pyroscience PICO-O2-SUB User manual

PyroScience GmbH www.pyroscience.com
Pico-O2-SUB
OEM Fiber-Optic Oxygen Meter
MANUAL
O2

Pico-O2-SUB | Manual
© PyroScience GmbH 2
Pico-O2-SUB
OEM Fiber-Optic Oxygen Meter
Document Version 1.08
The Pico-O2-SUB is released by:
PyroScience GmbH
Kackertstr. 11
52072 Aachen
Germany
Phone [phone]
Fax [phone]
Email [e-mail]
Web www.pyroscience.com
Registered: Aachen HRB 17329, Germany

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TABLE OF CONTENT
1Introduction .....................................................................................................................................5
2Overview..........................................................................................................................................7
2.1 Mounting of fiber connector in the housing ........................................................................7
2.2 Optical port for O2 sensors.........................................................................................................8
2.3 External temperature sensor......................................................................................................9
2.4 Status LED .......................................................................................................................................10
2.5 USB interface cable .....................................................................................................................11
3Option 1: Operating the Module with Pyro Workbench.................................................... 12
3.1 Installing the software Pyro Workbench............................................................................12
3.2 Using the software Pyro Workbench ...................................................................................13
4Option 2: Operating the module with Pyro Developer Tool ............................................ 14
4.1 Installing the software Pyro Developer Tool....................................................................14
4.2 Using the software Pyro Developer Tool ...........................................................................15
5Option 3: Simplified Custom Integration............................................................................... 16
5.1 Configuring the Module using PyroScience Software ...................................................16
5.2 Electrical Connector for Custom Integration.....................................................................16
5.3 Configuration of the Serial Interface....................................................................................17
5.4 Communication Protocol ...........................................................................................................18
5.4.1 General Definitions.........................................................................................................18
5.4.2 MEA –Trigger Measurement ......................................................................................19
5.4.3 CHI –Calibrate oxygen Sensor at ambient air ....................................................21
5.4.4 CLO –Calibrate oxygen Sensor at 0% (anoxic)....................................................22
5.4.5 SVS –Save Configuration Permanently in Flash Memory..............................22
5.4.6 #VERS –Get Device Information ..............................................................................22
5.4.7 #IDNR –Get Unique ID Number................................................................................23
5.4.8 #LOGO –Flash Status LED...........................................................................................24
5.4.9 #PDWN –Power Down Sensor Circuits .................................................................24
5.4.10#PWUP –Power Up Sensor Circuits........................................................................24
5.4.11#STOP –Enter Deep Sleep Mode..............................................................................24
5.4.12#RSET –Reset Device....................................................................................................25

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5.4.13#RDUM –Read User Memory ....................................................................................25
5.4.14#WRUM –Write User Memory ..................................................................................25
5.4.15#ERRO –Response if Error Occurred......................................................................26
5.5 Available Implementations of Communication Protocol..............................................27
6Option 4: Advanced Custom Integration ............................................................................... 28
7Technical Drawing....................................................................................................................... 29
8Specifications ............................................................................................................................... 30
1. Safety Guidelines......................................................................................................................... 32

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1INTRODUCTION
The Pico-O2-SUB (Item No. PICO-O2-SUB) is an OEM solution for fiber-optic oxygen
measurements under water. It is designed for integration into custom-made underwater
housings. The Pico-O2-SUB consists of three parts: Our standard Pico-O2 OEM (Pico-O2)
module, a pressure stable optical connector (SubPort) for connecting optical sensors and
an adapter. Pico-O2 is characterized by its small size, durability and low power
consumption. This OEM module is easy to integrate and is controlled with a simple serial
communication protocol.
Figure 1: Parts of Pico-O2-SUB
To control the Pico-O2,there are several options depending on the users´ level of
experience with optical sensors:
Option 1: For initial evaluation purposes, Pico-O2 can be operated with the
simple and customer-friendly logger software Pyro Workbench, which is
typically used by end-users. This software offers comfortable settings and
calibration wizards, as well as advanced logging features. Several modules can
be operated in parallel within a single window. This software requires an
encoded USB interface cable (item no. PICO-USB) for connecting the module to a
Windows PC (see chapter 3).

