ////.

CR LF = Carriage Return + Line Feed

NOTE: Cloud amounts and heights cannot be reported until the SkyVUE 8 has been in operation for 30 minutes.

LINE 4

ETX CRC-16 EOT CR LF

where

ETX = End-of-Text character CRC-16 (4 characters) = CRC-16 Checksum EOT = End-of-Transmission character CR LF = Carriage Return + Line Feed

6.3.4 MESSAGE 004 (profile, sky condition) — default message

Example message line outputs

CS0001004

10 092 00698 ///// ///// ///// 800000000000

99 //// 0 //// 0 //// 0 //// 0 ////

00100 05 2048 100 +40 02 0074 0070 30 000

071fc024d………………….000 (Line output cropped for clarity)

6212

SkyVUE™8 (CS136) LIDAR Ceilometer 72

LINE 1

SOH CS ID OS N STX CR LF

where

SOH = Start-of-Heading character

CS = Always CS

ID (1 character) = A single character, 0 to 9, a to z or A to Z, case sensitive. Default ID = 0

OS (3 characters) = Operating system, 001 to 999

N (3 characters) = Message number

STX = Start-of-Text Character

CR LF = Carriage Return + Line Feed

LINE 2

S WAVtrVh1Vh2Vh3Vh4Vflags CR LF

where

S (1 character) = detection status:

WA (1 character) = Warning or alarm status:

0 = No alarm or warning W = Warning A = Alarm

Tr (3 characters) = Window transmission, %

SkyVUE™8 (CS136) LIDAR Ceilometer 73

h2 (5 characters) = 2nd Height If detection status is 2, 3, or 4 h2 = Second cloud base reported If detection status is 5 h2 = Highest signal received If detection status is 0, 1, or 6 h2 = /////

h3 (5 characters) = 3rd Height If detection status is 3 or 4 h3 = Third cloud base reported If detection status is 0, 1, 2, 5, or 6 h3 = /////

h4 (5 characters) = 4th Height If detection status is 4 h4 = Fourth cloud base reported If detection status is 0, 1, 2, 3, or 5 h4 = /////

flags (12 characters in 3 groups of 4) = Alarm or warning information.

Refer to Message 001 for a breakdown of the flags.

CR LF = Carriage Return + Line Feed.

LINE 3

_d_h1h1h1__d2_h2h2h2__d3_h3h3h3__d4_h4h4h4__d5_h5h5h5 CR LF

(note spaces)

where

d (2 characters) = Data available _0 to _8Amount of lowest layer in oktas _9Vertical visibility only available

-1No sky condition data available 99Insufficient data

h1 (4 characters) = Height of the lowest cloud layer in 10 s of meters or 100 s of feet

d2 (1 character) = Cloud amount of the 2nd layer in oktas

h2 (4 characters) = Height of the 2nd cloud layer in 10s of meters or 100 s of feet, if no 2nd layer is reported h2 = ////.

d3 (1 character) = Cloud amount of the 3rd layer in oktas

h3 (4 characters) = Height of the 3rd cloud layer in 10s of meters or 100s of feet, if no 3rd layer is reported h3 = ////.

d4 (1 character) = Cloud amount of the 4th layer in oktas

h4 (4 characters) = Height of the 4th cloud layer in 10 s of meters or 100s of feet, if no 4th layer is reported h4 = ////.

d5 (1 character) = Cloud amount of the 5th layer in oktas

SkyVUE™8 (CS136) LIDAR Ceilometer 74

h5 (4 characters) = Height of the 5th cloud layer in 10s of meters or 100s of feet, if no 5th layer is reported h5 = ////.

CR LF= Carriage Return + Line Feed

NOTE: Cloud amounts and heights cannot be reported until the SkyVUE 8 has been operating for 30 minutes.

