Vaisala CARBOCAP Carbon Dioxide Probe GMP251 User Guide

M211799EN-F
User Guide
Vaisala CARBOCAPâ Carbon Dioxide Probe
GMP251
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
Visit our Internet pages at www.vaisala.com.
© Vaisala 2017
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.
Local rules and regulations may vary and
they shall take precedence over the
information contained in this manual.
Vaisala makes no representations on this
manual’s compliance with the local rules
and regulations applicable at any given
time, and hereby disclaims any and all
responsibilities related thereto.
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.
This product contains software developed
by Vaisala or third parties. 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.
Table of Contents
Table of Contents
1. About This Document........................................................................................ 7
1.1
Version Information............................................................................................... 7
1.2
Related Manuals..................................................................................................... 7
1.3
Documentation Conventions................................................................................ 8
1.4
Trademarks............................................................................................................. 8
1.5
Patent Notice.......................................................................................................... 8
2. Product Overview................................................................................................11
2.1
Introduction to GMP251 ........................................................................................11
2.2
Basic Features and Options.................................................................................12
2.2.1
Additional Features with Indigo Transmitters............................................ 12
2.3
Filter Options.........................................................................................................13
2.4
Operating Principle of CO2 Measurement......................................................... 14
2.5
Environmental Compensation.............................................................................15
2.5.1
Temperature Compensation......................................................................... 16
2.5.2
Pressure Compensation.................................................................................16
2.5.3
Background Gas Compensation................................................................... 17
2.6
Probe Startup........................................................................................................ 17
2.7
Filtering Factor......................................................................................................17
2.8
Analog Output Overrange Behavior.................................................................. 18
2.8.1
Analog Output Overrange Example............................................................ 18
2.9
Safety..................................................................................................................... 19
2.9.1
ESD Protection.............................................................................................. 20
2.10 Regulatory Compliances.................................................................................... 20
3. Installation............................................................................................................. 21
3.1
GMP251 Probe Dimensions.................................................................................. 21
3.2
Recommended Installation..................................................................................21
3.3
Installation Accessories........................................................................................21
3.3.1
243261SP Mounting Flange..........................................................................22
3.3.2
243257SP Mounting Clips.............................................................................23
3.3.3
ASM212017SP Spray Shield.......................................................................... 23
3.4
Power Supply....................................................................................................... 24
3.5
Wiring....................................................................................................................24
4. Vaisala Industrial Protocol............................................................................. 25
4.1
Overview...............................................................................................................25
4.2
Serial Interface Settings...................................................................................... 25
4.3
Physical Interface.................................................................................................25
4.4 Connecting with a Computer............................................................................. 25
4.4.1
Installing the Driver for the USB Service Cable......................................... 27
4.5
Accessing Serial Commands from Modbus or Analog Mode......................... 27
4.6 Enabling Modbus Mode from Vaisala Industrial Protocol...............................28
4.7
Changing From Digital Output to Analog Output...........................................28
4.8 Serial Commands.................................................................................................29
4.9 Device Information and Status............................................................................31
4.10 Serial Line Output and Communication........................................................... 34
4.11 Analog Output...................................................................................................... 41
4.12 Calibration and Adjustment............................................................................... 45
4.13 Environmental Compensation Commands...................................................... 49
4.14 Other Commands................................................................................................ 55
5.
Modbus...................................................................................................................57
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GMP251 User Guide
6. Using GMP251 with Indigo Transmitters.................................................. 59
6.1
Indigo Overview...................................................................................................59
6.1.1
Wireless Configuration Interface Overview...............................................60
6.2
Taking a Probe in Use with Indigo...................................................................... 61
6.2.1
Probe Compatibility......................................................................................62
6.3
Attaching Probes and Cables.............................................................................63
6.4 Connecting to Wireless Configuration Interface............................................. 64
6.5
Logging in to Wireless Configuration Interface...............................................65
6.6 Wireless Interface Menus....................................................................................66
6.7
Configuring Analog Outputs with Indigo 201.................................................. 67
6.7.1
Receiving Analog Output Settings from Probe.........................................68
6.7.2
Indigo 201 Analog Output Mode Selection................................................68
6.8
Using Modbus with Indigo 202..........................................................................69
6.8.1
Modbus Serial Communication Settings.................................................... 70
6.9 Configuring Relays with Indigo...........................................................................71
6.10 Changing Environmental Compensation Settings with Indigo......................72
6.11 Configuring Filtering Factor with Indigo.......................................................... 73
6.12 Calibrating GMP251 with Indigo......................................................................... 74
6.12.1
Indigo Calibration Overview........................................................................ 74
6.12.2 Restoring Factory Adjustment.....................................................................75
6.12.3 Calibration PIN Code.....................................................................................76
6.12.4 1-point Adjustment with Indigo...................................................................76
6.12.5 2-point Adjustment with Indigo.................................................................. 78
7. Operating with MI70 Indicator..................................................................... 81
7.1
Overview of MI70 Support.................................................................................. 81
7.2
Basic Display......................................................................................................... 81
7.3
Graphical Display.................................................................................................. 81
7.4
Main Menu.............................................................................................................82
7.5
Connecting Probe to MI70 Indicator................................................................. 82
7.6
MI70 Indicator Parts............................................................................................ 83
7.7
Holding and Saving the Display.........................................................................83
7.8
Recording Data.................................................................................................... 84
7.9
Changing Environmental Compensation Settings with MI70 Indicator....... 84
7.10 Calibration and Adjustment with MI70 Indicator.............................................85
7.10.1
1-Point Adjustment with an MI70-Compatible Reference Probe............ 85
7.10.2 1-Point Adjustment with a Reference Gas..................................................87
8. Maintenance........................................................................................................ 89
8.1
Cleaning................................................................................................................ 89
8.1.1
Chemical Tolerance....................................................................................... 89
8.2
Changing the Filter............................................................................................. 90
8.3
Calibration and Adjustment...............................................................................90
8.3.1
Calibration Setup............................................................................................91
Effect of Environmental Compensations.................................................... 91
8.3.2
8.3.3
Limits of Adjustment.................................................................................... 92
8.3.4
Adjustment Types......................................................................................... 92
8.3.5
DRW244827SP Calibration Adapter...........................................................93
9. Troubleshooting.................................................................................................95
9.1
Problem Situations.............................................................................................. 95
9.2
Error Messages.....................................................................................................95
9.3
Analog Output Error State................................................................................. 96
9.4 Indigo Wireless Connection Troubleshooting.................................................. 97
2
M211799EN-F
Table of Contents
10. Technical Data.................................................................................................... 99
10.1 GMP251 Specifications........................................................................................ 99
10.2 Spare Parts and Accessories............................................................................. 101
10.3 GMP251 Probe Dimensions............................................................................... 102
10.4 243261SP Mounting Flange Dimensions......................................................... 103
10.5 DRW244827SP Calibration Adapter Dimensions..........................................104
10.6 ASM212017SP Spray Shield Dimensions......................................................... 104
Appendix A: Modbus Reference....................................................................... 107
A.1
Function Codes.................................................................................................. 107
A.2 Modbus Registers...............................................................................................107
A.2.1
Measurement Data...................................................................................... 107
A.2.2 Configuration Registers..............................................................................108
A.2.3 Status Registers............................................................................................110
A.2.4 Device Identification Objects....................................................................... 111
A.3 Modbus Communication Examples.................................................................. 112
A.4 Filtering Factor.................................................................................................... 114
Warranty........................................................................................................................115
Technical Support..................................................................................................... 115
Recycling.......................................................................................................................115
3
GMP251 User Guide
List of Figures
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
Figure
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Figure 15
Figure 16
Figure 17
Figure 18
Figure 19
Figure 20
Figure 21
Figure 22
Figure 23
Figure 24
Figure 25
Figure 26
Figure 27
Figure 28
Figure 29
Figure 30
Figure 31
Figure 32
Figure 33
Figure 34
4
GMP251 Probe Parts........................................................................................... 11
Probe Cuvette with Mirror and Sensor Chips.............................................14
CO2 Measurement in the Measurement Cuvette....................................... 15
Example of Analog Output Overrange Behavior .....................................19
GMP251 Dimensions.......................................................................................... 21
Probe with 243261SP Mounting Flange......................................................22
Probe in 243257SP Mounting Clips..............................................................23
Probe with ASM212017SP Spray Shield ..................................................... 23
Example of Analog Output Overrange Behavior.....................................44
GMP251 Attached to Indigo Transmitter.................................................... 59
Desktop and Mobile Example Views...........................................................60
Serial Number on Probe Body (GMP251 Example)..................................62
Attaching Probes and Cables to Indigo......................................................63
Enabling and Accessing Indigo's Wireless Configuration
Interface.............................................................................................................. 64
Indigo Login View.............................................................................................65
Wireless Configuration Interface, Desktop Browser View.................... 66
Indigo 201 Analog Output Configuration Options.................................. 67
Clearing Analog Output Settings ................................................................68
Selecting Indigo 201 Analog Output Mode............................................... 69
Relay Configuration Options.......................................................................... 71
Calibration Menu Main View...........................................................................74
Start Calibration Button.................................................................................. 75
MI70 Basic Display.............................................................................................81
MI70 Indicator Parts.........................................................................................83
CO2 Reading with Tcomp and Pcomp on MI70 Screen.......................... 84
Probe Compensation Settings on MI70 Screen........................................85
Opening the Filter............................................................................................ 90
DRW244827SP Calibration Adapter with Probe Inserted.....................93
GMP251 Dimensions....................................................................................... 102
243261SP Mounting Flange Dimensions...................................................103
243261SP Mounting Flange Dimensions, Cross Section.......................103
DRW244827SP Calibration Adapter Dimensions.................................. 104
ASM212017SP Spray Shield Dimensions...................................................104
GMP251 Spray Shield Cross Section...........................................................105
M211799EN-F
List of Tables
List of Tables
Table 1
Table 2
Table 3
Table 4
Table 5
Table 6
Table 7
Table 8
Table 9
Table 10
Table 11
Table 12
Table 13
Table 14
Table 15
Table 16
Table 17
Table 18
Table 19
Table 20
Table 21
Table 22
Table 23
Table 24
Table 25
Table 26
Table 27
Table 28
Table 29
Table 30
Table 31
Table 32
Table 33
Table 34
Table 35
Table 36
Table 37
Table 38
Table 39
Table 40
Table 41
Table 42
Table 43
Table 44
Table 45
Table 46
Table 47
Table 48
Table 49
Table 50
Table 51
Document versions...............................................................................................7
Related Manuals.................................................................................................... 7
Applicable Patents................................................................................................8
Analog Output Overrange Clipping and Error Limits................................18
M12 Male Connector........................................................................................... 24
Default Serial Interface Settings.....................................................................25
Basic Serial Commands.....................................................................................29
Advanced Serial Commands........................................................................... 30
? Command........................................................................................................... 31
Errs Command......................................................................................................31
Help Command.....................................................................................................31
Snum Command..................................................................................................32
System Command...............................................................................................32
Time Command................................................................................................... 33
Vers Command.................................................................................................... 33
Addr Command...................................................................................................34
Close Command..................................................................................................34
Form Command.................................................................................................. 34
Output Parameters for Form Command...................................................... 36
Modifiers for Form Command.........................................................................36
Intv Command..................................................................................................... 37
Open Command.................................................................................................. 37
R Command..........................................................................................................38
S Command..........................................................................................................38
Sdelay Command............................................................................................... 39
Send Command...................................................................................................39
Seri Command..................................................................................................... 39
Smode Command.............................................................................................. 40
Amode Command............................................................................................... 41
Aover Command.................................................................................................42
Asel Command....................................................................................................44
Adate Command.................................................................................................45
Atext Command..................................................................................................45
Cdate Command.................................................................................................46
Ctext Command..................................................................................................46
CCO2 Command..................................................................................................47
Env Command.....................................................................................................50
O2cmode Command..........................................................................................52
Pcmode Command.............................................................................................53
Rhcmode Command.......................................................................................... 53
Tcmode Command............................................................................................. 54
Frestore Command.............................................................................................55
Pass Command....................................................................................................55
Reset Command..................................................................................................55
Default Modbus Serial Communication Settings....................................... 57
Indigo 202 Modbus Registers......................................................................... 69
Performance........................................................................................................ 99
Operating Environment.................................................................................. 100
Inputs and Outputs............................................................................................101
Mechanics.............................................................................................................101
Supported Function Codes............................................................................ 107
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GMP251 User Guide
Table
Table
Table
Table
6
52
53
54
55
Modbus Measurement Data Registers (Read-Only)............................... 107
Modbus Configuration Data Registers (Writable)...................................108
Modbus Status Registers (Read-Only)........................................................ 110
Device Identification Objects...........................................................................111
M211799EN-F
Chapter 1 – About This Document
1. About This Document
1.1 Version Information
Table 1 Document versions
Document Code
Date
Description
M211799EN-F
June 2017
This version. Added information about using the probe with
Vaisala Indigo transmitters. Modbus status register values
updated. Spray shield accessory ASM212017SP added. Calibration
uncertainty specification updated. Calibration adapter order code
corrected.
M211799EN-E
August 2016
Previous version. Modbus status register values and descriptions
updated.
M211799EN-D
July 2016
Probe body design and power supply requirements updated.
Added Modbus communication examples and information about
the recommended use of volatile and non-volatile Modbus
configuration registers. Added information about the
requirement for environment-appropriate temperature and
pressure compensations when applying a relative humidity
compensation. Document template updated.
1.2 Related Manuals
Table 2 Related Manuals
Document Code
Description
M211798EN
Vaisala CARBOCAPâ Carbon Dioxide Probe GMP251 Quick Guide
M211897EN
Vaisala CARBOCAPâ Carbon Dioxide Probe GMP252 User Guide
M211893EN
Vaisala CARBOCAPâ Carbon Dioxide Probe GMP252 Quick Guide
M211877EN
Vaisala Indigo™ 201 Analog Output Transmitter User Guide
M211876EN
Vaisala Indigo™ 201 Analog Output Transmitter Quick Guide
M211966EN
Vaisala Indigo™ 202 Digital Transmitter User Guide
M211967EN
Vaisala Indigo™ 202 Digital Transmitter Quick Guide
7
GMP251 User Guide
M211799EN-F
1.3 Documentation Conventions
WARNING! alerts you to a serious hazard. If you do not read and follow instructions
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.