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Option 2: For advanced evaluation purposes, the module can be operated with
the software Pyro Developer Tool. It offers simple settings and calibration
procedures, as well as basic logging features. Furthermore, additional advanced
settings offer full control on all features of the module. This software requires
an encoded USB-interface cable (item no. PICO-USB) for connecting the module
to a Windows PC (see chapter 4).
Option 3: A simplified custom integration of the module can be realized by
adjusting the settings and performing sensor calibrations using the PyroScience
software Pyro Workbench or Pyro Developer Tool (requires the encoded USB
interface cable PICO-USB). After closing the software, the configuration is
automatically saved within the internal flash memory of the module. The
module can then be integrated into a specific setup, and your custom software
can perform measurements using a proprietary USB/UART communication
protocol (see chapter 5).
Option 4: For advanced custom integration the full USB/UART communication
protocol is available on request, allowing custom software full control on all
settings, calibration and measurement features of the module (see chapter 6).

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2OVERVIEW
Figure 2 provides an overview of the Pico-O2. The front provides the port for
connecting an optical fiber used for read-out of optical oxygen sensors, as well as solder
points for an external temperature sensor enabling automatic temperature
compensation. The backside of the module provides the connector for the power supply
and the digital communication interface, as well as a red status LED.
Figure 2: Overview of Pico-O2
2.1 Mounting of fiber connector in the housing
The fiber connector can be installed in two ways, depending on the housing. In thick-
walled housings, the connector can be screwed directly into a threaded hole. For thinner
walls, fixing of the connector with the supplied hex nut is possible (Figure 3). In both
cases, the tightening force should not exceed 12 Nm. Note that the sealing surface must
be smooth to ensure a good sealing. The O-ring should be lubricated with a thin layer of
silicone grease before installation. The screw joint can be secured with bold adhesive,
e.g. Loctite™243. Recommendations for the mounting hole can be found in Figure 3.

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Figure 3: Mounting options
Pressure tests of the whole assembly prior to deployment are strongly advised.
2.2 Optical port for O2 sensors
The Pico-O2-SUB is compatible with special Pyro Science fiber-optic sensors for
underwater applications designated by the appendix ‘-SUB’ in the item number. An index
matching liquid inside the connector enhances the sensor signals. Before connecting a
sensor, insert the provided Pasteur pipette to the bottom of the connector and fill it
completely with deionized water (Figure 4). Alternatively and mandatory for the optical
fiber with lens (item no. SPFIB-LNS-SUB/SPFIB-LNS-CL2-SUB) for read-out of sensor
spots, the optical port should be filled with silicone oil before inserting the optical fiber.
The sensor is secured with the cap nut. Do not use a wrench. It is sufficient to tighten
the nut by hand.

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Figure 4 Connecting sensors to the SUB port
For more detailed information on handling, maintenance, calibration and measurements
of the oxygen sensors, information on calibration, please refer to the oxygen sensor
manual for more information.
2.3 External temperature sensor
The signal of oxygen sensors is temperature dependent, which can be automatically
compensated. Pico-O2 offers a high-precision sensor interface, which can be directly
connected to a Pt100 temperature sensor (not included, item no. TSUB21-NC). The
temperature sensor has to be soldered to the 4 solder pads at the front of the module.
Then temperature sensor has to be placed into the sample of the oxygen measurement.
Figure 5: Connecting a resistive temperature sensor to the module

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The Pt100 temperature sensor has to be soldered to the 4 solder pads at the front of the
module (Figure 5). For short distances (e.g. 10 cm) a simple 2-wire connection might be
sufficient. For this, it is important to shortcut the outer with the inner solder pads as
indicated in Figure 4. For longer distances and/or for high precision measurements a 4-
wire connection should be preferred.
In order to minimize potential electrical noise coupling into the external
temperature sensor, the cables should be twisted and kept as short as possible.
2.4 Status LED
The behavior of the status LED is given in Table 1.
Table 1: Status LED
Status
Description
Behavior of status LED
Power-Up
The power supply is switched
on.
A correct startup of the module
is indicated by 4 flashes within
1-2 seconds.
Active
The module is either in idle
mode waiting for a new
command, or it is executing a
command.
The LED flashes periodically
with 1s interval.
Deep sleep
While the power supply is still
enabled, the module can be put
into deep sleep mode by the
#STOP command.
The LED is switched off.
#LOGO-command
The #LOGO-command is sent to
the module.
The LED flashes 4 times within
1-2 seconds.

