Vaisala GMP231 User Manual

USER'S GUIDE
Vaisala CARBOCAP® Carbon Dioxide Probe
GMP231
M211501EN-C
PUBLISHED BY Vaisala Oyj
Street address: Vanha Nurmijärventie 21, FI-01670 Vantaa, Finland Mailing address: P.O. Box 26, FI-00421 Helsinki, Finland Phone: +358 9 8949 1 Fax: +358 9 8949 2227
Visit our Internet pages at www.vaisala.com.
© Vaisala 2014 No part of this manual may be reproduced, published or publicly displayed in any form
or by any means, electronic or mechanical (including photocopying), nor may its contents be modified, translated, adapted, sold or disclosed to a third party without prior written permission of the copyright holder. Translated manuals and translated portions of multilingual documents are based on the original English versions. In ambiguous cases, the English versions are applicable, not the translations.
The contents of this manual are subject to change without prior notice. This manual does not create any legally binding obligations for Vaisala towards
customers or end users. All legally binding obligations and agreements are included exclusively in the applicable supply contract or the General Conditions of Sale and General Conditions of Service of Vaisala.
_________________________________________________________________________________

Table of Contents

CHAPTER 1
GENERAL INFORMATION ............................................................................ 7
About This Manual ................................................................... 7
Contents of This Manual ....................................................... 7
Version Information ............................................................... 8
Related Manuals ................................................................... 8
Documentation Conventions ................................................. 8
Safety ......................................................................................... 9
ESD Protection ...................................................................... 9
Recycling .................................................................................. 9
Regulatory Compliances ....................................................... 10
Patent Notice .......................................................................... 10
Trademarks ............................................................................. 10
Software License .................................................................... 10
Warranty .................................................................................. 11
CHAPTER 2
PRODUCT OVERVIEW ................................................................................ 12
Introduction to GMP231 ......................................................... 12
Basic Features and Options .................................................. 13
GMP231 Parts ......................................................................... 14
Operating Principle of CO2 Measurement ............................ 15
Environmental Compensation .............................................. 17
Pressure Compensation ...................................................... 17
Temperature Compensation ............................................... 17
Background Gas Compensations ....................................... 18
Probe Startup .......................................................................... 18
Analog Output Overrange Behavior ..................................... 19
CHAPTER 3
INSTALLATION ............................................................................................ 20
Thermal Management ............................................................ 20
Avoiding Condensation ......................................................... 21
Probe Installation Depth ........................................................ 21
Dimensions ............................................................................. 22
Recommended Installation ................................................... 23
Wiring ...................................................................................... 24
Power Supply .......................................................................... 24
CHAPTER 4
VAISALA INDUSTRIAL PROTOCOL .......................................................... 25
Overview ................................................................................. 25
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Physical Interface ................................................................... 25
Connecting with a Computer ................................................. 26
Installing the Driver for the USB Service Cable ............. 26
Terminal Application Settings ......................................... 27
Serial Commands ................................................................... 28
Showing Device Information ................................................. 29
Show Probe Information ...................................................... 29
Show Serial Number ............................................................ 30
Show Firmware Version ...................................................... 30
Show Firmware Information ................................................ 30
Show Probe Uptime ............................................................. 30
Show Command List ........................................................... 31
Serial Line Output Commands .............................................. 31
Start Measurement Output .................................................. 31
Stop Measurement Output .................................................. 32
Set Output Interval ............................................................... 32
Output a Reading Once ....................................................... 32
Set Measurement Output Format ........................................ 33
FORM Command Examples .......................................... 34
Changing Measurement Settings .......................................... 35
Set Compensation Modes ................................................... 35
Change Compensation Setpoint Values ............................. 36
Set Measurement to Standby Mode .................................... 37
Configuring Serial Line Operatio n ........................................ 38
Set Serial Line Operating Mode .......................................... 38
Set Serial Line Settings ....................................................... 39
Set Probe Address .............................................................. 39
Set Serial Line Response Time ........................................... 40
Set Serial Line Echo ....................................................... 40
Calibration Commands .......................................................... 41
Adjust CO2 Measurement .................................................... 41
Set Calibration Date ............................................................ 42
Set Calibration Info Text ...................................................... 43
Adjust Temperature Measurement ...................................... 43
Adjust Pressure Measurement ............................................ 44
Configuring Analog Output ................................................... 45
Set Analog Output Scaling .................................................. 45
Set Analog Output Mode ..................................................... 45
Set Analog Output Clipping and Error Limit ........................ 46
Test Analog Output .............................................................. 47
Other Commands.................................................................... 47
Enable Advanced Commands ............................................. 47
Connecting to Probe in POLL Mode .................................... 48
Closing the Connection to a Probe in POLL Mode ............. 48
Show Active Errors .............................................................. 48
Reset Probe ......................................................................... 49
Restore Factory Settings ..................................................... 49
CHAPTER 5
I2C INTERFACE ............................................................................................ 50
Overview .................................................................................. 50
Physical Interface ................................................................ 50
Communication Param eters ................................................ 51
Addressing ........................................................................... 51
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Communication Flow ............................................................. 52
GMP231 State Machine ...................................................... 53
Examples of Communication Flow ...................................... 54
Timing .................................................................................. 56
Status Byte .......................................................................... 56
Checksum ........................................................................... 56
Status Word......................................................................... 57
Commands .............................................................................. 58
Get_Interface_Version ........................................................ 58
Get_Parameter .................................................................... 59
Example: Read CO2 Measurement Result .................... 60
Set_Parameter .................................................................... 61
Example: Set Compensation Temperature ......................... 62
Get_Parameter_Info ............................................................ 63
Adjust .................................................................................. 64
Adjusting Measurement......................................................... 65
One Point Adjustment ......................................................... 65
Two Point Adjustment ......................................................... 66
Data Registers ........................................................................ 66
Data Formats....................................................................... 66
Register Table ..................................................................... 67
CHAPTER 6
MAINTENANCE ........................................................................................... 70
Cleaning .................................................................................. 70
Chemical Tolerance ............................................................ 70
Changing the Filter ................................................................. 71
Changing the Silicone Plug ................................................... 72
Calibration and Adjustment .................................................. 73
Calibration Setup ................................................................. 73
Using Ambient Air as Reference .................................... 74
Using a Calibration Gas as Reference........................... 74
Effect of Environmental Compensations ............................. 74
Limits of Adjustment ............................................................ 75
Adjustment Types ............................................................... 75
I2C Interface ................................................................... 76
Vaisala Industrial Protocol ............................................. 76
MI70 Hand-Held Indicator .............................................. 76
CHAPTER 7
OPERATING WITH MI70 INDICATOR ........................................................ 77
Overview of MI70 Support ..................................................... 77
Connecting GMP231 to MI70 Indicator ................................. 77
Changing Environmental Compensation Settings with MI70
Indicator .................................................................................. 78
Calibration and Adjustment with MI70 Indicator ................. 79
1-Point Adjustment with an MI70-Compatible Reference
Probe ................................................................................... 79
1-Point Adjustment with a Reference Gas .......................... 81
CHAPTER 8
TROUBLESHOOTING ................................................................................. 83
Problem Situations ................................................................. 83
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Analog Output Error State ..................................................... 84
Technical Support .................................................................. 84
Product Returns...................................................................... 84
CHAPTER 9
TECHNICAL DATA ...................................................................................... 85
Specifications ......................................................................... 85
Spare Parts and Accessories ................................................ 87
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List of Figures
Figure 1 GMP231 Installed Through a Chamber Wall (Example) .......... 12
Figure 2 GMP231 Parts .......................................................................... 14
Figure 3 CARBOCAP® Sensor of the GMP231 ...................................... 15
Figure 4 CO2 Measurement Inside the Incubator ................................... 16
Figure 5 Probe Installation Depth ........................................................... 21
Figure 6 Probe Dimensions without Silico ne Plu g .................................. 22
Figure 7 Probe Dimensions with Silicone Plug ....................................... 22
Figure 8 Electronics Housing Dimensions .............................................. 22
Figure 9 Attachment Bracket Dimensions .............................................. 22
Figure 10 Recommended Installation ....................................................... 23
Figure 11 PuTTY Terminal Application..................................................... 27
Figure 12 Hardware Schematic ................................................................ 50
Figure 13 GMP231 State Machine ........................................................... 54
Figure 14 Get_Parameter with ACK ......................................................... 54
Figure 15 Set_Parameter with ACK ......................................................... 55
Figure 16 Get_Parameter with NACK ...................................................... 55
Figure 17 Get_Parameter with Alarm ....................................................... 55
Figure 18 Changing the Filter ................................................................... 71
Figure 19 Changing the Silicone Plug ...................................................... 72
Figure 20 Inserting the Calibration Adapter over the Filter ...................... 73
Figure 21 CO2 Reading on MI70 Screen .................................................. 77
Figure 22 CO2 Reading with Tcomp and Pcomp on MI70 Screen ........... 78
Figure 23 GMP231 Compensation Settings on MI70 Screen .................. 78
Figure 24 Functions Menu ........................................................................ 79
Figure 25 Comparing Readings in MI70 Adjustment Mode ..................... 80
Figure 26 Selecting the Adjustment Mode ............................................... 80
Figure 27 Functions Menu ........................................................................ 81
Figure 28 MI70 Adjustment Mode ............................................................ 81
Figure 29 Selecting the Adjustment Mode ............................................... 82
Figure 30 Entering the Reference CO2 Concentration ............................. 82
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List of Tables
Table 1 Manual Revisions ....................................................................... 8
Table 2 Related Manuals ......................................................................... 8
Table 3 Applicable Patents .................................................................... 10
Table 4 GMP231 Connector Pinout ....................................................... 24
Table 5 Cable DRW240977 ................................................................... 24
Table 6 Default Serial Interface Settings ............................................... 25
Table 7 Basic Serial Commands ........................................................... 28
Table 8 Advanced Serial Commands .................................................... 29
Table 9 FORM Command Parameters .................................................. 33
Table 10 FORM Command Modifiers ...................................................... 33
Table 11 Selection of Output Modes ....................................................... 38
Table 12 GMP231 I2C Address ............................................................... 51
Table 13 GMP231 Device Address ......................................................... 51
Table 14 Invoke Message in GMP231 I2C Interface ............................... 52
Table 15 Response Message in GMP231 I2C Interface .......................... 53
Table 16 Timing ....................................................................................... 56
Table 17 Status Byte ............................................................................... 56
Table 18 Status Word Content ................................................................ 57
Table 19 Get_Interface_Version Invoke Message .................................. 58
Table 20 Get_Interface_Version Response Message ............................. 58
Table 21 Get_Parameter Invoke Message .............................................. 59
Table 22 Get_Parameter Response Message ........................................ 59
Table 23 Get_Parameter Invoke Message Example ............................... 60
Table 24 Get_Parameter Response Mes s age Example ......................... 60
Table 25 Set_Parameter Invoke Message .............................................. 61
Table 26 Set_Parameter Response Message......................................... 61
Table 27 Set_Parameter Return Codes .................................................. 61
Table 28 Example Set_Parameter Invoke Message ............................... 62
Table 29 Example Set_Parameter Response Message ......................... 62
Table 30 Get_Parameter_Info Invoke Message ...................................... 63
Table 31 Get_Parameter_Info Response Message ................................ 63
Table 32 Parameter Data Types ............................................................. 63
Table 33 Parameter Persistence ............................................................. 63
Table 34 Adjust Invoke Message ............................................................ 64
Table 35 Adjust Response Message ....................................................... 64
Table 36 Adjustment Subcommands ....................................................... 64
Table 37 Adjustment Parameters ............................................................ 64
Table 38 Adjustment Return Codes ........................................................ 65
Table 39 Data Formats ............................................................................ 66
Table 40 GMP231 Register Table ........................................................... 67
Table 41 Possible Problem Situations and Their Remedies ................... 83
Table 42 Performance ............................................................................. 85
Table 43 Operating Environm ent ............................................................. 86
Table 44 Inputs and Outputs ................................................................... 86
Table 45 Mechanics ................................................................................. 86
Table 46 Spare Parts and Accessories for GMP231 ............................... 87
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Chapter 1 _________________________________________________________ General Information
CHAPTER 1

GENERAL INFORM ATION

This chapter provides general notes for the manual and the GMP231 probe.

About This Manual

This manual provides information for installing, operating, and maintaining the Vaisala CARBOCAP® Carbon Dioxide Probe GMP231.