Tip gives information for using the product more efficiently.
1.4 Trademarks
Vaisalaâ and CARBOCAPâ are registered trademarks of Vaisala Oyj.
Windowsâ is either a registered trademark or trademark of Microsoft Corporation in the
United States and other countries.
All other product or company names that may be mentioned in this publication are trade
names, trademarks, or registered trademarks of their respective owners.
1.5 Patent Notice
This product is protected by the following patents and their corresponding national rights:
Table 3 Applicable Patents
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
8
69615635
Chapter 1 – About This Document
Patent Issued By
Patent Number
Japan Patent Office
4263285
Finnish Patent Office
112005
105598
9
GMP251 User Guide
10
M211799EN-F
Chapter 2 – Product Overview
2. Product Overview
2.1 Introduction to GMP251
GMP251 is designed for CO2 measurement in demanding applications that require reliable
and accurate performance. The measurement range is 0 ... 20 %CO2.
The probe is based on Vaisala’s patented 2nd generation CARBOCAPâ technology and
equipped with Vaisala Microglow infrared light source. The probe is easy to install with a
plug-in/plug-out M12 connection.
Sensor performance is optimized at 5 %CO2 measurement. For compensation purposes, the
probe also includes an internal temperature sensor that allows measurement compensation
according to ambient temperature. As dust and most chemicals do not affect the
measurement, and the effect of temperature, pressure and background gas can be
compensated for, the probe can provide accurate and stable measurements in a wide range
of applications.
1
2
3
4
5
Figure 1 GMP251 Probe Parts
1
2
3
4
5-pin M12 connector. For pinout, see 3.5 Wiring (page 24).
Probe name and orientation mark for Vaisala transmitter installations (front) and laserprinted type label (back).
Probe body. Contains the main component board.
Measurement cuvette with optics and CARBOCAPâ CO sensor.
5
Filter (see 2.3 Filter Options (page 13).
2
CAUTION! Do not attempt to open the probe body. There are no user serviceable parts
inside the probe body.
11
GMP251 User Guide
M211799EN-F
2.2 Basic Features and Options
• CO2 measurement range 0 ... 20 %.
• Vaisala CARBOCAPâ CO sensor with excellent long-term stability.
2
• Measurement compensated for effects of temperature, pressure, and background gas.
The temperature compensation can be based on an integrated temperature sensor or
use a set temperature. Pressure and background gas parameters can be set to the
probe.
• Heating to avoid condensation on optical elements.
• Digital output with RS-485:
• Modbus RTU
• Vaisala Industrial Protocol
• Analog output:
• Current output (0 ... 20 mA or 4 ... 20 mA)
• Voltage output (0 ... 5 V or 0 ... 10 V)
• Compatible with MI70 hand-held meter
• Compatible with Vaisala Indigo™ transmitters.
• Easy plug-in, plug-out.
More Information
‣
‣
‣
‣
‣
Operating Principle of CO2 Measurement (page 14)
Environmental Compensation (page 15)
GMP251 Specifications (page 99)
Modbus (page 57)
Overview of MI70 Support (page 81)
2.2.1 Additional Features with Indigo Transmitters
GMP251 probes manufactured from 2017 onwards are compatible with Vaisala Indigo
transmitters. Connecting the probe to an Indigo transmitter provides a range of additional
options for outputs, measurement viewing, status monitoring, and configuration interface
access.
Examples of additional features available with Indigo transmitters include:
• 3.5” TFT LCD color display or non-display model with LED indicator
• Digital or analog output, 2 configurable relays
• Wireless browser-based configuration interface for mobile devices and computers
(IEEE 802.11 b/g/n WLAN)
The selection of available additional features (for example, output and connectivity options)
varies depending on the Indigo transmitter model. For more information on Indigo
transmitters, see www.vaisala.com/indigo.
More Information
‣ Indigo Overview (page 59)
‣ Probe Compatibility (page 62)
12
Chapter 2 – Product Overview
2.3 Filter Options
1
2
3
The following filter options are available for GMP251:
1. Standard membrane filter, order code ASM211650SP. Gas can enter only through the
top of the filter (plastic grid covered with membrane), the sides of the filter are solid.
2. Porous sintered PTFE filter for extra protection, order code DRW243649SP. The porous
material of the filter allows gas to enter from all sides of the filter.
3. Flow-through adapter, order code ASM211697SP. Two gas ports for controlled gas feed
(port outer diameter 4.6 mm, port hole inner diameter 2 mm, suitable for tubing with 4
mm inner diameter).
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GMP251 User Guide
M211799EN-F
2.4 Operating Principle of CO2
Measurement
1
2
3
The Vaisala CARBOCAPâ sensor used in the
probe is a silicon-based, nondispersive
infrared (NDIR) sensor for the measurement
of gaseous carbon dioxide in air-like gases.
Figure 2 Probe Cuvette with Mirror and Sensor
Chips
1
2
3
Cuvette
Mirror
Sensor chips under TO5 package
The sensitivity to carbon dioxide is based on absorption of infrared light at a characteristic
wavelength. During measurement, infrared light is routed through the cuvette that contains
the gas to be measured. A mirror reflects the light from the cuvette to a thermopile detector
that measures the light intensity at a wavelength determined by a Fabry–Pérot
interferometer (FPI) and a band pass filter.
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. Measuring 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.
TO5 packages with hermetic windows are used to protect the sensor chips from moisture
and contamination. A heater chip is utilized to prevent condensation in normal operation.
14
Chapter 2 – Product Overview
1
2
3
6
4
5
7
Figure 3 CO2 Measurement in the Measurement Cuvette
1
2
3
4
5
6
7
Gold-plated mirror
Light absorbed by CO2 in the measured gas
Hermetic window
Fabry-Perot interferometer
Light source (Microglow)
Hermetic window
Thermopile detector
2.5 Environmental Compensation
When necessary, various environmental compensations can be applied to improve the CO2
measurement accuracy of the probe.
The probe can compensate for the effects of the following parameters:
•
•
•
•
Temperature
Pressure
Background gas oxygen (O2) content
Background gas relative humidity (%RH)
To apply an accurate relative humidity compensation, make sure that also the temperature
compensation and pressure compensation configurations match the measurement
environment.
15
GMP251 User Guide
M211799EN-F
The probe has an on-board temperature sensor that can be used to compensate for
temperature. Additionally, if the probe is integrated in a system that measures one or more
of the compensation parameters (T, P, RH, O2), they can be updated to the probe
continuously.
Compensation parameters are configured on the order form when ordering the probe, and
can later be updated using Vaisala Industrial Protocol or Modbus protocol.
You can also turn off any of the compensations. In that case, the probe uses the default
compensation value that is mathematically neutral for the probe’s internal compensation
model.
You can configure the environmental compensation settings with any of the following
options:
•
•
•
•
Vaisala Industrial Protocol serial commands
MI70 hand-held indicator
Indigo transmitter's wireless configuration interface
Modbus configuration registers
More Information
‣
‣
‣
‣
‣
Effect of Environmental Compensations (page 91)
Environmental Compensation Commands (page 49)
Configuration Registers (page 108)
Changing Environmental Compensation Settings with MI70 Indicator (page 84)
Changing Environmental Compensation Settings with Indigo (page 72)
2.5.1 Temperature Compensation
The probe can measure the approximate temperature of the CARBOCAPâ 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 probe. If the measurement is
made in a constant temperature, this fixed temperature setpoint can be set as the
compensation value.
If temperature compensation is turned off, the probe uses the default value of +25 °C
(+77 °F).
When the probe is installed through a flange and part of the probe and the cable is left
outside the measuring environment, it is possible that temperature conduction from the
probe body and cable outside the measurement environment affects the temperature
compensation and decreases measurement accuracy.
2.5.2 Pressure Compensation
The probe does not have on-board pressure measurement. However, a pressure reading
from an external source can be used as a setpoint value for compensation using Vaisala
Industrial Protocol or Modbus.
16
Chapter 2 – Product Overview
If pressure compensation is turned off, the probe uses the default compensation value of
1013 hPa.
2.5.3 Background Gas Compensation
The probe does not have on-board oxygen or relative humidity measurement. However,
oxygen and relative humidity readings from an external source can be used as setpoint
values for compensation via Vaisala Industrial Protocol or Modbus. The default setpoint
values are as follows:
• Oxygen concentration: 19.7 %O2 or 21 %O2
• Relative humidity: 50 %RH or 93 %RH
If background gas compensations are turned off, the probe uses the value 0 % for both.
More Information
‣ Environmental Compensation (page 15)
‣ Configuration Registers (page 108)
2.6 Probe Startup
When powered on, the probe starts up within 20 seconds. Measurements from the outputs
(digital and analog) become available during this time but note that they will only reach
specified accuracy after a 4-minute warm-up period. For this reason, you should design your
system so that it does not rely on measurements from the probe during this time.
Specifically note that the CO2 reading will rise to the correct reading as the sensor’s
infrared emitter achieves operation temperature.
2.7 Filtering Factor
You can set a filtering factor that affects the speed at which the latest CO2 measurement is
integrated into the output of the probe. This allows averaging the output if the measuring
environment produces occasional exceptionally high or low readings.
The filtering factor can be set either with Modbus configuration registers or with an Indigo
transmitter's wireless configuration interface.
More Information
‣ Configuration Registers (page 108)
‣ Configuring Filtering Factor with Indigo (page 73)
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GMP251 User Guide
M211799EN-F
2.8 Analog Output Overrange Behavior
The analog output of the probe has a defined behavior when the values measured by the
probe are outside the scaled analog output range. At first, the output is clipped when the
measurement exceeds a set limit (the measurement continues, but the output does not
change from the clipped value).
When the measurement exceeds the second limit (error limit), the analog output switches to
the error state defined for the output.
The table below lists the clipping and error limits and default error state outputs for the
analog voltage and current outputs.
Table 4 Analog Output Overrange Clipping and Error Limits
Output voltage / current
Clipping Limit
Error Limit
Default Error State Output
0 ... 5 V
>5 %
>10 %
0V
0 ... 10 V
>1 %
>10 %
0V
0 ... 20 mA
>5 %
>10 %
23 mA
4 ... 20 mA
>5 %
>10 %
2 mA
The same clipping and error limits are applied when the measured value drops back to the
scaled range: at first the output returns to the clipped value from the error state, and then to
normal output.
Clipping and error state limits differ for 0 ... 10 V and 0 ... 5 V outputs. For 0 ... 10 V output
the limits are 1 % and 10 %, and for 0 ... 5 V output the limits are 5 % and 10 %.
More Information
‣ Analog Output (page 41)
‣ Configuring Analog Outputs with Indigo 201 (page 67)
2.8.1 Analog Output Overrange Example
Consider a probe with 0 ... 5 V output, scaled to 0 ... 200 000 ppm (= 0 ... 20 %) CO2.
• When the measured CO2 rises above 20 %, the output rises above 5 V.
• The output keeps rising until the measurement is 21 %CO2, at which point the probe
outputs 5.25 V.
• If the CO2 level rises above 21 %CO2, the output still remains at 5.25 V.
• If the CO2 level rises above 22 %CO2, the output enters the error state, which is 0 V for
the 0 ... 5 V output.
18
Chapter 2 – Product Overview
Output
voltage (V)
0.00
5.25
5.00
Error level
Output clipping limit
In error state at
>220000 ppm
(200000 ppm + 10%)
Clipped at
210000 ppm
(200000 ppm + 5%)
Regular
measurement
Time
Figure 4 Example of Analog Output Overrange Behavior
This example uses output scaled to 0 ... 5 V and 0 ... 200000 ppm, error level set to 0 V,
clipping set to 5 % overrange, and error limit set to 10 % overrange. CO2 concentrations
(ppm) are indicated for the clipping point and error limit point.
This overrange and error behavior is specific to the analog output, and does not affect the
readings of the digital outputs.
You can change the analog output overrange behavior using the aover command.
2.9 Safety
The probe delivered to you has been tested for safety and approved as shipped from the
factory. Note the following precautions:
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.
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CAUTION! Do not modify the unit or use it in ways not described in the documentation.
Improper modification may lead to safety hazards, equipment damage, failure to
perform according to specification, or decreased equipment lifetime.
CAUTION! Do not attempt to open the probe body. There are no user serviceable parts
inside the probe body.
2.9.1 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. However, it is
possible to damage the product by delivering electrostatic discharges 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.
2.10 Regulatory Compliances
The probe is in conformity with the provisions of the following EU directives:
• RoHS Directive
• EMC Directive
Conformity is shown by compliance with the following standards:
• EN 50581: Technical documentation for the assessment of electrical and electronic
products with respect to the restriction of hazardous substances.
• EN 61326-1: Electrical equipment for measurement, control, and laboratory use – EMC
requirements – Generic environment.
• EN 55022: Information technology equipment – Radio disturbance characteristics –
Limits and methods of measurement.
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Chapter 3 – Installation
3. Installation
3.1 GMP251 Probe Dimensions
The dimensions are given in millimeters (mm).
96 mm, Ø 25 mm
Filter
M12 male
connector
12 mm
75 mm
9 mm
Figure 5 GMP251 Dimensions
3.2 Recommended Installation
The probe can be installed in an environment with an operating temperature range -40 ...
+60 °C (-40 ... +140 °F). Make sure the probe is in a location that represents the
measurement environment properly.
The 5-pin male M12 connector on the probe provides an easy plug-in/plug-out connection to
a compatible cable.
3.3 Installation Accessories
The probe can be installed through a surface using the optional flange accessory (Vaisala
product code 243261SP), or attached for example to a wall with the optional clip accessory
(two-clip set, Vaisala product code 243257SP).
For installations where a pressure washer is used to clean the measurement area, a spray
shield with an IP9X rating (Vaisala product code ASM212017SP) is available as an optional
accessory.
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3.3.1 243261SP Mounting Flange
The optional flange accessory is used to install the probe body through a wall or other
surface.
1
2
3
Figure 6 Probe with 243261SP Mounting Flange
1
2
3
4 Phillips head screws (included)
Mounting flange (diameter 60 mm) with four Ø 4.2 mm screw holes
Gasket ring
Leaving part of the probe body and the cable outside the measurement environment can
cause heat conduction that affects the temperature compensation and measurement
accuracy.