LINE 4

scaleVresVnVenergyVltVti_blVpulseVrateVsum CR LF

where

scale (5 characters) = Scale parameter,%, 0 to 99999. 100% is default

res (2 characters) = Backscatter profile resolution in meters

n (4 characters) = Profile length

energy (3 characters) = Laser pulse energy, %.

lt (3 characters including leading +/-) = Laser temperature, degrees C

ti (2 characters) = Total tilt angle, degrees

bl (4 characters) = Background light, millivolts at internal ADC input (0 to 2500)

pulse (4 characters) = Pulse quantity x 1000 (0000 to 9999)

rate (2 characters) = Sample rate, MHz, (00 to 99)

sum = (3 characters) Sum of detected and normalized backscatter, 0 to 999. Multiplied by scaling factor times 104. At scaling factor 100 the SUM range 0 to 999 corresponds to integrated backscatter 0 to 0. srad-1.

CR LF = Carriage Return + Line Feed

LINE 5

SSSSSSSSSSSSSSSSSSSSSSSSSSSSS........(2048 x 5 bytes) CR LF

The two-way attenuated normalized backscatter profile (Backscatter profile reporting (p. 7)

CR LF = Carriage Return + Line Feed

LINE 6

ETX CRC-16 EOT CR LF

SkyVUE™8 (CS136) LIDAR Ceilometer 75

where

ETX = End-of-Text character CRC-16 (4 characters) = CRC-16 Checksum EOT = End-of-Transmission character CR LF = Carriage Return + Line Feed

6.4 CL31 messages

6.4.1 MESSAGES 101 - 106, (CL31 MESSAGE 1)

Example message 101 line outputs

CL017011

10 01128 ///// ///// 00000000E080

00100 10 0770 100 +40 094 02 0032 L0112HN30 000

036B200CC1002………………..EEFFB3F(Line output cropped for clarity)

e515

LINE 1

SOH CL ID OS 1 Samples STX CR LF

where

SOH = Start-of-Heading character

CL = Always CL

ID = A single character, 0 to 9, a to z or A to Z, case sensitive. Default ID = 0

OS = Operating system, 100 to 999

1 = Always 1

Samples = backscatter resolution and number of samples

1 = MESSAGE 101, 10 m x 770 samples, range 7700 m 2 = MESSAGE 102, 20 m x 385 samples, range 7700 m 3 = MESSAGE 103, 5 m x 1500 samples, range 7500 m 4 = MESSAGE 104, 5 m x 770 samples, range 3850 m 5 = MESSAGE 105, no backscatter profile 0 = MESSAGE 106, extended range, 5 m x 2048 samples, range 10,240 m

STX = Start-of-Text Character

CR LF = Carriage Return + Line Feed

SkyVUE™8 (CS136) LIDAR Ceilometer 76

LINE 2

S WAVh1Vh2Vh3Vflags CR LF

6.4.2 MESSAGE 005 (no profile, sky condition, mixing layer heights)

Available only when a key is entered (see Locked features (p. 60))

LINE 1

SOH CS ID OS N STX CR LF

where

SOH = Start-of-Heading character

CS = Always C

ID (1 character) = A single character, 0 to 9, a to z or A to Z, case sensitive. Default ID = 0

OS (3 characters) = Operating system, 001 to 999

N (3 characters) = Message number

STX = Start-of-Text Character

CR LF = Carriage Return + Line Feed

LINE 2

S WAVtrVh1Vh2Vh3Vh4Vflags"

where

S (1 character) = detection status:

0 = No significant backscatter 1 = One cloud base detected 2 = Two cloud bases detected 3 = Three cloud bases detected 4 = Full obscuration determined but no cloud base detected 5 = Some obscuration detected but determined to be transparent / = Raw data input to algorithm missing or suspect

WA (1 character) = Warning or alarm status:

0 = No alarm or warning W = Warning A = Alarm

h1 (5 characters) = 1st Height If detection status is 1, 2, 3 or 4 h1 = Lowest cloud base reported

SkyVUE™8 (CS136) LIDAR Ceilometer 77

If detection status is 5 h1 = Vertical visibility as calculated If detection status is 0 or 6 h1 = /////

h2 (5 characters) = 2nd Height If detection status is 2 or 3 h2 = Second cloud base reported If detection status is 4 h2 = Highest signal received If detection status is 0, 1, or 5 h2 = /////

h3 (5 characters) = 3rd Height If detection status is 3 h3 = Third cloud base reported If detection status is 0, 1, 2, 4, or 5 h3 = /////

flags (12 characters) = Alarm or warning information (refer to Table 6-4 (p. 78), Table 6-5 (p. 79), and Table 6-6 (p. 79) for a breakdown of flags)

