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© 2010 SST Sensing Ltd                                        7                                             www.sstsensing.com 
DS0074 Rev 7 

CONFIGURATION 

The O2I-FLEX may be reconfigured at any time by  
adjusting the position of the header pin jumper links on the 
interface PCB.  
 

WARNING

: Prior to re-configuration the O2I-FLEX 

MUST 

be powered down. The jumper links 

MUST

 also be  

repositioned correctly and in the correct orientation.  
 

 

Power down the O2I-FLEX 

 

Adjust the position of the jumper links to the desired 
configuration. The diagram below shows the  

 

Interface PCB and the correct orientation of the 

 

Jumper Links. Thin nosed pliers should be used to 

 

remove and replace the Jumper Links. Ensure the 

 

Jumper Links are correctly seated before reapplying 

 

the power 

 
NOTE: Each Jumper Link must be placed in one of the two  
positions, either Manual (MANUAL CAL) or Automatic 
(AUTO CAL) Calibration and 100% or 25% Measuring 
Range. 

 
 
RS232 OPERATION 

With the O2I-FLEX RS232 outputs connected to a PC or 
any other RS232 compatible device the user has the    
ability to access two modes of operation, continuous data 
streaming and the menu screens. Recommended         
programs for communicating via PC serial RS232 are 
Hyperterminal (windows default), Teraterminal and PuTTY.  
 
A freeware PuTTY link can be found below; 
  

http://the.earth.li/~sgtatham/putty/latest/x86/putty.exe

 

 

Continuous Data Streaming 

On power up, after the initial 60s heater delay, the O2I-
FLEX will automatically begin outputting the measured O

2

 

concentration and sensor Td as both an averaged and raw 
value.  
 
The averaged values give a stable output with the amount 
of averaging user variable whilst the raw un-averaged  
values allow the user to detect sudden oxygen changes.  
 
The averaged value is the measurement output on both 
the 4-20mA and 0-10V

DC

 outputs. The sensor Td value is 

the measure of the partial pressure of oxygen in the  
measurement gas. The O

2

 concentration (%) is the Td 

value scaled by the stored calibration value. 
 
To stop or restart the data streaming ‘s’ (lower or upper 
case) should be sent to the unit. Data streaming          
automatically ceases during calibration.  
 

Menu Screens 

If the O2I-FLEX receives an enter character from the    
connected PC or device it automatically enters the menu 
password screen and stops outputting O

2

 % and Td      

values. After the correct password is entered followed by 
the enter character, the menu screens are accessed. The 
menu screens are primarily for diagnostics and information 
although there are user configurable options that may be 
changed. These are the automatic O

2

 calibration %, the 

amount of output filtering (averaging) and the analogue 
output ranges . All three processes are further described 
on Page 7.  
 
The menu access password may also be changed by the 
user. 
 
 

Changing the Menu Access Password 

The password is factory set to ‘

default’

. This however may 

be changed to a user specific password. 
 

 

Connect the O2I-FLEX via the RS232 interface to 
the PC. 

 

 

Press Enter then enter your current security 

 

 

password. Press Enter to access the menu screen.

 

 

In the Configuration menu (menu 2) enter ‘3’ to   
access the password menu screen. 

 

 

Enter the new password then press Enter to save.

 

 

The new password is now stored in memory and is 
retained on power loss.

 

.

 

Pressing ESC returns the screen to the previous menu. 

 

O2I

-

Flex

 Oxygen Interface 

Содержание O2I-Flex

Страница 1: ...lectable output filtering allows adaptive fast and dynamic or slow and stable output response Power and Sensor Operating LEDs Removable polarised screw terminals for easy wiring SPECIFICATIONS Maximum ratings Supply voltage 24VDC 10 Current consumption 600mA max 24VDC 4 20mA Load 100 600Ω Temperature limits Storage 10 to 70 C Operating 10 to 70 C O2I Flex APPLICATIONS Combustion control including ...

Страница 2: ...ygen sensors do not directly measure the oxygen concentration but instead measure the partial pressure of oxygen within the measurement gas In order to output an oxygen concentration the O2I FLEX must be calibrated or more specifically re referenced in a known gas concentration typically normal air Calibration or re referencing is achieved by connecting the calibration input to GND or by pressing ...

Страница 3: ...ial pressure of oxygen PPO2 within the measurement gas deviations in the Barometric Pressure BP from that present during calibration will cause readout errors proportional to the change For example if the sensor was reading 21 O2 at 1013 25mbar and the BP increased by 1 the sensor readout would also increase by 1 to 21 21 O2 OXYGEN SENSOR HEATER ADJUSTMENT The Oxygen Sensor heater must be adjusted...

Страница 4: ...0 SST Sensing Ltd 4 www sstsensing com DS0074 Rev 7 OUTLINE DRAWING AND MOUNTING INFORMATION 60mm 60mm 67mm 67mm 4 x M4 Mounting holes on industry standard 60x60mm pitch PCB LAYOUT O2I Flex Oxygen Interface ...

Страница 5: ...ery SST oxygen sensor has two heater connections which should be connected to pins 1 2 of the O2I Flex the heater coil has no polarity However when connecting to a sensor where the sensor housing is one of the heater connections pin 1 of the O2I Flex should be connected to the housing SYSYEM BLOCK DIAGRAM PIN Description 1 Sensor Heater GND Yellow H 2 Sensor Heater Yellow H 3 Sensor Sense Blue S 4...

Страница 6: ...onnections ensure Tx goes to Rx of the PC and Rx goes to Tx of the PC The O2I Flex communicates via standard COM port settings that are default on most PCs and many other RS232 compatible devices If however communication problems are occurring use the settings below to configure the PC or device COM Port O2I Flex Oxygen Interface ...

Страница 7: ...ith the amount of averaging user variable whilst the raw un averaged values allow the user to detect sudden oxygen changes The averaged value is the measurement output on both the 4 20mA and 0 10VDC outputs The sensor Td value is the measure of the partial pressure of oxygen in the measurement gas The O2 concentration is the Td value scaled by the stored calibration value To stop or restart the da...

Страница 8: ...onse to oxygen changes Press Enter to save The new averaging value is now stored in memory This value is retained on power loss Adjusting the Minimum and Maximum Ranges of the Analogue Outputs 4 20mA and 0 10VDC The O2I FLEX is factory default to output a range of 0 25 O2 via its two analogue outputs This range can be expanded to 0 100 O2 as described on Page 6 When the unit is reconfigured to out...

Страница 9: ...umed At this point remove GND from PIN 10 or release the calibration switch The output will now track to the correct value for the calibration gas Calibration is complete Calibration values are retained on power loss Manual Calibration Ensure the O2I FLEX is configured for manual calibration See CONFIGURATION on Page 6 Place the sensor probe in the calibration gas typically normal air Allow the ou...

Страница 10: ...ng from Water Droplets In environments where falling water droplets are likely the sensor should be protected from water falling directly onto the very hot sensor cap as this can cause massive temperature shocks to the cell and heater Popular methods include a hood over the sensor cap or for the sensor to be mounted in a larger diameter cylinder At a very minimum the sensor cap should be angled do...

Страница 11: ...te O2 measurement is required Investigated gases were H2 Hydrogen up to 2 stoichiometric combustion CO Carbon Monoxide up to 2 stoichiometric combustion CH4 Methane up to 2 5 stoichiometric combustion NH3 Ammonia up to 1500 ppm stoichiometric combustion 2 Heavy Metals Vapours of metals like Zn Zinc Cd Cadmium Pb Lead Bi Bismuth will have an effect on the catalytic properties of the Pt electrodes E...

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