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Chapter 3 – Installation
3.3.2 243257SP Mounting Clips
The optional mounting clips (set of two clips) are used to hold the probe in place for
example on a wall or other surface. Each clip base attaches to the installation surface with
one screw (screw hole Ø 4.2 mm).
Ø 4.2 mm
Figure 7 Probe in 243257SP Mounting Clips
3.3.3 ASM212017SP Spray Shield
The optional spray shield (Vaisala order code: ASM212017SP) allows washing the probe with
a pressure washer without exposing the sensor to moisture (IP9X rating).
O-ring
Remove lid to clean
Figure 8 Probe with ASM212017SP Spray Shield
The spray shield can limit or prevent the use of the probe mounting clips (243257SP).
More Information
‣ ASM212017SP Spray Shield Dimensions (page 104)
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3.4 Power Supply
The supply voltage range of the probe is 12 ... 30 VDC with the digital output option. If the
analog output is used, the supply voltage range is 12 ... 30 VDC for voltage output and
20 ... 30 VDC for current output.
Typical power consumption is less than 0.4 W in continuous operation, and the maximum is
0.5 W.
3.5 Wiring
3
4
5
2
1
Table 5 M12 Male Connector
Pin#
Function
Note
Cable 223263SP
Wire Colors
1
Power in
• With digital output: 12 ... 30 VDC
• With voltage output: 12 ... 30 VDC
• With current output: 20 ... 30 VDC
Typical average power consumption <0.4 W, maximum
0.5 W.
Brown
2
RS-485-
Voltage:
White
or voltage output
0 ... 5 VDC or 0 ... 10 VDC (default analog output scaling)
3
GND
–
Blue
4
RS-485 +
Current:
Black
or current output
0 … 20 mA or 4 ... 20 mA (default analog output scaling)
Output control
Connecting pin #5 to GND (pin #3) forces the probe to
analog output mode. If an analog output configuration
has not been selected, default 0 ... 10 VDC and 4 ... 20 mA
scalings are used.
5
Gray
If pin #5 is not connected, the analog or digital output
selected when ordering or set later through configuration
is used.
Note that the probe always remains in analog mode when pin #5 is connected to pin #3,
and cannot be switched to digital output in this wiring option.
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Chapter 4 – Vaisala Industrial Protocol
4. Vaisala Industrial Protocol
4.1 Overview
RS-485 line of the probe provides an implementation of the Vaisala Industrial Protocol that
can be used for service and configuration use, or for interfacing with the system to which
the probe is integrated. The protocol is a plaintext protocol suitable for use both by human
operators and automated systems.
4.2 Serial Interface Settings
Table 6 Default Serial Interface Settings
Property
Description/Value
Bit rate
19200
Parity
None
Data bits
8
Stop bit
1
Flow control
None
4.3 Physical Interface
The physical interface is a non-isolated 2-wire interface. The data lines are RS-485 D- and
RS-485 D+. Ground is shared with power supply. The connector is a 5-pin male M12.
4.4 Connecting with a Computer
• Vaisala USB service cable (order code 242659)
• Computer with:
• Windows operating system
• Terminal application (for example PuTTy, available from www.vaisala.com/
software)
• Free USB port
• Driver for Vaisala USB service cable installed (available on the cable installation
media and at www.vaisala.com/software)
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The steps below describe how to connect to the probe using the PuTTY terminal application
for Windows and a USB computer connection cable. Connecting with a computer allows you
to configure and troubleshoot your probe using serial line commands.
1. If you have not used the Vaisala USB cable before, install the driver before attempting
to use the cable.
2. Connect the USB serial interface cable between your computer and the M12 connector
of the probe.
3. Start the PuTTY application.
4. 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.
5. 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.
6. Select Terminal. Use the following settings:
•
•
Local Echo
Select Force on. This setting ensures that your typing is shown on the session
window.
Send line ends with line feeds (CR+LF)
Set to Selected. This setting ensures that all text lines remain visible on the
session window.
7. To open the connection window and start using the serial line, select Open.
If PuTTY is unable to open the serial port you selected, it shows you an error
message instead. If this happens, restart PuTTY and check the settings.
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Chapter 4 – Vaisala Industrial Protocol
4.4.1 Installing the Driver for the USB Service 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/software.
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.
4.5 Accessing Serial Commands from
Modbus or Analog Mode
1. Connect the USB cable to your PC and start the terminal application as instructed in 4.4
Connecting with a Computer (page 25).
2. Start a new terminal session using the default serial settings.
3. Keep the Enter key pressed down and connect the probe to the USB cable. When the
probe is powered on (connected to your PC with the USB cable), you must send five
carriage returns (Enter key presses) within 0.7 seconds to force the probe to serial
command mode. The probe model information appears in the terminal application
when the mode has been succesfully changed, and Vaisala Industrial Protocol
commands are available for use.
4. To test the connection, enter for example the ? command. If the mode change failed,
close the terminal application, disconnect the probe from the USB cable, and repeat
step 2 and step 3.
5. To keep the serial mode in use (forced serial mode access is temporary and switches off
at reset), select a serial output option (stop/run/poll) with the smode command.
Note that the probe always remains in analog mode when pin #5 is connected to pin
#3, and cannot be switched to digital output in this wiring option.
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4.6 Enabling Modbus Mode from Vaisala
Industrial Protocol
If you need to switch from Vaisala Industrial Protocol to Modbus mode, you must configure
the following settings:
• Serial line operating mode
• Modbus address
• Serial line settings (bit rate, parity, stop and data bits)
1. Connect the USB cable to your PC and start the terminal application as instructed in 4.4
Connecting with a Computer (page 25).
2. Set the serial mode to Modbus with the smode command:
smode modbus
3. Set the Modbus address to 240 with the addr command:
addr 240
4. Set the serial line settings to 19200/N/8/2 with the seri command:
seri 19200 N 8 2
5. Power off (disconnect) the probe or reset with the reset command. The new
configuration is available at the next restart.
4.7 Changing From Digital Output to
Analog Output
1. Set up a terminal connection as instructed in 4.4 Connecting with a Computer
(page 25).
2. Change the mode from digital to analog with the smode serial command: smode
analog.
3. Reset the probe (disconnect and reconnect the cable or use the reset serial command)
to power on in analog output mode.
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Chapter 4 – Vaisala Industrial Protocol
4.8 Serial Commands
The notation <cr> refers to the carriage return control character, which you can send in a
terminal application by pressing enter on your keyboard. Before entering commands, send a
<cr> to clear the command buffer.
You can enter the commands in uppercase or lowercase. In the command examples, the
keyboard input by the user is in bold type.
Table 7 (page 29) lists the basic serial commands that are available by default. To access
advanced serial commands (listed in Table 8 (page 30)), enter the command pass 1300.
Table 7 Basic Serial Commands
Command
Description
Device information and status
?
Show probe information.
??
Show probe information (will respond in POLL mode).
errs
Show currently active errors.
help
Show list of currently available serial commands.
snum
Show probe serial number.
system
Show probe firmware information.
time
Show probe operation hours and uptime.
vers
Show probe firmware version.
Serial line output and communication
close
Close connection to probe (POLL mode)
form [modifier string]
Show or set output format.
intv [0 ... 255 s/min/h]
Set continuous output interval for R command.
open [address]
Open connection to probe in POLL mode.
r
Start the continuous outputting.
s
Stop the continuous outputting.
sdelay [0 ... 255]
Show or set serial line transmission delay in milliseconds.
send
Output a single measurement message.
seri [baud data stop
parity]
Show or set the serial interface settings.
smode [mode]
Show or set startup serial mode: RUN, STOP, or POLL.
Environmental compensation
env
Show or set environmental parameters.
Adjustment information
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Command
Description
adate
Show CO2 factory adjustment date.
atext
Show CO2 factory adjustment information.
Other commands
reset
Reset the probe.
pass [1300]
Access advanced serial commands.
Table 8 Advanced Serial Commands
Command
Description
Serial line output and communication
addr [0 … 254]
Show or set probe address.
Analog output
amode
Show or set analog output mode (analog output limits and error level).
aover
Show or set analog output overrange and clipping behavior.
asel
Show or set analog output parameter and scaling.
Calibration and adjustment
cco2
Adjust CO2 measurement gain and offset.
cdate
Show or set calibration date.
ct
Adjust temperature measurement offset.
ctext
Show or set calibration information.
Environmental compensation
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.
Other commands
frestore
30
Restore probe to factory settings.
Chapter 4 – Vaisala Industrial Protocol
4.9 Device Information and Status
Table 9 ? Command
Syntax
Description
?<cr>
Show listing of device information.
??<cr>
Show listing of device information even if device is in
poll mode and connection has not been opened using
the open command.
Example:
?
Device : GMP251
Copyright : Copyright (c) Vaisala Oyj 2015. All rights
reserved.
SW Name : GMP251
SW version : 1.0.0
SNUM : GMP233_5_18
SSNUM : S1234567
CBNUM : c1234567
Calibrated : 20150604 @ Vaisala/R&D
Address : 0
Smode : STOP
Table 10 Errs Command
Syntax
Description
errs<cr>
Show active error(s). For a list of possible errors and
their remedies, see 9.2 Error Messages (page 95).
Example (no active errors):
errs
NO CRITICAL ERRORS
NO ERRORS
NO WARNINGS
STATUS NORMAL
Table 11 Help Command
Syntax
Description
help<cr>
Show list of currently available serial commands.
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Syntax
M211799EN-F
Description
Example (showing a list of the basic commands):
help
ADATE
ADDR
ATEXT
CLOSE
ENV
ERRS
FORM
HELP
INTV
PASS
RR
ESET
RX
SDELAY
SEND
SENDX
SERI
SMODE
SNUM
SYSTEM
UNIQID
TIME
VERS
Table 12 Snum Command
Syntax
Description
snum<cr>
Show serial number of the probe.
Example:
snum
SNUM : M0220028
Table 13 System Command
Syntax
Description
system<cr>
Show probe firmware information.
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Chapter 4 – Vaisala Industrial Protocol
Syntax
Description
Example:
system
Device Name : GMP251
SW Name : GMP251
SW version : 1.0.0
Operating system : TSFOS1.0
Table 14 Time Command
Syntax
Description
time<cr>
Show how long the probe has been in operation since
the last startup or reset.
The operation counter is in format hh:mm:ss.
Example:
time
Time : 01:41:24
Table 15 Vers Command
Syntax
Description
vers<cr>
Show firmware version of the probe.
Example:
vers
SW version : 1.0.0
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4.10 Serial Line Output and
Communication
Table 16 Addr Command
Syntax
Description
addr<cr>
Show current device address. Addresses are required
for POLL mode.
addr [aaa]<cr>
Set new device address. aaa = address, 0 ... 254
(default = 0)
Example (shows 0 as current address, enter 5 as the new address):
addr
Address : 0
addr 5
Address : 5
Table 17 Close Command
Syntax
Description
close<cr>
Close the connection that was opened with the open
command.
Example:
close
line closed
Table 18 Form Command
Syntax
Description
form<cr>
Show the currently used measurement format.
form /<cr>
Reset measurement format to default.
form [sss]<cr>
Set a new measurement format.
sss = String consisting of modifiers and
abbreviations for measured parameters.
See Table 19 (page 36) and Table 20 (page 36).
Maximum length is 150 characters. Maximum length
may be shorter when text strings are used.
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Chapter 4 – Vaisala Industrial Protocol
Syntax
Description
Example (show currently used measurement format (default format shown here)):
form
6.0 "CO2=" CO2 " " U3 #r #n
Output example (continuous output from RUN mode):
CO2= 452 ppm
Example (set output format as %CO2):
form 3.1 "CO2=" CO2% " " U4 #r #n
OK
Output example (continuous output from RUN mode):
CO2= 5.1 %CO2
CO2= 5.1 %CO2
CO2= 5.0 %CO2
...
Example (set output format as CO2 ppm with Modulus-65536 checksum):
form 6.0 "CO2=" CO2 " " U3 " " CS4 #r #n
OK
Output example (continuous output from RUN mode):
CO2= 3563 ppm 9F
CO2= 3562 ppm 9E
CO2= 3559 ppm A4
...
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Syntax
Description
Example (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
OK
Output example (continuous output from RUN mode, 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
...
Table 19 Output Parameters for Form Command
Output 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
Table 20 Modifiers for Form Command
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.
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Chapter 4 – Vaisala Industrial Protocol
Modifier
Description
time
Cumulative operating hours of the probe.
ux
Name of the measurement unit using x number of
characters. For example, u3 shows the name of the
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.
You can also use the backslash character \ instead of the hash character #.
Table 21 Intv Command
Syntax
Description
intv<cr>
Show the output interval of the automatically
repeating measurement messages (r command and
run mode).
intv [iii uuu]<cr>
Set the output interval.
• iii = interval, range 0 ... 255
• u = unit for interval setting:
• s = seconds
• min = minutes
• h = hours
If you set the interval to 0, the output messages are
output as quickly as they are generated, without
additional delay.
Example:
intv 5 s
Output interval: 5 S
Table 22 Open Command
Syntax
Description
open [aaa]<cr>
Open a connection to a device at the specified
address. Required when device is in poll mode.
aaa = address, range 0 ... 254.
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Syntax
Description
Example (target probe in POLL mode, with address 52):
open 52
GMP251: 52 Opened for operator commands
Table 23 R Command
Syntax
Description
r<cr>
Start the continuous outputting of measurement
values as an ASCII text string to the serial line. The
probe keeps outputting measurement messages at
the interval that has been set with the intv
command until stopped with the s command.
Example:
r
CO2=
CO2=
CO2=
CO2=
CO2=
...
5.1
5.1
5.1
5.0
5.0
%CO2
%CO2
%CO2
%CO2
%CO2
Table 24 S Command
Syntax
Description
s<cr>
Stop the continuous outputting that was started with
the r command.
Example:
...
CO2= 5.1 %CO2
CO2= 5.0 %CO2
CO2= 5.0 %CO2
s
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Chapter 4 – Vaisala Industrial Protocol
Table 25 Sdelay Command
Syntax
Description
sdelay<cr>
Show serial line transmission delay in milliseconds.
sdelay [delay]<cr>
Set a new serial line transmission delay.
delay = Serial line delay, range 0 … 255
(milliseconds).