Table 6-4: Most significant alarm word for CS31 messages

Bit

Description

8000 XXXX XXXX Transmitter shut-off

4000 XXXX XXXX Transmitter failure

2000 XXXX XXXX Receiver failure

1000 XXXX XXXX Reserved for future use

0800 XXXX XXXX Reserved for future use

0400 XXXX XXXX Memory error

0200 XXXX XXXX Light path obstruction

0100 XXXX XXXX Receiver saturation

0080 XXXX XXXX Reserved for future use

0040 XXXX XXXX Reserved for future use

0020 XXXX XXXX Reserved for future use

0010 XXXX XXXX Reserved for future use

0008 XXXX XXXX Reserved for future use

0004 XXXX XXXX Reserved for future use

0002 XXXX XXXX Reserved for future use

0001 XXXX XXXX Ceilometer engine board failure

Alarm words are sum of error bits.

SkyVUE™8 (CS136) LIDAR Ceilometer 78

Table 6-5: Middle alarm word for CS31 messages

Bit

Description

XXXX 8000 XXXX Window contamination

XXXX 4000 XXXX Battery voltage low

XXXX 2000 XXXX Transmitter expires

XXXX 1000 XXXX High humidity

XXXX 0800 XXXX Reserved for future use

XXXX 0400 XXXX Blower failure

XXXX 0200 XXXX Reserved for future use

XXXX 0100 XXXX Humidity sensor failure

XXXX 0080 XXXX Heater fault

XXXX 0040 XXXX High background radiance

XXXX 0020 XXXX Ceilometer engine board failure

XXXX 0010 XXXX Reserved for future use

XXXX 0008 XXXX Laser monitor failure

XXXX 0004 XXXX Receiver warning

XXXX 0002 XXXX Tilt beyond limit set by user, default 45 degrees

XXXX 0001 XXXX Reserved for future use

Alarm words are sum of error bits.

Table 6-6: Least significant alarm word for CS31 messages

Bit

Description

XXXX XXXX 8000 Blower is on

XXXX XXXX 4000 Blower heater is on

XXXX XXXX 2000 Internal heater is on

XXXX XXXX 1000 Working from battery

XXXX XXXX 0800 Reserved for future use

XXXX XXXX 0400 Self test in progress

SkyVUE™8 (CS136) LIDAR Ceilometer 79

Table 6-6: Least significant alarm word for CS31 messages

Bit

Description

XXXX XXXX 0200 Reserved for future use

XXXX XXXX 0100 Reserved for future use

XXXX XXXX 0080 Units are meters if on, else feet

XXXX XXXX 0040 Reserved for future use

XXXX XXXX 0020 Polling mode is on

XXXX XXXX 0010 Reserved for future use

XXXX XXXX 0008 Reserved for future use

XXXX XXXX 0004 Reserved for future use

XXXX XXXX 0002 Reserved for future use

XXXX XXXX 0001 Reserved for future use

Alarm words are sum of error bits.

CR LF = Carriage Return + Line Feed

LINE 3

scaleVresVnV energyVltVtrVti_blVL0112HN15Vsum CR LF

where,

scale (5 characters) = Scale parameter,%, 0 to 99999. 100% is typical

res (2 characters) = Backscatter profile resolution in meters

n (4 characters) = Profile length 385, 770, 1400, or 1500 samples

energy (3 characters) = Laser pulse energy, %

lt (3 characters including leading +/-) = Laser temperature, degrees C

tr (3 characters) = Window transmission, %

ti (2 characters) = Total tilt angle, degrees

bl (4 characters) = Background light, millivolts at internal ADC input (0 to 2500)

"L0112HN15" (9 characters) = Reserved, defaults shown

sum = (3 characters) Sum of detected and normalized backscatter, 0 to 999.

CR LF = Carriage Return + Line Feed

SkyVUE™8 (CS136) LIDAR Ceilometer 80

NOTE: This line is omitted from message 105.