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2.5 USB interface cable
For the operation of Pico-O2 with a Windows PC, a coded USB interface cable (item no.
PICO-USB) is available from PyroScience. It includes a license for the comfortable logger
software Pyro Workbench and the software Pyro Developer Tool. Especially for initial
testing purposes this software packages can speed up OEM-developments significantly.
Additionally, the USB interface cable PICO-USB provides a virtual COM-port. Custom
software can use this virtual COM-port for communicating directly with the module
based on the communication protocol.

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3OPTION 1: OPERATING THE MODULE WITH
PYRO WORKBENCH
For initial evaluation purposes the module can be operated with the simple and
customer-friendly software Pyro Workbench, which is typically used by end-users. This
software offers comfortable settings and calibration wizards, as well as advanced
logging features. Several modules can be operated in parallel within a single window.
This software requires an encoded USB interface cable PICO-USB for connecting the
module to a Windows PC.
3.1 Installing the software Pyro Workbench
System requirements: PC with Windows 7/8/10 and min. 1000 MB free disk space.
Do not connect the USB-interface cable to your PC before the Pyro Workbench software
has been installed. The software will automatically install the appropriate USB-drivers.
Installation steps:
•Download the Pyro Workbench from the downloads tab on www.pyroscience.com
•unzip and start the installer and follow the instructions
•connect the interface plug of the USB interface cable to the connector X1 of the
Pico-O2

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•connect the USB plug to an USB port of the PC. The status LED of the Pico-O2
should flash shortly indicating the correct startup of the module.
•Start the Pyro Workbench software.
3.2 Using the software Pyro Workbench
Please refer to the Pyro Workbench manual for general operation instructions for the
software (available on our website).
Please refer to the Oxygen Sensor manual for general information on handling and
calibration of the oxygen sensors (available on our website).

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4OPTION 2: OPERATING THE MODULE WITH
PYRO DEVELOPER TOOL
For advanced evaluation purposes the module can be operated with the software Pyro
Developer Tool. It offers simple settings and calibration procedures, as well as basic
logging features. Furthermore, additional advanced settings offer full control on all
features of the module. This software requires the encoded USB interface cable PICO-
USB for connecting the module to a Windows PC.
4.1 Installing the software Pyro Developer Tool
System requirements: PC with Windows 7/8/10 and min. 1000 MB free disk space.
Do not connect the USB-interface cable to your PC before the Pyro Developer Tool has
been installed. The software will install automatically the appropriate USB-drivers.
Installation steps:
•Download the Pyro Developer Tool from the downloads tab on
www.pyroscience.com
•unzip and start the installer and follow the instructions
•connect the interface plug of the USB interface cable the connector X1 of the
Pico-O2

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•connect the USB plug to an USB port of the PC. The status LED of the Pico-O2
should flash shortly indicating the correct startup of the module.
•Start the Pyro Developer Tool software.
4.2 Using the software Pyro Developer Tool
Please refer to the Pyro Developer Tool manual for general operation instructions for
the software (available on our website).
Please refer to the Oxygen Sensor manual for general information on handling and
calibration of the oxygen sensors (available on our website).