Example (set delay to 50 milliseconds):
sdelay 50
COM transmit delay : 50
Table 26 Send Command
Syntax
Description
send<cr>
Output a single measurement message.
send [aaa]<cr>
Output a single measurement message from a device
in poll mode.
aaa = address of the probe, range range 0 ... 254
Example:
send
CO2= 5.0 %CO2
Example (target probe in POLL mode, with address 52):
send 52
CO2= 5.0 %CO2
Table 27 Seri Command
Syntax
Description
seri<cr>
Show current serial line settings.
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Syntax
Description
seri [b p d s]<cr>
Set new serial line settings. The new settings will be
taken into use when the probe is reset or powered up.
b = baud rate (9600, 19200, or 38400)
p = parity
• n = none
• e = even
• o = odd
d = data bits (7 or 8)
s = stop bits (1 or 2)
For Modbus, baud rate must be 9600 ... 38400 and
parity must be none.
Example (show current settings):
seri
Com1
Com1
Com1
Com1
Baud rate : 19200
Parity : N
Data bits : 8
Stop bits : 1
Example (set serial line to 9600 baud, even, 7 data bits, and 1 stop bit, and reset the probe to take the new
settings in use):
seri 9600 e 7 1
OK
seri
Com1 Baud rate : 9600
Com1 Parity : E
Com1 Data bits : 7
Com1 Stop bits : 1
reset
GMP251 1.0.0
Table 28 Smode Command
Syntax
Description
smode<cr>
Show current start-up operating mode of the serial
line, and prompt to enter new mode.
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Chapter 4 – Vaisala Industrial Protocol
Syntax
Description
smode [mode]<cr>
Set serial line start-up operating mode. New mode is
taken into use when the device is reset or powered up.
Available modes:
stop = No automatic output. All commands available.
Default mode.
run = Automatic output of measurement messages.
You can stop the output with the s command, and
recontinue with the r command.
poll = No automatic output. Will respond to
addressed send command and ?? command. You
can use other commands after opening a connection
using an addressed open command. Use with RS485 buses where multiple probes can share the same
line.
modbus = Serial line communication uses the Modbus
protocol (see Modbus on page 54). Serial line
commands (Vaisala Industrial Protocol) are not
accessible in the Modbus mode. For instructions on
returning to serial mode, see 4.5 Accessing Serial
Commands from Modbus or Analog Mode (page 27).
analog = Switches the probe from digital output to
analog output (active after probe reset). Serial line
commands are not accessible in the analog mode: for
instructions on returning to serial mode, see 4.5
Accessing Serial Commands from Modbus or Analog
Mode (page 27).
Example (set serial mode to "poll"):
smode poll
Serial mode : POLL
4.11 Analog Output
Table 29 Amode Command
Syntax
Description
amode [channel]<cr>
Show currently set analog output limits and error
level.
channel = Analog output channel
• 1 = voltage output (V)
• 2 = current output (mA)
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Syntax
Description
amode [channel lo_value hi_value
error_value]<cr>
Set new analog output limits and error output value.
channel = Analog output channel
• 1 = voltage output (V)
• 2 = current output (mA)
lo_value = Low limit of the channel.
hi_value = High limit of the channel.
error_value = Error value of the channel.
Example (show current configuration):
pass 1300
amode 1
Aout 1 range (V) : 0.00 ... 10.00 (error : 0.00)
amode 2
Aout 2 range (mA) : 4.00 ... 20.00 (error : 2.00)
Example (set channel 1 to 0 … 5 V, and error output to 0.0 V; set channel 2 to 0 ... 20 mA, and error output to
23 mA):
amode 1 0 5 0.0
Aout 1 range (V) : 0.00 ... 5.00 (error : 0.00)
amode 2 0 20 23
Aout 2 range (mA) : 0.00 ... 20.00 (error : 23.00)
Table 30 Aover Command
Syntax
Description
aover [channel<cr>
Show the behavior of the analog output when the
measured value is outside the scaled output range.
channel = Analog output channel
• 1 = voltage output (V)
• 2 = current output (mA)
aover [channel clipping error_
limit]<cr>
Set the behavior of the analog output when the
measured value is outside the scaled output range.
channel = Analog output channel
• 1 = voltage output (V)
• 2 = current output (mA)
clipping = Output margin (%) at which the output
is clipped.
error_limit = Measurement value margin (%) at
which the output of the channel goes into the error
state. The current or voltage output of the error state
is defined using the amode command, see Table 29
(page 41) on the previous page.
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Chapter 4 – Vaisala Industrial Protocol
Syntax
Description
Example (view currently set analog output overrange behavior on channel 1):
pass 1300
aover 1
Aout 1 clipping :5.00 %
Aout 1 error limit :10.00 %
Example (for channel 1):
1. View currently set analog output scaling (asel command), limits and error level
(amode command), and overrange behavior (aover command):
pass 1300
asel 1
Aout 1 quantity : CO2(0 ... 200000)
amode 1
Aout 1 range (V) : 0.00 ... 5.00 (error : 0.00)
aover 1
Aout 1 clipping :1.00 %
Aout 1 error limit :5.00 %
2. Set analog output overrange clipping to 5 % and error limit to 10 %:
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 5.00 %, meaning the voltage output is allowed to vary between
0 ... 5.25 V. The analog channel will output the measurement for 0 ... 210 000 ppm, but
range 0 ... 5 V remains scaled to 0 ... 200 000 ppm.
• Error limit is 10 %, which means the output will show the error state (0 V) when the
measured CO2 concentration is 10 % outside the scaled output range. With the settings
above, this will happen if the measured CO2 concentration is outside range 0 ... 220
000 ppm.
• The voltage output will never be above 5.25 V because of clipping: the voltage output
is clipped when the output reaches 5.25 V, and if the measured CO2 concentration
keeps rising above 220 000 ppm, the output jumps directly to the error state 0 V.
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Output
voltage (V)
Error level
0.00
5.25
5.00
Output clipping limit
In error state at
>220000 ppm
(200000 ppm + 10%)
Clipped at
210000 ppm
(200000 ppm + 5%)
Regular
measurement
Time
Figure 9 Example of Analog Output Overrange Behavior
The example shown above uses output scaled to 0 ... 5 V and 0 ... 200 000 ppm, has error
level set to 0 V, clipping set to 5 % overrange, and error limit set to 10 % overrange. CO2
concentrations (ppm) are indicated for the clipping point and error limit point.
Table 31 Asel Command
Syntax
Description
asel [channel]<cr>
Show the parameter and scaling of the analog output
in ppm.
channel = Analog output channel
• 1 = voltage output (V)
• 2 = current output (mA)
asel [channel] [parameter lowlimit
highlimit]<cr>
Set the parameter and scaling of the analog output.
channel = Analog output channel
parameter = Parameter that is output on analog
channel. The only parameter available is CO2 (in ppm).
lowlimit = Lower limit of channel scaling in ppm.
Minimum value is -1000000 ppm (= - 100 %).
highlimit = High limit of channel scaling in ppm.
Maximum value is 1000000 ppm (= 100 %).
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Chapter 4 – Vaisala Industrial Protocol
Syntax
Description
Example (for channel 1, show the currently set analog output parameter and scaling):
pass 1300
asel 1
Aout 1 quantity : CO2(0 ... 200000 ppm)
Example (for channel 1, set scaling to 0 ... 10 % (= 100 000 ppm)):
pass 1300
asel 1 co2 0 100000
Aout 1 quantity : CO2(0 ... 100000 ppm)
4.12 Calibration and Adjustment
CAUTION! Before using the calibration and adjustment commands, read through 8.3
Calibration and Adjustment (page 90). Make sure that the environmental
compensation settings of the probe are properly set for your calibration environment;
see 2.5 Environmental Compensation (page 15).
Table 32 Adate Command
Syntax
Description
adate<cr>
Show CO2 factory adjustment date.
Example:
adate
Adjustment date : 20150420
Table 33 Atext Command
Syntax
Description
atext<cr>
Show CO2 factory adjustment information.
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Syntax
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Description
Example:
atext
Adjusted at Vaisala/Helsinki
Table 34 Cdate Command
Syntax
Description
cdate<cr>
Show calibration date.
cdate [yyyymmdd]<cr>
Set a new calibration date.
yyyymmdd = Year (yyyy), month (mm) and day (dd)
of calibration
Example:
pass 1300
cdate
Calibration date : 20150220
Example (set a new calibration date to June 30, 2015):
cdate 20150630
Calibration date : 20150630
Table 35 Ctext Command
Syntax
Description
ctext<cr>
Show calibration information text.
ctext [text]<cr>
Set a new calibration information text to be shown
after the automatic text "Calibrated at".
Example:
pass 1300
ctext
Calibrated at 5.0% in lab
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Chapter 4 – Vaisala Industrial Protocol
Syntax
Description
Example (set a new information text):
ctext 0% 5% by NN
Calibrated at 0% 5% by NN
Table 36 CCO2 Command
Syntax
Description
cco2<cr>
Show current user adjustment status.
cco2 -lo [co2]<cr>
Perform a 1-point (only either low or high
concentration) or 2-point (both low and high
concentrations) calibration and adjustment.
cco2 -hi [co2]<cr>
-lo = Adjustment at low concentration (under
2 %CO2)
-hi = Adjustment at high concentration (over
2 %CO2)
co2 = CO2 concentration reference in ppm
cco2 -save<cr>
Save the currently entered adjustments.
Successfully saving the adjustment clears the
calibration date (cdate command) and calibration
text (ctext command) that have been stored in the
probe. Use those commands to enter a new
calibration date and text.
cco2 -cancel<cr>
Cancel currently entered adjustments.
cco2 -reset<cr>
Clear user adjustments.
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 high 200000
2.Meas. point high 200000
Gain : 1.0000
Offset : 0.0000
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Description
Example (perform a 1-point calibration):
1. Let the probe stabilize in the desired CO2 concentration (here: 5 %CO2 (=50000 ppm)).
2. Enter the calibration commands:
pass 1300
cco2 -hi 50000
OK
cco2 -save
OK
3. Enter a new calibration date and information text:
cdate 20150630
Calibration date : 20150630
ctext 5% in lab
Calibrated at 5% in lab
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Syntax
Description
Example (perform 2-point calibration):
1. Let the probe stabilize in the desired low CO2 concentration (here: 0 %CO2).
2. Enter the calibration commands:
pass 1300
cco2 -lo 0
OK
cco2 -save
OK
3. Let the probe stabilize in the desired high CO2 concentration (here: 5 %CO2 (=50000 ppm)).
4. Enter the calibration commands:
pass 1300
cco2 -hi 50000
OK
cco2 -save
OK
5. Enter a new calibration date and information text:
pass 1300
cdate 20150430
Calibration date : 20150430
ctext 0% 5% by NN
Calibrated at 0% 5% by NN
4.13 Environmental Compensation
Commands
To apply an accurate relative humidity compensation, the temperature and pressure
compensation configurations must also match your measurement environment. See the
rhcmode, tcmode and pcmode commands for instructions on enabling compensation
configuration, and env command for instructions on setting a compensation value.
For more information on environmental compensation and the default (neutral)
compensation values used for disabled compensations, see 2.5 Environmental
Compensation (page 15)
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Table 37 Env Command
Syntax
Description
env<cr>
Show current compensation values.
Before using this command, you must enable
environmental compensation using the following
commands:
•
•
•
•
env [temp | pres | oxy | hum]
[value]<cr>
o2cmode [on]
pcmode [on]
rhcmode [on]
tcmode [on | measured]
Set new permanent compensation values and store
them in EEPROM.
EEPROM:
• Non-volatile memory, values retained during power
off.
• Number of writes is limited to 30000 cycles by
memory implementation.
• Must only be used for writing permanent values, to
avoid wearing out the EEPROM.
temp = Compensation temperature. Range -40 ...
+100 °C (-40 ... +212 °F).
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 %.
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Syntax
Description
env [xtemp | xpres | xoxy | xhum]
[value]<cr>
Set new compensation values and store them in RAM.
RAM:
• Volatile memory that loses the values when probe
is reset, and where values are loaded from nonvolatile (EEPROM) memory at power-on
• Must be used for continuously updated values.
xtemp = Compensation temperature stored in RAM.
Range -40 ... 100 °C (-40 ... +212 °F).
xpres = Compensation pressure stored in RAM.
Range 500 ... 1150 hPa.
xoxy = Oxygen content of background gas stored in
RAM. Range 0 ... 100 %.
xhum = Relative humidity of background gas stored in
RAM. Range 0 ... 100 %.
Note: If temperature
compensation is configured to use
an internally measured value
(tcmode is set to measured), it
will continuously update the value
in RAM, overriding any
temperature value that is written
to RAM with the ENV command.
Example (Show current compensation values; all compensations are enabled. Note that temperature
compensation is in "measured" mode, so the value in use is constantly changing):
env
In eeprom:
Temperature (C) : 25.00
Pressure (hPa) : 1013.00
Oxygen (%O2) : 21.00
Humidity (%RH) : 50.00
In use:
Temperature (C) : 36.40
Pressure (hPa) : 1013.00
Oxygen (%O2) : 19.70
Humidity (%RH) : 93.00
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Syntax
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Description
Example (set temperature compensation to setpoint mode, and change temperature setpoint value to 37.2 in
RAM):
pass 1300
tcmode on
T COMP MODE : ON
env xtemp 37.2
In eeprom:
Temperature (C) : 25.00
Pressure (hPa) : 1013.00
Oxygen (%O2) : 21.00
Humidity (%RH) : 50.000
In use:
Temperature (C) : 37.2
Pressure (hPa) : 1013.00
Oxygen (%O2) : 19.70
Humidity (%RH) : 93.00
Table 38 O2cmode Command
Syntax
Description
o2cmode<cr>
Check current oxygen compensation mode.
Possible modes:
• on = Compensation enabled using setpoint value.
• off = Compensation disabled, default (neutral)
value used: see 2.5 Environmental Compensation
(page 15)
o2cmode [on | off]<cr>
Change oxygen compensation mode (on or off).
Example (check oxygen compensation mode; oxygen compensation is disabled, a neutral value is used):
pass 1300
o2cmode
O2 COMP MODE : OFF
Example (enable oxygen compensation):
pass 1300
o2cmode on
O2 COMP MODE : ON
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Table 39 Pcmode Command
Syntax
Description
pcmode<cr>
Check current pressure compensation mode.
Possible modes:
• on = Compensation enabled using setpoint value.
• off = Compensation disabled, default (neutral)
value used: see 2.5 Environmental Compensation
(page 15).
pcmode [on | off]<cr>
Change pressure compensation mode (on or off).