LINE 4

SSSSSSSSSSSSSSSSSSSSSSSSSSSSS........(5 x 770 bytes) CR LF

The two-way attenuated normalize backscatter profile; see Backscatter profile reporting (p. 7).

CR LF = Carriage Return + Line Feed

NOTE: This line is omitted from message 105.

LINE 5

ETX CRC-16 EOT CR LF

where

ETX = End-of-Text character CRC-16 (4 characters) = CRC-16 Checksum EOT = End-of-Transmission character CR LF = Carriage Return + Line Feed

6.4.3 MESSAGES 107 - 112, CL31 Message 2

Example message 107 line outputs

CL017021

10 01407 ///// ///// 00000000E080

99 /// 0 /// 0 /// 0 /// 0 ///

00100 10 0770 100 +40 095 02 0031 L0112HN30 000

03301009……………………..027F(Line output cropped for clarity)

e669

LINE 1

SOH CL ID OS 2 Samples STX CR LF

where

SOH = Start-of-Heading character

CL = Always CL

ID = A single character, 0 to 9, a to z or A to Z, case sensitive. Default ID = 0

SkyVUE™8 (CS136) LIDAR Ceilometer 81

OS = Operating system, 100 to 999

2 = Always 2

Samples = backscatter resolution and number of samples

1 = MESSAGE 107, 10 m x 770 samples, range 7700 m 2 = MESSAGE 108, 20 m x 385 samples, range 7700 m 3 = MESSAGE 109, 5 m x 1500 samples, range 7500 m 4 = MESSAGE 110, 5 m x 770 samples, range 3850 m 5 = MESSAGE 111, no backscatter profile 0 = MESSAGE 112, extended range, 5 m x 2048 samples, range 8000 m (samples after 1600 are

00000)

STX = Start-of-Text Character

CR LF = Carriage Return + Line Feed

LINE 2

S WAVh1Vh2Vh3Vflags CR LF

where

S (1 character) = detection status:

WA (1 character) = Warning or alarm status:

0 = No alarm or warning W = Warning A = Alarm

h1 (5 characters) = 1st Height If detection status is 1, 2, or 3 h1 = Lowest cloud base reported If detection status is 4 h1 = Vertical visibility as calculated If detection status is 0 or 5 h1 = /////

h2 (5 characters) = 2nd Height If detection status is 2 or 3 h2 = Second cloud base reported If detection status is 4 h2 = Highest signal received If detection status is 0, 1, or 5 h2 = /////

SkyVUE™8 (CS136) LIDAR Ceilometer 82

h3 (5 characters) = 3rd Height If detection status is 3 h3 = Third cloud base reported If detection status is 0, 1, 2, 4, or 5 h3 = /////

flags (12 characters) = Alarm or warning information.

Same as for messages 101 to 106

CR LF = Carriage Return + Line Feed

LINE 3

__d_h1h1h1__d2_h2h2h2__d3_h3h3h3__d4_h4h4h4__d5_h5h5h5 CR LF

(note spaces)

where

d (1 character) = Data available 0 to 8Amount of lowest layer in oktas 9Vertical visibility only available

-1No sky condition data available 99Insufficient data

h1h1h1 (3 characters) = Height of the lowest cloud layer in 10 s of meters or 100 s of feet

d2 (1 character) = Cloud amount of the 2nd layer in oktas

h2h2h2 (3 characters) = Height of the 2nd cloud layer in 10 s of meters or 100 s of feet, if no 2nd layer is reported h2h2h2 = ///.

d3 (1 character) = Cloud amount of the 3rd layer in oktas

h3h3h3 (3 characters) = Height of the 3rd cloud layer in 10 s of meters or 100 s of feet, if no 3rd layer is reported h3h3h3 = ///.

d4 (1 character) = Cloud amount of the 4th layer in oktas

h4h4h4 (3 characters) = Height of the 4th cloud layer in 10 s of meters or 100 s of feet, if no 4th layer is reported h4h4h4 = ///.

d5 (1 character) = Cloud amount of the 5th layer in oktas

h5h5h5 (3 characters) = Height of the 5th cloud layer in 10 s of meters or 100 s of feet, if no 5th layer is reported h5h5h5 = ///.