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5OPTION 3: SIMPLIFIED CUSTOM
INTEGRATION
A simplified custom integration of the module can be realized by adjusting the settings
and performing sensor calibrations using the PyroScience software Pyro Workbench or
the more advanced software Pyro Developer Tool (both requiring the encoded USB
interface cable PICO-USB). After closing the software, the configuration is automatically
saved within the internal flash memory of the module. The module can then be
integrated into a specific setup, and your custom software can perform measurements
using a proprietary USB/UART communication protocol.
5.1 Configuring the Module using PyroScience Software
Please install either the Pyro Workbench or the Pyro Developer Tool. Follow chapter 3
or chapter 4, respectively, how to operate the module with the PyroScience software.
Adjust the settings and perform the required calibrations of the sensor.
After the module has been configured, close the PyroScience software. The configuration
is automatically saved within the internal flash memory. This means that the adjusted
settings and the last sensor calibration are persistent even after a power cycle of the
module. Now the module can be integrated into a customer specific setup via its UART
interface (or via the USB interface cable with its virtual COM port).
5.2 Electrical Connector for Custom Integration
The electrical interface of the Pico-O2 consists of the connector X1 (Figure 6). The
package includes the fitting connector plug S1 (manufacturer: Phoenix Contact, type:
PTSM0,5/4-P-2,5, Item no.: 1778858). Stripped cable ends can be connected to S1
without any soldering or crimping. When inserting or removing a stripped cable end
(stripping length 6 mm, max. core diameter 0.5 mm²) into one of the connector holes of
the connector S1, an internal spring mechanism has to be unlocked. This can be achieved
by pushing relatively strongly with a small screw-driver (flat-bladed 2 mm in width) into
the adjacent rectangular hole (Figure 6). The same manufacturer offers also fitting
connector plugs for PCB mounting (details on request).

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Figure 6: Electrical connectors of Pico-O2
The pin configuration of the connector X1 is given in Table 2
Table 2: Pin configuration of the connector X1
Pin
Name
Function
Description
1
VCC
Power
Power supply
min. 3.3 VDC
max. 5.0 VDC
2
RXD
Digital input
3.0 V levels
(max. 3.3 V)
Data receive line
of the UART interface
3
TXD
Digital output
3.0 V levels
Data transmission line
of the UART interface
4
GND
Power
Ground
5.3 Configuration of the Serial Interface
Pico-O2 is operated via a serial interface, which is realized as a UART interface
consisting of a receive and a transmit line. The configuration of the UART-interface is as
follows:
19200 baud, 8 data bit, 1 stop bit, no parity, no handshake
Such an UART interface is very common for microcontrollers or microcontroller boards
(e.g. Arduino or Raspberry Pi). The module can be directly connected to such UART
interfaces without any further interface electronics.

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Note: The serial interface of this module is not an RS232 interface. However, the UART
interface can be made compatible to RS232 by integrating an appropriate "level shifter
electronics".
5.4 Communication Protocol
5.4.1 General Definitions
A command always starts with a specific command header (e.g. MEA, #VERS, #LOGO)
optionally followed by several input parameters. Input parameters are given as human
readable decimal numbers, separated by spaces from each other. Each command must
be terminated by a carriage return. If the command could be successfully interpreted by
the module, the response is sent back to the master after completion of the requested
task. The first part of response consists always of a copy of the original command,
optionally appended with output parameters, and again terminated by a carriage return.
After a response has been received by the master, the module is immediately ready for
receiving the next command. If the internal processing of the received command causes
any error within the module, the response will be the error header #ERRO followed by a
space and an error code (see below).
Syntax Definitions
MEA
#VERS
#LOGO
Examples for a command header
C
S
R
Examples for place holder for signed integer values transmitted
as human readable ASCII strings of decimal numbers. The
absolute maximum range of all values transmitted in the
communication protocol is from -2147483648 to [phone]
(signed 32bit integer), if not otherwise indicated.
˽
Space (ASCII code 0x20)
↵
Carriage return (ASCII code 0x0D)