Example (check pressure compensation mode; pressure compensation is enabled using a setpoint value):
pass 1300
pcmode
P COMP MODE : ON
Table 40 Rhcmode Command
Syntax
Description
rhcmode<cr>
Check current relative humidity compensation mode.
Possible modes:
• on = Compensation enabled using setpoint value.
• off = Compensation disabled, default (neutral)
value used: see 2.5 Environmental Compensation
(page 15).
To apply an accurate relative
humidity compensation, make
sure that the temperature
compensation and pressure
compensation configurations also
match the measurement
environment.
rhcmode [on | off]<cr>
Change relative humidity compensation mode (on or
off).
Example (check relative humidity compensation mode; relative humidity compensation is disabled, a neutral
value is used):
pass 1300
rhcmode
RH COMP MODE : OFF
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Syntax
M211799EN-F
Description
Example (enable temperature, pressure and relative humidity compensation using setpoint values):
pass 1300
tcmode on
T COMP MODE : ON
pcmode on
P COMP MODE : ON
rhcmode on
RH COMP MODE : ON
Table 41 Tcmode Command
Syntax
Description
tcmode<cr>
Check current temperature compensation mode.
Possible modes:
• on = Compensation enabled using setpoint value.
• off = Compensation disabled, default (neutral)
value used: see 2.5 Environmental Compensation
(page 15)
• measured = Compensation enabled using internal
measurement.
tcmode [on | off | measured]<cr>
Change temperature compensation mode (on, off or
measured).
Example (check temperature compensation mode; temperature compensation is enabled using a setpoint
value):
pass 1300
tcmode
T COMP MODE : ON
Example (change temperature compensation to use internal measurement):
pass 1300
tcmode measured
T COMP MODE : MEASURED
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4.14 Other Commands
Table 42 Frestore Command
Syntax
Description
frestore<cr>
Restore the probe to its factory configuration. All user
settings and user calibration parameters will be lost.
After using the frestore
command, reset the probe using
the reset command.
Example (restore the factory settings and reset the probe):
pass 1300
frestore
Parameters restored to factory defaults
reset
GMP251 1.0.0
Table 43 Pass Command
Syntax
Description
pass [code]<cr>
Access advanced serial commands.
Advanced commands can be used until the next reset.
code = Code for enabling advanced commands
(1300).
Example:
pass 1300
Table 44 Reset Command
Syntax
Description
reset<cr>
Reset the probe. The probe will restart as if it had just
been powered on.
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Syntax
Example:
reset
GMP251 1.0.0
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Description
Chapter 5 – Modbus
5. Modbus
The probe can be accessed using the Modbus serial communication protocol. The supported
Modbus variant is Modbus RTU (Serial Modbus) over RS-485 interface.
For instructions on enabling the Modbus mode when you are using the probe with Vaisala
Industrial Protocol, see 4.6 Enabling Modbus Mode from Vaisala Industrial Protocol
(page 28).
For instructions on switching to Vaisala Industrial Protocol when the probe is in Modbus
mode, see 4.5 Accessing Serial Commands from Modbus or Analog Mode (page 27).
For information on using Modbus with the Indigo 202 digital transmitter, see 6.8 Using
Modbus with Indigo 202 (page 69).
The pre-configured default Modbus serial settings are presented in the following table.
Table 45 Default Modbus Serial Communication Settings
Description
Default Value
Serial bit rate
19200
Parity
N
Number of data bits
8
Number of stop bits
2
Modbus device address
240
More Information
‣ Modbus Registers (page 107)
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Chapter 6 – Using GMP251 with Indigo Transmitters
6. Using GMP251 with Indigo
Transmitters
6.1 Indigo Overview
1
2
4
3
5
6
Figure 10 GMP251 Attached to Indigo Transmitter
1
2
3
4
5
6
3.5” TFT LCD color display: non-display option with LED available for certain models.
Probe locking wheel: insert probe, hold in place and turn the wheel counterclockwise.
Probe orientation mark: insert the probe with the orientation mark facing out.
Wireless configuration interface (WLAN) activation button
Rubber lead-through with strain relief. Cable feedthrough option also at back of
transmitter.
Input/output cable
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The probe can be connected to Vaisala Indigo transmitters, either directly on the transmitter
from the probe's connector, or by using a cable between Indigo and the probe.
Indigo transmitters are host devices that extend the feature set of connected probes with a
range of additional options for outputs, configuration access, measurement viewing, and
status monitoring.
The selection of available additional features (for example, output and connectivity options)
varies depending on the Indigo transmitter model. Depending on the model, a display is
available as an optional selection or as a standard feature. In the non-display model, an LED
indicator is used for notifications.
6.1.1 Wireless Configuration Interface Overview
Indigo transmitters are configured using a wireless browser-based configuration interface
(requires a mobile device or computer with IEE 802.11 b/g/n WLAN wireless connectivity). In
addition to probe and transmitter configuration and calibration, you can also use the
wireless interface to view measurement data and status information.
Figure 11 Desktop and Mobile Example Views
The wireless configuration interface has two user levels. All users have view-only access (no
configuration rights, not password protected), and personnel that carry out configuration
tasks can log in with an administrative password that allows changing the transmitter and
probe settings.
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Chapter 6 – Using GMP251 with Indigo Transmitters
To use the wireless configuration interface to modify the settings of your Indigo transmitter
and the connected probe, you must first enable the transmitter's wireless connection and
then connect to Indigo with your mobile device or computer. Most major browsers (for
example, Firefox, Chrome, Safari and Internet Explorer) are supported: using the most recent
version is recommended.
6.2 Taking a Probe in Use with Indigo
In order to use the probe with an Indigo transmitter, you need to connect the probe to an
Indigo transmitter and use a mobile device or computer to review the transmitter and probe
configuration with Indigo's wireless configuration interface.
• Indigo-compatible probe and Indigo transmitter
• Mobile device or computer that supports wireless connectivity (IEEE 802.11 b/g/n
WLAN)
• Web browser
To take the probe in use with Indigo:
1. Connect the probe to a wired and powered Indigo transmitter and check that the
transmitter recognizes the probe (green LED/display notification).
2. Enable Indigo's wireless connection and open the Indigo wireless configuration
interface in your mobile device or computer.
3. Use Indigo's wireless configuration interface to check that the probe and transmitter
settings are correct for your system. For instructions on using the wireless
configuration interface, see the User Guide of the Indigo transmitter.
More Information
‣
‣
‣
‣
Attaching Probes and Cables (page 63)
Connecting to Wireless Configuration Interface (page 64)
Wireless Interface Menus (page 66)
Logging in to Wireless Configuration Interface (page 65)
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6.2.1 Probe Compatibility
All Indigo-compatible probes can be used with all Indigo transmitter models. To verify that
your probe is compatible with Indigo, check the serial number on the probe body. All probes
intended for use with Indigo manufactured from 2017 onwards (serial numbers starting with
the letter N or latter in alphabetical order) have full compatibility.
Made in Finland, Vaisala Oyj
Vanha Nurmijärventie 21, FI-01670 Vantaa
CO2 PROBE GMP251 A2B0A1N1
Output: 0... 20% CO2 RS485 Vaisala protocol
Input: 12 – 30 V d
Serial No. N0310004
1
r
cR
Figure 12 Serial Number on Probe Body (GMP251 Example)
1
62
Probes with a serial number starting with the letter N have been manufactured in 2017.
Chapter 6 – Using GMP251 with Indigo Transmitters
6.3 Attaching Probes and Cables
2
3
1
Figure 13 Attaching Probes and Cables to Indigo
1
2
3
Insert probes into the probe connector with the orientation mark facing out.
Probes are locked in place with the locking wheel. Never turn from the probe body.
Connect probe cables in the same way as probes: insert the cable in the connector and
hold in place while turning the locking wheel.
1. Insert the probe into the probe connector with the orientation mark on the probe body
facing out.
2. Hold the probe in the probe connector and lock it in place by turning the locking wheel
counterclockwise. Never turn the probe body when attaching or removing probes, only
the locking wheel of the Indigo transmitter.
3. When the transmitter recognizes the connected probe, it shows a notification message
on the display (for example, Probe Connected: GMP251). In the non-display model, a
green LED is lit when Indigo recognizes the probe.
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6.4 Connecting to Wireless Configuration
Interface
1
2
Indigo 200
3

500
ppm
Carbon dioxide concentration

Select WLAN to connect to:
1. WLAN XYZ
2. Indigo_IDxx
3. WLAN ABC
WLAN on
Figure 14 Enabling and Accessing Indigo's Wireless Configuration Interface
1
2
3
Wireless connection activation button
Wireless connection indicator (WLAN symbol) on the Indigo display
Choose Indigo (Indigo_ID[xx]) from your wireless device's list of available connections
To connect to the wireless configuration interface:
1. Press the wireless connection activation button on the bottom of the transmitter.
2. When the wireless configuration interface becomes available, the Indigo display shows
a connection notification. In the Indigo models with an LED indicator, the LED blinks
green when the connection is active.
3. Open the wireless connection menu in your mobile device or computer and select
Indigo_ID[xx] (transmitter-specific SSID) from the list of available connections.
4. Depending on your device, the wireless configuration interface either launches
automatically in your browser after you connect to Indigo, or you may need to start
your browser application manually.
5. When you open the Indigo interface in your browser, you are prompted to log in. See
6.5 Logging in to Wireless Configuration Interface (page 65) for instructions.
Only one device can be connected to the wireless configuration interface at a time.
More Information
‣ Logging in to Wireless Configuration Interface (page 65)
‣ Wireless Interface Menus (page 66)
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Chapter 6 – Using GMP251 with Indigo Transmitters
6.5 Logging in to Wireless Configuration
Interface
Figure 15 Indigo Login View
When you open Indigo's wireless configuration interface in your browser, you are prompted
to log in. There are 2 available user levels:
• User: view-only access available for all users. Does not require a password.
• Admin: password-protected access. To change settings, you must log in as admin.
To log in:
1. Enter the user name and password:
a. To log in as user (view-only access, no configuration rights), select User from the
User name dropdown. Leave the Password field empty.
b. To log in as admin (required for configuration), select Admin in the User name
dropdown and type the admin password (default: 12345) in the Password field.
2. Select Log in after entering the login credentials. The wireless configuration interface
opens in the Measurements view.
The user level (User or Admin) is shown in the upper right corner of all menu views.
Select the user/admin icon in the upper right corner to change the user level.
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6.6 Wireless Interface Menus
1
2
3
4
5
Figure 16 Wireless Configuration Interface, Desktop Browser View
1
2
3
4
5
Measurements: displays the measurement data of the connected probe
Status: contains information about the status of Indigo and the connected probe (for
example, notifications and alarms)
Calibration: calibrate and adjust probes using references. Available options (for
example, adjustment points) vary depending on the probe model.
Settings: contains options for configuring the connection and display settings, outputs,
relays, probe-specific settings, and general device preferences
• General submenu: device information and general settings, wireless connection
and display settings
• Outputs submenu: options for configuring analog or digital outputs (depending on
transmitter model).
• Relays submenu: settings for controlling relays A and B
• Probe submenu: probe-specific settings such as environmental compensations and
filtering factor
Main display area for menus and measurement information (desktop browser example)
For more information on the configuration options available in Indigo transmitters, see the
User Guide of your transmitter.
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6.7 Configuring Analog Outputs with
Indigo 201
Indigo 201 analog output transmitters have 3 analog current (mA) or voltage (V) outputs.
Each analog output has the same set of configuration options (analog output 1 shown in
example).
Note that you must select either the current or voltage output mode: using both current and
voltage outputs is not possible.
When you enter a value into a field, the value is saved automatically when you exit the
input field (for example, tap on an area outside of the field).
Figure 17 Indigo 201 Analog Output Configuration Options
For detailed instructions on configuring analog outputs in the Indigo 201 wireless
configuration interface, see Indigo 201 Analog Output Transmitter User Guide.
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More Information
‣ Indigo 201 Analog Output Mode Selection (page 68)
6.7.1 Receiving Analog Output Settings from Probe
When you take Indigo 201 in use for the first time and have not entered an analog output
configuration, the transmitter automatically adapts the analog output configuration of the
first Vaisala Indigo-compatible probe you connect.
If an analog output configuration already exists in Indigo 201 (that is, you have previously
connected a probe or configured the settings), you need to set the analog output
configuration of the new probe manually. Analog output from the transmitter is halted and
does not resume until you have set the new probe's configuration.
Alternatively, you can clear the analog output settings in Indigo 201 configuration. This
returns the transmitter to a state where it automatically starts using the analog output
configuration of the next connected probe. The analog output settings can be cleared from
the Settings > General menu.
Figure 18 Clearing Analog Output Settings
6.7.2 Indigo 201 Analog Output Mode Selection
Indigo 201 has 3 analog output channels for either current (mA) or voltage (V) output. All 3
channels must use the same output mode (mA or V): it is not possible to use both voltage
and current outputs simultaneously.
The output mode selection is made in the Settings > Outputs menu of the wireless
configuration interface.
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Chapter 6 – Using GMP251 with Indigo Transmitters
Figure 19 Selecting Indigo 201 Analog Output Mode
6.8 Using Modbus with Indigo 202
Indigo 202 digital transmitters are designed for Modbus RTU (RS-485) communication.
There are 2 groups of Modbus register addresses in use in Indigo 202: probe registers and
Indigo registers. The probe registers are received from the connected probe, and are
organized according to the probe's register map. Indigo registers include transmitterspecific information.
Received Modbus requests for register operations are treated in two different ways
depending on the register address. Addresses above DFFFhex (that is, Indigo registers) are
handled as normal requests. Lower addresses (that is, probe registers 0000hex ... DFFFhex)
are passed to the measurement probe, and the response the from probe is again passed to
original Modbus client. Indigo can also have a cache for commonly requested registers
(Measurement registers).
The maximum response delay is 2 seconds (when data content needs to be fetched from the
probe). The minimum delay between requests is 10 ms.
For more details on the information relayed within Indigo 202 (transmitter-specific)
Modbus registers, see Indigo 202 Digital Transmitter User Guide.
