Campbell CS475A User manual

Revision: 06/2020
Copyright © 2009 – 2020
Campbell Scientific, Inc.

Table of contents
1. Introduction 1
2. Precautions 1
3. Initial inspection 2
4. QuickStart 2
5. Overview 5
5.1 Components and hardware 7
6. Specifications 7
6.1 Radar unit 8
6.2 Environmental 9
6.3 Physical 9
7. Installation 10
7.1 Wiring to data logger 10
7.1.1 Built-in self-test (BIST) 11
7.2 Data logger programming 11
7.2.1 SDI-12 programming 12
7.3 Field installation 12
7.4 Determine and set reference stage 16
8. Operation 17
8.1 Default settings 17
8.2 Configuring sensor using Device Configuration Utility 18
8.3 Updating operating system 20
8.4 Configuring sensor via extended SDI-12 commands and terminal emulator 21
8.5 SDI-12 measurement commands 37
9. Diagnostics, repair, and maintenance 41
9.1 Testing procedure 41
9.2 Cyclic redundancy check 41
9.3 Diagnostics 42
9.4 Maintenance 42
Table of Contents - i

Appendix A. Importing Short Cut code into CRBasic Editor 43
Appendix B. Example programs 44
Appendix C. SDI-12 version 1.4 identify measurement commands and
responses 46
Appendix D. FCC/IC equipment authorization (USA/Canada only) 49
Table of Contents - ii

1. Introduction
The CS475A radar sensor monitors the water level of rivers, lakes, tidal seas, and reservoirs, and is
ideal for areas where submersed sensors can be damaged due to corrosion, contamination,
flood-related debris, lightning, or vandalism. It outputs a digital SDI-12 signal to indicate
distance and stage. All contemporary Campbell Scientific data loggers can read the SDI-12 signal.
NOTE:
This manual provides information only for CRBasic data loggers. The CS475A is also
compatible with many of our retired Edlog data loggers. For Edlog data logger support,
contact Campbell Scientific.
2. Precautions
lREAD AND UNDERSTAND the Safety section at the back of this manual.
lFollow country-specific installation standards, prevailing safety regulations, accident
prevention rules, and this manual’s safety instructions. The sensor is designed for safe
operation in accordance with the current technical, safety, and ANSI standards.
lThe emitting frequencies of the CS475A is well below the internationally permitted limits.
When used correctly, the radar sensor presents no danger to people.
lDo not attempt to install the sensor unless you are qualified to perform the installation.
lHandle the sensor carefully, since it is a precision instrument.
lIf installing the sensor from tall structures over water, use appropriate safety equipment
such as a safety harness or a life preserver when installing or performing maintenance on
the sensor.
lThe user is responsible for ensuring that the sensor is maintained and functioning properly.
CS475A Radar Water Level Sensor 1

3. Initial inspection
When unpacking the equipment, do the following:
lUnpack the unit in a clean, dry area.
lCarefully open the shipping package, ensuring that the cable jacket is not damaged or cut.
Contact Campbell Scientific if the cable was damaged during unpacking.
lInspect the equipment for any damage that occurred during shipping. If equipment was
damaged during shipping, file a claim with the carrier and report the damage in detail.
4. QuickStart
A video that describes data logger programming using Short Cut is available at:
www.campbellsci.com/videos/cr1000x-data logger-getting-started-program-part-3 . Short Cut
is an easy way to program your data logger to measure the sensor and assign data logger wiring
terminals. Short Cut is available as a download on www.campbellsci.com. It is included in
installations of LoggerNet, RTDAQ, PC400, or PC200W.
1. Open Short Cut and click Create New Program.
2. Double-click the data logger model.
3. In the search box under the Available Sensors and Devices heading, start typing CS475A, or
find the sensor in the Sensors >Water >Level & Flow >CS475A Radar Water Level Sensor
folder. Double-click CS475A Radar Water Level Sensor (average stage) or CS475A Radar
Water Level Sensor (stage) (FIGURE 4-1 (p. 3)). The CS475A (stage) measurement issues the
M! command and collects four values (stage, distance, battery voltage at the sensor, and
error codes) (FIGURE 4-2 (p. 3)). The CS475A (average stage) issues the M1! command and
completes a NOAA PORTS measurement; the user must configure the sensor for the
number of measurements included in the average (FIGURE 4-3 (p. 3)).
SDI-12 Address defaults to 0. Enter the correct SDI-12 Address for the radar sensor if it has
been changed from the factory default value. Default units for stage and distance
measurements are in feet. Change the units to Meter if the System Units have been
changed to meters.
CS475A Radar Water Level Sensor 2