Contents of This Manual

This manual consists of the following chapters:
- Chapter 1, General Informati on, provides general notes for the manual and the GMP231 probe.
- Chapter 2, Product Overview, introduces the GMP231 probe and its features.
- Chapter 3, Installation, provides you with information that is intended to help you install the GMP231.
- Chapter 4, Vaisala Industrial Protocol, describes the Vaisala Industrial Protocol implementation of the GMP231.
- Chapter 5, I2C Interface, describes the I2C interface implementation of the GMP231.
- Chapter 6, Maintenance, provides information that is needed in the basic maintenance of the GMP231.
- Chapter 8, Troubleshooting, describes possible problems, their probable causes and remedies, and provides contact information for technical support.
- Chapter 9, Technical Data, provides the technical data of the GMP231.
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Manual Code
Description
M211501EN-C
May 2014. This manual. Updated description for Setpoint Values on page 36.
M211501EN-B
Previous version. Applicable from software version
and adjustment. Updated technical specification.
M211501EN-A
September 2013. First version.
Manual Code
Manual Name
M211603EN
GMP231 Quick Guide

Version Information

Table 1 Manual Revisions
ENV command in section Change Compensation
1.1.0 onward. Added instructions for operation with the MI70 hand-held indicator. Updated description
2
C interface and Vaisala Industrial Prot oc ol.
of I Updated description of envir onmental compensations. Updated instructions for calibration

Related Manuals

Table 2 Related Manuals
WARNING
CAUTION
NOTE

Documentation Conventions

Throughout the manual, important safety considerations are highlighted as follows:
Warning alerts you to a serious hazard. If you do not read and follow instructions very carefully at this point, there is a risk of injury or even death.
Caution warns you of a potential hazard. If you do not read and follow instructions carefully at this point, the product could be damaged or important data could be lost.
Note highlights important information on using the product.
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Chapter 1 _________________________________________________________ General Information
When returning a product for calibration or repair, make sure it has not been exposed to dangerous contamination, and is safe to handle without special precautions.
Do not modify the unit. Improper modification can damage the or lead to malfunction.
Do not open the inside.
Recycle all applicable material.
Dispose of the unit according to statutory regulations. Do not dispose of with regular household refuse.

Safety

The GMP231 probe delivered to you has been tested for safety and approved as shipped from the factory. Note the following precautions:
WARNING
CAUTION
CAUTION

Recycling

product
probe housing. There are no user serviceable parts

ESD Protection

Electrostatic Discharge (ESD) can cause immediate or latent damage to electronic circuits. Vaisala products are adequately protected against ESD for their intended use. It is possible to damage the product, however, by delivering an electrostatic discharge when touching an exposed contact on the product.
To make sure you are not delivering high static voltages yourself, avoid touching the pins on the M12 connector.
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Patent Issued By
Patent Number
United States Patent and Trademark Office US 5,827,438
US 6,177,673
European Patent Office EP0776023
EP0922972
German Patent and Trade Mark Office
69615635
Japan Patent Office
4263285
Finnish Patent Office 112005
105598

Regulatory Compliances

GMP231 is in conformity with the provisions of the following EU directives:
- EMC-Directive
- RoHS-Directive Conformity is shown by compliance with the following standards:
- EN 61326-1: Electrical equipment for measurement, control, and laboratory use – EMC requirements – Generic environment.
- EN 550022: Information technology equipment – Radio disturbance characteristics – Limits and methods of measurement.

Patent Notic e

GMP231 is protected by the following patents and their corresponding national rights:
Table 3 Applicable Patents

Trademarks

CARBOCAP® is a registered trademark of Vaisala Oyj. All other trademarks are the property of their respective owners.

Software License

This product contains software developed by Vaisala. Use of the software is governed by license terms and conditions included in the applicable supply contract or, in the absence of separate license terms and conditions, by the General License Conditions of Vaisala Group.
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Chapter 1 _________________________________________________________ General Information

Warranty

Visit our Internet pages for standard warranty terms and conditions:
www.vaisala.com/warranty.
Please observe that any such warranty may not be valid in case of damage due to normal wear and tear, exceptional operating conditions, negligent handling or installation, or unauthorized modifications. Please see the applicable supply contract or Conditions of Sale for details of the warranty for each product.
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CHAPTER 2

PRODUCT OVERVIE W

This chapter introduces the GMP231 probe and its features.

Introduction to GMP231

The Vaisala CARBOCAP® Carbon Dioxide Probe GMP231 is designed for incubator manufacturers requiring accurate and reliable carbon dioxide measurements and sterilization durability at high temperatures.
The GMP231 probe is based on Vaisala’s patented CARBOCAP® technology and a new type of infra-red light source. The probe can remain in place during high-temperature sterilization cycles that heat the chamber interior to 180 °C. Special design of the probe enables easy installation through the incubator wall and ensures that the sensor optics and electronics are separated and thermally insulated.
Sensor performance is optimized at 5 %CO2 measurement. GMP231 also has an internal pressure sensor, which allows compensation of the measurement according to ambient pressure. Since dust and most chemicals do not affect the measurement, and the effect of water vapor can be compensated for, GMP231 is accurate and stable at CO2 incubator conditions.
1403-144
Figure 1 GMP231 Installed Through a Chamber Wall (Example)
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Chapter 2 ___________________________________________________________ Product Overview

Basic Features and Options

- CO2 measurement range 0 ... 20 %CO2.
- Temperature durability in standby mode up to 195 °C (383 °F). See section Thermal Management on page 20.
- Vaisala CARBOCAP® CO2 sensor with excellent long-term stability. See sections Operating Principle of CO2 Measurement on page 15 and Specifications on page 85.
- Measurement compensated for effects of pressure, temperature, and background gas. Pressure compensation based on integrated pressure sensor. See section Environmental Compensation on page 17.
- Heating to avoid condensation on optical elements.
- Analog output: one current output channel (0 ... 20 mA or 4 ... 20 mA).
- Digital output:
- I2C.
- RS-485 (non-isolated) with Vaisala Industrial Protocol.
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1 = Electronics housing. Contains the main component board, including the digital pressure sensor.
2 = Holes for M4 screws on both sides of the housing. Maximum BN 10649 M4.
3 = Type label on housing cover (not shown).
4 = 8-pin M12 connector. For pinout, see Table 4 on page 24.
5 = Probe body.
6 = Measurement cuvette with optics and CARBOCAP® CO2 sensor.
7 = PTFE filter.
8 = Silicone plug for sealing the lead-through. Recommended accessory, suitable for 44 mm lead-throughs.
3
2
4
1
5
6
7
8

GMP231 Parts

CAUTION
1403-153
Figure 2 GMP231 Parts
screw depth 8 mm. Two screws included, type
Do not open the electronics housing; there are no user serviceable parts inside. All wiring is done through the M12 connector (4).
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Chapter 2 ___________________________________________________________ Product Overview
1 = Cuvette.
2 = Mirror.
3 = Window.
4 = Sensor chips.
2 3
4
1

Operating Principle of CO2 Measurement

The Vaisala CARBOCAP® sensor that is used in the GMP231 is a silicon­based, non-dispersive infrared (NDIR) sensor for the measurement of gaseous carbon dioxide. It is especially designed to tolerate high temperatures in standby mode, up to 195 °C (383 °F). This allows it to be used in applications that utilize high temperature for heat sterilization. The operating temperature range of the sensor is 0 … +70 °C (+32 ... +158 °F).
1403-160
Figure 3 CARBOCAP® Sensor of the GMP231
The sensitivity to carbon dioxide is based on absorption of infrared light at a characteristic wavelength. The light is emitted by a novel, silicon­based microchip emitter into the cuvette which contains the gas to be measured. After reflection from the mirror, the light intensity is measured with a thermopile chip at a wavelength chosen by a micromechanical Fabry–Pérot interferometer (FPI) and a band pass filter. A hermetically sealed sapphire window is used to protect the sensor chips from moisture and contamination. A heater chip is utilized to prevent condensation in normal operation.
The carbon dioxide measurement consists of two steps: First, the FPI is electrically tuned so that its pass band coincides with the characteristic absorption wavelength of carbon dioxide and the signal is recorded. Second, the pass band is shifted to a wavelength where no absorption occurs in order to get a reference signal. The ratio of these two signals, one at the absorption wavelength and the other at the reference wavelength, gives the fraction of light absorption from which the carbon dioxide concentration is calculated. The reference signal compensates the possible effects of sensor aging and signal attenuation due to dirt on optical surfaces, making the sensor very stable over time.
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1 = Chamber wall.
2 = Chamber interior.
3 = Light source.
4 = Band pass filter.
5 = Ambient air (400 ... 1000 ppm CO2).
6 = Light absorbed by CO2 in the incubator gas.
7 = Thermopile detector.
8 = Fabry-Perot interferometer.
9 = Sapphire window. Separates the sensor’s active components from the measured environment.
10 = Gold-plated mirror.
1
2
3 4
5
6
7
8
9 10
1403-161
Figure 4 CO2 Measurement Inside the Incubator
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Chapter 2 ___________________________________________________________ Product Overview

Environmental Compensation

GMP231 improves the CO2 measurement accuracy by applying various environmental compensations. GMP231 compensates for the effects of:
- Pressure
- Temperature
- Background gas oxygen (O2) content
- Background gas relative humidity (%RH)
Compensation parameters are configured on the order form when ordering the probe, and can later be updated using serial commands, MI70 Indicator, or I2C protocol. If the probe is integrated in a system that measures one or more of the compensation parameters, they can be updated to the probe continuously.
You can also turn off any of the compensations. In that case, GMP231 uses the default compensation value that is mathematically neutral for the probe’s internal compensation model.
For the effect of the compensations on measurement accuracy, refer to Table 42 on page 85.

Pressure Compensation

There is a pressure sensor on the component board of the GMP231 that provides a live measurement of ambient pressure. GMP231 can compensate the CO2 measurement based on this pressure reading, or it can use a fixed setpoint. Using the GMP231’s own sensor is recommended for most applications.
If pressure compensation is turned off, GMP231 uses the default compensation value of 1013.2 hPa.

Temperature Compensation

GMP231 can measure the approximate temperature of the CARBOCAP® sensor for compensation, or use a fixed setpoint. The temperature measurement is accurate enough to be useful for compensation, and is recommended for use unless a dedicated temperature measurement is available and can be regularly updated to the GMP231.
If temperature compensation is turned off, GMP231 uses the default value of +37 °C (+98.6 °F).
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Background Gas Com p e nsations

Compensation for background gas parameters are based on setpoint values only, as GMP231 has no internal measurement for oxygen concentration or humidity. The default setpoint values are as follows:
- Oxygen concentration: 19.7 %O2.
- Relative humidity: 93 %RH. If background gas compensations are turned off, GMP231 uses the value
0% for both.

Probe Startup

When powered on, GMP231 starts up within 10 seconds. Measurements from the outputs (digital and analog) become available during this time but note that they will only reach specified accuracy after a one minute warm-up period. For this reason, you should design the incubator’s control system so that it does not rely on measurements from GMP231 during this time.
NOTE
Specifically note that the CO2 reading will rise to the correct reading as the sensor’s infrared emitter achieves operation temperature.
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Chapter 2 ___________________________________________________________ Product Overview
This overrange and error state behavior is specific to the analog output, and

Analog Output Overrange Behavior

Analog output of the GMP231 has a defined behavior when the values measured by the probe are outside the scaled analog output range:
- Output is allowed to go 10% over the scaled range.
- Output is set to error state when measured value is more than 10% outside the scaled range. See section Analog Output Error State on page 84.
- Output resumes normal function when measured value returns to within 10% of the selected range.
For example, consider a GMP231 with 0 ... 20 mA analog output, scaled to 0 ... 10 %CO2.
- When measured CO2 rises above 10 %CO2, the output rises above 20 mA.
- The output keeps rising until the measurement is 11 %CO2, at which point the probe outputs 22 mA.
NOTE
- If the CO2 level rises above 11 %CO2, the output enters the error state, which is 23 mA for the 0 ... 20 mA output.
does not affect the readings provided by the digital outputs.
You can change the analog output overrange behavior using the AOVER command. See section Set Analog Output Clipping and Error Limit on page 46.
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CHAPTER 3

INSTALLATION

This chapter provides you with information that is intended to help you install the GMP231.

