In-situ RDO PRO-X User manual

RDO Pro-X
Operator’s Manual
Information subject to change without notice. In-Situ, In-Situ logo,“Water Simplied”, VuLink, RDO, RuggedCable, TROLL,
BaroTROLL, HydroVu, VuSitu, Baro Merge, and Win-Situ are trademarks or registered trademarks of In-Situ Inc. ©2023. All
rights reserved. This product may be covered by patents identied at www.in-situ.com/patents 2023-10-11 | 0090102

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Contents
Optical RDO PRO-X Dissolved Oxygen Probe Specications���������������������������������������������������������������������� 5
Optical RDO PRO-X Dissolved Oxygen Probe...................................................................................................................... 5
Introduction���������������������������������������������������������������������������������������������������������������������������������������������������� 6
System Description ....................................................................................................................................................................... 6
Serial Numbers................................................................................................................................................................................ 7
Unpack the Probe .......................................................................................................................................................................... 7
Calibrate the RDO PRO-X Probe �������������������������������������������������������������������������������������������������������������������� 9
1-Point Calibration......................................................................................................................................................................... 9
2-Point Calibration.......................................................................................................................................................................10
Probe Deployment ��������������������������������������������������������������������������������������������������������������������������������������� 11
Care and Maintenance ��������������������������������������������������������������������������������������������������������������������������������� 12
Clean the Sensor Cap..................................................................................................................................................................12
Clean the Optical Window ........................................................................................................................................................12
Clean the Probe ............................................................................................................................................................................12
Sensor Cap Storage.....................................................................................................................................................................12
Replace the Sensor Cap .............................................................................................................................................................12
Maintain Desiccant......................................................................................................................................................................13
Controller Requirements and Connections������������������������������������������������������������������������������������������������ 14
Wire Diagram.................................................................................................................................................................................14
Power Connections .....................................................................................................................................................................15
Communications..........................................................................................................................................................................15
Enabling analog output.............................................................................................................................................................15
Analog (4-20 mA) wiring diagram..........................................................................................................................................15
SDI-12 wiring diagram ...............................................................................................................................................................16
Modbus (RS485) wiring diagram............................................................................................................................................17
Modbus (RS232 with converter) wiring diagram .............................................................................................................18
Converter ........................................................................................................................................................................................18
Conguring SDI-12 Settings������������������������������������������������������������������������������������������������������������������������ 19
About SDI-12 .................................................................................................................................................................................19
Congure SDI-12 Settings in VuSitu......................................................................................................................................19
Modbus PLC Interface ���������������������������������������������������������������������������������������������������������������������������������� 19
Overview.........................................................................................................................................................................................19
Setting Up Instrument ...............................................................................................................................................................20
Programming the PLC ................................................................................................................................................................20
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Reading Device Information....................................................................................................................................................20
Reading Parameters....................................................................................................................................................................21
Dissolved Oxygen Equations����������������������������������������������������������������������������������������������������������������������� 22
Dissolved Oxygen Concentration ..........................................................................................................................................22
Dissolved Oxygen, % Saturation ............................................................................................................................................23
Communication Device�������������������������������������������������������������������������������������������������������������������������������� 24
Install and Open the Software.................................................................................................................................................24
Connect the Probe to the Communication Device..........................................................................................................24
Service ����������������������������������������������������������������������������������������������������������������������������������������������������������� 24
RDO Software Troubleshooting..............................................................................................................................................24
Declaration of Conformity ��������������������������������������������������������������������������������������������������������������������������� 25
Appendix ������������������������������������������������������������������������������������������������������������������������������������������������������ 27
Appendix A: Parameter Numbers and Locations ............................................................................................................27
Appendix B: Unit IDs...................................................................................................................................................................27
Appendix C: Calibration Registers..........................................................................................................................................28
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Optical RDO PRO-X Dissolved Oxygen Probe Specications
Optical RDO PRO-X Dissolved Oxygen Probe
Sensor Type Optical (luminescent) dissolved oxygen sensor
RDO PRO-X Probe
Range: 0 to 60 mg/L concentration
Accuracy: ±0.1 mg/L from 0 to 20 mg/L
±2% of reading from 20-60 mg/L
Resolution: 0.01 mg/L
Response time: T90 < 45 sec; T95 < 60 sec @ 25°C
Storage conditions: -5° to 60° C (23° to 140° F)
RDOClassic Cap
RDO-X Sensor Cap
RDO Fast Cap
Usage life: 2 years typical
Storage conditions: 1° to 60° C (33° to 140° F), in factory container
Temperature sensor
Range: 0° to 50° C (32° to 122° F)
Accuracy: ±0.1° C typical
Resolution: 0.01° C
Transmitter/local display Optional, or use with Con TROLL PRO System
Communications options Modbus/RS485, 4-20 mA, SDI-12
Max. power consumption 50 mA at 12 VDC
Measure current 6 mA typical at 24 VDC
Idle current (no measurement or
communication 160 µA typical at 24 VDC
Maximum cable length Up to 1,219 m (4,000 ft) (for Modbus and 4-20 mA) or up to 60.96 (200
ft) for SDI-12
Cable options 10 m xed stripped-and-tinned; Twist-lock connector with user-
selectable cable length
Internal mounting thread 1¼ - 11 ½ NPT
IP rating IP-67 with cap o, IP-68 with cap installed
Compliance Heavy industrial, IEC 61000-6-2:2005
Salinity compensation Fixed or real-time capable (using controller)
Barometric pressure Fixed or real-time capable (using controller)
Maximum pressure 150 psi from 0 to 50° C; 300 psi @ 25° C
Warranty Probe: 3 years from date of shipment
RDO-X Sensor Cap: 2 years in typical applications
Methods Standard Methods 4500-O; In-Situ Methods 1002-8-2009,1003-8-
2009, 1004-8-2009 (EPA approved)