CR LF = Carriage Return + Line Feed

NOTE: Cloud amount and height cannot be reported until the SkyVUE 8 has been operating for 30 minutes.

SkyVUE™8 (CS136) LIDAR Ceilometer 83

LINE 4

scaleVresVnV energyVltVtrVti_blVL0112HN15Vsum CR LF

where

scale (5 characters) = Scale parameter,%, 0 to 99999. 100% is typical

res (2 characters) = Backscatter profile resolution in meters

n (4 characters) = Profile length 385, 770, 1400, or 1500 samples

energy (3 characters) = Laser pulse energy, %

lt (3 characters including leading +/-) = Laser temperature, degrees C

tr (3 characters) = Window transmission, %

ti (2 characters) = Total tilt angle, degrees

bl (4 characters) = Background light, millivolts at internal ADC input (0 to 2500)

L0112HN15 (9 characters) = Reserved, defaults shown

sum = (3 characters) Sum of detected and normalized backscatter, 0 to 999. Not used in Operating System 1.

CR LF = Carriage Return + Line Feed

NOTE: This line is omitted from message 111.

LINE 5

SSSSSSSSSSSSSSSSSSSSSSSSSSSSS........(5 x 770 bytes) CR LF

The two-way attenuated normalized backscatter profile; see Backscatter profile reporting (p. 7).

CR LF = Carriage Return + Line Feed

NOTE: This line is omitted from message 111.

LINE 6

ETX CRC-16 EOT CR LF

ETX = End-of-Text Character

CRC-16 (4 characters) = CRC-16 Checksum

EOT = End-of-Transmission character

CR LF = Carriage Return + Line Feed

SkyVUE™8 (CS136) LIDAR Ceilometer 84

6.5 CT25K messages

6.5.1 MESSAGE 113, CT25K Data Message No. 1

Example message line outputs

CT02010

20 01333 01523 ///// 00000F00

LINE 1

SOH CT ID 20 10 STX CR LF

where

SOH = Start-of-Heading character

CT = Always CT

ID (1 character) = Unit number 0 to 9, A to Z (capitals only) Default ID = 0

20 = Always 20 10 = Always 10

STX = Start-of-Text Character

CR LF = Carriage Return + Line Feed

LINE 2

S WAVh1Vh2Vh3Vflags CR LF

where

S (1 character) = detection status:

WA (1 character) = Warning or alarm status:

0 = No alarm or warning W = Warning A = Alarm

SkyVUE™8 (CS136) LIDAR Ceilometer 85

h2 (5 characters) = 2nd Height If detection status is 2 or 3 h2 = Second cloud base reported If detection status is 4 h2 = Height of highest signal detected If detection status is 0, 1, or 5 h2 = /////

h3 (5 characters) = 3rd Height If detection status is 3 h3 = Third cloud base reported If detection status is 0, 1, 2, 4, or 5 h3 = /////

flags (8 characters) = Alarm or warning information 4-byte hex coded

Table 6-7: Most significant alarm word for CT25K messages

Bit

Description

8000 XXXX Transmitter shut-off

4000 XXXX Transmitter failure

2000 XXXX Receiver failure

1000 XXXX DSP, voltage or memory failure

0800 XXXX Reserved for future use

0400 XXXX Reserved for future use

0200 XXXX Reserved for future use

0100 XXXX Reserved for future use

0080 XXXX Window contaminated

0040 XXXX Battery low

0020 XXXX Transmitter expire warning

0010 XXXX Heater or humidity sensor failure

0008 XXXX High radiance warning, also XXXX 0004

0004 XXXX DSP, receiver, or laser monitor failure warning

0002 XXXX Relative humidity > 85 %

0001 XXXX Light path obstruction, receiver saturation or receiver failure

Alarm words are sum of error bits.