Thermal Management

GMP231 is designed to remain installed during typical heat sterilization cycles that raise the chamber temperature to 180 °C (356 °F). Since 180 °C is the target temperature for sterilization, it is likely that there will be hotspots inside the chamber that are above this temperature. Avoid installing the GMP231 near such hotspots, for example near heating elements. Do not expose the GMP231 to temperatures higher than 195 °C / 383 °F.
The following considerations are most important for achieving the specified heat durability and measurement stability:
- Only the sensor and its filter should be exposed to heat. The filter must be completely in the heated chamber. The probe body must remain inside the unheated chamber wall so that only the end of the probe body extends exactly 2.5 mm into the chamber.
- During the sterilization cycle, you must set the GMP231 to standby mode (turns off the CO2 measurement), or power off the probe completely. The GMP231 will automatically stop its measurement cycle if it detects a high temperature, but it is best if the incubator’s control system set the GMP231 to standby mode when the sterilization cycle is started.
- The installation tube must be sealed from the chamber side to limit heat conduction, and to prevent CO2 in the chamber from entering the probe. Vaisala recommends a 44 mm diameter installation tube together with Vaisala’s silicone plug.
- If the chamber wall contains heating elements, or has a construction where hot air is circulated inside the wall, design the installation tube so that excessive heat is not conducted to the GMP231.
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Chapter 3 ________________________________________________________________ Installation
2.5 mm

Avoiding Condensation

The sensor head of the GMP231 is heated during normal operation, which prevents condensation from forming inside the filter and on the optical surfaces. The heating is not on when GMP231 is in standby mode or unpowered. For this reason, keep the probe powered and operating when the incubator is in use and humidity inside the chamber is high.
Correct installation depth of the probe is also important for preventing condensation from running to the sensor along the chamber wall. See below.

Probe Installation Depth

GMP231 must be installed so that only the sensor element and the filter are inside the chamber. If the probe is longer the installation tube, the extra length should extend to the outside of the chamber.
The installation depth must be 2.5 mm. This installation depth provides the specified heat durability of the probe, and allows the silicone plug to seal the Ø44 mm installation tube properly.
1403-154
Figure 5 Probe Installation Depth
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163
118.5
Screw BN 10649 M4 x 8 mm (for 1 mm thick sheet metal attachment)
1121
Ø 30.2
1.3°
Ø 19
Ø 24.8
Position only the filter inside the heated chamber
163
118.5
Screw BN 10649 M4 x 8 mm (for 1 mm thick sheet metal attachment)
1121
Ø 30.2
Ø 19
2.5
Incubator’s inner wall
1.3°
Position only the filter inside the heated chamber
Recommended diameter for installation tube 44 mm
M12
54.4
87
Reserve space for M12 cable
40
4 × Ø3.5
52

Dimensions

1403-108
Figure 6 Probe Dimensions without Silicone Plug
1403-110
Figure 7 Probe Dimensions with Silicone Plug
1403-112
Figure 8 Electronics Housing Dimensions
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1403-109
Figure 9 Attachment Bracket Dimensions
Chapter 3 ________________________________________________________________ Installation
The probe and electronics housi chamber. The electronics housing should be in a ventilated space that is open to ambient air.
1 = Ambient air.
2 = Chamber wall.
3 = Chamber interior.
4 = GMP231 Electronics housing.
5 = M4 screw holes on both sides of the probe housing.
6 = 8-pin M12 connector. For pinout, see section Wiring on page 24.
7 = Cable.
8 = CARBOCAP® sensor under PTFE filter. The filter must be inside the chamber completely.
9 = Silicone plug. Insert the plug over the probe from inside the chamber.
10 = Ø 44 mm installation tube through the chamber wall. The diameter is important for proper sealing by the silicone plug.
4
1
2
3
5
6
7
9
8
10

Recommended Installation

GMP231 is designed to be installed through a chamber wall, and attached to the chamber chassis using an attachment bracket and the two screw holes on the side of the probe. As the installation depth of the probe inside the chamber is critical (see section Probe Installation Depth on page 21), the mounting method must allow the probe to be positioned exactly.
NOTE
ng must remain outside the heated
1403-123
Figure 10 Recommended Installation
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Male 8-pin M12
Pin #
Function
1
I2C SDA
2
RS-485 D-
3
I2C SCL
4
Analog output +
5
Standby
6
RS-485 D+
7
Power supply +
8
Ground
-
Shield
Female 8-pin M12
Pin #
Function
Wire Color
1
I2C SDA
White
2
RS-485 D-
Brown
3
I2C SCL
Green
4
Analog output +
Yellow
5
Standby
Gray
6
RS-485 D+
Pink
7
Power supply +
Blue
8
Ground
Red
-
Shield
Black
1
5 6
7
3
4 8
2
1
6 8
7
3
4
5
2

Wiring

GMP231 provides several outputs you can use. Connect the output pins you need, and the power supply and ground pins. Use a shielded cable, and connect the shield to the chassis of the GMP231’s M12 connector, and to ground on the other side.
Ground pin 5 to put the probe in standby mode (stops CO2 measurement). The probe resumes normal measurement operation when pin 5 is no longer grounded, unless its internal measurement shows the temperature is too high.
Table 4 GMP231 Connector Pinout
Vaisala’s standard connection cable for the GMP231 (order code DRW240977) is a 90 cm long cable with female 8-pin M12 connector on one end, and open ended wires on the other. It supports all outputs from the GMP231, and connects the cable shield to the connector chassis.
Table 5 Cable DRW240977

Power Supply

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The supply voltage range of the GMP231 is 11 ... 30 VDC. If the analog output is used, the supply voltage range is 20 ... 30 VDC.
The maximum power consumption is 1 W.
Chapter 4 ____________________________________________________ Vaisala Industrial Protocol
Property
Description / Value
Baud rate
19200
Parity
None
Data bits
8
Stop bits
1
Flow control
None
CHAPTER 4

VAISALA INDUSTRI AL PROTOCOL

This chapter describes the Vaisala Industrial Protocol implementation of the GMP231.

Overview

RS-485 line of the GMP231 provides an implementation of the Vaisala Industrial Protocol that can be used for service and configuration use, or for interfacing with the incubator’s control system. The protocol is a plaintext protocol suitable for use both by human operators and automated systems.
Table 6 Default Serial Interface Settings

Physical Interface

The physical interface is a non-isolated 3-wire interface. The data lines are RS-485 D- and RS-485 D+. Ground is shared with power supply.
The connector is an 8-pin male M12. For connector pinout and wiring information, see section Wiring on page 24.
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Connecting with a Computer

Connecting with a computer allows you to configure and troubleshoot your probe using serial line commands. For a list of commands, see section Serial Commands on page 28.
When connecting using a computer, use the Vaisala USB cable (Vaisala order code 221040) and a suitable terminal application:
- If you have not used the Vaisala USB cable before, install the driver before attempting to use the cable. Refer to section Installing the Driver for the USB Service Cable below for detailed instructions.
- For more information on using a terminal application, see section Terminal Application Settings on page 27.

Installing the Driver f or t he USB Servic e Cable

Before taking the USB service cable into use for the first time, you must install the provided USB driver on your computer (requires Windows). When installing the driver, you must accept any security prompts that may appear.
1. Check that the USB service cable is not connected. Disconnect the
cable if you have already connected it.
2. Insert the media that came with the cable, or download the latest
driver from www.vaisala.com.
3. Run the USB driver installation program (setup.exe), and accept
the installation defaults. The installation of the driver may take several minutes.
4. After the driver has been installed, connect the USB service cable
to a USB port on your computer. Windows will detect the new device, and use the driver automatically.
5. The installation has reserved a COM port for the cable. Verify the
port number, and the status of the cable, using the Vaisala USB Instrument Finder program that has been installed in the Windows Start menu.
Windows will recognize each individual service cable as a different device, and reserve a new COM port. Remember to use the correct port in the settings of your terminal program.
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If PuTTY is unable to open the serial port you selected, it will show you an error message instead. If this happens, restart PuTTY and check the settings.

Terminal Applic a tion Se t t ings

The steps below describe how to connect to the probe using the PuTTY terminal application for Windows (available for download at
www.vaisala.com) and a USB computer connection cable:
1. Connect the USB serial interface cable between your PC and the M12 connector of the probe.
2. Start the PuTTY application.
3. Select Connection > Serial & USB and check that the correct COM port is selected in the Serial or USB line to connect to field.
If you are using the PuTTY terminal application supplied by Vaisala, you can press the USB Finder button to open the Vaisala USB Instrument Finder program.
4. Check that the other serial settings are correct for your connection, and change if necessary. Flow control should be set to None unless you have a reason to change it.
NOTE
5. Click the Open button to open the connection window and start using the serial line.
6. You may need to adjust the Local echo setting in the Terminal category to see what you are typing on the serial line. To access the configuration screen while a session is running, click the right mouse button over the session window, and select Change
Settings... from the pop-up menu.
Figure 11 PuTTY Terminal Application
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Command
Description
?
Show probe information.
CLOSE
Close connection to probe (POLL mode)
ECHO
Show or set remote echo mode.
ENV
Show or set environmental parameters.
ERRS
Show currently active errors .
FORM [modifier string]
Show or set output format.
HELP
Show list of currently available serial commands.
INTV [0 ... 9999 s/min/h]
Set continuous output interval for R command.
OPEN [address]
Open connection to probe in POLL mode
PASS [1300]
Access advanced serial commands.
R
Start the continuous outputting.
RESET
Reset the probe.
S
Stop the continuous outputting.
SDELAY [0 ... 255]
Show or set serial line transmission delay in milliseconds.
SEND
Output measurement message once.
SERI [baud data stop parit y]
Show or set the serial interface settings
SMODE [mode]
Show or set startup serial mode: RUN, STOP, or POLL.
SNUM
Show probe serial number.
STANDBY [on/off]
Standby mode on/off (turn off measurement)
SYSTEM
Show probe firmware information
TIME
Show probe operation hours and uptime
VERS
Show probe firmware version.

Serial Commands

All commands can be issued either in uppercase or lowercase. In the command examples, the keyboard input by the user is in bold type.
The notation <cr> refers to pressing the carriage return (Enter) key on your computer keyboard. Enter a <cr> to clear the command buffer before starting to enter commands.
Table 7 Basic Serial Commands
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Command
Description
ADDR [0 … 254]
Show or set probe address.
AMODE
Show or set analog output mode.
AOVER
Show or set analog output overrange and clipping behavior.
ASEL
Show or set analog output parameter.
ATEST
Test analog putput.
CCO2
Adjust CO2 measurement gain and offset.
CDATE
Show or set calibration date.
CP
Adjust pressure measurement offset.
CT
Adjust temperature measurement offset.
CTEXT
Show or set calibrati on inf o rmation.
FRESTORE
Restore probe to factory settings.
O2CMODE
Show or set oxygen compensation mode.
PCMODE
Show or set pressure compensation mode.
RHCMODE
Show or set humidity compensation mode.
TCMODE
Show or set temperature compensation mode.
Table 8 Advanced Serial Commands

Showing Device Information

Show Probe Information

The ? command outputs a listing of probe information. ?<cr>
Command ?? is a similar command that is designed to be used if the probe is in POLL mode but its address is unknown. The probe will respond to the ?? command even while in POLL mode. Do not use the ?? command if you have more than one probe on an RS-485 line.
Example:
?
Device : GMP231 Copyright : Copyright (c) Vaisala Oyj 2013. All rights reserved. SW Name : GMP231 SW version : 1.0.1.1537 Snum : J1320082 Calibrated : 2014-03-11 Address : 1 Smode : STOP
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Show Serial Number

SNUM<cr> Example:
snum
Serial number : J1320082

Show Firmware Version

VERS<cr> Example:
vers
GMP231 / 1.1.0.1537

Show Firmware Information

SYSTEM<cr> Example:
system
Device Name : GMP231 SW Name : GMP231 SW version : 1.1.0.1537

Show Probe Uptime

Use the TIME command to show how long the probe has been in operation, and what is the current uptime since last reset (in seconds). The operation counter is in format ddddd:hh:mm:ss. Full days and hours are retained in the counter, minutes and seconds are cleared at reset.
TIME<cr> Example (cumulative uptime 23 hours, 56 minutes, and 49 seconds,
uptime since last reset 3409 seconds):
time
00000:23:56:49 Up time: 3409 s
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Show Command List

Use the HELP command to show a list of the currently available serial commands.
HELP<cr> Example (shows basic commands, advanced commands are not enabled):
CLOSE ECHO ENV ERRS FORM HELP INTV PASS R RESET S SDELAY SEND SERI SMODE SNUM STANDBY SYSTEM TIME VERS

Serial Line Output Commands

Start Measurement Output

Use the R command to start the continuous outputting of measurement values as an ASCII text string to the serial line.
R<cr> Example (measurement message in default format):
r
CO2= 490 ppm CO2= 490 ppm CO2= 491 ppm CO2= 491 ppm CO2= 491 ppm ...
The probe keeps outputting measurement messages at the interval that has been set INTV command until stopped.
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where
n = time interval, range 0 ... 255
xxx
=
time unit = "S", "MIN", or "H "

Stop Measurement Output

You can stop the measurement output by pressing the ESC key or with the S command.