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Introduction
The RDO PRO-X Probe is a rugged, reliable instrument designed to deliver accurate dissolved oxygen (DO)
data across a wide measurement range and to reduce maintenance costs. The probe features the latest
optical technology for DO measurement.
The RDO PRO-X system consists of the following items.
RuggedCable System
System Description
• Black probe body with removable nose cone
• Optical RDO-X Sensor Cap, Classic Cap, or Fast Cap
• Titanium thermistor
• 10-m standard length with stripped-and-tinned ends
• Customized lengths with titanium twist-lock connectors
1 Cable end, stripped-and-tinned
2 Nose cone
3 RDO-X Sensor Cap
4 Thermistor

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1 Probe
2Cable end, twist-lock connector and
RuggedCable System
1 Dust cap
2 Nose cone
Serial Numbers
Unpack the Probe
The probe serial number is engraved on the side of the unit. The cap serial number is programmed on the
memory chip inside the cap.
1. Remove the probe from the box and other packaging materials.
2. Unscrew the nose cone from the probe and remove the red protective dust cap from the sensor. Save
the dust cap for later use.
3. Remove the RDO cap from the storage sleeve.
4. Align the arrow on the cap with the index mark on the probe and rmly press the cap onto the probe,
without twisting, until it seals over the probe body.

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1 Alignment arrow on cap
2 Cap installed over lens
3 Nose cone
Do not allow moisture or atmospheric humidity inside the cap. Keep the cap in its sealed
package until you are ready to install it. Install promptly. Ensure that O-ring grooves are dry and
that the O-ring is not rolled or pinched inside the cap. The typical cap lifetime is two years after
the rst reading has been taken.
5. Reattach the nose cone.

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1 Storage cap
2 Vented calibration cap
Calibrate the RDO PRO-X Probe
Calibrate the sensor with Win-Situ 5 software or the VuSitu mobile app, or calibrate directly with your
controller.
The optical Rugged Dissolved Oxygen sensor is very stable. The factory calibration should produce readings
within 3% accuracy. If you require readings with greater accuracy we recommend that you perform a
1-point, 100% water-saturated air calibration as described below.
1. Remove the storage cap from the top of the calibration chamber and replace it with the vented
calibration cap.
1-Point Calibration
Water-Saturated Air
2. Place the sponge wafer in the bottom of the calibration chamber and saturate with approximately 10
mL water.
3. Gently dry the instrument and sensing material with a paper towel, making sure there is no water or
debris on the instrument or on the sensing surface.
4. Place the instrument into the calibration chamber about 2.5 cm (1 in.) above the water-saturated
sponge.
5. Allow 5 to 10 minutes for temperature stabilization prior to starting the calibration procedure.
Do not leave the instrument in the calibration chamber for more than 30 minutes. This can allow
condensation to form on the sensing material, which will produce false low readings after calibration.
If condensation does occur, remove the instrument, dry the sensing material, place the instrument in
the chamber, and calibrate.

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1. Set up the calibration procedure as previously described, and perform a water-saturated air
calibration.
2. Remove the water-saturated sponge from the calibration chamber and ll the chamber to the ll line
1 Fill line
2 Temperature sensor
with approximately 60 mL of fresh sodium sulte solution.
3. Place the instrument into the solution. Leave at least 13 mm (0.5 in.) between the surface of the
sensing material and the bottom of the chamber.
4. Ensure that the temperature sensor is completely submerged in the solution.
5. Allow at least 5 minutes for the temperature to stabilize prior to performing the calibration
procedure.
6. Once calibration is complete, remove the sensor, and thoroughly rinse to remove all of the sodium
sulte.
2-Point Calibration
100% and 0% Saturation
We recommend that you perform the 0 % oxygen calibration only if you intend to measure dissolved oxygen
at a concentration of less than 4 mg/L.

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1 10 m cable attached
2 Twist-lock Connector
3 1 1/4 NPT threading
Probe Deployment
The cable end of the RDO PRO-X Probe is internally threaded (1¼ – 11½ NPT) and can be attached to a male
threaded pipe. When deployed, make sure that the nose cone and thermistor are completely submerged.

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Care and Maintenance
Clean the Sensor Cap
Clean the Optical Window
Clean the Probe
Sensor Cap Storage
Replace the Sensor Cap
1. The cap and nose cone must remain on the probe.
2. Rinse the sensor with clean water from a squirt bottle or spray bottle.
3. Gently wipe with a soft-bristled brush or soft cloth if biofouling is present. Use Alconox to remove
grease.
4. If extensive fouling or mineral build-up is present, soak the cap end in vinegar for 15 minutes, then
soak in deionized (DI) water for 15 minutes.
5. After cleaning, perform a 1- or 2-point user calibration or calibration check.
1. Clean the optical window only when you change the cap. See full instructions in the sensor cap
replacement kit.
2. Remove the cap and gently wipe the lens with the supplied lens cloth.
1. Remove the probe nose cone.
2. Use a lint-free cloth to remove any moisture from the probe.
3. Pull the used RDO cap o of the sensor, without twisting.
4. Remove the existing O-rings from the sensor.
Do not use organic solvents—they will damage the sensing element. Do not remove the cap
from the sensor prior to cleaning.
Do not wet the lens area with water or any solution. Use only the supplied lens cloth for
cleaning. Do not use any other cloth or material.
Ensure that there is no moisture in the O-ring grooves. Do not touch or clean the lens with
anything other than the supplied lens wipe.
With the RDO cap installed on probe, gently scrub the probe with a soft-bristled brush or nylon dish
scrubber. Use Alconox to remove grease or other matter. Soak in vinegar and DI water to remove mineral
deposits or extensive fouling.
Prior to installation—Store in factory supplied container.
Installed—Store in the calibration chamber with the storage cap attached and a few drops of clean water.
5. Use your nger to apply a very light layer of silicone-based lubricant around the O-ring grooves.
6. Place the O-rings on the sensor. Apply another thin layer of lubricant to the O-rings and grooves.

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Maintain Desiccant
7. Clean the sensor lens with the wipe provided in the kit and allow it to thoroughly dry. Inspect for
scratches or dirt.
8. Remove the new cap from its sealed packaging and attach it to the sensor, being careful to press
rmly, without twisting, until it seals over the lens. Make sure that the O-rings are not pinched or
rolled between the cap and sensor.
9. Replace the nose cone.
10. Perform a 1- or 2-point calibration.
Desiccant installed in a controller or transceiver protects probe electronics from condensation. A desiccant
pack changes color from blue to pink as it becomes saturated with moisture.
It is extremely important to use the proper size desiccant for your deployment and to change
desiccant often. Desiccant should be changed before the entire pack has turned pink, and
you should use enough to eectively keep cables and probes dry until your next scheduled
maintenance. Desiccant lifespan is dependent on site conditions.

