SGX Sensortech IR-EK2 User Manual

SGX Infrared Gas Sensor Evaluation Kit IR-EK2

User Guide

SGX Sensortech(IS) Ltd Registered in England No.08067077 DAS767840AA Version 3, August 2013

IMPORTANT INFORMATION

Before using this product, please read and understand all the instructions and warnings. SGX Sensortech does not accept responsibility for damage or injury resulting from failure to follow the instructions provided.

WARNINGS:

• The Evaluation Kit is despatched from SGX Sensortech in a safe condition. Any unauthorised modifications may compromise safety and invalidate the warranty.

• The supplied power supply adapter is double insulated, indicated by the double square symbol. If the Evaluation kit is used with a power supply which is not double insulated, connect a Protective Earthing Connection to the Protective Earth terminal on the PCB indicated by the Protective Earth symbol in case of power supply faults.

• The Evaluation Kit is not certified as intrinsically safe and therefore must not be operated in potentially flammable or explosive atmospheres.

• Neglecting the above may result in injury or death.

CAUTIONS:

• The Evaluation Kit is intended for engineering development, demonstration or evaluation purposes only. It is not considered to be suitable for general consumer use and should be handled by people with suitable electronics training.

• The Evaluation Kit contains electrostatic discharge sensitive devices. Always observe handling precautions.

• The Evaluation Kit and Gas Sensor Devices should always be used within their ratings as given in their data sheets.

COMPLIANCE:

• The Evaluation Kit is intended for engineering development, demonstration or evaluation purposes only and not for sale on the open market.

• This Evaluation Kit has been tested (but not certified) and deemed to comply with the limits for a Class B digital device, pursuant to part 15 of the FCC Rules and European Union directives on electromagnetic compatibility. These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment. This equipment generates, uses, and can radiate radio frequency energy and if not installed and used in accordance with the instruction manual, may cause harmful interference to radio communications. The user is responsible for providing reasonable protection against interference with other electronic equipment.

• The Evaluation Kit is not intended for automotive use. It does not contain protection devices against vehicle supply transient voltages and must not be used for the control of a vehicle, a vehicular safety system or in a way that may disturb the driver, data bus or statutory devices fitted to a vehicle.

ENVIRONMENTAL:

• SGX Sensortech declares that the Evaluation Kit complies with EC directive 2002/95/EC (the RoHS Directive) restricting the use of certain hazardous materials in electrical and electronic equipment. See section 17 for China RoHS information.

• The Evaluation Kit is classified as Electronic and Electrical Equipment according to directive 2002/96/EC (the WEEE Directive) and should be segregated from domestic waste for disposal. Contact SGX Sensortech for disposal instructions.

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Contents

1 Introduction ....................................................................................................................................... 4

2 Quick Start Guide .............................................................................................................................. 5

3 Using the SGX Data Logging Software .............................................................................................. 7

4 Using HyperTerminal ......................................................................................................................... 9

5 User Interfaces, Controls and Indicators .......................................................................................... 11

5.1

Power Supply (SK4, TB1) ........................................................................................................................... 11

5.2

USB Interface (SK5) ................................................................................................................................... 11

5.3

Gas Sensors Sockets (S1, S2) ................................................................................................................... 11

5.4

Signal Monitor (PL3) ................................................................................................................................... 11

5.5

User Adjustments (VR0, VR1, VR2, VR3) .................................................................................................. 11

5.6

JTAG Port (PL1) ......................................................................................................................................... 11

5.7

Expansion Port (PL2) .................................................................................................................................. 12

5.8

LEDS (D1, D2, D3, D4, D5) ........................................................................................................................ 12

5.9

Reset Switch (SW2) .................................................................................................................................... 12

6 Operating Modes ............................................................................................................................. 13

6.1

Introduction ................................................................................................................................................. 13

6.2

Measurement Mode .................................................................................................................................... 13

6.3

Device Setup Mode..................................................................................................................................... 13

7 Lamp Drive ...................................................................................................................................... 14

7.1

Frequency ................................................................................................................................................... 14

7.2

Voltage ........................................................................................................................................................ 14

8 Channel Gains................................................................................................................................. 15

9 Sensor Set-up ................................................................................................................................. 16

10 Calibration ................................................................................................................................... 17

11 Analog Outputs ............................................................................................................................ 17

12 Alarm Outputs and LEDs ............................................................................................................. 18

13 Digital Inputs ................................................................................................................................ 18

14 Appendix: Evaluation Kit PCB Schematic Diagram ...................................................................... 19

15 Appendix: Evaluation Kit PCB Parts List ...................................................................................... 20

16 Appendix: Serial Message Protocol ............................................................................................. 21

17 Appendix: China RoHS Declaration ............................................................................................. 24

18 Appendix: Updating the IR-EK2 Embedded Software .................................................................. 25

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1 Introduction

Thank you for purchasing the SGX Infrared Gas Sensors Evaluation Kit

SGX Infrared Gas Sensors are reliable and stable devices capable of detecting many different gases as specified on individual device data sheets. These devices can be used in many different applications and this Evaluation Kit from SGX will allow you to experiment and find the most suitable mode of operation for your particular use.

This Evaluation Kit allows you to:

• Test one 6- or 7-pin single gas sensor or one 8-pin twin gas sensor

• Adjust the lamp drive voltage between 3.0 V and 5.0 V

• Adjust the channel gains for the reference and active channels

• Calibrate a gas sensor and measure gas concentration levels

• Set four alarm levels (2 per channel) which drive on-board LEDs and open collector outputs.

• Drive two analogue outputs

• Connect additional circuits to an expansion port

• Log readings of peak-to-peak output signal, gas concentration and temperature using the

supplied PC Data Logging Program.