SkyVUE™8 (CS136) LIDAR Ceilometer 86

Table 6-8: Second alarm word for CT25K messages

Bit

XXXX 8000 Blower failure

XXXX 4000 Reserved for future use

XXXX 2000 Reserved for future use

XXXX 1000 Reserved for future use

XXXX 0800 Blower on

XXXX 0400 Blower heater on

XXXX 0200 Internal heater on

XXXX 0100 Units meters if on, feet if off

XXXX 0080 Polling mode on

XXXX 0040 Working from battery

XXXX 0020 Always 0

Description

XXXX 0010 Always 0

XXXX 0008 Tilt beyond limit set by user, default 45 degrees

XXXX 0004 High radiance warning, also 0008 XXXX

XXXX 0002 Reserved for future use

XXXX 0001 Reserved for future use

Alarm words are sum of error bits.

CR LF = Carriage Return + Line Feed

LINE 3

ETX CR LF

ETX = End-of-Text Character

CR LF = Carriage Return + Line Feed

SkyVUE™8 (CS136) LIDAR Ceilometer 87

6.5.2 MESSAGE 114, CT25K Data Message No. 6

Example message line outputs

CT02060

10 01767 ///// ///// 00000F00

99 /// 0 /// 0 /// 0 ///

LINE 1

SOH CT ID 20 60 STX CR LF

where

SOH = Start-of-Heading character

CT = Always CT

ID (1 character) = Unit number 0 to 9, A to Z (capitals only) Default ID = 0

20 = always 20 60 = always 60

STX = Start-of-Text Character

CR LF = Carriage Return + Line Feed

LINE 2

S WAVh1Vh2Vh3Vflags CR LF

where

S (1 character) = detection status:

WA (1 character) = Warning or alarm status:

0 = No alarm or warning W = Warning A = Alarm

SkyVUE™8 (CS136) LIDAR Ceilometer 88

h3 (5 characters) = 3rd Height If detection status is 3 h3 = Third cloud base reported If detection status is 0, 1, 2, 4, or 5 h3 = /////

flags (8 characters) = Alarm or warning information 4-byte hex coded

As for CT25K message 1.

CR LF = Carriage Return + Line Feed

LINE 3 (Sky CONDITION)

__d_h1h1h1__d2_h2h2h2__d3_h3h3h3__d4_h4h4h4 CR LF

(note spaces)

where

d (1 character) = Data available 0 to 8Amount of lowest layer in oktas 9Vertical visibility only available

-1No sky condition data available 99Insufficient data

h1h1h1 (3 characters) = Height of the lowest cloud layer in 10 s of meters or 100 s of feet

d2 (1 character) = Cloud amount of the 2nd layer in oktas

h2h2h2 (3 characters) = Height of the 2nd cloud layer in 10 s of meters or 100 s of feet, if no 2nd layer is reported h2h2h2 = ///.

d3 (1 character) = Cloud amount of the 3rd layer in oktas

h3h3h3 (3 characters) = Height of the 3rd cloud layer in 10 s of meters or 100 s of feet, if no 3rd layer is reported h3h3h3 = ///.

d4 (1 character) = Cloud amount of the 4th layer in oktas

h4h4h4 (3 characters) = Height of the 4th cloud layer in 10 s of meters or 100 s of feet, if no 4th layer is reported h4h4h4 = ///.

SkyVUE™8 (CS136) LIDAR Ceilometer 89

CR LF = Carriage Return + Line Feed

NOTE: Cloud amount and height cannot be reported until the SkyVUE 8 has been operating for 30 minutes.

LINE 4

ETX CR LF

ETX = End-of-Text Character

CR LF = Carriage Return + Line Feed

7. Maintenance

7.1 General 90

7.2 Cleaning 90

7.3 Diagnostic LED indicators within the enclosure 91

7.4 Electrical safety testing 92

7.1 General

The SkyVUE 8 is a robust weather resistant instrument and there is no need for routine maintenance other than cleaning. The instrument performance is monitored, and any potential problems are indicated by error messages.

7.2 Cleaning

The SkyVUE 8 window will require cleaning from time to time. The frequency of required cleaning depends on the exposure of the instrument to contaminants such as salt and dust. This will vary depending on the site location. The SkyVUE 8 is capable of self diagnosing dirty lenses and will indicate in its output when the lenses are contaminated.