Set Output Interval

Use the INTV command to change the output interval of the automatically repeat in g measu remen t mes s a ges. T he measu r emen t messages are repeated in the RUN mode, or after the R command has been given.
INTV [n xxx]<cr>
The shortest output interval (with n = 0) outputs the measurement messages as quickly as the probe’s internal measurement cycle produces them, without additional delay.
Example:
intv 5 s
Output interval : 5 S

Output a Reading Once

Use the SEND command to output a single measurement message. SEND<cr>
Example:
send
CO2= 1702 ppm
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where
modifier string
=
String of parameters and modifiers that defines the output format, length 1 ... 15 See
Maximum length
may be shorter when text strings are used.
Measured Parameter
Abbreviation in FORM Command
Carbon dioxide in ppm
CO2
Carbon dioxide in percent
CO2%
Currently used temperature compensation value
TCOMP
Currently used pressure compensation value
PCOMP
Currently used oxygen concentration compensation value
O2COMP
Currently used relative humidity compensation value
RHCOMP
Modifier
Description
x.y
Length modifier (number of digits and decimal places)
#t
Tabulator
#r
Carriage-return
#n
Line feed
""
String constant, length 1 ... 15 characters
#xxx
ASCII code value (decimal) of a special character; for example, #027 for ESC
ADDR
Probe address (0 ... 254)
SN
Probe serial number
TIME
Cumulative operating hours of the probe.
Ux
Shows the name of the measurement unit using “x” number measurement unit with three characters
CS4
Modulus-65536 checksum of message sent so far, ASCII encoded hexadecimal notation
CSX
NMEA xor-checksum of message sent so far, ASCII encoded hexadecimal notation

Set Measurement Output Format

Use the serial line command FORM to change the measurement message sent by the probe. You can freely define the output message to include the desired parameters, formatting options, text strings, and additional fields.
FORM [modifier string]<cr>
0 characters.
Table 9 and Table 10 below.
You can return to the default format using the "FORM /" command.
Table 9 FORM Co m ma n d Parameters
Table 10 FORM Command Modifiers
of characters. For example, U3 shows the name of the
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FORM Command Examples
Example of default output (continuous output from RUN mode):
CO2= 860 ppm CO2= 861 ppm CO2= 861 ppm ...
Command to set output format as %CO2:
form 3.1 "CO2=" CO2% " " U4 #r #n
Output example:
CO2= 5.1 %CO2 CO2= 5.1 %CO2 CO2= 5.0 %CO2 ...
Command to set output format as CO2 ppm with Modulus-65536 checksum:
form 6.0 "CO2=" CO2 " " U3 " " CS4 #r #n
Output example:
CO2= 3563 ppm 9F CO2= 3562 ppm 9E CO2= 3559 ppm A4 ...
Command to set output format as CO2 ppm, with start of text (ASCII character 002) and end of text (003) ASCII codes, and without line feed and carriage return at the end:
form #002 6.0 "CO2=" CO2 " " U3 #003
Output example (ASCII codes not visible here):
CO2= 866 ppm CO2= 866 ppm CO2= 867 ppm CO2= 867 ppm CO2= 867 ppm CO2= 868 ppm CO2= 868 ppm CO2= 869 ppm ...
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where
on = Compensation enabled using setpoint value.
off = Compensation disabled, neutral value used.
measured
=
Compensation enabled using internal measurement. Available only for pressure and temperature compensations.

Changing Measurement Settings

Set Compensation Modes

You can change the mode of each environmental compensation type using a dedicated serial command. The commands are:
- PCMODE for pressure compensation mode.
- TCMODE for temperature compensation mode.
- O2CMODE for oxygen compensation mode.
- RHCMODE for relative humidity compensation.
Command syntax is as follows:
PCMODE [on | off | measured]<cr> TCMODE [on | off | measured]<cr> O2CMODE [on | off]<cr> RHCMODE [on | off]<cr>
Example (check temperature compensation mode):
pass 1300 tcmode
T COMP MODE : ON
Example (change temperature compensation mode to use internal measurement):
pass 1300 tcmode measured
T COMP MODE : MEASURED
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temp
=
Compensation temperature. Range -40 ... 100 °C.
pres
=
Compensation pressure. Range 500 ... 1150 hPa.
oxy
=
Oxygen content of background gas. Range 0 ... 100%.
hum
=
Relative humidity of background gas. Range 0 ... 100%.
xtemp
=
Compensation temperature that is stored in RAM.
xpres
=
Compensation pressure that is stored in RAM.
xoxy
=
Oxygen content of background gas that is stored in RAM.
xhum
=
Relative humidity of background gas that is stored in RAM.

Change Compensation Setpoint Values

Use the ENV command to show or set the setpoint values of the environmental compensation parameters. To chan ge a value, giv e the parameter name and value as arguments to the ENV command.
ENV [temp|pres|oxy|hum|xtemp|xpres|xoxy|xhum] [value]<cr> There are four compensation parameters. Values of the parameters are
stored in two places: eeprom (non-volatile memory, values retained during power off) and RAM (volatile memory that loses the values when probe is reset, and where values are loaded from non-volatile memory at startup). As the number of writes to eeprom is limited to 30000 cycles by memory implementation, you must write all continuously updated values to RAM to avoid wearing out the eeprom. A second set of parameters (with X prefix in the name) is provided for this purpose.
When writing permanent values to eeprom, use these parameter names. Note that updating these parameters does not update the parameters in RAM (the values that are currently used by the probe).
When writing to RAM, use the parameter names below. The ranges are the same as for the permanent parameters.
Example (Show current compensation values; all compensations are enabled. Note that temperature and pressure compensations use internal measurement, so the value in use is constantly changing):
env Temperature (C) : 37.00 Pressure (hPa) : 1013.20 Oxygen (%O2) : 19.70 Humidity (%RH) : 93.00
In use: Temperature (C) : 23.10 Pressure (hPa) : 1011.28 Oxygen (%O2) : 19.70 Humidity (%RH) : 93.00
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If temperature and pressure compensations are internally measured values, they will continuously update the values in RAM, overriding any temperature and pressure values that are written to RAM
Example below sets temperature compensation to setpoint mode, and changes temperature setpoint value to 37.2 in RAM.
pass 1300 tcmode on
T COMP MODE : ON
env xtemp 37.2
In eeprom: Temperature (C) : 37.00 Pressure (hPa) : 1013.20 Oxygen (%O2) : 19.70 Humidity (%RH) : 93.00
In use: Temperature (C) : 37.2 Pressure (hPa) : 1013.20 Oxygen (%O2) : 19.70 Humidity (%RH) : 93.00
NOTE
configured to use
with the ENV command.

Set Measurement to Standby Mode

Use the STANDBY command to set the probe to standby mode. In standby mode, the CO2 measurement is disabled. Probe returns to the normal measurement when the command STANDBY OFF is given or the probe is reset.
STANDBY [on | off]<cr> Example (enable standby mode):
standby on
Standby mode : ON
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where
mode
=
STOP, RUN, or POLL.
Mode
Measurement Output
Available Commands
STOP
Only with the SEND command.
All (default mode).
RUN
Automatic output.
Only command S.
POLL
Only with the SEND [addr]
SEND [addr] and OPEN [addr].
same line.

Configuring Serial Line Operation

Set Serial Line Op er at ing Mode

Use the SMODE command to set the start-up operating mode of the serial line.
SMODE [mode]<cr>
Table 11 Selection of Output Modes
command.
Other commands available after opening a line to the probe using the OPEN command.
Use with RS-485 buses wh er e multiple probes can share the
Selected output mode will be activated at next reset or power up. Example:
smode poll
Serial mode : POLL
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where
b = baud rate (9600, 19200, or 19200)
p = parity (n = none, e = even, o = odd)
d = data bits (7 or 8)
s = stop bits (1 or 2)
where
aaa
=
Device address of the probe, range 0 ... 254 (default = 0)

Set Serial Line Settings

Use the SERI command to set the serial line settings. The new settings will be taken into use when the probe is reset or powered up.
SERI [b p d s]<cr>
Example (shows default settings):
seri Com1 Baud rate : 19200 Com1 Parity : N Com1 Data bits : 8 Com1 Stop bits : 1
Example (set serial line to 9600 baud, even, 7 data bits, and 1 stop bit):
seri 9600 e 7 1
OK
seri
Com1 Baud rate : 9600 Com1 Parity : E Com1 Data bits : 7 Com1 Stop bits : 1

Set Probe Address

Use the ADDR command to set the device address of the probe. Addresses are required for POLL mode.
ADDR [aaa]<cr>
Example (change probe address to 52):
pass 1300 addr 52
Address : 52
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where
delay
=
Serial line delay, range 0 … 255 (milliseconds).

Set Serial Line Response Time

With the SDELAY command you can set delay (response time) of the serial line, or view the currently set delay value.
SDELAY [delay]<cr>
Example (set delay to 50 milliseconds):
sdelay 50
Serial delay : 50
Set Serial Line Echo
Use the ECHO command to enable or disable the echoing of characters received by the probe.
ECHO [on/off]<cr> Example:
echo
Echo : OFF
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Before calibrating GMP231 using serial line commands, read the instructions in section
Make sure that the environmental compensation settings of the GMP231 are properly set for your calibration environment; see section Measurement Settings
where
-lo = Select low concentration for adjustment. Adjusts
measurement offset.
-hi = Select high concentration for adjustment. Adjusts
measurement gain.
co2
=
CO2 concentration reference in ppm.
-save
=
Save currently entered adjustments.
-cancel
=
Cancel currently entered adjustments.
-reset
=
Clear user adjustments, set Gain to 1 and offset to 0.

Calibration Commands

NOTE
Calibration and Adjustment on page 73.
Changing
on page 35.

Adjust CO2 Measurement

Use the CCO2 command to adjust CO2 measurement in one or two points. You can use either a low or high concentration reference (one-point adjustment), or both (two-point adjustment).
The idea is to let the probe stabilize in the desired CO2 concentration, and then input the real CO2 concentration using the CCO2 command. If you are performing a two-point correction, repeat for the second point. Then commit the adjustment by giving the CCO2 –SAVE command. Note that successfully saving the adjustment clears the calibration date (CDATE) and calibration text (CTEXT) that have been stored in the probe. Use those commands to enter a new calibration date and text.
CCO2 [-lo | -hi] [co2] <cr> CCO2 [-save | -cancel]<cr> CCO2 [-reset]<cr>
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where
yyyy
=
Year of calibration in four digits
mm
=
Month of calibration in two digits
dd = Day of calibration in two digits
Example (show current user adjustment status – no adjustment done):
pass 1300 cco2
1.Ref. point low 0
1.Meas. point low 0
2.Ref. point low 200000
2.Meas. point low 200000 Gain : 1.0000 Offset : 0.0000
Example (one-point adjustment in 5% concentration (50000 ppm)):
pass 1300 cco2 –lo 50000
OK
cco2 –save
OK

Set Calibration Date

Use the CDATE command to view the date when the probe was last calibrated, or set a new date.
CDATE [yyyy mm dd]<cr>
Example (show currently stored calibration date):
>pass 1300 >cdate
Calibration date : 2013-10-03
Example (set calibration date to 2014-03-10):
>pass 1300 >cdate 2014 03 10
Calibration date : 2014-03-10
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where
text
=
Calibration information text string, max 19 characters. If you want to use spaces in the string, enclose the text in quotes.
where
temp
=
Correct temperature in degrees Celsius (°C).

Set Calibration Info Text

Use the CTEXT command to view or set calibration information text. CTEXT [text]<cr>
Example (shows the text “Calibrated at” followed by the currently stored calibration text):
pass 1300 ctext
Calibrated at Vaisala
Example (set calibration text to “Lab_1”):
pass 1300 ctext Lab_1
Calibrated at Lab_1

Adjust Temperature Measurement

Use the CT command to perform an offset correction to the internal temperature measurement. The correction is done by providing the correct temperature as an argument to the CT command.
CT [temp]<cr> CT [-reset]<cr>
Example (adjust the internal temperature measurement to 23 °C at the current conditions):
pass 1300 ct 23
OK
Example (clear the offset adjustment from internal temperature measurement):
pass 1300 ct -reset
OK
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where
pressure
=
Correct pressure in hectopascals (hPa).

Adjust Pressure Measu rement

Use the CP command to perform an offset correction to the internal pressure measurement. The correction is done by providing the correct pressure as an argument to the CP command.
CP [pressure]<cr> CP [-reset]<cr>
Example (adjust the internal pressure measurement to 990 hPa at the current conditions):
pass 1300 cp 990
OK
Example (clear the offset adjustment from internal pressure measurement):
pass 1300 cp -reset
OK
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where
channel
=
Analog output channel, only 1 can be selected.
parameter
=
Parameter that is output on analog channel. Only parameter available is CO2.
lowlimit
=
Lower limit of channel scaling in ppm.
highlimit
=
High limit of channel scaling in ppm.
where
channel
=
Analog output channel, only 1 can be selected.
lo_value
=
Low limit of the channel.
hi_value
=
High limit of the channel.
error_value
=
Error value of the channel.