Table 46 Indigo 202 Modbus Registers
Address
Name
Data Type
Probe registers (according to the connected probe's register map) 1)
0000hex
First measurement probe address
DFFFhex
Last measurement probe address
Indigo registers
E000hex
Status
16-bit
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Address
Name
Data Type
E001hex
Notification and error bits
16-bit
E002hex
Connected probe
text [30]
E011hex
Relay A status
enum
E012hex
Relay B status
enum
1)
See the connected probe's Modbus documentation for probe-specific register information
More Information
‣ Modbus Registers (page 107)
‣ Modbus (page 57)
6.8.1 Modbus Serial Communication Settings
The Settings > Outputs menu of the wireless configuration interface contains the
configuration options for Modbus serial communication.
Protocol
Speed
Stop Bits
Parity
Slave Address
70
Modbus protocol options. The Modbus RTU protocol is in use by default.
Select the baud rate used in Modbus communication: 4800, 9600, 19200,
38400, 57600, or 115200. Default: 19200.
Stop bits used in Modbus communication: 1 or 2. Default: 2.
Select EVEN, ODD or NONE. Default: NONE.
Address used when Indigo functions as a Modbus slave (range: 1 ... 247).
Default: 10.
Chapter 6 – Using GMP251 with Indigo Transmitters
6.9 Configuring Relays with Indigo
Indigo transmitters have 2 configurable relays (relay A and relay B). Both relays have
configuration options for selecting the parameter that is used to control the relay, activation
triggers, hysteresis, and error state behavior.
1
2
3
4
4
5
Figure 20 Relay Configuration Options
1
2
3
4
5
Output Mode: Select whether the relay activates above or below a set trigger value (or
set the relay Off).
Parameter: The measurement that is used to control the relay.
Unit: Select the unit of the measurement parameter that controls the relay (for example,
% if the measurement is in %CO2).
Low Trigger Level and High Trigger Level: If you want to activate the relay above or
below a single setpoint without using hysteresis, enter the same value for the low
trigger and the high trigger. The Output Mode selection defines whether the relay
activates above or below this value.
If you want to set a hysteresis, define the limits of the hysteresis with the low and high
triggers. See the Indigo documentation for instructions on setting a hysteresis.
Error State: Select which state the relay is set to when an error occurs (on, off, or
remains in its current state)
For detailed instructions on configuring relays with Indigo, see the Indigo transmitter's
User Guide.
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6.10 Changing Environmental
Compensation Settings with Indigo
The configuration options in Indigo transmitters include probe-specific settings that vary
depending on the features of the connected probe.
In the case of Vaisala CARBOCAPâ Carbon Dioxide Probes GMP251 and GMP252, the probespecific settings allow configuring the filtering factor and environmental compensations.
To change the environmental compensation settings:
1. Launch the Indigo wireless configuration interface and open the Settings > Probe
menu.
2. Enable the required environmental compensations (set the compensation On or Off)
you need to use in the Measurement selections. For temperature compensation, select
either the measurement from the probe sensor (Measured), or manual Setpoint entry.
3. Enter the setpoint values for the compensations you have enabled into the
Compensation setpoints text fields.
The values entered into the Compensation setpoints fields are only for temporary
use: when you reset the probe, the default values (see Compensation power-up
defaults) are restored.
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4. Enter the power-up default compensation values that are stored into the probe's
permanent memory.
The values entered into the Compensation power-up defaults fields remain in use
also after probe reset.
5. The values you enter are saved automatically when you exit the input field (for
example, tap on an area outside of the field).
Note that the environmental compensations you set in the Settings > Probe and the
compensations set on the Configuration tab of the Calibration menu are interconnected:
the configuration set in either menu is applied to both.
6.11 Configuring Filtering Factor with
Indigo
The filtering factor affects the speed at which the latest measurement is integrated into the
output of the probe: a new measurement is produced approximately every two seconds. You
can configure the filtering factor in the Settings > Probe menu of Indigo's wireless
configuration interface.
By default, the filtering factor is set to 1.0 (1.0 = 100 in the configuration range), which
means the latest measurement is shown directly in the output, without any filtering. To
apply filtering, enter a lower filtering factor to include previous measurements in the
calculation of measurement output. For example, changing the filtering factor to 0.1 results
in an output that is a combination of previous measurements (90%) and the latest
measurement (10%).
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The configuration range of the filtering factor is 0 ... 100: for example, to set the factor to
0.5, set the value to 50.
More Information
‣ Filtering Factor (page 114)
6.12 Calibrating GMP251 with Indigo
6.12.1 Indigo Calibration Overview
You can carry out 1-point and 2-point adjustments with the Indigo transmitter's wireless
configuration interface. In addition to calibrating and adjusting probes, you can view the
current adjustments and restore the probe's factory adjustment.
1
2
3
4
Figure 21 Calibration Menu Main View
1
2
3
4
Calibration tab
Configuration tab
Diagnostics tab
Measurements tab
There are 4 tabs in the Calibration menu:
• Calibration: the main adjustment view with options for making adjustments, viewing
adjustments, and restoring factory adjustments.
• Configuration: options for using environmental compensations (probe-specific range
of options) that allow compensating for the conditions present in the calibration
environment, for example, pressure, temperature, and background gases. Also includes
probe-specific configuration options that are not mandatory for use with Indigo.
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• Diagnostics: this tab contains information about the status of the measurement and
the probe, and shows the current environmental compensation configuration.
• Measurements: this tab shows the current probe measurement in numeric format (use
this view, for example, when you need to follow measurement stablization in a
reference environment without leaving the Calibration menu).
Before adjusting the probe's measurement, make sure you have gone through the
information in 8.3 Calibration and Adjustment (page 90).
Starting and Closing Calibration Mode in Indigo
In order to be able to use the calibration options, you must switch the operation of the probe
and Indigo to calibration mode with the Start calibration button.
1
Figure 22 Start Calibration Button
1
Start calibration button on the Calibration tab
When you start the calibration mode, the Start calibration button is replaced with the Stop
calibration button. The calibration mode remains active until you close it by selecting Stop
calibration.
You can use other menus while the calibration mode is active, and return to the Calibration
menu later to complete your adjustments.
Always close the calibration mode to return the probe and Indigo to normal operating
mode. The measurement performance of the probe can be affected when used in
calibration mode. You must close the calibration mode with the Stop calibration button
also when no changes are made.
6.12.2 Restoring Factory Adjustment
Always restore factory adjustment before entering a new adjustment. This prevents any
possible earlier adjustments having an effect on the new adjustment you make.
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To restore factory adjustment:
1. Connect to the wireless configuration interface and open the Calibration menu.
2. Start the calibration mode with the Start calibration button.
3. On the Calibration tab, scroll down to the parameter you want to adjust (for example,
CO2 adjustment) and select Restore factory adjustment.
4. Restore the factory adjustment with the Restore factory adjustment button for each
parameter separately as needed.
5. To verify that the factory adjustment was restored, check the adjustment data
information at the bottom of the Calibration tab view.
6. Close the calibration mode with the Stop calibration button.
6.12.3 Calibration PIN Code
Probe calibration can be locked and unlocked with a calibration PIN code in the Indigo
transmitter's Settings > Probe menu. By default, the calibration PIN code is in place and
calibration is enabled. Do not remove the PIN code from the probe settings unless you need
to block access to calibration settings.
For GMP251, the calibration PIN code is 1300.
6.12.4 1-point Adjustment with Indigo
Prepare the calibration reference (for example, a reference gas with a known concentration)
before starting the adjustment.
When you enter a value into a field, the value is saved automatically when you exit the
input field (for example, tap on an area outside of the field).
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To make a 1-point adjustment with Indigo wireless configuration interface:
1. Connect to the wireless configuration interface and open the Calibration menu.
2. Start the calibration mode with the Start calibration button.
If you cannot enter configurations after selecting Start calibration, check that the
calibration PIN code is in place in the Settings > Probe menu.
3. If you need to set environmental compensations, enable and set the required
compensations on the Configuration tab.
Note that the environmental compensations you set on the Configuration tab and
the compensations you set in the Settings > Probe menu are interconnected: the
configuration set in either menu is applied to both.
4. Remove any possible previous adjustments by restoring the factory adjustment: select
Restore factory adjustment for each parameter you are adjusting.
5. Enter the calibration date and calibration information into the corresponding text fields.
6. Place the probe in the reference environment (adjustment point 1) and wait until the
measurement has stabilized. You can follow the stabilization from the Measurements
tab.
7. Enter the value of the reference (for example, 500 if calibrating with a 500 ppmCO2
reference gas) into the Reference value, point 1 field.
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8. After you enter the reference value, the value of the Measured value, point 1 field
updates automatically.
9. After you have entered the reference point, select Store adjustment to save the
adjustment.
10. Close the calibration mode with the Stop calibration button.
11. To check that the adjustment was carried out correctly, review the information in the
Adjustment data fields at the bottom of the view.
6.12.5 2-point Adjustment with Indigo
To make a 2-point adjustment, you need a low reference and a high reference (select
references that are near the low and high ends of your measurement range). Prepare the
calibration references (for example, reference gases with known concentrations) before
starting the adjustment.
To make a 2-point adjustment with Indigo wireless configuration interface:
1. Open the wireless configuration interface in the browser of your wireless device and
open the Calibration menu.
2. Start the calibration mode with the Start calibration button.
3. If you need to set environmental compensations, enable and set the required
compensations on the Configuration tab.
4. Remove any possible previous adjustments by restoring the factory adjustment: select
Restore factory adjustment for each parameter you are adjusting.
5. Enter the calibration date and calibration information into the corresponding text fields.
6. Place the probe in the first reference environment (adjustment point 1) and wait until
the measurement has stabilized.
7. Enter the value of the first reference (for example, 0 if calibrating with a 0 ppmCO2
reference gas) into the Reference value, point 1 field.
8. After you enter the reference value, the value of the Measured value, point 1 field
updates automatically.
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9. Place the probe in the second reference environment (adjustment point 2) and wait
until the measurement has stabilized.
10. Enter the value of the second reference (for example, 2000 if calibrating with a 2000
ppmCO2 reference gas) into the Reference value, point 2 field.
11. When both reference points have been entered, select Store adjustment to save the
adjustment.
12. Close the calibration mode with the Stop calibration button.
13. To check that the adjustment was carried out correctly, review the information in the
Adjustment data fields at the bottom of the view.
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Chapter 7 – Operating with MI70 Indicator
7. Operating with MI70
Indicator
7.1 Overview of MI70 Support
The probe 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.
7.2 Basic Display
Figure 23 MI70 Basic Display
1
2
3
4
5
Measured parameter and compensations
(up to three items on display
simultaneously). You can change the
shown items in Main menu > Display >
Quantities and units.
Battery indicator. Shows current status
(charge) of the battery.
Function key Graphic shows the readings
as a curve.
Function key Hold/Save freezes the
display and you can save the reading in
the MI70 memory.
Function key Record is a quick access to
the Recording/Viewing menu.
You can change the default function key shortcuts (Graphic, Hold/Save, Record) to other
menus or functions in Main menu > Settings > User interface > Program shortcut keys.
7.3 Graphical Display
The graphical display shows you the measurements as a curve (the curve of the uppermost
quantity shown in the basic display). From the curve you can examine the data trend and
history of the last minutes.
To open the graphical display, select Graphic in the basic display or select Main menu >
Display > Graphic history > Show.
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To get the statistical info on the graph area (minimum, maximum, and average values), press
Info.
To get the curve of the other selected quantities, press Next. To get the curves of all the
quantities, press Next until the text All appears, and then select All .
To zoom in and out, press the up/down arrow keys.
To move back and forward in the timeline, use the left/right arrow keys.
7.4 Main Menu
In the main menu, you can configure the MI70 settings and basic display options, view
information about the probe, access recordings and clear the memory, set alarms, start
adjustments, and use the analog output option of the MI70 indicator.
To open the main menu and navigate in the menus:
1. Go to the basic display.
2. Press any arrow key, then select Open (must be pressed within 5 seconds or the
indicator returns to the basic display).
3. Move in the menus using the
4. Select an item with the
buttons.
button.
5. To return to the previous level, press
.
6. To return to normal operation, press
Exit.
7.5 Connecting Probe to MI70 Indicator
1. If the probe is installed permanently into a device (for example, an incubator or a
chamber), disconnect the probe from the connector.
2. If the MI70 indicator is on, turn it off.
3. Connect the probe to the MI70 indicator using the MI70 connection cable (Vaisala order
code: CBL210472).
4. Turn on the MI70 indicator (time and date are requested at first startup). MI70 detects
the probe and proceeds to show the measurement screen. The parameters measured
by probe will start to show valid measurement results after a few seconds.
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7.6 MI70 Indicator Parts
1
Figure 24 MI70 Indicator Parts
1
2
2
3
3
4
5
4
5
6
6
Charger socket
Function buttons . The functions
change according to what you are doing
with the indicator.
Arrow buttons:
Move up in a menu
Move down in a menu
Enter a sub-menu
Return to previous menu level
Power On/Off button
Battery compartment at the back of the
indicator
Two ports (labeled I and II) for
connecting probes and instruments.
To open menus, press an arrow button and then press the shortcut buttons. To activate a
function shown above the shortcut button, press the shortcut button. To navigate in the
menus, press arrow buttons.
7.7 Holding and Saving the Display
With the Hold/Save function, you can freeze a certain display reading. This reading can be
saved in the MI70 memory and it will be available even after MI70 is disconnected from the
transmitter.
1. In the basic display, select Hold/Save. Alternatively, select Main menu > Display >
Hold/Save display > Hold.
2. Press Save.
3. To view the saved display, go to basic display and select Record > View recorded data.
Alternatively, select Main menu > Recording/Viewing > View recorded data.
A list of saved displays and data recordings appears. The icons on the left of the date
and time indicate whether the file is a saved display or a longer recording of data:
Saved display
Data recording
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4. Select the saved display based on date and time by pressing the right arrow key.
7.8 Recording Data
With MI70, you can record transmitter measurement data over a certain period at chosen
intervals. These recordings are saved in MI70 memory and are available even after MI70 is
disconnected from the transmitter.
7.9 Changing Environmental
Compensation Settings with MI70
Indicator
You can see the compensation values that are currently used by the probe 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: currently active pressure compensation value.
Ocomp: currently active oxygen concentration compensation value.
Hcomp: currently active relative humidity compensation value.
Figure 25 CO2 Reading with Tcomp and Pcomp on MI70 Screen
You can change the compensation settings from Main menu > Settings > Measurement
settings.