Contents of Evaluation kit

• Evaluation PCB

• Mains Power Adapter

• USB Lead

• CD containing User Manual, SGX Data Logging Software and USB Drivers

• Gas Flow Hood

Accessories Available

• Additional gas flow hoods may be ordered using the part number: JAS767906AA

If you are not familiar with the principles of gas detection using infrared absorption, you are strongly recommended to read SGX Infrared Application Notes available at www.sgxsensortech.com

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2 Quick Start Guide

1. Read the Manual!

a. The supplied CD should auto-run on your PC when inserted into a CD drive. b. Select ‘User Guide’ from the CD menu.

2. Install the SGX Data Logging Software & USB Drivers on your PC

a. Run the file D:\Volume\setup.exe

(Note: The drive letter may vary)

b. Follow the on-screen instructions.

3. Set up the Evaluation PCB

a. Plug an SGX infrared gas sensor into the Evaluation Kit

6- or 7-pin single gas devices plug into S1; 8-pin twin-gas devices plug into S2 b. Adjust variable resistor VR3 fully anticlockwise (minimum bulb voltage) c. Adjust variable resistors VR0, VR1, VR2 fully anti-clockwise (minimum signal gains) d. Connect the supplied USB lead from SK5 to a USB socket on your PC

4. Connect the 9 V Power Supply Unit

a. Connect the DC output of the Power Supply Unit to SK4. b. Slide the correct pinned mains adapter to the Power Supply Unit to suit the mains sockets

in your country. Plug in the Power Supply Unit. Green LED D5 should be flashing. Other

LEDs may also come on. c. The PC may take a minute to recognise and initialise the new hardware drivers.

Basic Interfaces and Controls of Evaluation Kit

SK5

USB

To PC

(8 Pin)

(6/7 Pin)

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PL3

VR0 VR1 VR2

SK4

VR3

9V DC

From

PSU

Quick Start Guide (Continued)

5. Run the SGX Data Logging Software

a. Run the program from the start menu. b. The software will automatically detect which ‘Com Port’ is being used for the USB

connection. (If this does not happen, a Com Port can be manually selected by unticking

‘Automatically search for connected device’ on the ‘Hardware’ menu. c. The software will switch the Evaluation PCB into ‘Automatic Mode’ so that readings are

sent from the Evaluation Kit to the PC once every second. d. The outputs of the Evaluation Kit will now be displayed on the PC monitor.

6. Set the Bulb Voltage and Channel Gains

a. Select the ‘Readings’ tab. The bulb voltage is displayed. b. Adjust VR3 clockwise to the desired Bulb Voltage (between 3 V and 5 V) c. Adjust VR0 to set the Reference level output. Set to approximately 2 V peak-to-peak if

possible. The signal clips at 3 V. d. Adjust VR1 to set the Active level output in the same way. e. Adjust VR2 to set the Second Active level output in the same way, only if using a twin-

gas sensor. f. If desired, the channel outputs can be observed on an oscilloscope via PL3

Congratulations! You are now evaluating SGX Infrared Gas Sensors.

7. Further Settings

a. At this stage you may not have correct temperature or concentration readings. b. The software must be told which type of temperature sensor is being used. c. A calibration will need to be performed to obtain accurate concentration readings. d. To change any set-up parameters, the Evaluation Kit must be switched from

‘Measurement Mode’ to ‘Device Setup Mode’ using the PC Software. e. Refer to the relevant sections of the User Guide for detailed instructions on how to do the

above.

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3 Using the SGX Data Logging Software

Follow the instruction in the Quick Start guide to get the software operating. The screen should appear similar to that shown below:

The USB interface to the Evaluation Kit appears as a virtual ‘Com Port’. When the program is started the software will automatically detect which ‘Com Port’ is being used for the USB connection. (If this does not happen, a Com Port can be manually selected by unticking ‘Automatically search for connected device’ on the ‘Hardware’ menu. The Com Port can be manually selected, using trial and error to identify the correct one. If multiple Evaluation Kits are used at the same time, a separate instance of the program should be started for each one – it will be necessary to manually set each one to the correct Com Port.

The main screen gives a continuous display of gas concentration and temperature. The graph view can be changed to display various parameters in real time. The data can also be saved to a file in ‘csv’ format which can be read by most spreadsheet programs. Note that many spreadsheets will read a maximum of 65536 lines (18 hours of data at 1 second intervals). The measurement period can be increased from 1 second to allow longer tests to be imported. For example, a 10 second measurement period allows 7.5 days of data to be read into a spreadsheet. An averaging time can also be set to smooth out the data.

By default, the datalogging software autoscales the output readings (i.e. the graph axes expand to show all of the readings on x and y axes). However, it is possible to change these values in order to ‘zoom in’ on certain readings.

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In the Data Logging tab, right-click on the axis to be adjusted and untick ‘Autoscale’.

This stops the axis from automatically expanding.

The values in the axis can then be changed. To do this, double-click on the value you wish to edit and adjust using the keypad.

The ‘Readings’ tab provides measurement and control of the bulb and measurement of channel peak-topeaks and ratios, described in section 7 and 8

The ‘Alarms’ tab allows setting of alarm thresholds, described in section 12.

The ‘I/O’ tab only appears in ‘Device Setup Mode’ and allows setting of analog outputs (see section 11) and monitoring of digital inputs (see section 13).

The ‘Calibration’ tab allows calibration of sensor zero and span levels. When in ‘Device Setup Mode’ it also enables a number of important sensor settings to be sent to the Evaluation Kit (see section 9) including:

• Selection of temperature sensor

• ADC sampling delay time

• Temperature compensation and calibration coefficients

The ‘Hardware’ menu contains an Update Firmware feature which allows software updates to be loaded into the microprocessor without having to return the PCB to SGX for reprogramming. This feature should be used carefully following the instructions in section 18.