Configuring Analog Output

Set Analog Output Scaling

Use the ASEL command to show or set the scaling of the analog output. ASEL [channel] [parameter lowlimit highlimit]<cr>
Example (change channel scaling to 0 … 5%):
pass 1300 asel 1 co2 0 50000
Aout 1 quantity : CO2(0 ... 50000)

Set Analog Output Mode

Use the AMODE command to set the analog output limits and error level.
AMODE [channel lo_value hi_value error_value]<cr>
Example (show current configuration):
pass 1300 amode 1
Aout 1 range (mA) :4.00 ... 20.00 (error :21.00)
Example (set channel to 4 … 20 mA, and error level to 3.6 mA):
pass 1300 amode 1 4 20 3.6
Aout 1 range (mA) :4.00 ... 20.00 (error : 3.60)
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where
channel
=
Analog output channel, only 1 can be selected.
clip%
=
Output margin (%) at which the output is clipped.
valid%
=
Output margin (%) at which the output of the channel goes into the error state. the Mode on page 45.

Set Analog Output Clipping and Error Limit

Use the AOVER command to define the behavior of the analog output when the measured value is outside the scaled output range.
AOVER [channel clip% valid%]<cr>
The error state is defined using
AMODE command, see section Set Analog Output
For example, first check the analog output settings using ASEL, AMODE, and AOVER commands:
pass 1300 asel 1
Aout 1 quantity : CO2(0 ... 50000)
amode 1 Aout 1 range (mA) :0.00 ... 20.00 (error : 23)
aover 1 Aout 1 clipping :10.00 % Aout 1 error limit :10.00 %
Now give the following AOVER command:
aover 1 5 10 Aout 1 clipping : 5.00 % Aout 1 error limit :10.00 %
The analog output now behaves like this:
- Clipping is now set to 5%, meaning the output is allowed to vary between 0 ... 21 mA. The analog channel will output the measurement for 0 ... 52500 ppm, but range 0 ... 20 mA remains scaled to 0 ... 50000 ppm.
- Error limit is 10%, which means the output will show the error state (23 mA) when the measured value is 10% outside the scaled output range. With the settings above, this will happen if the measured CO2 concentration is outside range 0 ... 55000 ppm.
- The output will never actually be between 21 mA and 23 mA because of clipping.
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where
channel
=
Analog output channel, only 1 can be selected.
level
=
Level for analog output channel in mA.
where
code
=
Code for enabling advanced commands (1300).

Test Analog Output

You can test the operation of the analog output with the ATEST command by forcing the output to a given value. You can then measure the output with a calibrated multimeter. After testing the output, use the
ATEST command again to exit the test mode. ATEST [channel] [level]<cr>
Example (enable analog output test mode, set level to 20 mA):
pass 1300 atest 1 20
Aout 1 (mA) :20.000
Example (disabling analog output test mode, resuming normal output):
atest 1
Aout 1 test mode disabled.

Other Commands

Enable Advanced Commands

Use the PASS command to enable advanced serial commands. Advanced commands can be used until the next reset.
PASS [code]<cr>
Example:
pass 1300
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where
address
=
Probe address, range 0 ... 254.

Connecting to Probe in POLL Mode

Use the OPEN command to connect to a probe that is in POLL mode. OPEN [address]<cr>
Example (target probe in POLL mode, with address 52):
open 52
GMP231: 52 Opened for operator commands

Closing the Connection to a Probe in POLL Mode

The CLOSE command closes the connection to a probe. CLOSE<cr>
Example:
close
line closed

Show Active Errors

Use the ERRS command to display probe error messages. The possible errors and their identifying numbers correspond to content of the status word of the I2C interface. See section Status Word on page 57.
ERRS<cr> Example (showing normal status, no active errors):
errs NO CRITICAL ERRORS NO ERRORS NO WARNINGS STATUS NORMAL
Example (showing probe in standby mode, no active errors):
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errs
NO CRITICAL ERRORS NO ERRORS NO WARNINGS STATUS 25 : Device in standby mode (set by user)
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After using the
RESET

Reset Probe

Use the RESET command to reset the probe. RESET<cr>
When the RESET command is given, the probe will restart as if it had just been powered on.

Restore Factory Sett ings

Use the FRESTORE command to restore the probe to its factory configuration. All user settings will be lost.
FRESTORE<cr>
NOTE
FRESTORE command, reset the probe using the
command.
Example:
pass 1300 frestore
Parameters restored to factory defaults
reset
GMP231 - Version 1.1.0 Vaisala Oyj 2012 - 2014
VAISALA ________________________________________________________________________ 49
User's Guide _______________________________________________________________________
3.3 V 5.0 V
SDA
SCL
GND
2 x 10 kΩ 2 x 10 kΩ
uP
Buffer and level shift
CHAPTER 5

I2C INTERFACE

This chapter describes the I2C interface implementation of the GMP231.

Overview

GMP231 has an inter-integrated circuit (I2C) interface for interfacing with the incubator’s control computer. GMP231 implements I2C slave functionality, with the incubator’s computer acting as the master. The interface can be used to read measurement values and status information, set operation parameters, and make adjustments.

Physical Inter f ace

The physical interface is a non-isolated 3-wire interface. Wires are SDA, SCL and ground. SDA and SCL lines are buffered. Ground is shared with power supply. There are small pull-up resistors for SCL and SDA. Connector is 8 pin male M12. Maximum cable length should not exceed 5 m and maximum capacitance between communication lines and ground should not exceed 500 pF.
For connector pinout and wiring information, see section Wiring on page
24.
1403-149
50 ___________________________________________________________________ M211501EN-C
Figure 12 Hardware Schematic
Chapter 5 _______________________________________________________________ I2C Interface
0 0 0 1 0 0 1
R/W
Device type
Sub-address
Read/write bit (LSB)
0 0 0 0 1 0 0
1
MSB
Device type
Sub-address
Make sure there are no addressing conflicts if on the same bus page 67

Communication Parameters

GMP231 supports maximum 50 kHz clock speed. Protocol bits are sent most significant bit (MSB) first. Parameter bytes are sent using little endian order.

Addressing

GMP231 uses 7-bit addressing. The address consists of:
- 4-bit device type identifier part (default “0001” for GMP231)
- 3-bit sub address (default “001”) The full 7-bit default address is “0001001” (09h). In I2C communication,
the address should be provided by the master in the standard way after the I2C start condition, with the read/write bit as the least significant bit (LSB).
Table 12 GMP231 I2C Address
NOTE
The I2C implementation of the GMP231 also includes the address inside the message frame. The purpose of this is to make the I2C implementation easier, since the I2C address can be lost by the I2C hardware. This address is provided without the read/write bit, with zero as the MSB.
Table 13 GMP231 Device Address
other I2C devices are put
. The GMP231 address can be changed, see Table 40 on
.
VAISALA ________________________________________________________________________ 51
User's Guide _______________________________________________________________________
Message Segment
Length
Content
Start
I2C start condition.
I2C address
1 byte
See Table 12 on page 51.
Command
1 byte
Identifier of command.
Device address
1 byte
See Table 13 on page 51.
Frame length
1 byte
Length of invoke message in bytes
5 bytes.
Data
Variable length
Content and length depending on the
invoke message.
Checksum
2 bytes
See section Checksum on page 56.
Stop
I2C stop condition

Communication Flow

Basic communication flow always includes I2C write and read commands. First the master writes a command to the slave device, and then the master reads the results of that command from the slave.
When the master reads data from the slave, there is an ACK/NACK-bit in the status byte that informs the master whether or not communication was success. ACK is defined as zero and NACK is defined as one in the logical level.
NOTE
This ACK/NACK refers to the message level acknowlegdement. I2C protocol includes a separate byte level acknowledgement.
Command messages sent by the master are called invokes. Replies sent by the slave are called responses. Note that also responses include the device address.
Table 14 Invoke Message in GMP231 I2C Interface
(excluding I2C address, including CRC). Minimum invoke frame length is
command. May be left out if the command contains no data in the
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Chapter 5 _______________________________________________________________ I2C Interface
Message Segment
Length
Content
Start
I2C start condition.
I2C address
1 byte
See Table 12 on page 51.
Status
1 byte
See section Status B yte on page 56.
Command
1 byte
Identifier of command that was used in
invoke), the command code is FFh.
Device address
1 byte
See Table 13 on page 51.
Frame length
1 byte
Length of response message in bytes
6 bytes.
Data
Variable length
Content and length depending on the command.
Checksum
2 bytes
See section Checksum on page 56.
Stop
I2C stop condition
Table 15 Response Message in GMP231 I2C Interface
the invoke that the slave is responding to. If the slave is in Idle state (no valid
(excluding I2C address, including CRC). Minimum response frame length is

GMP231 State Machine

The main and initial state of the GMP231 is Idle, and it will change to WaitResponse state only when a valid invoke is received. In the WaitResponse state, the GMP231 expects to see an I2C read operation from the master. After seeing a read operation ,the GMP231 outputs its response with ACK/NACK and status signals.
If GMP231 is in WaitResponse state and master sends a new invoke, the GMP231’s response to the previous invoke is lost. When the master sends the next I2C read command, the GMP231 sends it the response to the latest invoke.
If GMP231 is in Idle state and the master sends an I2C read, GMP231 responds with a NACK-signal. This tells the master that the data which the master may have received in same I2C read is not valid.
If the GMP231 receives an invalid invoke, it goes to the Idle state. An invoke message can be invalid because of an unknown command, erroneous CRC, or invalid message length.
VAISALA ________________________________________________________________________ 53
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Wait
Response
Idle
Valid Invoke
Valid Invoke
Response
NACK
Response
ACK + data
Bad Invoke
Bad Invoke
Response
NACK
Master
Slave
Get_Parameter,CO2_ID
I2C write
Get_Parameter,CO2_ID,549, ACK
I2C read
1403-146
Figure 13 GMP231 State Machine

Examples of Communication Flow

The basic data transfer communication flows are presented in the figures below. Each arrow represents an I2C read or write operation The examples are simplified presentations. For actual message content, see section Commands on page 58.
For example, Figure 14 below shows the following message sequence:
1. The master invokes the Get_Parameter command to read the CO2
parameter using an I2C write operation. This command prepares the slave to wait for a read operation from the master.
2. The master begins an I2C read operation to read the results of the
Get_Parameter CO2 command. The slave sends the requested CO2 result and an ACK signal to the master.
54 ___________________________________________________________________ M211501EN-C
1403-116
Figure 14 Get_Parameter with ACK
Chapter 5 _______________________________________________________________ I2C Interface
The a
Master
Slave
Set_Parameter,Pressure_ID,1013.25
I2C Write
Set_Parameter,Pressure_ID,ACK
I2C Read
Master
Slave
Get_Parameter,CO2_ID
I2C Write
Get_Parameter,CO2_ID,nan,NACK
I2C Read
Master
Slave
Get_Parameter,CO2_ID
I2C Write
Get_Parameter, CO2_ID, 665, Alarm bit =1, ACK
I2C Read
Get_Parameter,Status_ID
I2C Write
Get_Parameter,Status_ID,statusword,ACK
I2C Read
1403-163
Figure 15 Set_Parameter with ACK
1403-118
Figure 16 Get_Parameter with NACK
NOTE
VAISALA ________________________________________________________________________ 55
1403-117
Figure 17 Get_Parameter with Alarm
larm can be any of the state bits in the status byte.
User's Guide _______________________________________________________________________
Operation
Minimum delay
Normal delay between invoke and response
10 ms
Delay when write to non-volatile memory
300 ms
Bit#
Description
0
ACK/NACK
1
Critical error
2
Error
3
Warning
4
Status
5 6 7

Timing

The minimum time delay that the master must wait between the invoke and response messages depends on the operation. If the operation includes a write to the non-volatile memory, it takes more time than other operations.
Table 16 Timing

Status Byte

The status byte gives the master device information about the slave device’s state, and information about the communication status with the ACK/NACK bit.
The status byte has bits for signaling Status, Warning, Error and Critical error statuses. These bits are cleared when the status word is read. Bits are set when the corresponding status or error state changes in the slave device.
Table 17 Status Byte