In any case, we suggest six monthly intervals for locations not prone to contaminants and monthly intervals for those prone to contamination (coastal, 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.

SkyVUE™8 (CS136) LIDAR Ceilometer 90

CAUTION: If the window requires cleaning, it is very important that only a proper lens cloth or lens tissue is used. The use of inappropriate materials to clean the windows can permanently damage or reduce their effectiveness leading to reduced performance.

When the top cover is removed, avoid spraying the fan assembly with liquids. Use damp lens wipes or a clean soft cloth to clean the windows.

Use an air duster to blow any loose dust and dirt from the window as a first step. Use a lint free lens cloth or lens tissue impregnated with a non-aggressive standard window cleaner. Clean the surface by dragging the cloth across it being careful not to apply excessive pressure.

Excessive pressure may lead to some types of contaminants scratching the window surface. Over time such scratches can lead to reduced sensitivity.

7.3 Diagnostic LED indicators within the enclosure

The LASER ON and STATUS green LEDs are visible on the DSP (see FIGURE 7-1 (p. 92)). Their function is as follows:

LASER ON LED:

Off = laser off Flashing = laser fault On = laser on

STATUS LED:

1 flash every 10 seconds = OK 2 flashes every 10 seconds = warning (possible degraded performance) 3 flashes every 10 seconds = alarm (measurements not possible)

The DSP STATUS LED provides the same function as the LED visible through the top window.

The red LED on the PSU flashes for 0.5 seconds:

Permanently on = PSU firmware fault 1 flash every 10 seconds = PSU OK 2 flashes every 10 seconds = running in battery mode 3 flashes every 10 seconds = no communications to the DSP. This takes 60 seconds to start after a communications failure.

SkyVUE™8 (CS136) LIDAR Ceilometer 91

FIGURE 7-1. Diagnostic LED indicators

The red LED on the laser module indicates:

Off = Laser off On = Laser on

7.4 Electrical safety testing

NOTE: If carrying out insulation tests, do not use test voltages above 300VRMS because the sensor is designed to clamp any mains input voltages above this level. Voltage clamping can result in a false failure being detected.

SkyVUE™8 (CS136) LIDAR Ceilometer 92

Appendix A. Measurement of the attenuated backscatter profile

A.1 Initial measurement 93

A.2 Backscatter onset height detection 93

A.3 Produce attenuated backscatter output message 94

A.1 Initial measurement

l Pulse the laser and measure the backscatter at optimal gains.

l Derive the impulse response and impulse correct the backscatter signal using the inverse

filter derived.

l Remove the residual offset and slope from the impulse corrected backscatter.

l Apply an overlap correction based on the known generic overlap function of the SkyVUE 8.

l Apply the backscatter calibration constants.

l Remove the laser and electronic artefact signature. This is specific to the individual SkyVUE

8 and determined during calibration.

A.2 Backscatter onset height detection

l Filter the backscatter with 20m (65.6ft) and 300m (984ft) width filters.

l Look for a 1500m (4921ft) block width where the standard deviation is at a minimum for

both the 20m (65.6ft) and 300m (984ft) width filtered backscatters.

l Create a detection threshold by multiplying the 20m (65.6ft) and 300m (984ft) standard

deviations by a constant.

l Find the onset of backscatter height by working from the highest height bin downwards

until the backscatter is above one or both of the two detection thresholds.

SkyVUE™8 (CS136) LIDAR Ceilometer 93

A.3 Produce attenuated backscatter output message

l Range correct the backscatter to produce the attenuated backscatter.

l Attenuated backscatter (output), calibrated, range corrected but not tilt corrected.

l Smooth with a 20m (65.6ft) width running average.

l A noise gate can be applied based on a multiple of the 20m (65.6ft) detection threshold

— this is customer configurable.

l The lower height range bins do not gate noise until the backscatter reaches zero. This

allows the full extent of mixing layers to be viewed in gating mode.

SkyVUE™8 (CS136) LIDAR Ceilometer 94

Appendix B. Cloud height calculation

The scatter profile is inverted (using the Klett inversion technique) and an extinction profile is calculated.