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4 Using HyperTerminal

The SGX Data Logging software provides full control and monitoring of all the operation modes of the Evaluation Kit. It is possible to communicate with the Evaluation Kit using the low level protocol. This can be done manually using a terminal emulation program such as HyperTerminal, or by writing your own PC software using a language such as Visual Basic or Labview. The low level message protocol is given in the appendices to this manual.

To communicate with the Evaluation Kit using HyperTerminal use the following procedure: (Note: the USB Drivers must be installed.)

• Run HyperTerminal from the Windows Start button

• Enter a name and choose an icon:

• Select the correct ‘COM Port’ being used by the USB

Driver:

• Select 9600 Bits per second (Baud), 8 data bits, no parity, 1 stop bit, no flow control:

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• Select File/Properties. Click the Settings tab, then the ASCII Setup button. Ensure ‘Echo typed characters locally’ is checked:

• Type [WHO] and a response should be received from the Evaluation Kit giving the firmware version and checksum.

Note that if the Evaluation Kit is already set in ‘Measurement Mode’ then a data packet will be displayed once per second. A full list of HyperTerminal commands can be found in Section 16.

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5 User Interfaces, Controls and Indicators

5.1 Power Supply (SK4, TB1)

The Evaluation Kit requires a 9 V ± 10% power supply. Either connect the supplied 9 V DC mains adapter to SK4 or a 9V ± 10% laboratory supply to the terminal block TB1. The supplied power supply adapter is double insulated, indicated by the double square symbol. If the Evaluation Kit is used with a power supply which is not double insulated, connect a Protective Earthing Connection to the Protective Earth terminal on the PCB indicated by the Protective Earth symbol in case of power supply faults.

5.2 USB Interface (SK5)

SK5 is a type B Mini-USB connector for communicating with a PC.

5.3 Gas Sensors Sockets (S1, S2)

The Evaluation Kit can drive one gas sensor which should be fitted in either S1 or S2 as follows:

S1: 6-pin or 7- pin (single gas) sensor S2: 8-pin (twin gas) sensor

5.4 Signal Monitor (PL3)

PL3 is a signal monitor port. It allows the amplified channel signals and the bulb drive control to be monitored on an oscilloscope.

1 Reference signal monitor 2 0 V 3 Active 1 signal monitor 4 0 V 5 Active 2 signal monitor 6 0 V 7 Bulb control (3V3 logic) 8 0 V

5.5 User Adjustments (VR0, VR1, VR2, VR3)

VR0: Reference channel gain adjust VR1: Active channel 1 gain adjust VR2: Active channel 2 gain adjust VR3: Lamp drive voltage (3.0 V to 5.0 V)

5.6 JTAG Port (PL1)

The JTAG Port can be used by engineers wishing to develop their own software for the Evaluation Board. The socket will connect to a Texas Instruments MSP430 Debug Interface, e.g. MSP-FET430UIF, for reprogramming and debugging.

TDO 1 2 VCCO

TDI 3 4 VCCI

TMS 5 6 Unused

TCK 7 8 Unused

0 V 9 10 Unused

TRST 11 12 Unused

Unused 13 14 Unused

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5.7 Expansion Port (PL2)

PL2 is an expansion port allowing connection to additional peripherals. The port provides access to the input and 3.3 V supplies, four open collector outputs, four digital inputs, two analogue outputs and a spare UART connection.

3V3 Regulated Power 1 2 9 V Unregulated Power

0 V 3 4 0 V Input 1 (3V3 logic) 5 6 Output 1 (Open collector) Input 2 (3V3 logic) 7 8 Output 2 (Open collector) Input 3 (3V3 logic) 9 10 Output 3 (Open collector) Input 4 (3V3 logic) 11 12 Output 4 (Open collector)

0VA 13 14 Analogue Output 1 (0 to 2.048 V) 0VA 15 16 Analogue Output 2 (0 to 2.048 V)

Serial RXD (3V3) 17 18 Serial TXD (3V3)

0V 19 20 Not used

5.8 LEDS (D1, D2, D3, D4, D5)

D1, D2, D3 and D4 indicate the state of each open collector output on the Expansion Port.

D5 flashes to indicate that the power is on and the software is operating normally.

5.9 Reset Switch (SW2)

Press and release SW2 to reset the microcontroller. This has the same function as removing and reconnecting the power supply.

PCB Layout:

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6 Operating Modes

6.1 Introduction

The Evaluation Kit has two operating modes, ‘Measurement Mode’ and ‘Device Setup Mode’. To switch between then, click on the appropriate radio button near the top left hand panel of the screen.

6.2 Measurement Mode

In order to take readings from the Evaluation Kit it must be in Measurement Mode. The PC Software will automatically switch the IR-EK2 into Measurement Mode when it is first connected, even if it was previously left in Device Setup Mode.

In Measurement Mode the Evaluation Kit sends readings to the PC once per second of the following:

• Peak-to-peak signal (Reference Channel)

• Peak-to-peak signal (Active Channel A)

• Peak-to-peak signal (Active Channel B)*

• Concentration (Channel A)

• Concentration (Channel B)*

• Bulb voltage

• Temperature

* Only applicable to twin-gas devices

As the Evaluation Kit operates at a 4 Hz signal frequency, the peak-to-peak and concentration readings are an average of the four measurements in the previous second.

6.3 Device Setup Mode

In order to change any of the programmable operating parameters of the Evaluation Kit it must be in Device Setup Mode. In this mode it is possible to adjust all of the following:

• Lamp mode (pulsing, on, off)

• Sensor type (single gas, twin gas)

• Temperature sensor type (thermistor, IC)

• Sampling delay time (time from bulb change to ADC sampling)

• Temperature compensation and calibration coefficients

The following sections describe how all these parameters can be set up.