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Controller Requirements and Connections
The RDO PRO-X Probe may be connected to a controller or logger for communication via the following
options.
• Analog (4-20 mA) provides a congurable 4-20 mA current loop output
• SDI-12
• RS485 Modbus
• RS232 to Modbus
Refer to the diagrams on the following pages for PLC wiring diagrams. Unused leads should not
be touching.
Power
Ground
RS485 (+) RS485 (-)
SDI-12
Analog (4-
20 mA)
Wire Diagram
Cable Wire Legend
Wire Color Signal
Red External Power
Black Ground
Blue RS485 (+)
Green RS485 (-)
White SDI-12
Brown Analog 4-20 mA

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Analog (4-20 mA) wiring diagram
Maximum cable length is 4000 
Analog must be enabled in VuSitu or the Comm Kit Soware
Power Connections
Communications
The red wire provides power for all system modes.
The device automatically switches between Modbus and SDI-12 modes depending on which of the two
interfaces has activity. Modbus and SDI-12 cannot be used at the same time—whichever one is currently in
use will block communication on the other. The 4-20 mA current loop output can be used in Modbus or SDI-
12 mode as long as analog output is enabled.
Enabling analog output
Analog output is disabled by default. Enable analog output from Comm Kit software or the settings tab in
Win-Situ 5. Analog output can be enabled with a PLC by setting Modbus device register 9507 to 1.

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SDI-12 wiring diagram
Cable length must not exceed 60.96 m (200 ft.)

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Modbus (RS485) wiring diagram
Cable length must not exceed 1219 m (4000 ft.)

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Modbus (RS232 with converter) wiring diagram
Cable between converter and master must not exceed 60.96 m (20 ft.) Cable between master
and slave must not exceed 1219 m (4000 ft.)
Converter

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Modbus PLC Interface
The Modbus PLC Interface is a simplied method of communicating with the RDO Pro-X using the Modbus
protocol. For information about the specic Modbus registers and Unit IDs for your RDO Pro-X, see
Appendices A and B. The RDO Pro-X conforms to the Modbus standard. For more information about Modbus
communication, see www.modbus.org.
Overview
Conguring SDI-12 Settings
You can congure the list of SDI-12 parameters in VuSitu under Instrument Settings�
The RDO Pro-X conforms to the general SDI-12 Standard Version 1.3. For more information about SDI-
12 commands, see the SDI-12 Standard Version 1.3 document from the SDI-12 Support Group Technical
Committee.
About SDI-12
Congure SDI-12 Settings in VuSitu
Drag and drop
parameters to change
the order.
Connect to VuSitu and
select Instrument
Settings�
Choose SDI-12 Settings� Use the checkboxes to
select parameters to
display.
Tap the gear icon to
adjust the units for each
parameter.

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Holding Register
Number
Holding Register
Address
Size
(Registers)
Data
Type
Description
9001 9000 1 uint16 Device Id: 31 = RDO Pro-X
9002 9001 2 uint32 Serial Number
9007 9006 1 uint16 Firmware version (100 = 1.00)
1. Connect power, and wire the instrument.
2. The setup below is using the instrument's factory default settings. Use VuSitu to reset the instrument to
factory defaults if they have been changed. Take note of any changes in default units setup.
Setting Up Instrument
2. Set the device address match the instrument address. The default device address is 1.
3. Set the PLC to wake-up the device by sending a carriage return (0x0D) or any Modbus command.
a. Allow one second before sending a second command. The instrument needs this time to wake up.
b. After the wake-up command, the next reading must be taken before the end of session timeout.
If the reading interval exceeds the end of session timeout, send a new wake-up command before
requesting a new reading. The default end of session timeout is 5 seconds, and may be longer if the
instrument has been connected to VuSitu.
4. Select the register to read on the PLC using the information in the following sections.
a. Some PLC devices use the register number directly in programming statements, others use register
addresses, which are one less than the register number. Refer to PLC manufacturer instructions to
determine which programming style to use.
b. Each register is a holding register. Some PLCs require you to add 40000 to the register number or
address. For example: 5451 would be 45451.
5. Set the type of register to: 32-bit oat
a. If asked by the PLC this is 2 registers
6. Set the byte order to: Big Endian (MSB)
a. This should be the default and may not be congurable on all PLCs
1. Set up the serial communication to match the instrument communication settings. Communication
settings can be changed with the VuSitu mobile app. The default communication settings are:
Programming the PLC
Mode Start Bit Baud Rate Data Bits Parity Stop Bit
RTU 1 19200 8 Even 1
Reading Device Information
Use the following registers to read general information about the instrument.