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5.4.2 MEA –Trigger Measurement
This command triggers a measurement and returns the results.
Command:
MEA˽C˽S↵
Response:
MEA˽C˽S˽R0˽R1…R17↵
Input Parameters:
C
Optical channel number. Set C=1.
S
If in doubt, then set S to 47!
This parameter defines the enabled sensor types,
given as decimal representation of the following bit field:
Bit 0 (add 1): optical channel
Bit 1 (add 2): sample temperature (typ. the external Pt100-
sensor)
Bit 2 (add 4): ambient air pressure
Bit 3 (add 8): relative humidity within the module
Bit 4 (add 16): reserved
Bit 5 (add 32): case temperature (temperature within the
module)
Example: S = 1 + 2 + 4 + 8 + 32 = 47 means, that the command will trigger
the following measurements: optical channel (oxygen), sample temperature,
case temperature, ambient air pressure, and relative humidity within the
module housing.
Output Parameters:
R0
Returns errors and/or warnings of the last measurement as a decimal
representation of the following bit field. The user has to distinguish between
warnings and errors. A warning indicates, that the measurement results are
in principle still valid, but their precision and/or accuracy might be
deteriorated. An error means, that the respective measurement result is not
at all valid.
Bit 0 (add 1): WARNING - automatic amplification level active
Bit 1 (add 2): WARNING - sensor signal intensity low
Bit 2 (add 4): ERROR - optical detector saturated
Bit 3 (add 8): WARNING - reference signal intensity too low
Bit 4 (add 16): ERROR - reference signal too high
Bit 5 (add 32): ERROR - failure of sample temperature sensor
(e.g. Pt100)
Bit 6 (add 64): reserved
Bit 7 (add 128): WARNING high humidity (>90%RH) within the
module
Bit 8 (add 256): ERROR - failure of case temperature sensor
Bit 9 (add 512): ERROR - failure of pressure sensor
Bit 10 (add 1024): ERROR - failure of humidity sensor
Example: R0= 34 = 2 + 32 means, that there is a warning about low signal
intensity of the optical sensor, and that the external temperature sensor
(Pt100) had a failure.
If R0 = 0 then no error or warning appeared.
R1…R17
The results of the measurement given as 17 values. The most important
result values are highlighted.
Name
Unit
Description

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R1
dphi
m°
Phase shift of optical measurement (raw
data)
R2
umolar
0.001
µmol/L
Oxygen level in units of μmol/L
(valid only in liquids)
R3
mbar
0.001 mbar
Oxygen level in units of mbar
(valid in gases and in liquids)
R4
airSat
0.001 %air
sat.
Oxygen level in units of % air saturation
(valid only in liquids)
R5
tempSample
0.001 °C
Sample temperature (typ. external Pt100
sensor)
R6
tempCase
0.001 °C
Case temperature (internal T-sensor within
module)
R7
signalIntensity
0.001 mV
Signal intensity of the optical measurement
R8
ambientLight
0.001 mV
Ambient light entering the sensor
R9
pressure
0.001 mbar
Ambient air pressure
R10
humidity
0.001 %RH
Relative humidity within the module
housing
R11
resistorTemp
0.001 Ohm
Resistance of the temperature sensor (raw
data)
R12
percentO2
0.001 %O2
Oxygen level in units of %O2
(valid only in gases)
R13-
R17
-reserved-
This command is the essential command for triggering measurements. If the input
parameter S is requesting several sensor types to be measured, the optical oxygen
measurement ("optical channel") is always performed as the last measurement. This
ensures that for enabled automatic temperature compensation the sample temperature
measurement (typ. external Pt100) is done before it is then used for compensating the
oxygen measurement.
IMPORTANT: If automatic temperature compensation is enabled for the optical sensor, it
is mandatory to enable Bit1 of the input parameter S!
The output parameters umolar, mbar, airSat, percentO2, and tempSample give the results
of the oxygen measurement and of the temperature measurement (typ. external Pt100).
The output parameter signalIntensity is a measure of the signal quality ("signal intensity")
of the connected optical sensor. As a rule of thumb, typical values will be in the range of
20-500 mV. Low signal intensities (<50 mV) might lead to noisy oxygen measurements.
A low signal intensity might be an indicator that the sensor is not configured optimally
and/or that the sensor is "worn out"/depleted and has to be replaced. Please note, that
the signal intensity is also dependent on the actually measured oxygen value. Low
oxygen values have a high signal intensity, high oxygen values have a lower signal
intensity.
The output parameter ambientLight is a measure how much ambient infrared light is
entering the oxygen sensor. In principle, such ambient light is not influencing the oxygen
measurement. However, excess ambient light might lead to a saturation of the optical
detector (indicated by an enabled ERROR Bit2 in R0), which will lead to an invalid oxygen
measurement. As a rule of thumb, the sum of signalIntensity and ambientLight should be
kept below ca. 2000 mV (the optical detector saturates around 2500 mV).