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7 Lamp Drive

7.1 Frequency

The Evaluation Kit drives the sensor lamp at a 4 Hz frequency. This is the frequency recommended by SGX for driving infrared gas sensors. The lamp control waveform can be monitored on an oscilloscope at PL3 pin 7 (pin 8 is 0 V).

7.2 Voltage

The lamp voltage can be changed on the circuit board by adjusting VR3. In ‘Measurement Mode’ the lamp voltage is measured and displayed on the ‘Readings’ tab.

The adjustment range will cover at least 3.0 V to 5.0 V. A 5.0 V lamp drive will give maximum infrared emission and the best system performance. Heat from the bulb will also keep the temperature of the optical reflector higher than ambient which is helpful in preventing condensation in humid environments. For battery powered portable instruments the sensors can also be operated very successfully with a 3.0 V lamp drive. Although the sensitivity to gas will be smaller, the power consumption will be less and the bulb lifetime increased. The graph below shows how the pyro outputs change with bulb voltage.

1.1

0.9

0.8

0.7

0.6

Normalised Output

0.5

0.4

0.3

2.5 3 3.5 4 4.5 5 5.5

Bulb Volta ge

Pyro Output Voltage vs. Lamp Supply

(IR12GJ Active Channel, Normalised at 5.0 V)

The bulb has a very low resistance when cold (turned off). This can cause a current surge at the instant of turn-on which might be undesirable in certain applications. This is mainly a problem when the equipment is turned on from cold – once the bulb is being driven at 4 Hz it maintains some heat even when ‘off’ to reduce this effect. It is possible to monitor the bulb current by monitoring the voltage across R26 (10R) using test points P16 and P24.

Some users reduce this current surge by biasing the bulb at about 0.4 V when ‘off’ to keep it just warm. This can be done on the IR-EK2 by fitting a 330R 0805 resistor in the empty R27 position (between VR0 and VR3).

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8 Channel Gains

A gas sensing instrument normally has fixed channel gains. However, the IR-EK2 is designed to operate with a wide range of sensors having different output levels so adjustable gain settings have been provided for optimum performance.

The channel gains should be adjusted after setting the lamp voltage as follows:

VR0 – Reference channel VR1 – Active channel A VR2 – Active channel B

These are best adjusted while monitoring the signals with an oscilloscope at the signal monitor PL3. Best performance will be obtained with the signals as high as possible. However the circuit will clip at 3 V so a setting of about 2 V peak-to-peak is suggested.

The channel amplifiers have the frequency response shown right. The gain is approximately 40 at 4 Hz when the variable resistors are at their minimum setting and all channels will have identical gain.

At the maximum setting the channel gains will be around 400, but component tolerances may cause some small variation between channels.

If an oscilloscope is not available then the peak-topeak levels are displayed on the ‘Readings’ tab when in Measurement Mode. However, if the ADC measurement delay time is not correctly set up then these may not be accurate. The timing diagram shows that there is a delay between the bulb switching point and the maximum or minimum of the signal response. This delay is typically around 20 – 25 ms but will depend on the model of gas sensor being used. The delay is related to the output level of the pyro devices and it may be observed that when the bulb drive is reduced from 5 V to 3 V the delay time will increase slightly. If an oscilloscope is not available then a process of trial and error can be used to determine the optimum delay time.

On some sensors where there is a difference in output level between the active and reference channels there will be a difference in delay time for each channel. In this situation the delay time should be set to the average value. The following section explains how to set the ADC measurement delay time and other sensor specific parameters.

Lamp

Drive

Amplified

Signal

Delay

Time

Sampling

Point

125ms 125ms

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Load File:

Refresh List:

Send to Unit:

Get Parameters From

Save Data to File:

Exit:

9 Sensor Set-up

Sensor specific settings are set up in the ‘Coefficient Editor’ which can be found on the ‘Calibration’ tab. The Coefficent Editor can only be entered in ‘Device Setup Mode’. In the Coefficient Editor the following parameters can be set up:

Sensor Channels

Time Delay (ms) Delay from bulb switch to ADC sampling point. See Section 8

Temperature

Sensor

Concentration

Range 1/2/3

Concentration

range (ppm)

a Linearisation coefficient

n Linearisation coefficient Betapos Span variation over positive temperature Betaneg Span variation over negative temperature

Alphapos Zero variation over positive temperature Alphaneg Zero variation over negative temperature

Span

concentration

Button Functions

Unit:

When the software is installed, coefficient files for a number of devices will be available on the PC. See the SGX website for any updates if available. These coefficients have typically been generated for a 5V bulb voltage but if a different lamp voltage, delay time or change in electronics is used then the coefficients may not be accurate. Customers are strongly advised to recalculate their own coefficients to suit the performance of their own instrument design. See IR Application Notes on the SGX website for more information about coefficients.

‘Single’: Single gas sensor plugged into S1 (reference and one active channel) ‘Dual’: Dual gas sensor plugged into S2 (reference and two active channels)

There are three different types of temperature sensors fitted to SGX infrared gas sensors. It is important to select the correct type so that the temperature readings are accurate. Some sensors have no integrated temperature sensor and so the PCB mounted sensor should be selected. The following options are available:

• External IC - uses IC temperature sensor on the IR-EK2 PCB

• Internal Thermistor (Twin Gas) – thermistor on twin gas devices

• Internal Thermistor (Single Gas) – thermistor on some single gas devices

• Internal IC – IC sensor used on some single gas devices

Some of the calibration coefficients for measuring concentration over a wide range (e.g. 100% CO2) will be slightly different to those used for a narrow range (e.g. 5% CO2) to give the optimum accuracy. The evaluation kit can store three sets of calibration coefficients for each gas channel. The ‘Select’ button allows you to select which range is in use. The upper limit of each concentration range. Note: 1000 ppm = 0.1% volume