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Figure 26 Probe Compensation Settings on MI70 Screen
When you turn a compensation off, the probe 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.
7.10 Calibration and Adjustment with
MI70 Indicator
Before using the MI70 indicator for calibration and adjustment, read the instructions in 8.3
Calibration and Adjustment (page 90). Make sure that the environmental compensation
settings of the probe are properly set for your calibration environment; see 7.9 Changing
Environmental Compensation Settings with MI70 Indicator (page 84).
When two probes are connected to the MI70 indicator, MI70 uses Roman numerals “I” and
“II” to indicate which port the parameter or function in question is connected to.
7.10.1 1-Point Adjustment with an MI70-Compatible Reference
Probe
1. Connect the GMP251 probe 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 GMP251’s sensor.
3. If you are using the calibration adapter to feed a calibration gas to the GMP251, 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.
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5. Start the adjustment sequence from Main menu > Functions > Adjustments.
6. MI70 notifies you that automatic power off is disabled during adjustment mode, press
OK to acknowledge.
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.
10. Select To same as CO2(II).
11. You will be prompted to confirm you want to adjust: select Yes.
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12. If the adjustment is successful, 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, 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.
7.10.2 1-Point Adjustment with a Reference Gas
1. Connect the GMP251 to Port I of the MI70 indicator.
2. Feed a calibration gas to the GMP251 using the calibration adapter accessory (Vaisala
order code: DRW244827SP). 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.
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.
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9. Select 1-point adjustment.
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.
13. You will be prompted if you really want to adjust. Select Yes.
14. If the adjustment is successful, 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, 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.
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8. Maintenance
8.1 Cleaning
You can clean the probe body by wiping it with a moist cloth. Standard cleaning agents can
be used.
When cleaning, follow these precautions:
• Do not immerse the probe in liquid to clean it.
• Be careful not to block the filter when cleaning the probe. The optional sintered PTFE
filter is especially sensitive to blockage.
• When changing the filter, you can use clean instrument air to gently blow any loose dirt
and filter material from the sensor. Do not attempt to clean the optical surfaces in any
other manner.
8.1.1 Chemical Tolerance
The following chemicals can be used to clean the probe:
• H2O2 (2000 ppm), non-condensing
• Alcohol-based cleaning agents such as ethanol and IPA (70 % Isopropyl Alcohol, 30 %
water)
• Acetone
• Acetic acid
Avoid exposing the probe to chemicals for unnecessarily long periods of time. Do not
immerse the probe in a chemical, and wipe chemicals off the probe after cleaning.
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8.2 Changing the Filter
Change the filter to a new one if it shows visible signs of contamination or dirt. When
changing the filter, use clean gloves to avoid blocking the pores of the new filter.
Figure 27 Opening the Filter
CAUTION! When changing the filter, you can use clean instrument air to gently blow
any loose dirt and filter material from the sensor. Do not attempt to clean the optical
surfaces in any other manner.
8.3 Calibration and Adjustment
Calibrate and adjust the CO2 measurement of the probe 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.
Performing an accurate calibration and adjustment takes some time and preparation.
Instead of doing it yourself, you can also have a Vaisala Service Center calibrate and adjust
your probe.
Calibration means comparing the measurement output of the device to a known
reference, such as a known environment in a calibration chamber or the output of a
reference instrument. Correcting the reading of the device so that is measures accurately
is referred to as adjustment.
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8.3.1 Calibration Setup
Using Hand-Held Meter as Reference
You can perform a 1-point calibration using a hand-held meter as a reference. You will need a
calibrated reference instrument to compare against, for example a GM70 hand-held meter
with a calibrated GMP221 probe.
With the probe and the reference instrument in the same space, allow the measurement to
stabilize before comparing the readings. Try to provide as stable an environment as you can
during this time. Avoid working around the probe and reference instrument during this time.
Using Calibration Gas as Reference
There are two easy ways to use a calibration gas as a reference:
• You can supply the gas to the probe using the calibration adapter accessory (Vaisala
order code DRW244827SP). 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. You can use calibration gas a
reference by putting the probe in a suitable chamber (for example, an incubator) and
filling that chamber 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.
8.3.2 Effect of Environmental Compensations
The probe has various environmental compensations that improve its CO2 measurement
accuracy (see 2.5 Environmental Compensation (page 15)). 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 the builtin temperature sensor or
an integrated system, make sure to correct the setpoints so that they correspond to
your calibration situation. Consider switching temperature compensation to use the
internal sensor and/or integrated system when calibrating, and then switching back
when calibration and adjustment is done.
• The effect of background gas compensations for humidity and oxygen may be
significant when using calibration gases, since these gases are often dry and oxygenfree. For example, pure nitrogen gas is typically used as a convenient 0 ppm CO2
reference. As it does not contain any oxygen or humidity, the compensations for them
must be set to zero.
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• Remember to restore the normal compensation settings after completing calibration
and adjustment. If you are integrating the calibration functionality of the probe as part
of a control software, also implement proper handling of the environmental
compensations.
More Information
‣ Environmental Compensation (page 15)
8.3.3 Limits of Adjustment
The probe 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 (the 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 probe depends on the interface
you are using for adjustment.
8.3.4 Adjustment Types
You can adjust the CO2 measurement of the probe in one or two points.
• One-point adjustment is recommended if you are interested in maintaining a fixed CO2
level. 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 probe. If you
want to integrate the functionality into a control system, the Modbus interface and the
Vaisala industrial protocol are recommended. If you want to compare the reading of the
probe to a reference instrument and adjust it accordingly, use an MI70 hand-held indicator
and a reference probe.
Vaisala Industrial Protocol
Vaisala industrial protocol supports 1-point and 2-point adjustment with the cco2
command. Configuration of the environmental compensation settings can be done using
serial line commands.
Modbus
The environmental compensation settings can be configured using Modbus registers.
MI70 Hand-Held Indicator
MI70 hand-held indicator supports 1-point adjustment, either using a calibration gas or using
a reference instrument that is connected to the MI70.
Indigo transmitters
You can use the Indigo transmitter's wireless configuration interface to carry out
adjustments and change the environmental compensation settings.
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More Information
‣
‣
‣
‣
Calibration and Adjustment (page 45)
Configuration Registers (page 108)
Calibration and Adjustment with MI70 Indicator (page 85)
Calibrating GMP251 with Indigo (page 74)
8.3.5 DRW244827SP Calibration Adapter
The optional calibration adapter accessory can be used to feed a reference gas to the probe
through a gas port when calibrating. 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.
1
3
2
Figure 28 DRW244827SP Calibration Adapter with Probe Inserted
1
2
3
O-ring inside the adapter
Gas outlet on each side of the adapter
Gas port (port outer diameter 4.6 mm, port hole inner diameter 2 mm, suitable for
tubing with 4 mm inner diameter)
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Chapter 9 – Troubleshooting
9. Troubleshooting
9.1 Problem Situations
Problem
Possible Cause
Remedy
Analog output reading is
unchanging and appears incorrect.
Analog output is in error state.
Remove the cause of the error
state and the analog output will
recover its normal function.
Probe outputs stars "****" on serial
line instead of measurement data.
Incorrect supply voltage.
Check the power supply.
Unable to access probe on the
RS-485 line.
Check the active errors using the
ERRS command on the serial line.
Unsuitable operating environment.
Verify that the operating
environment is within specified
operating limits.
Incorrect wiring.
Check that the RS-485 connection
is wired correctly.
Probe in POLL mode with unknown Power cycle or reset the probe and
address.
try again.
CO2 measurement not working.
Condensation on the sensor.
Remove the filter and 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-occurrence.
9.2 Error Messages
The error messages are categorized according to the severity of the status:
• Critical errors are fatal to the operation of the unit. It may not be able to respond to
communication at all, and will not measure correctly.
• Errors prevent CO2 measurement and cause the analog outputs to be set to the error
state. Depending on the problem, errors may resolve themselves. For example, sensor
heating will eventually dry out condensation on the optical surfaces.
• Warnings do not prevent normal operation but may indicate possible problems.
• Status indicates a known state of the unit.
Error Message
Description
Recommended Action
Program memory is corrupted.
Fatal error, contact Vaisala.
Critical errors
Program memory crc critical error
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Error Message
Description
Recommended Action
Parameter memory crc critical
error
Parameter memory is corrupted.
Fatal error, contact Vaisala.
Errors
Low supply voltage error
Check supply voltage.
Internal 30 V error
Low internal 30 V voltage.
Low RX signal error
Low input signal. Can be caused by
dirt or condensation on the optical
surfaces.
Internal 8 V error
Low internal 8 V voltage.
RX signal cut error
Signal distortion (EMC
interference)
Out of measurement range error
CO2 concentration is too high to
measure.
Sensor heater error
Sensor heater resistance is out of
range.
IR temperature error
IR source temperature error.
FPI slope error
Signal receiver error.
Internal 2.5 V error
Internal 2.5 V voltage out of range.
Internal 1.7 V error
Internal 1.7 V voltage out of range.
Low IR current error
IR source failure.
Contact Vaisala.
Signal too low warning
Low input signal. Can be caused by
dirt or condensation on the optical
surfaces.
Continue normally.
Cut warning
EMC interference error limit
approaching.
Check for EMC interference
sources.
Unexpected restart detected
Transmitter is reset by watchdog
process.
Continue normally.
Wait to see if condensation is
removed by heat.
Wait for CO2 concentration to fall
into the measurable range.
Contact Vaisala.
Warnings
Status messages
CO2 adjustment mode active
Complete the CO2 adjustment.
9.3 Analog Output Error State
The probe 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 significantly outside the scaled output range.
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The default error level depends on the output type:
Output
Default Error Level
0 ... 20 mA
23 mA
4 ... 20 mA
2 mA
0 ... 5 V
0V
0 ... 10 V
0V
The probe resumes normal operation of the analog output when the cause of the error state
is removed.
9.4 Indigo Wireless Connection
Troubleshooting
The following table contains troubleshooting information related to accessing the wireless
(WLAN) configuration interface of Vaisala Indigo transmitters.
Problem
Possible Cause
Remedy
The wireless device has connected
to the Indigo access point, but the
configuration interface does not
launch.
The device you are using to
connect to Indigo does not launch
the browser automatically after
connecting to the access point.
After connecting to Indigo, open
your browser application.
The wireless connection requires
an authentication or
acknowledgement before the
Indigo interface opens in your
browser.
Check your device's notifications to
see if an authentication or login
prompt is present for the Indigo
connection. Acknowledge the
connection and open your browser
application if the interface does
not launch automatically.
Indigo access point is not enabled
or an error is has occurred.
Switch off the Indigo WLAN
connection, enable the connection
again and retry.
Your device is too far from the
transmitter or obstacles are
blocking the signal.
Move closer to the transmitter and
refresh your device's access point
list.
Indigo shows up in the list of
available wireless connections, but
connecting to it does not work.
A device is already connected to
the Indigo access point.
Ensure that your device is the only
one that is connecting to the
wireless configuration interface.
The interface does not open in the
browser.
The browser has issues with
loading the landing page.
Enter the default Indigo IP address
http://192.168.1.1 in the browser's
address bar.
The Indigo access point does not
show up in your device's list of
available WLAN connections.
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Problem
Possible Cause
Remedy
Cannot connect to the Indigo
access point with iPhone.
The iPhone WLAN settings prevent
establishing a connection.
See the iPhone connection
instructions in the Indigo
transmitter's User Guide.
Indigo does not respond when
pressing the wireless connection
activation button.
WLAN functionality has been
disabled with the WLAN ON/OFF
DIP switch on Indigo's circuit
board.
Enable WLAN functionality with
the WLAN ON/OFF DIP switch. See
the instructions in the Indigo
transmitter's User Guide.
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Chapter 10 – Technical Data
10. Technical Data
10.1 GMP251 Specifications
Table 47 Performance
Property
Specification
Measurement range
0 ... 20 %CO2
Accuracy at 25 °C (77 °F) and 1013 hPa (Incl. Repeatability and Nonlinearity)
at 5 %CO2
±0.1 %CO2
0 ... 8 %CO2
±0.2 %CO2
8 ... 20 %CO2
±0.4 %CO2
Calibration Uncertainty
at 5 %CO2
±0.07 %CO2
at 20 %CO2
±0.22 %CO2
Long-term Stability
0 ... 8 % %CO2
±0.3 %CO2/year
8 ... 12 %CO2
±0.5 %CO2/year
12 ... 20 %CO2
±1.0 %CO2/year
Temperature Dependence
with compensation at 5 %CO2, 0 ... 50 °C (32 ... 122 °F)
<±0.05 %CO2
with compensation, 0 … 20 %CO2, -40 … 60 °C (-40 ...
140 °F)
±0.045 % of reading/°C
without temperature compensation at 5 %CO2
(typical)
-0.25 % of reading/°C
Pressure Dependence
with compensation at 5 %CO2, 700 ... 1100 hPa
±0.05 %CO2
with compensation, 0 … 20 %CO2, 500 ... 1200 hPa
±0.015 % of reading/hPa
without compensation (typical)
+0.15 % of reading/hPa
Humidity Dependence
with compensation, 0 … 20 %CO2, 0 … 100 %RH
±0.7 % of reading (at 25 °C (77 °F))
without compensation (typical)
+0.05 % of reading/%RH
O2 Dependence
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Property
Specification
with compensation, 0 … 20 %CO2, 0 ... 90 %O2
±0.6 % of reading (at 25 °C (77 °F))
without compensation (typical)
-0.08 % of reading/%O2
Flow Rate Dependence (For Flow-through Model Option)
< 1 l/min flow
no effect
1 … 10 l/min flow
<0.6% of reading/ l/min
Start-up, Warm-up and Response Time
Start-up time at 25 °C (77 °F)
< 10 s
Warm-up time for full spec.