Cloud base heights are identified using two criteria as follows (cloud is detected if either of them is met).

Criterion 1: likely cloud bases are estimated based on increasing slope of the extinction profile of at least 7m (22.9ft) per bin (bin width is 5m (16.4ft) and an extinction threshold. This threshold is based on an extinction coefficient (EXCO) of 3, equivalent to a horizontal visibility (MOR) of 1000m (3280ft). This results in a number of possible cloud bases at different heights.

Criterion 2: horizontal visibility falls below an average of 4800m (15,748ft) over 300m (984ft) starting at an altitude of 1000m (3280ft).

To report a cloud layer above a lower one the scatter coefficient first has to fall below the extinction threshold used for cloud definitions (less a small hysteresis offset). The scatter profile must then again meet the criteria above.

If rain is detected, the sensitivity of detection is increased by a factor of 3.

To avoid many very narrow close layers being reported when they have little significance a minimum separation based on WMO reporting intervals is applied. The separation is ±30m (98ft) below 1500m (4921ft) and 300m (984ft) above 1500m (4921ft). The lowest cloud height is used. If a thin cloud identified by Criterion 2 above is within ±150m (492ft) of a cloud identified by criterion 1, then the thin cloud is ignored.

SkyVUE™8 (CS136) LIDAR Ceilometer 95

Campbell Scientific SkyVUE 8 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Table of contents

1. General information

1.1 Packing list

1.2 General safety

1.3 Sensor unit safety

1.4 Laser safety

1.5 Electrical safety

2. Product overview

2.1 Introduction

2.1.1 Cloud height detection

2.1.2 Sky condition

2.1.3 Backscatter profile reporting

2.2 Optical measurement

2.2.1 Optical arrangement

2.3 Internal monitoring

2.4 Specifications

2.4.1 Measurement specifications

2.4.2 Mechanical specifications

2.4.3 Electrical specifications

2.4.4 Optical specifications

2.4.5 Environmental specifications

2.4.6 Communications specifications

2.4.7 Compliance and testing

3. Initial preparation and checks

4. Installation

4.1 Location and orientation

4.2 Grounding

4.3 Mounting the SkyVUE 8

4.4 Tilt angle

4.5 Connectors and wiring

4.5.1 Base connectors

4.5.2 Wiring using supplied Campbell Scientific cables

4.5.2.1 Power connections

4.5.2.2 Communications connections

4.5.3 USB connection

4.5.4 I/O connection

4.6 Connecting the back-up battery

4.7 Bird spike kit

4.8 Storage information

5. Operation

5.1 Terminal mode

5.1.1 Entering/exiting the SkyVUE 8 terminal mode

5.1.2 Terminal mode commands general

5.1.3 Terminal mode command examples

5.1.4 Application command message types

5.1.5 MCFG command message types

5.1.6 Measurement and message intervals

5.1.7 Status command

5.1.8 Message polling

5.1.9 Loading a new operating system (OS)

5.1.10 Stratocumulus backscatter calibration

5.1.11 CRC-16 codes on terminal commands

5.1.12 Service command

5.1.13 Locked features

5.2 Restoring factory defaults

5.3 LED indicator

6. Messages

6.1 Data messages general

6.2 Checksums used in SkyVUE 8 messages

6.3 CS messages

6.3.1 MESSAGE 001 (no profile, no sky condition)

6.3.2 MESSAGE 002 (Profile, no sky condition)

6.3.3 MESSAGE 003 (no profile, sky condition)

6.3.4 MESSAGE 004 (profile, sky condition) — default message

6.4 CL31 messages

6.4.1 MESSAGES 101 - 106, (CL31 MESSAGE 1)

6.4.2 MESSAGE 005 (no profile, sky condition, mixing layer heights)

6.4.3 MESSAGES 107 - 112, CL31 Message 2

6.5 CT25K messages

6.5.1 MESSAGE 113, CT25K Data Message No. 1

6.5.2 MESSAGE 114, CT25K Data Message No. 6

7. Maintenance

7.1 General

7.2 Cleaning

7.3 Diagnostic LED indicators within the enclosure

7.4 Electrical safety testing