For more information about calibration coefficients and how to calculate them

see Infrared Sensor Applications Notes

2 and 5 available from

www.sgxsensortech.com

The concentration of the calibration gas used when performing the ‘span’ calibration

Loads a set of coefficients from the indicated file on the PC

Updates the list of available coefficient files

Sends the data from the Coefficient Editor to the Evaluation Kit

Reads the data currently stored in the Evaluation Kit and displays it on the Coefficient Editor

Saves the data from the Coefficient Editor to a file on the PC

Exits the Coefficient Editor

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Set Zero

Set Span

Write Value:

Reference Pk

Pk:

Channel A/B Pk

Pk:

Channel A/B Conc:

10 Calibration

Before performing calibration, the following activities should have already been completed:

• Set lamp drive voltage, VR3 (Section 7)

• Set the channel gains, VR0, VR1, VR2 (Section 8)

• Set the sensor type, temperature sensor type and coefficients (Section 9)

A two point calibration is performed by setting the ‘zero’ and ‘span’ levels when in ‘Measurement Mode’. It is recommended that the Evaluation Kit be turned on and driving the sensor for at least 30 minutes so that the system can temperature stabilise before calibrating.

A source of dry nitrogen should be used to set the zero level. Once the gas is passing

Each zero and span calibration will take about 10 seconds as averaging is used to increase accuracy. This period is independent of the averaging time set in the PC software.

The above procedure should be repeated for the second gas if a twin-gas sensor is used. The gas sensing system is now calibrated and the correct level of gas concentrations will be displayed on the PC screen.

over the sensor, press the ‘Set Zero’ button on the ‘Calibration’ tab.

A source of the target gas with known concentration is required to set the span. Note that the concentration does not need to be the same as the span range. The ‘Span Concentration’ level in the Coefficient Editor should be adjusted to be equal to the concentration of the calibration gas. Once the gas is passing over the sensor, press the ‘Set Span button on the ‘Calibration’ tab.

11 Analog Outputs

The outputs of two 12 bit digital to analog converters (DACs) are provided on the expansion port PL2. Each analogue output is buffered by an operational amplifier and can give outputs in the range 0 V (000 hex) to 2.048 V (FFF hex). The analog outputs can be configured on the ‘I/O’ tab which is only available in ‘Device Setup Mode’.

Button Functions (I/O Tab)

Fixes the DAC output at a fixed voltage level set on the PC Software

DAC tracks the Reference Peak to Peak value (Note: DAC 0 V - 2.048 V output corresponds to 0 V – 3 V input range)

DAC tracks the Active Channel Peak to Peak value (Note: DAC 0 V - 2.048 V output corresponds to 0 V – 3 V input range)

DAC tracks the Concentration value (Note: DAC 0 V - 2.048 V output corresponds to Zero – Span input range)

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12 Alarm Outputs and LEDs

Four open collector alarm outputs are provided on the expansion port PL2. Each alarm has an associated LED (D1-D4) to indicate the status of the alarm output.

To use the open collector outputs, a resistor or other load should be connected to the desired external voltage. The 9 V input and 3V3 microcontroller supply are also available on the expansion connector for this purpose.

LED ON = alarm enabled (open collector driven - low) LED OFF = alarm disabled (open collector released – high)

The ‘Alarms’ tab is only visible when in ‘Device Setup Mode’ Each of the four alarm outputs can be set to one of the following options:

• Monitor Gas The alarm can be set to come on when the concentration is above or below a particular concentration level on either Channel A or Channel B.

• Force Alarm ON

• Force Alarm OFF

• Follow Input

The alarm will follow the value of the corresponding digital input (used for testing)

Click ‘Refresh Settings’ to read the current settings from the PCB.

Click ‘Write All Alarm Settings’ to write new alarm settings to the PCB.

Note that when the alarms are set to monitor concentration levels they use the one second averaged values, independent of what averaging is set on the PC data logging software.

13 Digital Inputs

Four digital inputs are provided on the expansion port PL2. They can be used by engineers writing their own application software to run on the Evaluation Kit. The status of each digital input can be viewed on the ‘I/O’ tab which is only present in ‘Device Setup Mode’

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14 Appendix: Evaluation Kit PCB Schematic Diagram

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Item Description

Manufacturer

Part No.

Qty Reference

Components not fitted:

15 Appendix: Evaluation Kit PCB Parts List

1 Blank PCB, DPP767434AA Issue 2 Any manufacturer 1 HW1 2 Feet, stick on, black, 11.1mm dia. 3M SJ5003BLACK 4 HW2, HW3, HW4, HW5 3 Resistor 0603 0.063W 1% 0R0 Any manufacturer 2 R15, R20 4 Resistor 0603 0.063W 1% 10R Any manufacturer 1 R32 5 Resistor 0603 0.063W 1% 100R Any manufacturer 5 R17, R18, R78, R79, R80 6 Resistor 0603 0.063W 1% 470R Any manufacturer 5 R9, R10, R11, R12, R13 7 Resistor 0603 0.063W 1% 2k2 Any manufacturer 6 R66, R67, R68, R75, R76, R77 8 Resistor 0603 0.063W 1% 2k7 Any manufacturer 4 R5, R6, R7, R8 9 Resistor 0603 0.063W 1% 6k8 Any manufacturer 3 R60, R61, R62 10 Resistor 0603 0.063W 1% 8k2 Any manufacturer 9 R19, R23, R24, R69, R70, R71,