Checksum

GMP231 uses a CRC16-CCITT checksum in its protocol frame. CCITT (x.25) polynomial is X16+X12+X5+1 = 11021h. Initial value is 0000h and the final value is XORed with FFFFh. The checksum uses a bit reversed algorithm.
When the invoke message is received, the checksum is calculated using bytes from the command byte to the last byte of the data field. The checksum needs to be valid before data can be accepted. If the checksum is not valid, the message is rejected and the internal state of the GMP231 is set to Idle.
When the response message is transmitted, the checksum is calculated using bytes from the status byte to the last byte of the data field.
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Chapter 5 _______________________________________________________________ I2C Interface
Bit#
Type
Purpose
0
Critical Error
Program memory corrupted (CRC error)
1
Critical Error
Parameter memory corrupted (CRC error)
2
Error
Low IR current
3
Error
4 Error
Low supply voltage
5
Error
Internal 30V voltage error
6
Error
Low input (RX) signal
7
Error
Internal 8V voltage error
8
Error
Too high input (RX) signal (ADC dynamic range)
9
Error
Pressure sensor communication error
10
Error
Pressure sensor out of range
11
Error
Incubator temperature too high for operation
12
Error
CO2 measurement out out range
13
Error
Sensor heater error
14
Error
IR source temperature error
15
Warning
16
Warning
17
Warning
18
Warning
19
Warning
20
Warning
Low input signal
21
Status
22
Status
23
Status
24
Status
25
Status
26
Status
27
Status
28
Status
29
Status
30
Status
31
Status

Status Word

The status word is used to monitor the status of the GMP231 device. It can be read in the same way as any other slave parameter. The status word is used as a 32-bit long bit field, where each bit represents a state of some error or other essential status.
Changes in the status word bits can be monitored by reading the status byte. See section Status Byte on page 56.
Table 18 Status Word Content
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Message Segment
Length
Content
I2C address
1 byte
I2C address (write)
Command ID
1 byte
Always 80h
Device address
1 byte
See Table 13 on page 51
Frame length
1 byte
Always 05h
Checksum
2 bytes
See section Checksum on page 56
Message Segment
Length
Content
I2C address
1 byte
I2C address (read)
Status
1 byte
See section Status B yte on page 56
Command ID
1 byte
Always 80h
Device address
1 byte
See Table 13 on page 51
Frame length
1 byte
Always 0Ah
Data
1 byte
Device version
1 byte
Protocol frame version
1 byte
Command set version
1 byte
Parameter set version
Checksum
2 bytes
See section Checksum on page 56

Commands

Get_Interface_Version

Get_Interface_Version command (ID 80h) reads the interface version information. This command is recommended for verifying version compatibility before reading or writing parameters.
Table 19 Get_Interface_Version Invoke Message
Table 20 Get_Interface_V ersi on Res p on se Message
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Chapter 5 _______________________________________________________________ I2C Interface
Message Segment
Length
Content
I2C address
1 byte
I2C address (write)
Command ID
1 byte
Always 81h
Device address
1 byte
See Table 13 on page 51
Frame length
1 byte
Always 06h
Data
1 byte
ID of parameter to be read
Checksum
2 bytes
See section Checksum on page 56
Message Segment
Length
Content
I2C address
1 byte
I2C address (read)
Status
1 byte
See section Status B yte on page 56. If NACK bit is set in the status byte.
Command ID
1 byte
Always 81h
Device address
1 byte
See Table 13 on page 51
Frame length
1 byte
Varies according to data length, 07h ... 39h.
Data
1 byte
ID of parameter
1 ... 50 bytes
Value of parameter. If requested bytes are left out of the response.
Checksum
2 bytes
See section Checksum on page 56

Get_Parameter

Get_Parameter command (ID 81h) reads parameter values. You can use it to read both measurement results and operational parameters. If the master tries to read more bytes than message size, the slave sends FFh bytes.
Table 21 Get_Parameter Invoke Message
Table 22 Get_Parameter Response Message
requested parameter ID was unknown,
parameter ID is unknown, these data
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User's Guide _______________________________________________________________________
Message Bytes (hex)
Content
12
I2C address
81
Get_parameter command
09
Device address
06
Frame length
0A
CO2 Parameter ID
AA
CRC high
9F
CRC lo
Message Bytes (hex)
Content
13
I2C address
00
Status byte (no errors, ACK)
81
Get_parameter command
09
Device address
0B
Frame length
0A
CO2 Parameter ID
69
CO2 value 653.6314 ppm
68
23
44
75
CRC high
7D
CRC lo
Example: Read CO2 Measurement Result
Table 23 Get_Parameter Invoke Message Example
Table 24 Get_Parameter Response Message Example
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Chapter 5 _______________________________________________________________ I2C Interface
Message Segment
Length
Content
I2C address
1 byte
I2C address (write)
Command ID
1 byte
Always 82h
Device address
1 byte
See Table 13 on page 51
Frame length
1 byte
Varies according to data length, 07h ... 38h.
Data 1 byte
Parameter ID
1 ... 50 bytes
Parameter value
Checksum
2 bytes
See section Checksum on page 56
Message Segment
Length
Content
I2C address
1 byte
I2C address (read)
Status
1 byte
See section Status B yte on page 56.
Command ID
1 byte
Always 82h
Device address
1 byte
See Table 13 on page 51
Frame length
1 byte
Always 08h.
Data 1 byte
Parameter ID
1 byte
Return code. See Table 27 below.
Checksum
2 bytes
See section Checksum on page 56
Code
Meaning
0
Ok 1 Unknown parameter ID
2
Not writeable parameter
3
Value field too long
4
Value field too short
5
Data value not accepted

Set_Parameter

Set_Parameter command (ID 82h) writes parameter values to non­volatile memory. You can use it to set the operational parameters of the GMP231. Depending on the change, the functionality of the GMP231 may not change immediately.
The length of the invoke message varies depending on the data length. The master must write as many bytes as indicated in the frame length of the invoke message. If the master tries to write a longer or shorter message, GMP231 rejects the message.
Table 25 Set_Parameter Invoke Message
Table 26 Set_Parameter Response Message
Table 27 Set_Parameter Retu rn C od es
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Message Bytes (hex)
Content
12
I2C address
82
Set_parameter command
09
Device address
0A
Frame length
10
Parameter ID of compensation temperature
00
Temperature 37C
00
14
42
0C
CRC high
6E
CRC lo
Message Bytes (hex)
Content
13
I2C address
04
Status byte (error active, ACK)
82
Set_parameter command
09
Device address
08
Frame length
10
Parameter ID of compensation temperature
00
Return code: Ok
D1
CRC high
CE
CRC lo

Example: Set Compensation Temperature

Table 28 Example Set_Parameter Invoke Message
Table 29 Example Set_Parameter Response Message
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Chapter 5 _______________________________________________________________ I2C Interface
Message Segment
Length
Content
I2C address
1 byte
I2C address (write)
Command ID
1 byte
Always 83h
Device address
1 byte
See Table 13 on page 51
Frame length
1 byte
Always 06h.
Data
1 byte
Parameter ID
Checksum
2 bytes
See section Checksum on page 56
Message Segment
Length
Content
I2C address
1 byte
I2C address (read)
Status
1 byte
See section Status B yte on page 56.
Command ID
1 byte
Always 83h
Device address
1 byte
See Table 13 on page 51
Frame length
1 byte
Always 12h.
Data
1 byte
Parameter ID
1 byte
Parameter datatype. See Table 32 below.
1 byte
Parameter length in bytes.
1 byte
Parameter persistence. Describes if the
Table 33 below.
8 bytes
Parameter name. If name is shorter 00h.
Checksum
2 bytes
See section Checksum on page 56
Code
Meaning
0
Unknown parameter ID
1
Byte
2
Integer (16-bit)
3
Unsigned Integer (16–bit)
4
Float (32-bit)
5
String
Code
Meaning
0
Void
1
Volatile
2
Non volatile

Get_Parameter_Info

Get_Parameter_Info command (ID 83h) reads the properties of a single parameter from the GMP231. The command is useful for adapting to parameters that have been added in a new software version. If the requested parameter ID is not valid, data type Unknown Parameter ID is returned.
Table 30 Get_Parameter_Info Invoke Message
Table 31 Get_Parameter_Info Response Message
parameter value is volatile (lost at reset) or non-volatile (survives reset). See
than 8 bytes, extra bytes are filled with
Table 32 Parameter Data Types
Table 33 Parameter Persistence
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Message Segment
Length
Content
I2C address
1 byte
I2C address (write)
Command ID
1 byte
Always 84h
Device address
1 byte
See Table 13 on page 51
Frame length
1 byte
Varies according to data length, 07h ... 0Bh.
Data
1 byte
Adjustment subcommand. See Table 36 below.
1 byte
Parameter to be adjusted. See Table 37 below.
4 bytes
Value of parameter. Used only with subcommands 2 and 3.
Checksum
2 bytes
See section Checksum on page 56
Message Segment
Length
Content
I2C address
1 byte
I2C address (read)
Status
1 byte
See section Status B yte on page 56.
Command ID
1 byte
Always 84h
Device address
1 byte
See Table 13 on page 51
Frame length
1 byte
Always 07h.
Data
1 byte
Return code. See Table 38 on page 65.
Checksum
2 bytes
See section Checksum on page 56.
Code
Adjustment operation
0
Start 1 point adjustment
1
Start 2 point adjustment
2
Record measured point 1, reference value is given in parameter
3
Record measured point 2, reference value is given in parameter
4
Cancel adjustment (previous adjustment is reverted)
5
End (adjustment is saved and new values are taken in use)
6
Revert to factory calibration (clear user adjustment)
Code
Purpose
0
All parameters (valid with revert to factory calibration)
1
CO2

Adjust

Adjust command (ID 84h) controls the user adjustment sequence of CO2 measurement.
Table 34 Adjust Invoke Message
Table 35 Adjust Response Message
Table 36 Adjustment Subcommands
Table 37 Adjustment Parameters
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Chapter 5 _______________________________________________________________ I2C Interface
Code
Meaning
0
Ok 1 Function not supported
2
Sequence error
3
Recorded-Reference difference too large
4
2-point adjustment: Points too close
5
Given reference value is invalid
Before implementing an adjustment sequence using the Adjust command, read the general instructions for calibration and adjustment in section Calibration
Table 38 Adjustment Return Codes

Adjusting Measurement

NOTE
and Adjustment on page 73.
Create the reference environment inside the chamber, and use the Adjust command to perform the adjustment sequence.
Adjustment can fail for a number of reasons. Refer to the list of return codes for the Adjust command in Table 38 above.

One Point Adj ustment

To perform a one point adjustment of carbon dioxide (CO2), measurement using I2C protocol, you must perform the following sequence:
1. Using the Adjust command, start 1 point adjustment for the
chosen parameter.
2. Place the sensor in the reference environment and wait until the measurement has stabilized.
3. Using the Adjust command, record the measured point and give the reference value.
4. Use the Adjust command to end the adjustment.
VAISALA ________________________________________________________________________ 65
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Data type name
Size (Bytes)
Other
Byte
1
Value range 0...255
Integer
2
Value range -32768...32767.
Unsigned integer
2
Value range 0…65535
Long integer
4
Value range
−2,147,483,648…2,147,483,647
Unsigned long integer
4
Value range 0…4,294,967,295
Float
4
According to IEEE-754. N a n is available.
String
Max. 50
All characters accepted (00h…FFh)

Two Point Adjustment

To perform a two point adjustment of CO2 measurement using I2C protocol, you must perform the following sequence:
1. Using the Adjust command, start 2 point adjustment for CO2.
2. Supply the low concentration CO2 reference gas to the sensor and wait for three minutes until the measurement has stabilized.
3. Using the Adjust command, record the first measured point and give the first reference value.
4. Supply the high concentration CO2 reference gas to the sensor and wait for three minutes until the measurement has stabilized.
5. Using the Adjust command, record the second measured point and give the second reference value.
6. Use the Adjust command to end the adjustment.

Data Registers

The register table describes all available parameters and their properties. The properties are: parameter meaning, ID, name, data type, length and persistence. Persistence defines if the parameter is saved in eeprom (non­volatile memory) or in RAM. Make sure not to write excessively to the eeprom, as it has a maximum lifetime of approximately 30000 cycles.