< 4 min
Response time (T90) with standard filter
< 1 min
Flow-through option response time (T90) with > 0.1
l/min
< 1 min
Response time (T90) with spray shield
< 2 min
Table 48 Operating Environment
Property
Specification
Operating temperature of CO2 measurement
-40 ... +60 °C (-40 ... +140 °F)
Storage temperature
-40 ... +70 °C (-40 ... +158 °F)
Humidity
0 ... 100 %RH, non-condensing
Condensation prevention
Sensor head heating, when power on
Electromagnetic compatibility
EN61326-1, Generic Environment
Chemical tolerance (temporary exposure during
cleaning)
• H2O2 (2000 ppm, non-condensing)
• Alcohol-based cleaning agents (for example
ethanol and IPA)
• Acetone
• Acetic acid
Pressure
Compensated
500 ... 1100 hPa
Operating
< 1.5 bar
Gas Flow (For Flow-through Option)
Operating range
< 10 l/min
Recommended range
0.1 … 0.8 l min
100
Chapter 10 – Technical Data
Table 49 Inputs and Outputs
Property
Specification
Operating Voltage
With digital output in use
12 ... 30 VDC
With voltage output in use
12 ... 30 VDC
With current output in use
20 ... 30 VDC
Digital output
Over RS-485:
• Modbus
• Vaisala Industrial Protocol
Analog outputs
• 0 ... 5/10 V (scalable), min load 10 kΩ
• 0/4 ... 20 mA (scalable), max load 500 Ω
Power Consumption
Typical (continuous operation)
0.4 W
Maximum
0.5 W
Table 50 Mechanics
Property
Specification
Materials
Probe housing material
PET plastic
Filter
PTFE membrane, PET plastic grid
Connector
Nickel plated brass, M12 / 5 pin
IP rating, probe body
IP65
Connector
M12 5-pin male
Weight, probe
45 g
Dimensions
Probe diameter
25 mm
Probe length
96 mm
10.2 Spare Parts and Accessories
Information on spare parts, accessories, and calibration products is available online at
www.vaisala.com and store.vaisala.com.
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Name
Order Code
Standard membrane filter
ASM211650SP
Porous sintered PTFE filter (extra protection)
DRW243649SP
Probe cable with open wires (1.5 m)
223263SP
Probe cable with open wires and 90° plug (0.6 m)
244669SP
Probe cable with open wires (10 m)
216546SP
Flow-through adapter with gas ports
ASM211697SP
USB cable for PC connection
242659
MI70 connection cable for probe
CBL210472
Flat cable for GMP250 probes, M12 5-pin
CBL210493SP
Probe mounting clips (2 pcs)
243257SP
Probe mounting flange
243261SP
Calibration adapter
DRW244827SP
Spray shield
ASM212017SP
10.3 GMP251 Probe Dimensions
The dimensions are given in millimeters (mm).
96 mm, Ø 25 mm
Filter
M12 male
connector
12 mm
Figure 29 GMP251 Dimensions
102
75 mm
9 mm
Chapter 10 – Technical Data
10.4 243261SP Mounting Flange
Dimensions
50
Ø 4.2
35.4
mm
Figure 30 243261SP Mounting Flange Dimensions
Ø 60
5
5
17
Ø 36
Ø 25.6
Ø 28.5
Ø 42
mm
Figure 31 243261SP Mounting Flange Dimensions, Cross Section
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10.5 DRW244827SP Calibration Adapter
Dimensions
mm
Figure 32 DRW244827SP Calibration Adapter Dimensions
10.6 ASM212017SP Spray Shield
Dimensions
72 mm
Ø 40 mm
Shield + GMP251: 113 mm
Shield + GMP252: 146 mm
Figure 33 ASM212017SP Spray Shield Dimensions
104
Chapter 10 – Technical Data
mm
Figure 34 GMP251 Spray Shield Cross Section
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Appendix A – Modbus Reference
Appendix A. Modbus
Reference
A.1 Function Codes
Table 51 Supported Function Codes
Function Code (Decimal)
Function Code (Hexadecimal)
Name
03
03hex
Read Holding Registers
16
10hex
Write Multiple Registers
43/14
2Bhex / 0Ehex
Read Device Identification
A.2 Modbus Registers
CAUTION! The decimal numbering of register addresses used in this manual is 1-based
(the register addresses start from 1). Note that the register addresses in actual Modbus
messages (Modbus Protocol Data Unit (PDU)) start from zero. Subtract 1 from the
decimal addresses presented in this manual to get the address used in the Modbus
message (for example, the decimal register address 1 (Measured CO2 value) becomes
register address 0 in the actual Modbus message).
Accessing unavailable (temporarily missing) measurement data does not generate an
exception. “Unavailable” value (a quiet NaN for floating point data or 0000hex for integer
data) is returned instead. An exception is generated only for any access outside the
applicable register ranges.
A.2.1 Measurement Data
Table 52 Modbus Measurement Data Registers (Read-Only)
Address
(Decimal)
Address
(Hexadecimal)
Register Description
Data Format
Unit
1
0000hex
Measured CO2 value
32-bit float
ppm
3
0002hex
Compensation T
32-bit float
°C
5
0004hex
Measured T
32-bit float
°C
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Address
(Decimal)
Address
(Hexadecimal)
Register Description
Data Format
257
0100hex
Measured CO2 value
16-bit signed integer ppm (up to 32 000
ppm)
258
0101hex
Measured CO2 value
16-bit signed integer ppm1) (scaled, up to
approx. 320 000
ppm)
1)
Unit
The ppm output of the second Measured CO2 value register (address 258) is scaled and must be multiplied by 10.
A.2.2 Configuration Registers
CAUTION! Default power-up values (registers 513-519) are written into non-volatile
EEPROM memory. The EEPROM memory implementation has a limit of 30000 writes,
and is intended to be used only when saving long-term or permanent configurations.
Use the volatile memory (registers 521-527, values cleared on power-up) for nonpermanent configurations (for example, if the probe is used in a system that regularly
updates the compensation values).
Table 53 Modbus Configuration Data Registers (Writable)
Address
(Decimal)
Address
(Hexadecimal)
Register Description
Data
Format
Unit / Valid Range
513
0200hex
Power-up value for
pressure
compensation
32-bit float
hPa
700 ... 1500 hPa
Operating <1.5 bar
(Init/default: 1013.25)
515
517
519
0202hex
0204hex
0206hex
Power-up value for
temperature
compensation
32-bit float
Power-up value for
humidity
compensation
32-bit float
Power-up value for
oxygen compensation
32-bit float
°C
-40 ... +80
(Init/default: 25)
%RH
0 ... 100 %
(Init/default: 0)
%O2
0 ... 100 %
(Init/default: 0)
521
108
0208hex
Volatile (value cleared
at probe reset)
pressure
compensation
32-bit float
Range 700...1500 hPa
(Init copied from power-up value)
Appendix A – Modbus Reference
Address
(Decimal)
Address
(Hexadecimal)
Register Description
Data
Format
Unit / Valid Range
523
020Ahex
Volatile (value cleared
at probe reset)
temperature
compensation
32-bit float
Range -40...+80 °C
Volatile (value cleared
at probe reset)
humidity
compensation
32-bit float
Volatile (value cleared
at probe reset) oxygen
compensation
32-bit float
525
527
020Chex
020Ehex
(Init copied from power-up value)
Range 0...100 %RH
(Init copied from power-up value)
Range 0...100 %O2
(Init copied from power-up value)
769
0300hex
Modbus address
16-bit
integer
Valid range 1...247 (default: 240)
770
0301hex
Serial speed
enum
Valid range 4800...115200
0 = 4800
1 = 9600
2 = 19200
3 = 38400
4 = 57600
5 = 115200
(default: 2 (19200))
771
0302hex
Serial parity
enum
0 = None
1 = Even
2 = Odd
(default: 0 (None))
772
773
0303hex
0304hex
Serial stop bits
Pressure
compensation mode
16-bit
integer
Valid range 1...2
enum
0 = Off
(default: 2)
1 = On
(default: 1 (On))
774
0305hex
Temperature
compensation mode
enum
0 = Off
1 = Given
2 = Measured
(default: 2 (Measured))
775
0306hex
Humidity
compensation mode
enum
0 = Off
1 = On
(default: 0 (Off))
776
0307hex
Oxygen compensation
mode
enum
0 = Off
1 = On
(default: 0 (Off))
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Address
(Decimal)
Address
(Hexadecimal)
Register Description
Data
Format
Unit / Valid Range
777
0308hex
CO2 filtering factor
16-bit
integer
Valid range 0 ... 100
(default: 100 (no filtering)).
For information on setting the
filtering factor, see A.4 Filtering
Factor (page 114).
To apply an accurate relative humidity compensation (775), you must also enable
temperature compensation (774) and pressure compensation (773).
A.2.3 Status Registers
Table 54 Modbus Status Registers (Read-Only)
Address
(Decimal)
Address
(Hexadecimal)
Register
Description
Data
Format
Notes
2049
0800hex
Device status
16-bit
0 = Status OK.
1 = Critical error.
2 = Error.
4 = Warning.
2050
0801hex
CO2 status
16-bit
0 = Status OK.
2 = CO2 reading not reliable. Appears
during transmitter start-up.
256 = Measurement not ready. Appears
during transmitter start-up.
Multiple statuses can be present simultaneously. In those cases, the value of the status
register is the sum of the status values. For example, the value of the device status register
is 6 if a warning (4) and an error (2) are present simultaneously.
More Information
‣ Error Messages (page 95)
110
Appendix A – Modbus Reference
A.2.4 Device Identification Objects
Table 55 Device Identification Objects
Object ID (Decimal)
Object ID
(Hexadecimal)
Object Name
Example Contents
0
00hex
VendorName
"Vaisala"
1
01hex
ProductCode
"GMP25x Carbon Dioxide
Probe "
2
02hex
MajorMinorVersion
Software version (for
example "1.2.3")
3
03hex
VendorUrl
"http://
www.vaisala.com/"
4
04hex
ProductName
"GMP25X "
128
80hex
SerialNumber1)
Transmitter serial number
(for example,
"K0710040")
129
81hex
Calibration date1)
Date of the factory
calibration
130
82hex
Calibration text1)
Information text of the
factory calibration
1)
Vaisala-specific device information object
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A.3 Modbus Communication Examples
Reading CO2 Value
Device address used in the following examples is 240 (F0hex).
The values returned by the device differ depending on the ambient conditions and/or
device settings. Your device might not return exactly same values.
Request
Response
Bytes on the Line
(Hexadecimal)
Description
Bytes on the Line
(Hexadecimal)
Description
(silence for 3.5 bytes)
Start of Modbus RTU
frame
(silence for 3.5 bytes)
Start of Modbus RTU
frame
F0hex
GMP25x address
F0hex
GMP25x address
03hex
Function (Read Holding
Registers)
03hex
Function (Read Holding
Registers)
00hex
Register address
04hex
Number of data bytes
D4hex
Value of first register
(least significant word)
00hex
00hex
02hex
D1hex
Number of 16-bit
registers to read (2)
Modbus RTU checksum
2Ahex
(silence for 3.5 bytes)
7Ahex
43hex
E8hex
33hex
End of Modbus RTU
frame
Value of second register
(most significant word)
Modbus RTU checksum
ABhex
(silence for 3.5 bytes)
End of Modbus RTU
frame
Communication Description
Register address
1 (1-based Modbus documentation format) = 0000hex
(0-based format used in actual communication).
Data format
Two 16-bit Modbus registers interpreted as IEEE 754
binary32 floating point value, least significant word
first.
Returned value
43E8D47Ah, which is binary32 representation of
465.65997 (ppm).
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Appendix A – Modbus Reference
Writing Volatile Compensation Pressure Value
Request
Response
Bytes on the Line
(Hexadecimal)
Description
Bytes on the Line
(Hexadecimal)
Description
(silence for 3.5 bytes)
Start of Modbus RTU
frame
(silence for 3.5 bytes)
Start of Modbus RTU
frame
F0hex
GMP25x address
F0hex
GMP25x address
10hex
Function (Write Multiple
Registers)
10hex
Function (Write Multiple
Registers)
02hex
Register address
02hex
Register address
08hex
00hex
08hex
Number of registers to
write (2)
00hex
04hex
Number of data bytes
D4hex
50hex
Value for the first
register (least significant
word)
93hex
02hex
00hex
44hex
7Dhex
Value for the second
register (most significant
word)
0Ehex
Modbus RTU checksum
B7hex
(silence for 3.5 bytes)
End of Modbus RTU
frame
Number of 16-bit
registers written (2)
02hex
Modbus RTU checksum
(silence for 3.5 bytes)
End of Modbus RTU
frame
The response to a write function
informs that the function was
correctly received by the device.
It does not guarantee that the
written value was accepted by
the device (for example, in case
out-of-range values).
To verify that the value was really
accepted by the device, read the
register value after writing.
Communication Description
Register address
521 (1-based Modbus documentation format) =
0208hex (0-based format used in actual
communication).
Data format
Two 16-bit Modbus registers interpreted as IEEE 754
binary32 floating point value, least significant word
first.
Value to write
1013.25 (hPa), in binary32 format 447D5000hex.
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A.4 Filtering Factor
Modbus register 777 sets the CO2 filtering factor.
The filtering factor affects the speed at which the latest CO2 measurement is integrated into
the output of the probe. A new measurement is produced approximately every two seconds.
By default, the filtering factor is set to 1.0, which means the latest measurement is shown
directly in the output, without any filtering. If the measuring environment produces
occasional exceptionally high or low readings that need to be averaged out in the output,
filtering can be applied.
To apply filtering, you need to set a filtering factor that determines how much the previous
measurements affect the calculation of measurement output. For example, when using
filtering factor of 0.1, the new output is a combination of previous measurements (90%) and
the latest measurement (10%).
Examples of the effect of filtering on output:
• Filtering factor 1.0 = No filtering, the latest measurement is output directly without
integrating previous measurements.
• Filtering factor 0.5 = The reading output shows ~75% of the measurement change after
two two-second measurement cycles and ~93% after four cycles.
• Filtering factor 0.1 = The reading output shows ~90% of the measurement change after
22 measurement cycles.
The configuration range of the filtering factor is 0 ... 100 in the 16-bit register: for example, to
set the factor to 0.5, set the value of the register to 50.
The following formula is used when calculating the output:
�new = �old + �new − �old × �
onew
oold
mnew
f
114
New output
Previous output
New measurement
Filtering factor
Warranty
For standard warranty terms and conditions, see 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.
Technical Support
Contact Vaisala technical support at helpdesk@vaisala.com. Provide at least the following
supporting information:
• Product name, model, and serial number
• Name and location of the installation site
• Name and contact information of a technical person who can provide further
information on the problem
For more information, see www.vaisala.com/support.
Recycling
Recycle all applicable material.
Follow the statutory regulations for disposing of the product and packaging.
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www.vaisala.com