11 Resistor 0603 0.063W 1% 47k Any manufacturer 4 R16, R51, R52, R53 12 Resistor 0603 0.063W 1% 100k Any manufacturer 7 R1, R2, R3, R4, R25, R30, R34 13 Resistor 0603 0.063W 1% 360k Any manufacturer 3 R63, R64, R65 14 Resistor 0603 0.063W 1% 820k Any manufacturer 6 R54, R55, R56, R57, R58, R59 15 Resistor 0603 0.063W 0.1% 25ppm 10k Any manufacturer 3 R21, R22, R29 16 Resistor 0805 0.1W 1% 0R0 Any manufacturer 2 R28, R31 17 Resistor 1206 0.125W 1% 10R Any manufacturer 1 R26 18 Resistor Variable 20k 0.5W Multiturn Bourns 3296W-1-203LF 4 VR0, VR1, VR2, VR3 19 Capacitor Cer. 0603 X7R 50V 10% 10nF Any manufacturer 2 C17, C18 20 Capacitor Cer. 0603 X7R 16V 10% 82nF Any manufacturer 3 C57, C58, C59 21 Capacitor Cer. 0603 X7R 50V 10% 100nF Any manufacturer 17 C2, C4, C8, C12, C13, C15,

22 Capacitor Cer. 0603 X7R 16V 10% 1uF Any manufacturer 8 C9, C10, C11, C14, C51, C52,

23 Capacitor Cer. 1206 X7R 6.3V 10% 10uF Any manufacturer 6 C1, C3, C29, C54, C55, C56 24 Capacitor Alum. Elec 50V 20% 10uF Panasonic EEE1HA100SP 2 C7, C19 25 Capacitor Tant. TPSC 25V 10% 10uF AVX TPSC106K025R0500 2 C21, C23 26 Diode Schottkyx2 SOT23-5 BAT54C Any manufacturer BAT54C 1 D9 27 Diode LED Green SMD Kingbright KP-1608SGC 5 D1, D2, D3, D4, D5 28 Diode Schottky 1A 30V SMB On-Semi MBRS130LT3G 1 D6 29 Diode TVS 12V 600W Any manufacturer SMBJ12A 1 D7 30 Diode Pack TVS 6V 500W ST-Micro USB6B1 1 D8 31 Diode Zener 3V9 3W OnSemiconductor 1SMB5915BT3G 1 D10 32 Transistor NPN SOT23 NXP BC846B 4 TR1, TR2, TR3, TR4 33 IC Micro 16 bit 64LQFP 34 IC Serial Eeprom SO8 Microchip 25LC80A-I/SN 1 IC2 35 IC USB to UART Bridge MLP-28 Silicon Labs CP2102 1 IC3 36 IC Regulator 3V3 DPAK ST LD1117DT33C 1 IC4 37 IC Reference 2.048V SOT23 Texas REF3120AIDBZT 1 IC5 38 IC Op-amp Rail-to-rail I/O SO8 Analog AD8629ARZ 4 IC6, IC7, IC8, IC9 39 IC Regulator Adj SO8 Micrel MIC39102YM 1 IC10 40 IC Reference 3.0V SO8 Analog ADR443ARZ 1 IC11 41 IC ADC 8x16bit 20QFN Analog AD7689ACPZ 1 IC12 42 Connector Press Mount Socket Wearnes Cambion 450-1804-01-03-00 15 S1 (7 off), S2 (8 off) 43 IC Temp. Sensor SOT23 National LM60BIM3 1 S3 44 Connector SKT DC Power 2.5mm Lumberg 1613 14 1 SK4 45 Connector SKT USB Mini Type B Molex 675031020 1 SK5 46 Connector PLG 14 Way Box Header Amp 1-1634688-4 1 PL1 47 Connector 2x10 Way 2.54mm Harwin M20-9981045 1 PL2 48 Connector 8 Way Vertical Friction Lock Molex 22-27-2081 1 PL3 49 Fuse Polyswitch 500mA Hold Tyco MICROSMD050F 1 F1 50 Terminal Block 2 Way Elkay 15001/2 1 TB1 51 Switch Push button SMD C&K KSR221G LFS 1 SW2 52 Crystal SMD 32.768kHz Epson Toyocom MC-146 32.768kHz

53 Transistor MOSFET P-Channel SOT23 Fairchild FDN338P 1 TR5

Capacitor Ceramic 0603 2 C5, C6 Resistor SMD 0603 1 R14, R33 Resistor SMD 0805 1 R27 Crystal HC49/4H 1 XT2

Texas **

MSP430F2616TPM 1 IC1

+/-20ppm 7.0pF

R72, R73, R74

C16, C20, C22, C24, C25, C26, C27, C28, C60, C61, C62

C53, C63

1 XT1

SGX Sensortech(IS) Ltd Registered in England No.08067077 DAS767840AA Version 3, August 2013, Page 20

Enquire Status

Command

Response

Notes

Available

aa.bb cccc dddd

aa.bb

aaa] aaa

aaa bbb

aaa

aa bbb

aaa bbb

aaa

aaa bbb

aaa bbb ccc

aaa

abcd] a

Set Lamp

Command

Response

Notes

Set Mode

Command

Response

Notes

aaaa

Set DAC

Command

Response

Notes

aaa

Set Alarms

Command

Response

Notes

Available

16 Appendix: Serial Message Protocol

PCB [WHO]

Lamp [EK2 LMP ENQ] Analog Out (DAC) Alarms (individual)

Alarms (all) [EK2 AL0 ENQ]

Digital Inputs [EK2 DIN ENQ]

Calibration Table

Zero Value (greater accuracy) Span Value (greater accuracy)

[EK2 DA1 ENQ] [EK2 DA2 ENQ] [EK2 AL1 ENQ]

[EK2 AL2 ENQ]

[EK2 AL3 ENQ]

[EK2 AL4 ENQ]

[EK2 CAx ENQ] [EK2 CAx aaaaaaa

[EK2 CAx ZERO ENQ]