Data Formats

Table 39 Data Formats
(7FC00000) is returned if no value
NOTE
NOTE
66 ___________________________________________________________________ M211501EN-C
Maximum string size refers to maximum communication buffer size. The actual reserved storage space for each parameter can be seen in Table 40 on page 67.
Integers and floating point numbers are sent LSB first.
Chapter 5 _______________________________________________________________ I2C Interface
Meaning
Name
ID
Size (bytes)
Type
Read/ Write
Persistent
Other Factory information
Device address
ADDR
0 1 Byte
R
Yes
Default is 09h.
Device serial number
SNUM
1
12
Str R Yes
Example: A1234567
Sensor number
SSNUM
2
12
Str R Yes
Example: B1234567
Component board number
CBNUM
3
12
Str R Yes
Example: C1234567 Software version number
VERS
4
12
Str R Yes
Example: 1.2.3.4567
Factory adjustment date Year
ADATEY
5 2 Uint R Yes
Example: 2014
Factory adjustment date Month
ADATEM
6 1 Byte
R
Yes
Example: 3
Factory adjustment date Day
ADATED
7 1 Byte
R
Yes
Example: 29
General parameters and variables
Device status word
STATUS
8 4 Str R No
See section Status Word on page 57.
CO2 measurement mode
CO2_MODE
9 1 Byte
R/W
Yes
0 = Standby mode.
setting
Final CO2 result
CO2
10 4 Float
R
No
ppm CO2
Raw CO2 unfiltered)
CO2_RAW
11 4 Float
R
No
ppm CO2 Compensated CO2 (unfiltered)
CO2_COMP
12 4 Float
R
No
ppm CO2
CO2 measurement
CO2_FILT
13 1 Byte
R/W
Yes
Range 0 … 1, 1 = filtering (default)
Sensor heating
HEAT
14 1 Byte
R/W
Yes
Range 0…1 1 = heating (default)

Register Table

Table 40 GMP231 Register Table
(uncompensated,
filtering
Measurement and probe heating is off 1 = Measurement on Note: Internal logic can override this
0 = no filtering
0 = no heating
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Meaning
Name
ID
Size (bytes)
Type
Read/ Write
Persistent
Other Compensation settings
Temperature
TC_MODE
15 1 Byte
R/W
Yes
0 = Compensation off
sensor temperature
Compensation temperature
T_COMP
16 4 Float
R/W
No
Celsius
Measured temperature (internal sensor)
T
17 4 Float
R
No
Celsius
Pressure compensation
PC_MODE
18 1 Byte
R/W
Yes
0 = Compensation off
(default)
Compensation pressure
P_COMP
19 4 Float
R/W
No
hPa
Measured pressure (internal sensor)
P
20 4 Float
R
No
hPa
Humidit y compensation
RHC_MODE
21 1 Byte
R/W
Yes
0 = Compensation off value (default)
Compensation Humidity
RH_COMP
22 4 Float
R/W
No
%RH
Oxygen compensation
O2C_MODE
23 1 Byte
R/W
Yes
0 = Compensation off
value (default)
Compensation Oxygen
O2_COMP
24 4 Float
R/W
No
%02
Adjustment settings
Reference CO2 point 1
CO2_RP1
25 4 Float
R/W
Yes
ppm CO2 0 ppm
Measured CO2 point 1
CO2_MP1
26 4 Float
R
Yes
ppm CO2 0 ppm
Reference CO2 point 2
CO2_RP2
27 4 Float
R/W
Yes
ppm CO2 20%
Measured CO2 point 2
CO2_MP2
28 4 Float
R
Yes
ppm CO2 20%
Reference temperature point 1
T_RP1
29 4 Float
R/W
Yes
Celsius 0C
Measured temperature point 1
T_MP1
30 4 Float
R
Yes
Celsius 0C
Reference pressure point 1
PRE_RP1
31 4 Float
R/W
Yes
hPa 1013.25
Measured pressure point 1
PRE_MP1
32 4 Float
R
Yes
hPa 1013.25
Analog output settings
Analog output mode
A_MODE
33 1 Byte
R/W
No
0 = Off (0 mA)
value
Analog output test current
A_TC
34 4 Float
R/W
No
0 … 25 mA
Analog output error state current
A_EC
35 4 Float
R/W
Yes
0 … 25 mA
Analog output low end current
A_LC
36 1 Byte
R/W
Yes
0 = 0 mA 1 = 4 mA
Analog output scale low (0/4 mA)
A_LOW
37 4 Float
R/W
Yes
ppm CO2
Analog output scale high (20 mA)
A_HI
38 4 Float
R/W
Yes
ppm CO2
compensation mode
mode
mode
mode
1 = Use temperature setpoint value (default) 2 = Use Internal
1 = Use pressure setpoint value 2 = Use internal pressure sensor
1 = Use RH setpoint
1 = Use oxygen concentration setpoint
68 ___________________________________________________________________ M211501EN-C
1 = Testmode 2 = Normal (default) 3 = Locked to latest
Chapter 5 _______________________________________________________________ I2C Interface
Meaning
Name
ID
Size (bytes)
Type
Read/ Write
Persistent
Other Other
Persistent compensation values (used if volati le values are not given)
Compensation temperature
T_COMP2
39 4 Float
R/W
Yes
37 °C (default) Compensation pressure
P_COMP2
40 4 Float
R/W
Yes
1013.25 hPa (default)
Compensation Humidity
RH_COMP2
41 4 Float
R/W
Yes
90 %RH (default)
Compensation Oxygen
O2_COMP2
42 4 Float
R/W
Yes
19.7 %O2 (default)
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CHAPTER 6

MAINTENANCE

This chapter provides information that is needed in the basic maintenance of the GMP231.

Cleaning

When correctly installed, the GMP231 is minimally exposed to contaminants in the chamber. There is little reason to perform cleaning other than normal chamber sterilization, and changing the filter and/or silicone plug if they appear contaminated. See the following sections for instructions:
CAUTION
- Changing the Filter on page 71.
- Changing the Silicone Plug on page 72.
The CARBOCAP® sensor of the GMP231 is well protected by the PTFE filter, and it can tolerate some dirt on the optics as the measurement is compensated for the reduction of signal.
When changing the filter, you can use clean instrument air to gently blow any loose dirt and filter material away from the sensor. Do not attempt to clean the optical surfaces of the sensor in any other manner.

Chemical Toleran ce

GMP231 tolerates the following sterilization chemicals:
- DMSO
- IPA (70% Isopropyl Alcohol, 30% water)
- H2O2 (2000 ppm), non-condensing
- Ethanol
- Acetic acid
CAUTION
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The electronics housing of the GMP231 is not sealed, so do not expose it to these chemicals. If necessary, you can clean the housing by wiping with a moist cloth.
Chapter 6 _______________________________________________________________ Maintenance

Changing the Filter

Change the filter to a new one if it shows visible signs of contamination.
1. Pull the white PTFE filter away from the sensor. Rotating the filter
slightly makes it easier to detach.
2. Use clean instrument air to gently blow any loose dirt and filter
material away from the sensor.
3. Take a new clean filter and push it onto the sensor. If you are using
the Vaisala silicone plug for sealing, push and rotate the filter slightly to make sure the filter reaches below the edge of the plug.
1403-156
Figure 18 Changing the Filter
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Changing the Silicone Plug

Change the silicone plug if it shows visible signs of contamination. It is best to replace the filter also.
1. Pull the white PTFE filter away from the sensor. Rotating the filter slightly makes it easier to detach
2. Lift one edge of the plug and pull it away from the installation tube.
3. Use clean instrument air to gently blow any loose dirt and filter material away from the sensor.
4. Clean the installation tube and the wall around the plug.
5. Place the new silicone plug over the sensor and push it into the installation tube.
6. Take a new clean filter and push it onto the sensor. Push and rotate the filter slightly to make sure it is fully in place.
1403-157
Figure 19 Changing the Silicone Plug
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Chapter 6 _______________________________________________________________ Maintenance
Performing an accurate preparation. Instead of doing it yourself, you can also have a Vaisala service center calibrate and adjust your GMP231. For contact information, see section
C as calibration gas or GMP231 so that is measures accurately is referred to as

Calibration and Adjustment

Calibrate and adjust the CO2 measurement of the GMP231 as needed. Before starting, read through this section completely so that you are aware of your options, and the main factors that affect the result.
NOTE
NOTE
calibration and adjustment takes some time and
Product Returns on page 84.
alibration means comparing the GMP231 to a known reference, such
a reference instrument. Correcting the reading of the
adjustment.

Calibration Setup

GMP231 is designed to be calibrated while it remains installed through an incubator wall. If you calibrate the GMP231 without it being installed, note the following:
- If you are using a calibration gas, prevent it from entering the
electronics housing of the GMP231. Otherwise it will diffuse through the probe to the sensor and alter the CO2 reading.
- Make sure the PTFE filter is in place when performing calibration.
- If you are using the calibration adapter accessory to feed the
calibration gas to the sensor, note that you must have the silicone plug and the PTFE filter installed on the probe. Without both of them in place, the calibration adapter will not function properly. Vaisala recommends replacing the silicone plug and the PTFE filter before calibration.
1403-147
Figure 20 Inserting the Calibration Adapter over the Filter
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Using Ambient Air as Reference
You can use ambient air to do a 1-point calibration with the background CO2 level as your reference. You will need a calibrated reference instrument to compare against, for example a GM70 hand-held meter with a calibrated GMP222 probe.
With the GMP231 and the reference instrument in the same space (for example, inside the incubator with the door open), allow the measurement to stabilize before comparing the readings. Try to provide as stable environment as you can during this time. Avoid working around the incubator during this time.
Using a Calibration Gas as Reference
There are two easy ways to use a calibration gas as a reference:
- You can supply the gas to the GMP231 using the calibration adapter
accessory. Gas flow should be in the range 0.5 ... 1.1 l/min, recommendation is 1 l/min. Allow the measurement to stabilize for three minutes before starting the calibration.
- You can fill the entire incubator with the calibration gas.
To perform a two-point adjustment, you need two calibration gases: one gas that is below 2 %CO2 (low-end reference) and one that is above 2 %CO2 (high-end reference).
When supplying the gas from a gas bottle, make sure the gas bottle has stabilized to room temperature before starting.

Effect of Environmental Compensations

GMP231 has various environmental compensations that improve its CO2 measurement accuracy (see section Environmental Compensation on page 17). As the calibration and adjustment environment may differ from the actual measurement environment, you must make sure that the compensation settings are properly set. Here are some key points to remember:
- Pressure and temperature compensations have a significant effect on
accuracy. If you are using setpoint values instead of the values from built-in pressure and temperature sensors, make sure to correct the setpoints so that they corresponds to your calibration situation. Consider switching the compensations to use the internal sensors when calibrating, and then switching back when calibration and adjustment is done.
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Chapter 6 _______________________________________________________________ Maintenance
- The effect of background gas compensations for humidity and oxygen
may be significant when using calibration gases, since they are often dry and oxygen-free. For example, pure nitrogen gas is typically used as a convenient 0 ppm CO2 reference.
- Remember to restore the normal compensation settings after
completing calibration and adjustment. If you are integrating the calibration functionality of the GMP231 as part of the incubator’s control software, also implement proper handling of the environmental compensations.

Limits of Adjustment

GMP231 limits the amount of adjustment that is allowed to the CO2 measurement. The maximum correction that you can apply is 1000 ppm + 25 % of the probe’s uncorrected reading. Previous user adjustments do not affect this limit (correction is not cumulative). This feature limits the possible error introduced by incorrect adjustment.
For example, if you are adjusting using a 5 %CO2 calibration gas (50000 ppm), the maximum correction you can apply is approximately 13500 ppm. Attempting to apply a greater adjustment will fail. Notification of failure from the GMP231 depends on the interface you are using for adjustment.

