Campbell CS215 Instruction Manual

INSTRUCTION MANUAL

CS215 Temperature and

Copyright © 2005- 2018

Campbell Scientific, Inc.

Relative Humidity Probe

Revision: 4/18

Limited Warranty

“Products manufactured by CSI are warranted by CSI to be free from defects in
materials and workmanship under normal use and service for twelve months
from the date of shipment unless otherwise specified in the corresponding
product manual. (Product manuals are available for review online at

www.campbellsci.com.) Products not manufactured by CSI, but that are resold

by CSI, are warranted only to the limits extended by the original manufacturer.
Batteries, fine-wire thermocouples, desiccant, and other consumables have no
warranty. CSI’s obligation under this warranty is limited to repairing or
replacing (at CSI’s option) defective Products, which shall be the sole and
exclusive remedy under this warranty. The Customer assumes all costs of
removing, reinstalling, and shipping defective Products to CSI. CSI will return
such Products by surface carrier prepaid within the continental United States of
America. To all other locations, CSI will return such Products best way CIP
(port of entry) per Incoterms ® 2010. This warranty shall not apply to any
Products which have been subjected to modification, misuse, neglect, improper
service, accidents of nature, or shipping damage. This warranty is in lieu of all
other warranties, expressed or implied. The warranty for installation services
performed by CSI such as programming to customer specifications, electrical
connections to Products manufactured by CSI, and Product specific training, is
part of CSI's product warranty. CSI EXPRESSLY DISCLAIMS AND

EXCLUDES ANY IMPLIED WARRANTIES OF MERCHANTABILITY
OR FITNESS FOR A PARTICULAR PURPOSE. CSI hereby disclaims,
to the fullest extent allowed by applicable law, any and all warranties and
conditions with respect to the Products, whether express, implied or
statutory, other than those expressly provided herein.”

Assistance

Products may not be returned without prior authorization. The following
contact information is for US and international customers residing in countries
served by Campbell Scientific, Inc. directly. Affiliate companies handle repairs
for customers within their territories. Please visit www.campbellsci.com to
determine which Campbell Scientific company serves your country.

To obtain a Returned Materials Authorization (RMA) number, contact
CAMPBELL SCIENTIFIC, INC., phone [phone]. Please write the
issued RMA number clearly on the outside of the shipping container. Campbell
Scientific’s shipping address is:

CAMPBELL SCIENTIFIC, INC.
RMA#_____
815 West 1800 North
Logan, Utah 84321-1784

For all returns, the customer must fill out a “Statement of Product Cleanliness
and Decontamination” form and comply with the requirements specified in it.
The form is available from our website at www.campbellsci.com/repair. A
completed form must be either emailed to [e-mail] or faxed to
[phone]. Campbell Scientific is unable to process any returns until we
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receipt or is incomplete, the product will be returned to the customer at the
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concerns for our employees.

Safety

DANGER — MANY HAZARDS ARE ASSOCIATED WITH INSTALLING, USING, MAINTAINING, AND WORKING ON OR AROUND

TRIPODS, TOWERS, AND ANY ATTACHMENTS TO TRIPODS AND TOWERS SUCH AS SENSORS, CROSSARMS, ENCLOSURES,
ANTENNAS, ETC. FAILURE TO PROPERLY AND COMPLETELY ASSEMBLE, INSTALL, OPERATE, USE, AND MAINTAIN TRIPODS,

TOWERS, AND ATTACHMENTS, AND FAILURE TO HEED WARNINGS, INCREASES THE RISK OF DEATH, ACCIDENT, SERIOUS
INJURY, PROPERTY DAMAGE, AND PRODUCT FAILURE. TAKE ALL REASONABLE PRECAUTIONS TO AVOID THESE HAZARDS.
CHECK WITH YOUR ORGANIZATION'S SAFETY COORDINATOR (OR POLICY) FOR PROCEDURES AND REQUIRED PROTECTIVE
EQUIPMENT PRIOR TO PERFORMING ANY WORK.

Use tripods, towers, and attachments to tripods and towers only for purposes for which they are designed. Do not exceed design limits.
Be familiar and comply with all instructions provided in product manuals. Manuals are available at www.campbellsci.com or by
telephoning [phone] (USA). You are responsible for conformance with governing codes and regulations, including safety
regulations, and the integrity and location of structures or land to which towers, tripods, and any attachments are attached. Installation
sites should be evaluated and approved by a qualified engineer. If questions or concerns arise regarding installation, use, or
maintenance of tripods, towers, attachments, or electrical connections, consult with a licensed and qualified engineer or electrician.

General

• Prior to performing site or installation work, obtain required approvals and permits. Comply

with all governing structure-height regulations, such as those of the FAA in the USA.

• Use only qualified personnel for installation, use, and maintenance of tripods and towers, and

any attachments to tripods and towers. The use of licensed and qualified contractors is highly
recommended.

• Read all applicable instructions carefully and understand procedures thoroughly before

beginning work.

• Wear a hardhat and eye protection, and take other appropriate safety precautions while

working on or around tripods and towers.

• Do not climb tripods or towers at any time, and prohibit climbing by other persons. Take

reasonable precautions to secure tripod and tower sites from trespassers.

• Use only manufacturer recommended parts, materials, and tools.

Utility and Electrical

• You can be killed or sustain serious bodily injury if the tripod, tower, or attachments you are

installing, constructing, using, or maintaining, or a tool, stake, or anchor, come in contact with
overhead or underground utility lines.

• Maintain a distance of at least one-and-one-half times structure height, 20 feet, or the distance

required by applicable law, whichever is greater, between overhead utility lines and the
structure (tripod, tower, attachments, or tools).

• Prior to performing site or installation work, inform all utility companies and have all

underground utilities marked.

• Comply with all electrical codes. Electrical equipment and related grounding devices should be

installed by a licensed and qualified electrician.

Elevated Work and Weather

• Exercise extreme caution when performing elevated work.

• Use appropriate equipment and safety practices.

• During installation and maintenance, keep tower and tripod sites clear of un-trained or non-

essential personnel. Take precautions to prevent elevated tools and objects from dropping.

• Do not perform any work in inclement weather, including wind, rain, snow, lightning, etc.

Maintenance

• Periodically (at least yearly) check for wear and damage, including corrosion, stress cracks,

frayed cables, loose cable clamps, cable tightness, etc. and take necessary corrective actions.

• Periodically (at least yearly) check electrical ground connections.

WHILE EVERY ATTEMPT IS MADE TO EMBODY THE HIGHEST DEGREE OF SAFETY IN ALL CAMPBELL SCIENTIFIC PRODUCTS,
THE CUSTOMER ASSUMES ALL RISK FROM ANY INJURY RESULTING FROM IMPROPER INSTALLATION, USE, OR
MAINTENANCE OF TRIPODS, TOWERS, OR ATTACHMENTS TO TRIPODS AND TOWERS SUCH AS SENSORS, CROSSARMS,
ENCLOSURES, ANTENNAS, ETC.

Table of Contents

PDF viewers: These page numbers refer to the printed version of this document. Use the
PDF reader bookmarks tab for links to specific sections.

1. Introduction ................................................................ 1

2. Precautions ................................................................ 1

3. Initial Inspection ......................................................... 1

4. QuickStart ................................................................... 1

5. Overview ..................................................................... 3

6. Specifications ............................................................. 4

6.1 Temperature Measurement................................................................... 4

6.2 Relative Humidity Measurement ......................................................... 5

7. Installation .................................................................. 5

7.1 Wiring to Datalogger ........................................................................... 5

7.2 Datalogger Programming ..................................................................... 6

7.3 SDI12Recorder() Instruction ................................................................ 6

7.4 Installation............................................................................................ 6

7.4.1 Installation in a 41303-5A or 41303-5B 6-Plate Shield ................ 7

7.4.2 Installation in a 41003-5 or 41003-5A 10-Plate Shield

Using 6637 Collar Adapter ........................................................ 8

7.4.3 Installation in a RAD06 6-Plate Shield or RAD10 10-Plate

Shield ......................................................................................... 8

7.4.4 Mount the Shield ........................................................................... 8

8. Operation .................................................................... 9

8.1 Sensor Measurement ............................................................................ 9

8.2 Measurements at Fast Scan Rates ...................................................... 10

8.3 Long Cables ....................................................................................... 10

8.4 Power Conservation ........................................................................... 10

8.5 Measuring Multiple SDI-12 Sensors .................................................. 11

9. Troubleshooting and Maintenance ......................... 11

9.1 Troubleshooting ................................................................................. 11

9.2 Maintenance ....................................................................................... 11

9.3 Calibration.......................................................................................... 12

9.4 Sensor Element Replacement Procedure ............................................ 12

10. Attributions and References ................................... 15

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Table of Contents

Appendices

A. Importing Short Cut Code Into CRBasic Editor ... A-1

B. Example Programs ................................................. B-1

C. Environmental Performance.................................. C-1

C.1 Tests to Defined Standards .............................................................. C-1

C.2 Exposure to Pollutants ..................................................................... C-1

C.3 Operating Range of RH Element ..................................................... C-2

C.4 Measurement Below 0 °C................................................................ C-2

D. SDI-12 Sensor Support .......................................... D-1

D.1 Introduction ..................................................................................... D-1

D.2 SDI-12 Command Basics ................................................................ D-1

D.2.1 Acknowledge Active Command (a!) ........................................ D-2

D.2.2 Send Identification Command (aI!) .......................................... D-2

D.2.3 Start Verification Command (aV!) ........................................... D-3

D.2.4 Address Query Command (?!) ................................................. D-3

D.2.5 Change Address Command (aAb!) .......................................... D-3

D.2.6 Start Measurement Commands (aM!) ...................................... D-3

D.2.7 Start Concurrent Measurement Commands (aC!) .................... D-4

D.2.8 Start Measurement Commands with Cyclic Redundancy

Check (aMC! and aCC!) ....................................................... D-6

D.2.9 Stopping a Measurement Command ........................................ D-6

D.2.10 Send Data Command (aD0! … aD9!) ...................................... D-6

D.2.11 Continuous Measurement Command (aR0! … aR9!) .............. D-7

D.3 SDI-12 Transparent Mode ............................................................... D-7

D.3.1 Changing an SDI-12 Address ................................................... D-7

D.3.2 Changing an SDI-12 Address – CR200(X) Series ................... D-8

D.4 References ....................................................................................... D-9

Figures

Tables

7-1. CS215 and 41303-5A Radiation Shield (left) and RAD06

Radiation Shield (right) on a tripod mast ......................................... 8

7-2. CS215 and 41303-5A Radiation Shield on a CM200 Series

Crossarm .......................................................................................... 9

9-1. Correct fit of sensor element (side view)........................................... 14

9-2. Incorrect fit of sensor element (side view) ........................................ 15

C-1. Normal operating conditions of RH element ................................... C-2

D-1. CR1000 example of using the SDI-12 transparent mode to

change the SDI-12 address from 0 to 3. Sensor is connected to

control port 1. ............................................................................... D-8

D-2. CR200(X) example of using the SDI-12 transparent mode to

change the SDI-12 address from 0 to 1 ........................................ D-9

7-1. Wire Color, Function, and Datalogger Connection ............................. 5

C-1. Environmental Tests ........................................................................ C-1

D-1. Campbell Scientific Sensor SDI-12 Command and Response Set .. D-1

D-2. Example aM! Sequence ................................................................... D-4

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Table of Contents

D-3. Example aC! Sequence ................................................................... D-5

CRBasic Examples

B-1. CR1000X Program for Measuring the CS215 ................................. B-1

B-2. CR200(X) Program for Measuring the CS215 ................................. B-2

iii

CS215 Temperature and Relative
Humidity Probe

1. Introduction

The CS215 Temperature and Relative Humidity probe is designed for general
meteorological and other datalogging applications. It uses the SDI-12
communications protocol to communicate with any SDI-12 recorder,
simplifying installation and programming.

For Edlog datalogger support, check the availability of an older manual at

www.campbellsci.com/old-manuals.

2. Precautions

• READ AND UNDERSTAND the Safety section at the front of this

manual.

• When opening the shipping package, do not damage or cut the cable

jacket. If damage to the cable is suspected, contact Campbell Scientific.

• Although rugged, the CS215 should be handled as a precision scientific

instrument.

• Santoprene

cable, will support combustion in air. It is used because of its resistance to
temperature extremes, moisture, and UV degradation. It is rated as slow
burning when tested according to U.L. 94 H.B. and passes FMVSS302.
However, local fire codes may preclude its use inside buildings.

3. Initial Inspection

• Check the packaging and contents of the shipment. If damage occurred

during transport, immediately file a claim with the carrier. Contact
Campbell Scientific to facilitate repair or replacement.

• Check model information against the shipping documents to ensure the

expected products and the correct lengths of cable are received. Model
numbers are found on each product. On cables and cabled items, the model
number is usually found at the connection end of the cable. Report any
shortages immediately to Campbell Scientific.

4. QuickStart

A video that describes datalogger programming using Short Cut is available at:

www.campbellsci.com/videos/cr1000x-datalogger-getting-started-program­part-3. Short Cut is an easy way to program your datalogger to measure the

CS215 sensor and assign datalogger wiring terminals. Short Cut is available as
a download on www.campbellsci.com. It is included in installations of
LoggerNet, PC200W, PC400, or RTDAQ.

®

rubber, which composes the black outer jacket of the CS215

1

CS215 Temperature and Relative Humidity Probe

The following procedure also describes programming with Short Cut.

1. Open Short Cut and click Create New Program.

2. Double-click the datalogger model.

3. In the search box under the Available Sensors and Devices heading, start

typing CS215, or find the sensor in the Sensors | Meteorological |

Relative Humidity & Temperature folder. Double-click CS215
Temperature & Relative Humidity Sensor. Temperature defaults to

degree Celsius. This can be changed by clicking the Deg C box and
selecting Deg F, for degrees Fahrenheit, or K for Kelvin. SDI-12 Address
defaults to 0. Type the correct SDI-12 Address for the CS215 if it has
been changed from the factory-set default value. After entering the
Properties, click on the Wiring tab to see how the sensor is to be wired to
the datalogger.

4. Select any other sensors you have.

2

CS215 Temperature and Relative Humidity Probe

5. In Output Setup, type the scan rate and Data Output Storage Interval.

6. Select the output options.

5. Overview

7. If the sensor is connected to the datalogger, check the output of the sensor

in the datalogger support software data display to make sure it is making
reasonable measurements.

The CS215 probe uses a single chip element that incorporates both a
temperature and an RH sensor. Each element is individually calibrated with the
calibration corrections stored on the chip. The element is easily changed in the
field, reducing downtime and calibration costs.

Electronics within the CS215 control the measurement made by the sensor
element, apply temperature and linearization corrections to the readings, and
present the data via SDI-12 to a datalogger.

3

CS215 Temperature and Relative Humidity Probe

An inner expanded PTFE filter minimizes the effects of dust and dirt on the
sensor. The filter is lightweight and hydrophobic, thereby diminishing its effect
on the time response of the sensor.

The probe housing is designed to withstand permanent exposure to all weather
and to fit into a range of radiation shields, including compact shields.

6. Specifications

Features:

• Accurate, stable measurements

• Field-changeable element allows on-site recalibration

• Individually calibrated sensor elements require no further adjustment

of the probe

• Low power consumption

• Digital SDI-12 output

• Compatible with Campbell Scientific dataloggers CR200(X) series,

CR300 series, CR6 series, CR800 series, CR1000, CR1000X series,
CR3000, and CR5000

Sensor Element: Sensirion SHT75

Calibration Traceability: NIST and NPL standards

Supply Voltage: 7 to 28 Vdc for serial numbers E13405 and newer

6 to 18 Vdc for older models

Current Consumption: 70 µA quiescent, typical

1.7 mA during 0.7 s measurement

Diameter: 12 mm at sensor tip, maximum 18 mm at cable end

Length: 180 mm, including cable strain relief

Housing Material: Anodized aluminum

Housing Classification: IP65 (NEMA 4)

Filter Material: Inner expanded PTFE filter. Filter material has a

EMC Compliance: Tested and conforms to IEC61326:2002

6.1 Temperature Measurement

Operating Range: –40 to +70 °C

porosity of 64% and a pore size of < 3µm.

4

Accuracy: ±0.3 °C at 25 °C
±0.4 °C over 5 to 40 °C

±0.9 °C over –40 to 70 °C

Response Time
with Filter: 120 s (63% response time in air moving at 1 m/s)

Default Units: Degrees Celsius

CS215 Temperature and Relative Humidity Probe

TABLE 7-1. Wire Color, Function, and Datalogger Connection

6.2 Relative Humidity Measurement

Operating Range: 0 to 100% RH (–20 to 60 °C; see Appendix C,

Environmental Performance

Accuracy at 25 °C: ±2% over 10 to 90%
±4% over 0 to 100%

Short-Term Hysteresis: <1% RH

Temperature
Dependence: Compensated to better than ±2% over –20 to 60 °C

Typical Long-Term
Stability: Better than ±1.0% per year

Response Time
with Filter: <10 s (63% response time in air moving at 1 m/s at

humidity <85%)

Environmental
Performance: See Appendix C, Environmental Performance

(p. C-1))

(p. C-1)

7. Installation

7.1 Wiring to Datalogger

If you are programming your datalogger with Short Cut, skip Section 7.1,
Wiring to Datalogger
Short Cut does this work for you. See Section 4, QuickStart

(p. 5), and Section 7.2, Datalogger Programming (p. 6).

(p. 1), for a Short

Cut tutorial.

Wire Color Wire Function Datalogger Connection Terminal

Red Power 12V

White Power ground G

Black Power ground G

Green SDI-12 signal C terminal1 or U configured for SDI-12

2

Clear Shield G

1

Dedicated SDI-12 terminal on CR5000

2

U channels are automatically configured by the measurement instruction.

To use more than one probe per datalogger, either connect the different probes
to different terminals on the datalogger or change the SDI-12 addresses of the
probes and wire them to the same terminal. Using the SDI-12 address reduces
the use of terminals on the datalogger and allows probes to be connected in a
“daisy-chain” fashion which can minimize cable runs in some applications.
(See below for limits on the total cable length.)

5

CS215 Temperature and Relative Humidity Probe

NOTE

The SDI-12 address of the CS215 can be set two ways:

• By sending the required commands to the sensors by using an SDI-12

recorder/datalogger that allows talk through to the sensor.

• By loading a program into the recorder that sends the required

commands

See Appendix D, SDI-12 Sensor Support

7.2 Datalogger Programming

Short Cut is the best source for up-to-date datalogger programming code.

If your data acquisition requirements are simple, you can probably create and
maintain a datalogger program exclusively with Short Cut. If your data
acquisition needs are more complex, the files that Short Cut creates are a great
source for programming code to start a new program or add to an existing
custom program.

Short Cut cannot edit programs after they are imported and edited
in CRBasic Editor.

A Short Cut tutorial is available in Section 4, QuickStart (p. 1). If you wish to
import Short Cut code into CRBasic Editor to create or add to a customized
program, follow the procedure in Appendix A, Importing Short Cut Code Into
CRBasic Editor

(p. A-1). Programming basics for CRBasic dataloggers are

provided in the following sections. Complete program examples for select
dataloggers can be found in Appendix B, Example Programs

7.3 SDI12Recorder() Instruction

The SDI12Recorder() measurement instruction programs CRBasic
dataloggers to measure the CS215 sensor. This instruction sends a request to
the sensor to make a measurement and then retrieves the measurement from the
sensor. See Section 8.1, Sensor Measurement

(p. D-1), for detailed instructions.

(p. B-1).

(p. 9), for more information.

6

For most CRBasic dataloggers, the SDI12Recorder() instruction has the
following syntax:

SDI12Recorder(Destination, SDIPort, SDIAddress, "SDICommand",

Multiplier, Offset, FillNAN, WaitonTimeout)

The Destination parameter must be an array of length 2, with the first index for
air temperature (in °C) and the second for relative humidity (as a percent).

Set SDICommand to “M!”, “C!”, or “R!” – see Section 8.1, Sensor
Measurement

FillNAN and WaitonTimeout are optional parameters (refer to CRBasic Help
for more information).

7.4 Installation

Locate the sensor over an open, level area at least 9 m (EPA) in diameter. The
surface should be covered by short grass or the natural earth surface where

(p. 9), to determine which is best for your application.

CS215 Temperature and Relative Humidity Probe

grass does not grow. Sensors should be located at a distance of at least four
times the height of any nearby obstruction and at least 30 m (EPA) from large,
paved areas. Sensors should be protected from thermal radiation and
adequately ventilated. Protect the filter at the top of the sensor from exposure
to liquid water. The hydrophobic nature of the filter repels light rain, but
driving rain can force itself into the pore structure of the filter and take time to
dry out.

Standard measurement heights:

• 1.5 m (AASC)

• 1.25 to 2.0 m (WMO)

• 2.0 m (EPA)

See Section 10, Attributions and References

(p. 15), for a list of references that

discuss temperature and relative humidity sensors.

When used in the field, the CS215 must be housed in a radiation shield.
Typically, the 41303-5A or RAD06 six-plate solar radiation shield is used.

A 41003-5 or RAD10 ten-plate solar radiation shield can also house the CS215
sensor. Using a 10-plate shield will give slightly more accurate readings. The
41003-5 shield will require a special adapter. The RAD10 will not require any
additional parts.

The white color of these shields reflects solar radiation, and the louvered
construction allows air to pass freely through, thereby keeping the probe at or
near ambient temperature. The RAD06 and RAD10 use a double-louvered
design that offers improved sensor protection from insect intrusion and driving
rain and snow. In addition, the RAD06 and RAD10 shields have lower self­heating in bright sunlight combined with higher temperatures (> 24 °C (75 °F))
and low wind speeds (< 2 m/s (4.5 mph)), giving a better measurement.

Each of these solar radiation shields attaches to a crossarm, mast, or user­supplied pipe with a 2.5 to 5.3 cm (1.0 to 2.1 inch) outer diameter.

Tools required for installing a radiation shield to a tripod or tower include:

• 1/2-inch open-end wrench

• small screwdriver provided with datalogger

• small Phillips screwdriver

• UV-resistant cable ties

• small pair of diagonal-cutting pliers

• adjustable wrench with a minimum 1-7/8 inch jaw size

7.4.1 Installation in a 41303-5A or 41303-5B 6-Plate Shield

1. With a small Phillips screwdriver, loosen the plastic split collar at the base

of the shield (reversing the removable portion if necessary), and gently
insert the probe.

2. Tighten the screws on the collar until it firmly grips the probe body. See

FIGURE 7-1 (left) and FIGURE 7-2.

7

CS215 Temperature and Relative Humidity Probe

CAUTION

7.4.2 Installation in a 41003-5 or 41003-5A 10-Plate Shield Using 6637 Collar Adapter

1. Loosely thread the collar adapter into the base of the 10-plate shield.

2. Insert the CS215 sensor through the collar as far as it will go.

3. Hold the collar and sensor, and finish threading the collar into the shield

by hand. Tighten the collar around the sensor until it firmly grips the probe
body. Use an adjustable wrench if necessary, but do not overtighten the
collar.

7.4.3 Installation in a RAD06 6-Plate Shield or RAD10 10-Plate Shield

1. Loosen the nut on the entry gland at the bottom of the shield.

2. Insert the sensor into the gland as far as it will go (FIGURE 7-1 (right)).

3. Using an adjustable wrench, tighten the nut on the gland until the sensor is

held firmly in place. Do not overtighten.

7.4.4 Mount the Shield

1. Attach the radiation shield to the tripod mast, crossarm, or tower leg using

the supplied U-bolt or band clamp (FIGURE 7-1 and FIGURE 7-2).

2. Route the cable to the datalogger, and secure the cable to the mounting

structure using cable ties.

Failure to secure the cable can lead to breakage of the wires
due to fatigue caused by blowing back and forth in the wind.

8

FIGURE 7-1. CS215 and 41303-5A Radiation Shield (left) and RAD06

Radiation Shield (right) on a tripod mast

CS215 Temperature and Relative Humidity Probe

NOTE

FIGURE 7-2. CS215 and 41303-5A Radiation Shield on a

CM200 Series Crossarm

8. Operation

8.1 Sensor Measurement

The CS215 sensor responds to the ?!, M!, MC!, C!, CC!, R!, and RC! SDI-12
commands. For the ?! command, the sensor returns the SDI-12 address. For the
other commands, the sensor returns two values: temperature in degrees Celsius
and relative humidity as a percentage (0 to 100).

When using the M! command, the datalogger waits for the time specified by
the sensor, sends the D! command, pauses its operation, and waits until either it
receives the data from the sensor or the sensor timeout expires. If the
datalogger receives no response, it will send the command a total of three
times, with three retries for each attempt, or until a response is received.
Because of the delays this command requires, it is only recommended in
measurement scans of 10 seconds or more.

The C! command follows the same pattern as the M! command with the
exception that it does not require the datalogger to pause its operation until the
values are ready. Rather, the datalogger picks up the data with the D! command
on the next pass through the program. Another measurement request is then
sent so that data are ready on the next scan.

The R! command switches the sensor to automatically make measurements and
send data every 11 seconds, ±2 seconds, based on the internal clock of the
sensor. If measurements are requested at 2 seconds or faster, the sensor will
increase its measurement rate to approximately every 5 seconds. This instruction
usually takes less than 300 milliseconds to execute. The automatic measurement
mode can only be cancelled by powering down the sensor to reset it.

Only CS215 sensors with serial numbers higher than E1587 or
those with an upgraded operating system support the R! command.

9

CS215 Temperature and Relative Humidity Probe

NOTE

The CS215 also supports the MC!, CC!, and RC! commands, which are the
same as the instructions above, but where the C at the end of the instruction
forces a validation for the data received from the sensor using a checksum. If
the checksum is invalid, the datalogger will re-request the data up to three
times. The checksum validation increases the measurement time by about 40
milliseconds if there are no errors. Retries will increase the measurement time
in proportion to the number of retries. The checksum option is necessary only
for long cable runs.

See Appendix D, SDI-12 Sensor Support
details of the SDI-12 protocol.

8.2 Measurements at Fast Scan Rates

Using the SlowSequence() function allows the SDI-12 instruction to run as a
background process, causing minimum interference to other measurements that
use the analog hardware. Measuring the sensor in a SlowSequence() section of
the program allows faster programs to run as the main scan.

For the CR5000, use a control terminal rather than the SDI-12
terminal to allow the SDI12recorder instruction to run in the slow
sequence.

8.3 Long Cables

Digital data transfer eliminates offset errors due to cable lengths. However,
digital communications can break down when cables are too long, resulting in
either no response from the sensor or corrupted readings. The original SDI-12
standard specifies the maximum total cable length to be 200 feet (61 meters).
To ensure proper operation with long cables, follow these guidelines:

• Use low capacitance, low resistance, screened cable (as fitted by

Campbell Scientific) to reach distances of several hundred meters.

(p. D-1), for additional commands and

10

• Ensure that the power ground cable has low resistance and is

connected to the same ground reference as the datalogger control
terminal.

• Be aware that “daisy-chaining” sensors reduces the maximum cable

length roughly in proportion to the number of sensors connected in
parallel.

8.4 Power Conservation

The CS215 draws less than 70 µA of current between measurements. In most
applications this is insignificant compared to the datalogger and other power
draws, so the sensor can be permanently connected.

In low-power applications, conserve battery power by turning the 12 V supply
to the CS215 on just before the measurement (allowing a warm-up time of at
least 100 ms) and then turning it off afterwards. If available, the switched 12 V
output of the datalogger can be used.

CS215 Temperature and Relative Humidity Probe

NOTE

8.5 Measuring Multiple SDI-12 Sensors

Multiple SDI-12 sensors can be connected to a single datalogger control
terminal if they have unique SDI-12 addresses. The CS215 can have an SDI-12
address of 0 to 9. Some SDI-12 devices can have an SDI-12 address of 0 to 9, A
to Z, or a to z. See Appendix D.2.5, Change Address Command (aAb!)
change the CS215 SDI-12 address from its default address of 0.

9. Troubleshooting and Maintenance

All factory repairs and recalibrations require a returned material
authorization (RMA) and completion of the “Declaration of
Hazardous Material and Decontamination” form. Refer to the

Assistance page at the beginning of this manual for more

information.

9.1 Troubleshooting

Symptom: Temperature is reported as –9999 or NAN, and relative humidity is
reported as 0 or as an unchanging value.

(p. D-3), to

Recheck wiring. Verify the green wire is connected to the control terminal
specified by the SDI12Recorder() instruction. Verify the red wire is
connected to a 12V terminal.

Check the voltage to the sensor with a digital voltage meter. If a switched
12V terminal is used, temporarily connect the red wire to a 12V terminal
(non-switched) for test purposes.

Verify the CS215 SDI-12 address matches the address entered for the
SDI12Recorder() instruction. The default address is 0. The address can be
verified or changed with the commands described in Appendix D, SDI-12
Sensor Support

Remove the filter tip and verify that the sensing element has been installed
with the proper orientation as described in Section 9.4, Sensor Element
Replacement

Symptom: Incorrect temperature or relative humidity is reported.

If using the SW12 terminal to power the sensor, verify the program is
allowing a warm-up time of at least 100 ms.

Check to see if the filter tip has been contaminated. Replace the filter tip,
or clean with distilled water as needed.

(p. D-1).

(p. 12).

9.2 Maintenance

The CS215 probe requires minimal maintenance, but dust, debris, and salts on
the filter cap will degrade sensor performance. Check the white filter on the
end of the sensor for debris. If dirt or salt is ingrained in the filter, clean with
distilled water or replace it. Make sure the filter is connected firmly with your
fingers—do not over tighten

11

CS215 Temperature and Relative Humidity Probe

NOTE

CAUTION

Check the radiation shield monthly to make sure it is free from dust and
debris. To clean the shield, first remove the sensor. Dismount the shield. Brush
all loose dirt off. If more effort is needed, use warm, soapy water and a soft
cloth or brush to thoroughly clean the shield. Allow the shield to dry before
remounting.

9.3 Calibration

The life of the humidity chip element is quoted as many years with a typical
drift of less than 1% per year when used in ‘clean’ environments. Because it
can be difficult to know what the sensor has been exposed to and because the
element is relatively inexpensive, the sensor element is often replaced annually,
which is the normal interval for recalibrating similar probes. Replacing the
element should return the CS215 to factory calibration for temperature and
relative humidity.

9.4 Sensor Element Replacement Procedure

1. Wash your hands to avoid getting dirt or grease on the element.

Dirt, salt, or grease left on the plastic while handling the element
may influence the measurements.

2. Disconnect the CS215 from the 12 V power supply.

3. Remove the filter by unscrewing it counterclockwise when looking

towards the tip of the sensor.

The filter cap unscrews from the probe. Attempting to pull it
off will destroy it.

4. Identify the sensor element. FIGURE 9-1 below shows a side view of the

end of the probe and sensor element. Before removing the element,
carefully study the probe, note its orientation, and read the following
description:

• The element plugs into the black plastic socket that protrudes by about

1 mm from the end of the metal body of the sensor.

• Eight holes are in the socket, while the element only has four pins.

• The element will work when fitted into either side of socket but must

be installed in one of the two possible orientations to work.

• The correct orientation is with the black molded tip of the element

(that contains the sensing components) mounted directly above the
center of the socket.

12

• FIGURE 9-1 shows the correct orientation, while FIGURE 9-2 shows

the incorrect orientation.

CS215 Temperature and Relative Humidity Probe

CAUTION

CAUTION

An incorrectly oriented element will not work, will draw
excessive power, and may be damaged if left powered in
this state for more than a few seconds.

5. Grasp the body of the sensor (this also ensures you are at the same

electrical potential as the element) and, holding the black tip of the
element between your fingertips, pull the element out of the socket. Store
the old element in electrostatic protective packaging if you wish to retain
it.

6. With the element removed, check for dirt and/or corrosion around the

socket. Clean any dirt away using a damp cloth to remove any salts that
might be there.

7. Unpack the replacement element, avoiding static discharges to the element

by making sure you touch the packaging before the element.

8. Either hold the element by the black top of the package (the other end to

the gold plated pins) or use a pair of fine nosed pliers or tweezers to grip
the sensor by the pins. Carefully match the pins to the socket in the end of
probe.

9. Confirm the correct orientation and gently push the pins into the socket

until they will not go in any further.

10. Before replacing the filter element and turning on power to the sensor,

double-check that the sensor is inserted in the correct orientation. Refer to
FIGURE 9-1.

11. Screw the filter back onto the end of the probe, making sure it clears the

sensor element. If the element appears too close to the filter, it likely has
been inserted in the incorrect orientation or the legs of the element have
been bent. Screw the filter onto the thread and tighten gently with your
fingers.

Only tighten the filter approximately an eighth of a turn by
hand when the filter is fully screwed onto the thread. Over­tightening the filter will damage it and cause problems in
inserting and removing the probe from some shields.

13

CS215 Temperature and Relative Humidity Probe

Sensor
connector
sticking out of
the end of the
tube

Gold pins

Sensing
Element

Sensing part of
the element.
Print ing on this
side.

Center line of
the sensor
body and
socket

Thread for the
filt er

Gold colored
side o f the tip

FIGURE 9-1. Correct fit of sensor element (side view)

14

CS215 Temperature and Relative Humidity Probe

Sensing part of
element NOT on
the center line

Center line o f the
sensor body

FIGURE 9-2. Incorrect fit of sensor element (side view)

10. Attributions and References

Santoprene® is a registered trademark of Exxon Mobile Corporation.

AASC, 1985: The State Climatologist (1985) Publication of the American

Association of State Climatologists: Heights and Exposure Standards for
Sensors on Automated Weather Stations, v. 9, No. 4 October, 1985.
(www.stateclimate.org/sites/default/files/upload/pdf/state-

climatologist/00000029.pdf)

EPA, 2008: Quality Assurance Handbook for Air Pollution Measurement

Systems, Vol. IV, Meteorological Measurements, Ver. 2.0, EPA-454/B-08-

002 (revised 2008). Office of Air Quality Planning and Standards,
Research Triangle Park, NC 27711.

Goff, J. A. and S. Gratch, 1946: Low-pressure properties of water from -160°

to 212°F, Trans. Amer. Soc. Heat. Vent. Eng., 51, 125-164.

Lowe, P. R., 1977: An approximating polynomial for the computation of

saturation vapor pressure, J. Appl. Meteor., 16, 100-103.

15

CS215 Temperature and Relative Humidity Probe

Meyer, S. J. and K. G. Hubbard, 1992: Nonfederal Automated Weather

Stations and Networks in the United States and Canada: A Preliminary
Survey, Bulletin Am. Meteor. Soc., 73, No. 4, 449-457.

Weiss, A., 1977: Algorithms for the calculation of moist air properties on a

hand calculator, Amer. Soc. Ag. Eng., 20, 1133-1136.

WMO, 2008. Guide to Meteorological Instruments and Methods of

Observation. World Meteorological Organization No. 8, 7th edition,
Geneva, Switzerland.

16

NOTE

Appendix A. Importing Short Cut Code Into CRBasic Editor

This tutorial shows:

• How to import a Short Cut program into a program editor for

additional refinement

• How to import a wiring diagram from Short Cut into the comments of

a custom program

Short Cut creates files, which can be imported into CRBasic Editor. Assuming
defaults were used when Short Cut was installed, these files reside in the
C:\campbellsci\SCWin folder:

• .DEF (wiring and memory usage information)

• .CR2 (CR200(X)-series datalogger code)

• .CR300 (CR300-series datalogger code)

• .CR6 (CR6-series datalogger code)

• .CR8 (CR800-series datalogger code)

• .CR1 (CR1000 datalogger code)

• .CR1X (CR1000X-series datalogger code)

• .CR3 (CR3000 datalogger code)

• .CR5 (CR5000 datalogger code)

Use the following procedure to import Short Cut code and wiring diagram into
CRBasic Editor.

1. Create the Short Cut program following the procedure in Section 4,
QuickStart

CRBasic Editor button. The program opens in CRBasic with the name
noname.CR_. Now save the program with your desired name in any

folder.

Once the file is edited with CRBasic Editor, Short Cut can no
longer be used to edit the datalogger program. Change the name
of the program file or move it, or Short Cut may overwrite it next
time it is used.

2. The program can now be edited, saved, and sent to the datalogger.

3. Import wiring information to the program by opening the associated .DEF
file. By default, it will be in the c:\campbellsci\SCWin folder. Copy and
paste the section beginning with heading “–Wiring for CRXXX–” into the
CRBasic program, usually at the head of the file. After pasting, edit the
information such that an apostrophe (') begins each line. This character
instructs the datalogger compiler to ignore the line when compiling. You
can highlight several lines of CRBasic code then right-click and select
Comment Block. (This feature is demonstrated at about 5:10 in the

CRBasic | Features video.)

(p. 1). Finish the program. On the Advanced tab, click the

A-1

CRBasic Example B-1. CR1000X Program for Measuring the CS215

'Program measures one CS215 sensor every 5 seconds and stores the average

EndProg

Appendix B. Example Programs

This CR1000X program can be adapted for use with CR300-, CR6-, and
CR800-series, CR1000, CR3000, and CR5000 dataloggers.

'temperature and a sample of relative humidity every 10 minutes.

'Wiring Diagram
'==============
'CS215

' Wire
' Color Function Datalogger
' ----- -------- ---------­' Red Power (12V) 12V
' Green SDI-12 signal C7
' Black Power ground G
' White Power ground G
' Clear Shield G

'Declare the variable array for the measurement

Public TRHData(2)

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

Units AirTC=Deg C
Units RH=%

'Define Data Tables

DataTable(TenMin,True,-1)

DataInterval(0,10,Min,10)
Average(1,AirTC,FP2,False)
Sample(1,RH,FP2)

EndTable

'Main Program

BeginProg

'Main Scan

Scan(5,Sec,1,0)

'CS215 Temperature & Relative Humidity Sensor measurements 'AirTC' and 'RH'

SDI12Recorder(TRHData(),C7,"0","M!",1,0)

'Call Data Tables and Store Data

CallTable(TenMin)
NextScan

B-1

Appendix B. Example Programs

CRBasic Example B-2. CR200(X) Program for Measuring the CS215

'CR200(X) Series Datalogger

EndProg

'Program measures one CS215 sensor every 30 seconds and stores the average
'temperature and a sample of relative humidity every 10 minutes.

'Wiring Diagram
'==============
'CS215

' Wire
' Color Function CR200(X)
' ----- -------- ------­' Red Power (12V) Battery +
' Green SDI-12 signal C1/SDI-12
' Black Power ground G
' White Power ground G
' Clear Shield G

'Declare the variable array for the measurement

Public TRHData(2)

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

Units AirTC=Deg C
Units RH=%

'Define a data table for ten-minute data

DataTable(TenMin,True,-1)

DataInterval(0,10,Min)
Average(1,AirTC,False)
Sample(1,RH)

EndTable

'Main Program

BeginProg

Scan (30,Sec) 'Scan every 30 seconds

'CS215 Temperature & Relative Humidity Sensor measurements 'AirTC' and 'RH'

SDI12Recorder(TRHData(),"0M!",1,0)

'Call Data Tables and Store Data

CallTable TenMin
NextScan

This example program shows the measurement of a single CS215 and can be
used directly with CR200(X) series dataloggers.

B-2

TABLE C-1. Environmental Tests

Appendix C. Environmental Performance

This Appendix details tests and limitations of the sensor when exposed to extremes of the
environment.

C.1 Tests to Defined Standards

The sensor element has been tested by the manufacturer and found to comply
with various environmental test standards as shown in TABLE C-1 below:

Environment Norm Results

JESD22-A104-B

Temperature Cycles

–40/+125 °C,

1000 cycles

Within Specifications

HAST Pressure

Cooker

Salt Atmosphere DIN-50021SS Within Specifications

Condensing Air – Within Specifications

Freezing cycles Fully

Submerged

Various Automotive

Chemicals

Cigarette Smoke

N.B. The temperature sensor passed all tests without any detectable drift. Package and
electronics also passed 100%

C.2 Exposure to Pollutants

All capacitative sensors are susceptible to pollutants to some degree. The
vapors may interfere with the polymer layers used in the structure of the
sensing element. The diffusion of chemicals into the polymer may cause
temporary or even permanent shifts in both offset and sensitivity.

After low levels of exposure, in a clean environment the contaminants will
slowly outgas and the sensor recovers. High levels of pollutants may cause
permanent damage to the sensing polymer.

JESD22-A110-B 2.3bar

125 °C 85% RH

–20/+90 °C, 100 cycles,

30 min dwell time

DIN 72300-5 Within Specifications

Equivalent to 15years in

a mid-size car

Reversible shift by

+2% RH

Reversible shift by

+2% RH

Within Specifications

As a general rule, the sensor will not be damaged by levels of chemicals which
are not too dangerous to human health (see TABLE C-1), so damage is not
normally a problem in outdoor applications. Avoid exposing the sensor to
chemicals at higher concentrations.

C-1

Appendix D. SDI-12 Sensor Support

C.3 Operating Range of RH Element

The RH sensor is specified to work over the entire humidity range of 0–100%
RH for the temperature range –20 to 60 °C. It will give readings over an
extended range as shown in FIGURE C-1 below (although the electronics of
the CS215 probe are not specified to operate beyond 70 °C).

When used outside the range of normal conditions or when subject to
prolonged periods of condensation or freezing, the sensor calibration may be
temporarily altered, normally resulting in a change of <+3% RH. Upon
returning to normal conditions, the calibration will settle back to the “standard”
calibration over the course of several days. In laboratory conditions, it is
possible to speed up this process by a reconditioning process, as follows:
80–90 °C at < 5 %RH for 24 h (baking) followed by 20–30 °C at > 74% RH
for 48 h (re-hydration).

FIGURE C-1. Normal operating conditions of RH element

C.4 Measurement Below 0 °C

The CS215 provides a humidity reading that is referenced to the saturated
water vapor pressure above liquid water, even at temperatures below 0 °C,
where ice might form. This is the common way to express relative humidity
and is as defined by the World Meteorological Organization. If an RH value is
required to be referenced to ice, the CS215 readings will need to be corrected.

One consequence of using water as the reference is that the maximum humidity
that will normally be output by the sensor for temperatures below freezing is as
follows:

100% RH at 0 °C
95% RH at –5 °C
91% RH at –10 °C
87% RH at –15 °C
82% RH at –20 °C
78% RH at –25 °C
75% RH at –30 °C

In practical terms this means that, for instance, at –20 °C the air is effectively
fully saturated when the sensor outputs 82% RH.

C-2

TABLE D-1. Campbell Scientific Sensor SDI-12 Command and

Appendix D. SDI-12 Sensor Support

D.1 Introduction

SDI-12, Serial Data Interface at 1200 baud, is a protocol developed to simplify
sensor and datalogger compatibility. Only three wires are necessary — serial
data, ground, and 12 V. With unique addresses, multiple SDI-12 sensors can
connect to a single SDI-12 terminal on a Campbell Scientific datalogger.

This appendix discusses the structure of SDI-12 commands and the process of
querying SDI-12 sensors. For more detailed information, refer to version 1.4 of
the SDI-12 protocol, available at www.sdi-12.org.

For additional information, refer to the SDI-12 Sensors | Transparent Mode
and SDI-12 Sensors | Watch or Sniffer Mode videos.

D.2 SDI-12 Command Basics

SDI-12 commands have three components:

Sensor address (a) – a single character and the first character of the command.
The default address of zero (0) can be used unless multiple sensors are
connected to the same port.

Command body – an upper case letter (the “command”), optionally followed by
one or more alphanumeric qualifiers.

Command termination (!) – an exclamation mark.

An active sensor responds to each command. Responses have several standard
forms and always terminate with <CR><LF> (carriage return and line feed).
Standard SDI-12 commands are listed in TABLE D-1.

Response Set

Name Command Response1

Acknowledge

Active

Send Identification aI!

Start Verification aV! atttn <CR><LF>

Address Query ?! a<CR><LF>

a! a<CR><LF>

allccccccccmmmmmmvvvxxx...xx

<CR><LF>

Change Address aAb! b<CR><LF>

Start Measurement

Start Measurement

and Request CRC

aM!

aM1!...aM9!

aMC!

aMC1!...aMC9!

atttn<CR><LF>

atttn <CR><LF>

D-1

Appendix D. SDI-12 Sensor Support

TABLE D-1. Campbell Scientific Sensor SDI-12 Command and

Response Set

Name Command Response1

Start Concurrent

Measurement

Start Concurrent

Measurement and

Request CRC

aC!

aC1!...aC9!

aCC!

aCC1!...aCC9!

Send Data aD0!...aD9!

Continuous

Measurement

aR0!...aR9! a<values><CR><LF>

Continuous

Measurement and

Request CRC

1

Information on each of these commands is given in following sections.

aRC0!...aRC9! a<values><CRC><CR><LF>

D.2.1 Acknowledge Active Command (a!)

The Acknowledge Active command (a!) is used to test a sensor on the SDI-12
bus. An active sensor responds with its address.

D.2.2 Send Identification Command (aI!)

atttnn<CR><LF>

atttnn<CR><LF>

a<values><CR><LF>

or

a<values><CRC><CR><LF>

Sensor identifiers are requested by issuing command aI!. The reply is defined
by the sensor manufacturer but usually includes the sensor address, SDI-12
version, manufacturer’s name, and sensor model information. Serial number or
other sensor specific information may also be included.

aI! allccccccccmmmmmmvvvxxx...xx<CR><LF>

a Sensor SDI-12 address

ll SDI-12 version number (indicates compatibility)

cccccccc 8-character vendor identification

mmmmmm 6 characters specifying the sensor model

vvv 3 characters specifying the sensor version (OS)

An optional field up to 13 characters in length, used for a serial

xxx…xx

number or other specific sensor information that is not relevant
for operation of the datalogger

<CR><LF> Terminates the response.

Source: SDI-12: A Serial-Digital Interface Standard for Microprocessor-Based Sensors
(see Appendix D.4, References

(p. D-9)).

D-2

Appendix D. SDI-12 Sensor Support

D.2.3 Start Verification Command (aV!)

The response to a Start Verification command can may include hardware
diagnostics, but like the aI! command, the response is not standardized.

Command: aV!
Response: atttn<CR><LF>

a = sensor address

ttt = time, in seconds, until verification information is available

n = the number of values to be returned when one or more subsequent D!

commands are issued

D.2.4 Address Query Command (?!)

Command ?! requests the address of the connected sensor. The sensor replies
to the query with the address, a. This command should only be used with one
sensor on the SDI-12 bus at a time.

D.2.5 Change Address Command (aAb!)

Multiple SDI-12 sensors can be connected to a single SDI-12 terminal on a
datalogger. Each device on a single terminal must have a unique address.

A sensor address is changed with command aAb!, where a is the current
address and b is the new address. For example, to change an address from 0 to
2, the command is 0A2!. The sensor responds with the new address b, which in
this case is 2.

D.2.6 Start Measurement Commands (aM!)

A measurement is initiated with the M! command. The response to each
command has the form atttn<CR><LF>, where

a = sensor address

ttt = time, in seconds, until measurement data are available. If the data is ready

before then, the sensor notifies the datalogger, and the datalogger begins
issuing D commands.

n = the number of values to be returned when one or more subsequent D
commands are issued. For the aM! command, n is an integer from 0 to 9.

When the aM! is issued, the datalogger pauses its operation and waits until
either it receives the data from the sensor or the time, ttt, expires.
Depending on the scan interval of the datalogger program and the response
time of the sensor, this may cause skipped scans to occur. In this case make
sure your scan interval is longer than the longest measurement time (ttt).

D-3

Appendix D. SDI-12 Sensor Support

TABLE D-2. Example aM! Sequence

0M!

00352<CR><LF>

The datalogger makes a request to sensor 0 to start
a measurement.

Sensor 0 immediately indicates that it will return 2
values within the next 35 seconds.

Within 35 seconds, sensor 0 indicates that it has

0<CR><LF>

completed the measurement by sending a service
request to the datalogger.

0D0!

0+.859+3.54<CR><LF>

The datalogger immediately issues the first D
command to collect data from the sensor.

The sensor immediately responds with the sensor
address and the two values.

D.2.7 Start Concurrent Measurement Commands (aC!)

A concurrent measurement (aC!) command follows the same pattern as the
aM! command with the exception that it does not require the datalogger to

pause its operation, and other SDI-12 sensors may take measurements at the
same time. The sensor will not issue a service request to notify the datalogger
that the measurement is complete. The datalogger will issue the aD0!
command during the next scan after the measurement time reported by the
sensor has expired. To use this command, the scan interval should be 10
seconds or less. The response to each command has the form atttn<CR><LF>,
where

a = the sensor address

ttt = time, in seconds, until the measurement data are available

nn = the number of values to be returned when one or more subsequent D

commands are issued.

See the following example. A datalogger has three sensors wired into terminal
C1. The sensors are addresses X, Y, and Z. The datalogger will issue the
following commands and receive the following responses:

D-4

TABLE D-3. Example aC! Sequence

XC!

X03005<CR><LF>

YC!

Y04006<CR><LF>

ZC!

Appendix D. SDI-12 Sensor Support

The datalogger makes a request to
sensor X to start a concurrent
measurement.

Sensor X immediately indicates that
it will have 5 (05) values ready for
collection within the next 30 (030)
seconds.

The datalogger makes a request to
sensor Y to start a concurrent
measurement.

Sensor Y immediately indicates that
it will have 6 (06) values ready for
collection within the next 40 (040)
seconds.

The datalogger makes a request to
sensor Z to start a concurrent
measurement.

Z02010<CR><LF>

ZD0!

Z+1+2+3+4+5+6+7+8+9+10<CR><LF>

XD0!

X+1+2+3+4+5<CR><LF>

YD0!

Y+1+2+3+4+5+6<CR><LF>

Sensor Z immediately indicates that it
will have 10 values ready for
collection within the next 20 (020)
seconds.

After 20 seconds have passed, the
datalogger starts the process of
collecting the data by issuing the first
D command to sensor Z.

Sensor Z immediately responds with
the sensor address and the 10 values.

10 seconds later, after a total of 30
seconds have passed, the datalogger
starts the process of data from sensor
X by issuing the first D command.

The sensor immediately responds
with the sensor address and the 5
values.

Ten seconds later, after a total of 40
seconds have passed, the datalogger
starts the process of data from sensor
Y by issuing the first D command.

The sensor immediately responds
with the sensor address and the 6
values.

D-5

Appendix D. SDI-12 Sensor Support

D.2.8 Start Measurement Commands with Cyclic Redundancy

Check (aMC! and aCC!)

Error checking is done by using measurement commands with cyclic
redundancy checks (aMC! or aCC!). This is most commonly implemented
when long cable lengths or electronic noise may impact measurement
transmission to the datalogger. When these commands are used, the data
returned in response to D or R commands must have a cyclic redundancy
check (CRC) code appended to it. The CRC code is a 16-bit value encoded
within 3 characters appended before the <CR><LF>. This code will not be
returned in the data table but checked by the datalogger as it comes. The code
returned is based on the SDI-12 protocol. See the SDI-12 communication
specification for version 1.3 available at www.sdi-12.org to learn more about
how the CRC code is developed.

D.2.9 Stopping a Measurement Command

A measurement command (M!) is stopped if it detects a break signal. A break
signal is sent by the datalogger before most commands.

A concurrent measurement command (C!) is aborted when any other valid
command is sent to the sensor before the measurement time has elapsed.

D.2.10 Send Data Command (aD0! … aD9!)

The Send Data command requests data from the sensor. It is issued
automatically with every type of measurement command (aM!, aMC!, aC!,
aCC!). When the measurement command is aM! or aMC!, the datalogger
issues the aD0! command once a service request has been received from the
sensor. When the datalogger is issuing concurrent commands (aC! or aCC!),
the Send Data command is issued after the required time has elapsed (no
service request will be sent by the sensor). In transparent mode (Appendix D.3,
SDI-12 Transparent Mode

Depending on the type of data returned and the number of values a sensor
returns, the datalogger may need to issue aD0! up to aD9! to retrieve all data.
A sensor may return up to 35 characters of data in response to a D command
that follows an M! or MC! command. A sensor may return up to 75 characters
of data in response to a D command that follows a C! or CC! command.

Command: aD0! (aD1! … aD9!)
Response: a<values><CR><LF> or
a<values><CRC><CR><LF>

where:

a = the sensor address

<values> = values returned with a polarity sign (+ or –)

<CR><LF> = terminates the response

<CRC> = 16-bit CRC code appended if data was requested with aMC! or

aCC!.

(p. D-7)), the user asserts this command to obtain data.

D-6

D.2.11 Continuous Measurement Command (aR0! … aR9!)

Sensors that are able to continuously monitor the phenomena to be measured
can be read directly with the R commands (R0!...R9!). The response to the R
commands mirrors the Send Data command (aD0!). A maximum of 75
characters can be returned in the <values> part of the response to the R
command.

D.3 SDI-12 Transparent Mode

System operators can manually interrogate and enter settings in probes using
transparent mode. Transparent mode is useful in troubleshooting SDI-12
systems because it allows direct communication with probes. Datalogger
security may need to be unlocked before transparent mode can be activated.

Transparent mode is entered while the computer is communicating with the
datalogger through a terminal emulator program. It is accessed through
Campbell Scientific datalogger support software or other terminal emulator
programs. Datalogger keyboards and displays cannot be used.

The terminal emulator is accessed by navigating to the Datalogger menu in
PC200W, the Tools menu in PC400, or the Datalogger menu in the Connect
screen of LoggerNet.

Appendix D. SDI-12 Sensor Support

Watch the video: SDI-12 Sensors | Transparent Mode.

The following examples show how to enter transparent mode and change the
SDI-12 address of an SDI-12 sensor. The steps shown in Appendix D.3.1,
Changing an SDI-12 Address
dataloggers. Appendix D.3.2, Changing an SDI-12 Address – CR200(X) Series

(p. D-8), lists the steps used for CR200(X)-series dataloggers.

(p. D-7), are used with most Campbell Scientific

D.3.1 Changing an SDI-12 Address

The example below was done with a CR1000, but the steps are only slightly
different for CR1000X-series, CR300-series, CR6-series, CR800-series, and
CR3000 dataloggers. For CR200(X)-series dataloggers, see Appendix D.3.2,
Changing an SDI-12 Address – CR200(X) Series

1. Connect an SDI-12 sensor to the CR1000.

2. In LoggerNet Connect, in the Datalogger menu, click Terminal
Emulator. The terminal emulator window opens.

3. In the Select Device menu located in the lower left side of the window,
select the CR1000 station.

4. Click Open Terminal.

(p. D-8).

5. Select All Caps Mode.

6. Press Enter until the datalogger responds with the CR1000> prompt.

7. Type SDI12 and press Enter.

D-7

Appendix D. SDI-12 Sensor Support

8. At the Select SDI12 Port prompt, type the number corresponding to the

9. To query the sensor for its current SDI-12 address, type ?! and press Enter.

10. To change the SDI-12 address, type aAb!, where a is the current address

11. To exit SDI-12 transparent mode, click Close Terminal.

control port where the sensor is connected and press Enter. The response
Entering SDI12 Terminal indicates that the sensor is ready to accept SDI­12 commands.

The sensor responds with its SDI-12 address. If no characters are typed
within 60 seconds, the mode is exited. In that case, simply type SDI12
again, press Enter, and type the correct control port number when
prompted.

from the above step and b is the new address (see FIGURE D-1). Press
Enter. The sensor will change its address and respond with the new
address.

D-8

FIGURE D-1. CR1000 example of using the SDI-12 transparent mode

to change the SDI-12 address from 0 to 3. Sensor is connected to
control port 1.

D.3.2 Changing an SDI-12 Address – CR200(X) Series

1. Connect a single SDI-12 sensor to the CR200(X).

2. In LoggerNet Connect, in the Datalogger menu, click Terminal

Emulator. The terminal emulator window opens.

3. In the Select Device menu located in the lower left side of the window,

select the CR200Series station.

4. Click Open Terminal.

Appendix D. SDI-12 Sensor Support

5. Select All Caps Mode.

6. Press Enter until the datalogger responds with the CR2XX> prompt.

7. Type SDI12 and press Enter.

8. The response SDI12> indicates that the sensor is ready to accept SDI-12

commands.

9. To query the sensor for its current SDI-12 address, type ?! and press Enter.

The sensor responds with its SDI-12 address. If no characters are typed
within 60 seconds, the mode is exited. In that case, simply type SDI12
again and press Enter.

10. To change the SDI-12 address, type aAb!, where a is the current address

from the above step and b is the new address (see FIGURE D-1). Press
Enter. The sensor will change its address and respond with the new
address.

11. To exit SDI-12 transparent mode, click Close Terminal.

D.4 References

FIGURE D-2. CR200(X) example of using the SDI-12 transparent

mode to change the SDI-12 address from 0 to 1

SDI-12 Support Group. SDI-12: A Serial-Digital Interface Standard for

Microprocessor-Based Sensors – Version 1.4. River Heights, UT: SDI-12

Support Group, 2017. www.sdi-12.org/specification.php?file_id=1.

D-9

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