[EK2 CAx SPAN ENQ]

[EK2

[EK2 LMP [EK2 DA1 [EK2 DA2 [EK2 AL1 cccccccc] [EK2 AL2 cccccccc] [EK2 AL3 cccccccc] [EK2 AL4 cccccccc] [EK2 AL0 ddd]

[EK2 DIN

aaaaaaa aaaaaaa bbbc bbbc bbbc ddde ddde ddde fgggh ijjjk lmmmn lmmmn lmmmn opppq opppq opppq rrrs tttu vvvvvvv www xxx y z]

[EK2 CAx ZERO aa.aaaaaa]

[EK2 CAx SPAN aa.aaaaaa]

]

] ]

cccc dddd

bbb

cccccccc

bbb ccc ddd

b c d

aaaaaaa bbbc ddde fgggh ijjjk lmmmn opppq rrrs tttu vvvvvvv www xxx y z

aa.aaaaaa

Software version Software checksum Serial number Lamp setting: OFF, ONX, PLS Set-up DAC setting: 000-FFF, M00, M01, M02 DAC output: 000-FFF Alarm status ONX, OFF Alarm setting: MAN, FOL, 1GT, 1LT, 2GT, 2LT Alarm threshold 0000000-1000000 (ppm)

Alarm 1 output ONX, OFF Alarm 2 output ONX, OFF Alarm 3 output ONX, OFF Alarm 4 output ONX, OFF Digital Input 1 status: 0, 1 Digital Input 2 status: 0, 1 Digital Input 3 status: 0, 1 Digital Input 4 status: 0, 1 Channel A or B Concentration range (3 for each chan) A coefficient bbb x 10-c (3 for each ch) N coefficient, as above Alphapos (f = +/-), as above Alphaneg Betapos Betaneg Zero (to 3 significant figures) Span (to 3 significant figures) Span gas concentration Delay time (ms) Current Range Temp sensor type S or D (single or duel type sensor) Channel A or B Value to 6 decimal places

Channel A or B Value to 6 decimal places

in Mode

Set-up

Set-up Set-up Set-up

Set-up

Lamp off [EK2 LMP OFF] [ACK] Set-up Lamp on [EK2 LMP ONX] [ACK] Set-up Lamp pulsing [EK2 LMP PLS] [ACK] Set-up

Measurement Mode

Set-up Mode [EK2 SEN SET] [ACK] All

Fixed value

Automatic mode

Manual On (individual: 1-4) (all together: 0)

SGX Sensortech(IS) Ltd Registered in England No.08067077 DAS767840AA Version 3, August 2013, Page 21

[EK2 SEN MEA] Output every second

[EK2 DA1 [EK2 DA2 [EK2 DA1 Maa] [EK2 DA2 Maa]

[EK2 AL1 MAN ONX] [EK2 AL2 MAN ONX]

[EK2 SEN aaaa bbbb cccc ddddddd eeeeeee fffff gggg]

]

[ACK]

]

[ACK] Set-up [ACK] [ACK] Set-up

[ACK] Set-up

bbbb

cccc

ddddddd eeeeeee fffff

gggg

Reference pk-pk 1s mean: 0000–FFFF (hex) Active ChA pk-pk 1s mean: 0000–FFFF (hex) Active ChB pk-pk 1s mean: 0000–FFFF (hex) Concentration ChA 1s (ppm) Concentration ChB 1s (ppm) Temperature reading °C: -99.9 to +99.9 or ERR Bulb Voltage pk-pk 1s mean: 0000– FFFF (hex)

000-FFF Set-up

00: Track reference ADC 01: Track Active ADC 02: Track Concentration

Set-up

in mode

System

Command

Response

Notes

Calibration

Command

Response

Notes

aaaaaaa

aaab

aaa

aaab

-b

Manual Off (individual: 1-4) (all together: 0)

Follow digital inputs (individual: 1-4) (all together: 0)

On if Channel a concentration is Greater Than

bbbbbbbb

(individual: 1-4) (all together: 0)

On if Channel a concentration is Less Than

bbbbbbbb

(individual: 1-4) (all together: 0)

[EK2 AL3 MAN ONX] [EK2 AL4 MAN ONX] [EK2 AL0 MAN ONX] [EK2 AL1 MAN OFF] [EK2 AL2 MAN OFF] [EK2 AL3 MAN OFF] [EK2 AL4 MAN OFF] [EK2 AL0 MAN OFF] [EK2 AL1 FOL] [ACK] Set-up [EK2 AL2 FOL] [ACK] Set-up [EK2 AL3 FOL] [ACK] Set-up [EK2 AL4 FOL] [ACK] Set-up [EK2 AL0 FOL] [ACK] Set-up [EK2 AL1 aGT bbbbbbbb] [EK2 AL2 aGT bbbbbbbb] [EK2 AL3 aGT bbbbbbbb] [EK2 AL4 aGT bbbbbbbb] [EK2 AL0 aGT bbbbbbbb] [EK2 AL1 aLT bbbbbbbb] [EK2 AL2 aLT bbbbbbbb] [EK2 AL3 aLT bbbbbbbb] [EK2 AL4 aLT bbbbbbbb] [EK2 AL0 aLT bbbbbbbb]

[ACK] Set-up

[ACK]

[ACK] Set-up

bbbbbbb

Channel: 1 or 2

Concentration

Set-up

Invalid command

Set temp senor type

Set the zero [EK2 CAx

Set the span [EK2 CAx

Set span concentration gas Set number of sensor channels Set concentration Range

Set A coefficient [EK2 CAx A1

Set n coefficient [EK2 CAx N1

Set n coefficient [EK2 CAx N2

SGX Sensortech(IS) Ltd Registered in England No.08067077 DAS767840AA Version 3, August 2013, Page 22