Adjustment Types

You can adjust the CO2 measurement of the GMP231 in one or two points.
- One-point adjustment is recommended if you are interested in
maintaining a fixed CO2 level inside the chamber. For best result, use a calibration gas with a CO2 concentration that is close to the intended level.
- Two-point adjustment is recommended if you typically measure a
variable CO2 level.
Available adjustment functions depend on the interface you use to operate the GMP231. If you want to integrate the functionality into the incubator’s control system, the I2C interface and the Vaisala industrial protocol are recommended. If you want to compare the reading of the GMP231 to a reference instrument as adjust it accordingly, use an MI70 hand-held indicator and a reference probe.
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I2C Interface
I2C interface supports one and two-point adjustment sequences as well as configuration of the environmental compensation settings using the Get_Parameter and Set_Parameter commands. See the following sections:
- Adjust on page 64
- Get_Parameter on page 59
- Set_Parameter on page 61
Vaisala Industrial Protocol
Vaisala industrial protocol supports one and two-point adjustment with the CCO2 command. You can also adjust the internal pressure and temperature measurements with a simple offset correction. Configuration of the environmental compensation settings can be done using serial line commands. See the following sections:
- Calibration Commands on page 41
- Changing Measurement Settings on page 35
MI70 Hand-Held Indicator
MI70 hand-held indicator supports one-point adjustment, either using a calibration gas or using a reference instrument that is connected to the MI70. See section Calibration and Adjustment with MI70 Indicator on page 79.
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Chapter 7 _________________________________________________ Operating with MI70 Indicator
CHAPTER 7

OPERATING WITH MI70 INDICATOR

Overview of MI70 Support

GMP231 is compatible with instruments that utilize the MI70 Indicator, for example the GM70 Hand-Held Carbon Dioxide Meter. The MI70 indicator is a convenient service tool for viewing the measurement readings, adjusting the environmental compensation settings, and performing calibration and one-point adjustment.
1403-120
Figure 21 CO2 Reading on MI70 Screen

Connecting GMP231 to MI70 Indicator

1. If the GMP231 is installed in an incubator, disconnect the
incubator’s cable from the 8-pin M12 connector. Note that GMP231 can remain physically connected to the incubator.
2. If the MI70 indicator is on, turn it off.
3. Connect the GMP231 to the MI70 indicator using the GMP231
service cable for MI70. See section Spare Parts and Accessories on page 87.
4. Turn on the MI70 indicator. MI70 detects the probe and proceeds
to show the measurement screen. The parameters measured by GMP231 will start to show valid measurement results after a few seconds.
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Changing Environmental Compensati on Settings with MI70 Indicator

You can see the compensation values that are currently used by the GMP231 by selecting them as display quantities from Main menu > Display > Quantities and Units. The quantities are as follows:
- Tcomp: currently active temperature compensation value.
- Pcomp: cu rr ent l y active p ress ure co mp ens ati on val ue.
- Ocomp: currently active oxygen concentration compensation value.
- Hcomp: currently active relative humidity compensation value.
NOTE
1403-143
Figure 22 CO2 Reading with Tcom p and Pcomp on MI70 Screen You can change the compensation settings from Main menu > Settings
> Measurement settings. For more information about the possible
settings and their meaning, see Environmental Compensation on page 17.
1403-137
Figure 23 GMP231 Compensation Settings on MI70 Screen
When you turn a compensation off, GMP231 still shows a value for the corresponding display quantity (for example, Pcomp shows 1013.2 hPa). This is the default compensation value that is mathematically neutral for the probe’s internal compensation model.
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Chapter 7 _________________________________________________ Operating with MI70 Indicator
Before using the MI70 indicator for calibration and adjustment, read the instructions in section
M are properly set for your calibration environment; see section Environmental Compensation Settings with MI70 Indicator
When two probes are connected to the MI70 numerals “I” and “II” to indicate which port the parameter or function in question is connected to.

Calibration and Adjustment with MI70 Indicator

NOTE
Calibration and Adjustment on page 73.
ake sure that the environmental compensation settings of the GMP231
Changing
on page 78.
NOTE
indicator, it uses Roman
1-Point Adjustme nt with an MI70­Compatible Reference Probe
1. Connect the GMP231 to Port I of the MI70 indicator.
2. Connect the calibrated reference probe to Port II. Make sure the
reference probe is in the same environment as the GMP231’s sensor.
3. If you are using the calibration adapter to feed a calibration gas to
the GMP231, you must feed the same gas to the reference probe also. Refer to the documentation of your reference probe on how to do this, and what accessories you need.
4. Turn on the MI70 indicator.
5. Start the adjustment sequence from Main menu > Functions >
Adjustments.
1403-131
Figure 24 Functions Menu
6. MI70 notifies you that automatic power off is disabled during
adjustment mode, press OK to acknowledge.
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7. To proceed with the adjustment, select the CO2(I) parameter in the Select Quantity screen.
In the Select Quantity screen you can also view the currently used compensation values, and the Last adjustment date information. You can update the date and text using the CDATE and CTEXT commands on the serial line.
8. You may be prompted to check the environmental settings of the reference probe before proceeding. Press Yes to check the settings and Exit when you have checked and corrected the settings.
9. The adjustment mode is now active, and you can see the measured CO2 readings and their difference on the screen. Allow the measurement to stabilize. To proceed with the adjustment, press Adjust.
1403-134
Figure 25 Comparing Readings in MI70 Adjustment Mode
10. Select To same as CO2(II).
1403-142
Figure 26 Selecting the Adjustment Mode
11. You will be prompted if you really want to adjust. Select Yes.
12. If the adjustment is successful, the MI70 will show the text Adjustment Done, after which you will return to the adjustment mode. At this point you can press Back and Exit to leave the adjustment mode. The adjustment is now completed.
If the adjustment cannot be applied, the MI70 will show the text Cannot adjust, possibly followed by a text stating the reason. A possible reason for an adjustment failure is attempting to apply a very large correction to the reading. See section Limits of Adjustment on page 75.
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Chapter 7 _________________________________________________ Operating with MI70 Indicator

1-Point Adjustment with a Reference Gas

1. Connect the GMP231 to Port I of the MI70 indicator.
2. Feed a calibration gas to the GMP231 using the calibration adapter
accessory. If you are using ambient air as the calibration gas, you must have a reference meter in the same environment to verify the CO2 concentration.
3. Turn on the MI70 indicator.
4. Start the adjustment sequence from Main menu > Functions >
Adjustments.
1403-131
Figure 27 Functions Menu
5. MI70 notifies you that automatic power off is disabled during
adjustment mode, press OK to acknowledge.
6. Select the CO2 parameter when prompted.
7. You may be prompted to check the environmental settings of the
reference probe before proceeding. Press Yes to check the settings and Exit when you have checked and corrected the settings.
8. The adjustment mode is now active, and you can see the measured
CO2 reading on the screen. To proceed with the adjustment, press Adjust.
1403-132
Figure 28 MI70 Adjustment Mode
9. Select 1-point adjustment.
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1403-126
Figure 29 Selecting the Adjustment Mode
10. You will be prompted if you really want to adjust. Select Yes.
11. You are now in the 1-point adjustment screen. Allow the measurement to stabilize and press Ready.
12. Enter the CO2 concentration of the reference gas and press OK.
1403-125
Figure 30 Entering the Reference CO2 Concentration
13. You will be prompted if you really want to adjust. Select Yes.
14. If the adjustment is successful, the MI70 will show the text Adjustment Done, after which you will return to the adjustment mode. At this point you can press Back and Exit to leave the adjustment mode. The adjustment is now completed.
If the adjustment cannot be applied, the MI70 will show the text Cannot adjust, possibly followed by a text stating the reason. A possible reason for an adjustment failure is attempting to apply a very large correction to the reading. See section Limits of Adjustment on page 75.
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Chapter 8 ____________________________________________________________ Troubleshooting
Problem
Possible Cause
Remedy
Analog output reading
Analog output is in
State on page 84
Remove the cause of the
function.
Probe outputs stars
Incorrect supply
Check the power supply.
on the serial line.
Unsuitable operating
Verify that the operating specified operating limits.
Unable to access
Incorrect wiring. Check that the RS-485
on page 24.
Power cycle or reset the probe and try again.
Probe in POLL mode
Issue the ?? command to
line to the probe’s address.
CO2 measurement not
Condensation on the
Remove the PTFE f ilter and
occurrence.
CHAPTER 8

TROUBLESHOOTING

This chapter describes possible problems, their probable causes and remedies, and provides contact information for technical support.

Problem Situations

Table 41 Possible Problem Situations and Their Remedies
is unchanging and appears incorrect.
"****" on serial line instead of measurement data.
probe on the RS-485 line.
working.
error state. See section Analog Output Error
voltage.
environment.
with unknown address.
sensor.
error state and the analog output will recover its normal
Check the active errors using the ERRS command
environment is within
connection is wired according to section
make the probe output its information. The use the OPEN command to open a
check if condensation has formed on the sensor. If yes, dry out the condensation with instrument air and insert a new dry filter. Keep the probe powered and operating to prevent re-
Wiring
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Analog Output Error State

GMP231 sets the analog output channel into a defined error level instead of the measured result in two situations:
- Probe detects a measurement malfunction. This means an actual
measurement problem, such as sensor damage or unsuitable environmental conditions.
- Measured value(s) are well outside the scaled output range. For a
more detailed explanation, see section Analog Output Overrange Behavior on page 19.
The default error level depends on the output type:
- For 4 ... 20 mA output, the default error level is 3.6 mA
- For 0 ... 20 mA output, the default error level is 23 mA.
The probe resumes normal operation of the analog output when the cause of the error state is removed.

Technical Support

For technical questions, contact the Vaisala technical support by e-mail at
helpdesk@vaisala.com. Provide at least the following supporting
information:
- Name and model of the product in question
- Serial number of the product
- Name and location of the installation site
- Name and contact information of a technically competent person who
can provide further information on the problem.

Product Returns

WARNING
When returning a product for calibration or repair, make sure it has not been exposed to dangerous contamination, and is safe to handle without special precautions.
If the product must be returned for service, see www.vaisala.com/returns. For contact information of Vaisala Service Centers, see
www.vaisala.com/servicecenters.
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Chapter 9 _____________________________________________________________ Technical Data
Property
Description / Value
Measurement range
0 ... 20 %CO2
Accuracy at 37 °C, 1013 hPa
Repeatability at 0 ... 8 %CO2
±0.1 %CO2
Repeatability at 8 ... 12 %CO2
±0.2 %CO2
Repeatability at 12 ... 20 %CO2
±0.4 %CO2
Non-linearity at 0 ... 20 %CO2
±0.1 %CO2
Calibration uncertainty at 5 %CO2
±0.1 %CO2
Temperature dependence
with compensation at 3 … 12 %CO2, 20 … 60 °C
±0.1 %CO2
0 … 16 %CO2, 0 … 70 °C
±(0.1 %CO2 + 0.05 % of reading / °C)
16 … 20 %CO2, 0 … 70 °C
±1.5 %CO2
without compensation (typical)
-0.4 % of reading / °C
Pressure dependence
with compensation at 3 … 12 %CO2, 700 … 1100 hPa
±0.015 % of reading / hPa
0 … 20 %CO2, 500 … 1100 hPa
±(10 ppm + 0.020 % of reading) / hPa
without compensation (typical)
+0.15 % of reading / hPa
Humidity dependence
with compensation at 0 … 20 %CO2, 0 … 100 %RH
±0.9% of reading (37 °C)
without compensation (typical)
+0.05% of reading / %RH
O2 dependence
with compensation at 0 … 20 %CO2, 0…90 %O2
±0.6 % of reading
without compensation (typical)
-0.08 % of reading / %O2
Start-up time
10 s
Warm-up time for full spec.
1 min
Response time
T63
< 30 s
T90
< 50 s
Long-term stability
0 … 8 %CO2
< ±0.2 %CO2 / year
8 % ...12 %CO2
< ±0.5 %CO2 / year
12 % ... 20 %CO2
< ±1.0 %CO2 / year
CHAPTER 9

TECHNICAL DATA

This chapter provides the technical data of the GMP231.

Specifications

Table 42 Performance
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Property
Description / Value
Operating temperature of CO2 measurement
0 … 70 °C
Max. temperature durability in standby mode
up to +195 °C
Heat sterilization (+180 °C) durability
At least 120 cycles
Storage temperature
-40 … +75 °C
Pressure
Compensated
500 … 1100 hPa
Operating
< 1500 hPa
Humidity
0 … 100 %, non-condensing
Condensation preventio n
Sensor head heating when power on
Chemical tolerance
DMSO
Acetic acid
Electromagnetic compatibility
EN61326-1, Generic environment
Property
Description / Value
Operating voltage
When digital output in use
11…30 VDC
When analog output in use
20…30 VDC
Digital outputs
I2C 5 V
RS-485 (2-wire wi th Vaisala Industrial Protocol)
Analog output
0 … 20 mA (scalable) max. load 600 Ω
Power consumption
< 1 W (pulsed)
Property
Description / Value
Materials
Housing
Metal coated plastic ABS+PC
Inner tube
Aluminum
Probe tube
PPSU
Filter
PTFE
Housing classifications
Sensor head
IP54
Electronics housing
IP20
Connector
M12 / 8 pin
Weight
Probe with cable
200 g
Probe without cable
150 g
Dimensions
Probe tube max. diameter
30.2 mm
Probe tube min. diameter
24.8 mm
Probe tube length
118.5 mm
Sensor filter diameter
19 mm
Sensor filter length
12 mm
Table 43 Operating Environment
IPA (70% Isopropyl Alcohol, 30% water) H2O2 (2000 ppm), non-condensing Ethanol
Table 44 Inputs and Outputs
Table 45 Mechanics
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Chapter 9 _____________________________________________________________ Technical Data
Description
Order Code
M12 Connection Cable 0.9 m with open ends
DRW240977SP
M12 Connection Cable 0.6 m with Milli-Grid connector
ASM210903SP
Service cable for MI70
221801
USB PC connection cable
221040
PTFE filter
DRW240494SP
Silicone plug
DRW240015SP
Attachment bracket
DRW240247SP
Calibration adapter for GMP231
239523

Spare Parts and Accessori es

Table 46 Spare Parts and Accessories for GMP231
VAISALA ________________________________________________________________________ 87
*M211501EN*
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