NOTE:
Changing the units in Short Cut will NOT change the units in the device or provide any
unit conversions by the data logger. It will only update the units label in the data table.
FIGURE 4-1. Short Cut, Sensor Selection
FIGURE 4-2. Short Cut, CS475A Stage Properties
FIGURE 4-3. Short Cut, CS475A Average Stage Properties
CS475A Radar Water Level Sensor 3

4. Click the Wiring tab to see how the sensor is wired to the data logger. You can change a
wire location by selecting the control terminal (C) (FIGURE 4-4 (p. 4)). Click OK after wiring
the sensor.
FIGURE 4-4. Short Cut, Change Wire Location
CAUTION:
Wire the sensor in this order: white, clear, red, black.
5. Repeat steps three and four for other sensors.
CS475A Radar Water Level Sensor 4

6. In Output Setup, type the scan rate, a Table Name, and Data Output Storage Interval
(FIGURE 4-5 (p. 5)). Click Next.
FIGURE 4-5. Short Cut, Output Setup
NOTE:
Because of the delays using SDI-12, Campbell Scientific recommends measurement
scans of 10 seconds or more.
7. Select the output options.
8. Click Finish and save the program. Send the program to the data logger if the data logger
is connected to the computer.
9. If the sensor is connected to the data logger, check the output of the sensor in the data
display in LoggerNet, RTDAQ, PC400, or PC200W to make sure it is making reasonable
measurements.
5. Overview
The CS475A emits short microwave pulses and measures the elapsed time between the emission
and return of the pulses. The elapsed time measurement is used to calculate the distance
between the sensor face and the target (for example, water, grain, slurry). The distance value can
be used to determine depth of the medium (FIGURE 5-1 (p. 6)).
This radar sensor outputs a digital SDI-12 signal to indicate distance and stage. The output is
acceptable for recording devices with SDI-12 capability.
CS475A Radar Water Level Sensor 5

The CS475A can measure distances up to 35 m (114.8 ft) with an accuracy of ±2 mm (0.0065 ft).
Once the water surface gets within 0.5 m of the sensor, the accuracy will decrease linearly the
closer the water surface gets to the sensor.
FIGURE 5-1. CS475A stage, distance, and offset
Features:
lMeets USGS Office of Surface Water (OSW) requirements for accuracy
lSDI-12 1.4 functionality including SHEF coded metadata
l1 Hz measurements
lMonitors tides for NOAA physical oceanographic real-time system (PORTS®)
lSupports False Echo Suppression via extended SDI-12 command
lEasy to set up and configure over USB or SDI-12
lLow power mode available
lOptional display
lFCC compliant; individual FCC license not required
lLow maintenance—no moving parts significantly reduces maintenance cost and time
lRugged enough for harsh environments—IP68 rating
lCompatible with Campbell Scientific data loggers CR6, CR3000, CR1000X, CR800 series,
CR300 series, and CR1000
CS475A Radar Water Level Sensor 6

5.1 Components and hardware
The radar sensor consists of an integrated microwave transmitter and sensor together with a horn
antenna (FIGURE 5-2 (p. 7)). The horn antenna serves to focus the transmitted signal and to
receive the reflected echo. A built-in SDI-12 interface provides data processing and SDI-12
communications with the data logger.
1 Mounting loop
2 Housing side cap
3 Housing cap
4Unit secondary 0.5 inch NPT cable port,
primary port on opposite side
5 Instrument horn
FIGURE 5-2. Components and hardware
6. Specifications
Measurement range: 0.5 to 35 m (1.64 to 114.8 ft); d in FIGURE 6-1 (p. 8)
Accuracy: ±2 mm (±0.0065 ft)
Resolution: 1 mm (0.0033 ft)
CS475A Radar Water Level Sensor 7

Output protocol: SDI-12 1.4
Complianceinformation: View the EU Declaration of Conformity at:
www.campbellsci.com/cs475a-l
FIGURE 6-1. Reference line for measurement range
6.1 Radar unit
Frequency: ~26 GHz
Pulse energy: 1 mW maximum
Beam angle: 10° (3-inch diameter horn)
Powerrequirements
Input voltage: 9.6 to 32 VDC
Surge protection: 1.5 kVA
CS475A Radar Water Level Sensor 8

Table 6-1: Power mode, current draw, and measurement response
Power
mode
Nominal Current Draw
Measurement response time
Sleep
state
Measurement
state Maximum
Normal 5 mA < 7 mA 8 mA < 1 s
Low <550µA <7mA 8mA
60 s + (5 × Integration Time) + (Measurement
Time)
For example:
The measurement response time for the default
integration time of 2 s and a measurement time of
1 s is:
Measurement Response Time = 60 s + (5 × 2 s) + 1
s = 71 s
6.2 Environmental
Operatingtemperaturerange: –40 to 80 °C
Storage ranges
Temperature: –40 to 80 °C
Relative humidity: 20 to 80% RH
Vibration resistance: Mechanical vibrations with 4 g and 5 to 100 Hz
6.3 Physical
See FIGURE 6-2 (p. 10) for dimensions.
Mechanicalrating: IP66/68
Housing material: Aluminum
Horn material: PVDF plastic
Weight: 2 kg (4 lb)
CS475A Radar Water Level Sensor 9

FIGURE 6-2. CS475A dimensions
7. Installation
If you are programming your data logger with Short Cut, skip Wiring to data logger (p. 10) and
Data logger programming (p. 11). Short Cut does this work for you. See QuickStart (p. 2) for a
Short Cut tutorial.
7.1 Wiring to data logger
Connections to Campbell Scientific data loggers are given in Table 7-1 (p. 11).
CAUTION:
Connect the wires in the order shown in Table 7-1 (p. 11).
CS475A Radar Water Level Sensor 10

Table 7-1: Wire color, function, and data logger connection
Wire color Wire function Data logger or RTU terminal
White SDI-12 signal SDI-12 Data,C,SDI-12,
or Uconfigured for SDI-121
Clear Shield ⏚(analog ground)
Red Power 12V
Black Power ground G
1Uand Cterminals are automatically configured by the measurement instruction for Campbell Scientific CR6 data
logger.
Campbell Scientific recommends using separate terminals when possible. However, multiple SDI-
12 sensors can be connected to a single data logger control or Uterminal. Each SDI-12 device
must have a unique SDI-12 address.
For the CR6 and CR1000X Campbell Scientific data loggers, triggering conflicts may occur when a
companion terminal is used for a triggering instruction such as TimerInput(),PulseCount(),
or WaitDigTrig(). For example, if the CS475A is connected to C3 on a CR1000X, C4 cannot
be used in the TimerInput(),PulseCount(), or WaitDigTrig() instructions.
7.1.1 Built-in self-test (BIST)
After connecting the sensor to power, the sensor performs a BIST (built-in self-test) for
approximately 50 seconds (factory default). During this self-check, an internal check of the
electronics occurs.
7.2 Data logger programming
Short Cut is the best source for up-to-date programming code for Campbell Scientific data
loggers. If your data acquisition requirements are simple, you can probably create and maintain a
data logger 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.
NOTE:
Short Cut cannot edit programs after they are imported and edited in CRBasic Editor.
A Short Cut tutorial is available in QuickStart (p. 2). If you wish to import Short Cut code into
CRBasic Editor to create or add to a customized program, follow the procedure in Importing
Short Cut code into CRBasic Editor (p. 43). Programming basics for CRBasic data loggers are
CS475A Radar Water Level Sensor 11

provided in the following sections. Complete program examples can be found in Example
programs (p. 44).
7.2.1 SDI-12 programming
The SDI12Recorder() instruction is used to measure a CS475A configured for SDI-12
measurements. This instruction sends a request to the sensor to make a measurement and then
retrieves the measurement from the sensor. See SDI-12 measurement commands (p. 37) for more
information.
For most data loggers, the SDI12Recorder() instruction has the following syntax:
SDI12Recorder(Destination, SDIPort, SDIAddress, “SDICommand”, Multiplier,
Offset, FillNAN, WaitonTimeout)
For the SDIAddress, alphabetical characters need to be enclosed in quotes (for example, “A”).
Also enclose the SDICommand in quotes as shown. The Destination parameter must be an
array. The required number of values in the array depends on the command (see Table 8-4 (p.
39)).
FillNAN and WaitonTimeout are optional parameters (refer to CRBasic Help for more
information).
7.3 Field installation
Consider the following while selecting the site:
lSensor height: Mount the sensor high enough to prevent submersion during flooding
conditions.
WARNING:
Since the sensor is commonly installed over water from tall structures, use appropriate
safety equipment such as a safety harness or a life preserver when installing or
performing maintenance on the sensor.
lWater surface: Install the sensor above the smoothest part of the water surface.
NOTE:
The smoothest part of the water surface is typically found halfway between bridge piers.
However, bridges with long spans between the piers experience more vibration. For
these bridges, vibration can be minimized by mounting the sensor a quarter to a third
of the distance to the next pier.
CS475A Radar Water Level Sensor 12

lHorizontal structures: Avoid mounting near horizontal structural surfaces such as beams,
brackets, and sidewall joints because these surfaces reflect a strong signal. If these
structures cannot be avoided, use the False Echo Supression command
(aXFES=xxx.xx!) to map out the interfering structures in the beam profile.
lObstructions: Mount the sensor away from obstructions (both above and under water) in
the radiation beam path, which spreads as it leaves the sensor. Obstructions to be aware of
include excessive waves, splashing, pipes, wires, rocks, bridge piers, and logs. Determine
the required clearance for the beam angle using the following formula and FIGURE 7-1 (p.
13).
Clearance radius formula:
CONEradius = 0.167(CONEdistance)
Where,
CONEdistance = the distance to the reference line (FIGURE 6-1 (p. 8))
CONEradius = clearance radius in the same measurement units as the CONEdistance
FIGURE 7-1. Beam path clearance
CAUTION:
Be aware that bridges contract and expand with temperature changes. Traffic loads or
trucks can also cause changes to the bridge height.
CS475A Radar Water Level Sensor 13

After choosing an appropriate site, mount and align the sensor using the following procedure:
1. Orient the sensor such that one of its polarization markings is aligned or parallel with the
wall or pier (FIGURE 7-2 (p. 14)). The polarization markings are designated by the
mounting loop screws.
FIGURE 7-2. Polarization markings
2. Securely mount the sensor. Mounting hardware is included with the sensor.
3. After mounting, you can rotate the housing up to 350° to simplify access to the conduit
entry and terminal compartment. To rotate the housing to the desired position:
a. Loosen the set screw on the housing (FIGURE 7-3 (p. 15)).
b. Rotate the housing as desired.
c. Tighten the set screw.
CS475A Radar Water Level Sensor 14

FIGURE 7-3. Housing set screw, mounting loop screws and ground lug
4. Use a bubble level to make certain the antenna horn is aligned within 1° of vertical. A
measurement error will be introduced if the antenna is not perpendicular to the water
surface. The maximum range is reduced because of the off-axis return signal. To use the
bubble level available from Campbell Scientific, do the following:
a. Remove the top cap from the CS475A.
b. Place the bubble level on the top of the CS475A (FIGURE 7-4 (p. 16)).
c. Verify the sensor is level or make the needed changes to level the sensor.
d. Remove the bubble level and replace the cap.
CS475A Radar Water Level Sensor 15

FIGURE 7-4. Campbell Scientific bubble level properly mounted on top of
CS475A
5. Connect the sensor ground lug (FIGURE 7-3 (p. 15)) to a local earth ground using at least a
14 AWG wire. Connection to a local earth ground provides better surge or electrostatic
discharge (ESD) protection than just grounding it via the sensor cable. While connected to
local earth ground, the energy will pass to the local ground instead of traveling through
the cable possibly damaging the electronics in the enclosure.
7.4 Determine and set reference stage
Change the reference stage setting at deployment. This setting allows the sensor to complete an
offset calculation. Every future measurement will use the offset and the current distance
measurement to calculate water stage or depth.
Using a staff plate or other physical datum, measure water level at the measurement site. Record
the measurement. Ensure that the measurement is in the same units as the sensor unit setting.
Default value is feet.
Enter reference stage using a terminal emulator (Configuring sensor via extended SDI-12
commands and terminal emulator (p. 21)).
CS475A Radar Water Level Sensor 16

8. Operation
This section discusses the following.
8.1 Default settings 17
8.2 Configuring sensor using Device Configuration Utility 18
8.3 Updating operating system 20
8.4 Configuring sensor via extended SDI-12 commands and terminal emulator 21
8.5 SDI-12 measurement commands 37
8.1 Default settings
Table 8-1 (p. 17) shows the default settings. The reference stage settings must be changed using a
terminal emulator (Configuring sensor via extended SDI-12 commands and terminal emulator (p.
21)). The other default settings can be used in most circumstances.
Table 8-1: Default settings
Setting Default Read or write
SDI-12 address
0 (change only if two sensors
are connected to the same
port) valid addresses are 0
through 9, A through Z, and a
through z.
Read/write
Power mode 1 = normal Read/write
System units 0 = feet Read/write
Stage reference 0
Read only in DevConfig (must
be set using terminal
emulation (Configuring sensor
via extended SDI-12 commands
and terminal emulator (p. 21))
Offset 0 Read/write though it can only
be written in SDI-12
CS475A Radar Water Level Sensor 17