Invalid command

[EK2 CAL TEM aa]

ZERO]

SPAN] [EK2 CAx SCG aaaaaaa]

[EK2 CAL aCH]

[EK2 CAx RA1 aaaaaaa] [EK2 CAx RA2 aaaaaaa] [EK2 CAx RA3 aaaaaaa]

aaab] [EK2 CAx A2 aaab] [EK2 CAx A3 aaab]

aaaa]

aaaa] [EK2 CAx N3 aaaa]

[NAK] Set-up

[ACK]

[ACK] Set-up

[ACK]

[ACK] Set-up

[ACK]

[ACK] Set-up

Sets the temp sensor type – e.g. 00= Use PCB temperature sensor 01 = Twin Gas Thermistor 02 = IrxxEx Thermistor 03 = LM60 internal to sensor (IRxxGx) A = Channel A B = Channel B A = Channel A B = Channel B span concentration gas (ppm) Set-up

1 or 2 Set-up

Sets concentration range to aaaaaaa ppm

A = Channel A B = Channel B

co-efficient a =

A = Channel A B = Channel B

co-efficient n = A = Channel A B = Channel B

aaa x 10

Set-up

aaab

-b

aaab

-b

aaab

Set Alphapos coefficient

Set Alphaneg coefficient

Set Beta coefficient

Set Betaneg coefficient

Use medium concentration range parameters Use high concentration range parameters

[EK2 CAx ALPHA saaaa]

[EK2 CAx ALPHAN saaaa]

[EK2 CAx BETA1 saaaa] [EK2 CAx BETA2 saaaa] [EK2 CAx BETA3 saaaa] [EK2 CAx BETA1N saaaa]

[EK2 CAx BETA2N saaaa] [EK2 CAx BETA3N saaaa] [EK2 CAx RMI] [ACK]

[EK2 CAx RHI] [ACK]

[ACK]

[ACK] Set-up

[ACK]

s x

co-efficient alpha = Sign +/A = Channel A B = Channel B

co-efficient beta = Sign +/A = Channel A B = Channel B

co-efficient beta = Sign +/A = Channel A B = Channel B Set-up

Set-up

A = Channel A B = Channel B

aaa x 10

Set-up

SGX Sensortech(IS) Ltd Registered in England No.08067077 DAS767840AA Version 3, August 2013, Page 23

17 Appendix: China RoHS Declaration

有毒有害

有毒有害物物物物质质质质或元素

有毒有害有毒有害

(Hazardous Substances or Elements)

或元素

或元素或元素

零件

零件项项项项目目目目(名称

零件零件

(Component Name) IR-EK2 Evaluation Kit

印制

印制电电电电路路路路配配配配件件件件

印制印制

(

Printed Circuit Assemblies)

DAS767434AA Evaluation Kit PCB

外接

外接电电电电((((

外接外接

(External Cables) E100918 USB Lead

电电电电源源源源供供供供应应应应器器器器

(Power Supply Unit) DAS766693AA Power Supply Unit

文件

文件说说说说明明明明书书书书

文件文件

(Paper Manuals) DF767801A Quick Start Guide

光光光光盘说

(CD Manual)

DAS766762AA CD-ROM Manual/Software

表示该有毒有害物质在该部件所有均质材料中的含量均在

O: Indicates that this toxic or hazardous substance contained in all of the homogeneous materials for this part is below the limit requirement in SJ/T11363-2006.

表示该有毒有害物质至少在该部件的某一均质材料中的含量超出

X: Indicates that this toxic or hazardous substance contained in at least one of the homogeneous materials used for this part is above the limit requirement in SJ/T11363-2006

线线线线))))

盘说明明明明书书书书

盘说盘说

名称))))

名称名称

缆缆缆缆

铅铅铅铅

Lead (Pb)

SJ/T 11363-2006

汞汞汞汞

Mercury (Hg)

O O O O O O

标准规定的限量要求以下.

镉镉镉镉

Cadmiu m (Cd)

标准规定的限量要求.

六六六六价价价价

铬铬铬铬

Chromium VI Compounds (Cr6+)

多溴

多溴联联联联苯苯苯苯

多溴多溴

Polybrominated Biphenyls (PBB)

多溴二苯醚

多溴二苯醚多溴二苯醚

Polybrominated Diphenyl Ethers (PBDE)

SGX Sensortech(IS) Ltd Registered in England No.08067077 DAS767840AA Version 3, August 2013, Page 24

18 Appendix: Updating the IR-EK2 Embedded Software

From time to time SGX may release updates to the PC datalogging software or the embedded software (firmware) which runs on the IR-EK2 microprocessor. These will normally be available for download from the SGX website www.sgxsensortech.com. To install a new version of embedded software on the IREK2, follow these instructions very carefully:

1. Download the firmware zip file. Unzip and save the text file (ir_ek2_.....txt) to the computer hard

drive.

2. Connect up the IR-EK2 evaluation kit to the PC via the USB lead and connect the power.

3. Run the PC software (installed from the supplied CD)

4. Make sure the device is shown as connected.

5. Change the mode to 'Device Setup Mode'

6. Select the 'Hardware' menu, then 'Update Firmware'

7. Click 'Start Update'

8. Select the firmware file (ir_ek2_.....txt) on the computer hard drive

9. Click OK

**** Warning: Do not disconnect device during update ****

10. When the progress bar has completed, the installation is complete. The new version number will be shown on the PC screen.

Please read any compatibility notes provided in the readme.txt file supplied in the zip file. It may be necessary to upgrade to a later version of PC software at the same time.

SGX Sensortech(IS) Ltd Registered in England No.08067077 DAS767840AA Version 3, August 2013, Page 25

SGX Sensortech IR-EK2 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual