Vaisala GMP231 User Manual

M211501EN-E

User Guide

Carbon dioxide probe for CO2 incubators

GMP231

PUBLISHED BY

Vaisala Oyj Vanha Nurmijärventie 21, FI-01670 Vantaa, Finland P.O. Box 26, FI-00421 Helsinki, Finland +358 9 8949 1

Visit our Internet pages at www.vaisala.com.

No part of this document 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 documents 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 document are subject to change without prior notice.

Local rules and regulations may vary and they shall take precedence over the information contained in this document. Vaisala makes no representations on this document’s compliance with the local

rules and regulations applicable at any given time, and hereby disclaims any and all responsibilities related thereto.

This document 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

1. Commands......................................................................................................... 7

1.1 Version information.......................................................................................... 7

1.2 Related manuals................................................................................................7

1.3 Documentation conventions............................................................................7

1.4 Trademarks........................................................................................................8

1.5 Patent notice..................................................................................................... 8

2. Product overview............................................................................................ 9

2.1 Introduction to GMP231....................................................................................9

2.2 Basic features and options.............................................................................10

2.3 GMP231 parts.....................................................................................................11

2.4 Operating principle of CO2 measurement....................................................12

2.5 Environmental compensation........................................................................13

2.5.1 Pressure compensation...........................................................................14

2.5.2 Temperature compensation ...................................................................14

2.5.3 Background gas compensations............................................................14

2.6 Probe startup...................................................................................................14

2.7 Analog output overrange behavior...............................................................15

2.8 Safety................................................................................................................15

2.8.1 ESD protection......................................................................................... 16

2.9 Regulatory compliances................................................................................. 16

3. Installation........................................................................................................ 17

3.1 Thermal management.....................................................................................17

3.2 Avoiding condensation................................................................................... 17

3.3 Probe installation depth................................................................................. 17

3.4 Dimensions.......................................................................................................18

3.5 Recommended installation...........................................................................20

3.6 Wiring...............................................................................................................22

3.7 Power supply...................................................................................................23

4. Vaisala Industrial Protocol........................................................................ 24

4.1 Overview of Vaisala Industrial Protocol.......................................................24

4.2 Serial interface settings................................................................................. 24

4.3 Physical interface............................................................................................24

4.4 Connecting with a computer........................................................................ 24

4.4.1 Installing driver for the USB service cable........................................... 25

4.4.2 Connecting to probe...............................................................................26

4.5 Serial commands............................................................................................ 27

4.6 Device information and status......................................................................29

4.7 Serial line output commands......................................................................... 31

4.8 Changing measurement settings..................................................................35

4.9 Conﬁguring serial line operation.................................................................. 38

4.10 Calibration commands.................................................................................. 40

4.11 Conﬁguring analog output........................................................................... 44

4.12 Other commands............................................................................................47

GMP231 User Guide M211501EN-E

5. I2C interface....................................................................................................50

5.1 Overview of I2C interface.............................................................................. 50

5.1.1 Physical interface....................................................................................50

5.1.2 Communication parameters..................................................................50

5.1.3 Addressing...............................................................................................50

5.1.4 Timing........................................................................................................ 51

5.1.5 Status byte................................................................................................ 51

5.1.6 Checksum.................................................................................................52

5.1.7 Status word..............................................................................................52

5.2 Commands...................................................................................................... 54

5.2.1 Get_Interface_Version .......................................................................... 54

5.2.2 Get_Parameter........................................................................................ 55

5.2.3 Set_Parameter.........................................................................................57

5.2.4 Get_Parameter_Info............................................................................... 59

5.2.5 Adjust.........................................................................................................61

5.3 Adjusting measurement................................................................................ 63

5.3.1 1-point adjustment ................................................................................. 63

5.3.2 2-point adjustment................................................................................. 63

5.4 Data registers..................................................................................................64

5.4.1 Data formats............................................................................................ 64

5.4.2 Register table.......................................................................................... 64

6. Maintenance....................................................................................................69

6.1 Cleaning...........................................................................................................69

6.1.1 Chemical tolerance................................................................................. 69

6.2 Changing the ﬁlter......................................................................................... 69

6.3 Changing the silicone plug............................................................................70

6.4 Calibration and adjustment............................................................................ 71

6.4.1 Calibration setup...................................................................................... 71

6.4.2 Eect of environmental compensations.............................................. 73

6.4.3 Limits of adjustment............................................................................... 73

6.4.4 Adjustment types ...................................................................................73

7. Operating with MI70 indicator................................................................75

7.1 Overview of MI70 support.............................................................................75

7.2 Connecting GMP231 to MI70 Indicator.........................................................75

7.3 Changing environmental compensation settings with MI70 indicator....75

7.4 Calibration and adjustment with MI70 indicator........................................ 77

7.4.1 1-point adjustment with an MI70-compatible reference probe.........77

7.4.2 1-point adjustment with a reference gas..............................................79

8. Troubleshooting............................................................................................. 81

8.1 Problem situations...........................................................................................81

8.2 Analog output error state...............................................................................81

9. Technical data................................................................................................83

9.1 GMP231 speciﬁcations....................................................................................83

9.2 Spare parts and accessories..........................................................................85

Table of contents

Online store.......................................................................................................87

Warranty............................................................................................................ 87

Technical support............................................................................................ 87

Recycling........................................................................................................... 87

GMP231 User Guide M211501EN-E

List of ﬁgures

Figure 1 GMP231 installed through a chamber wall.................................................. 9

Figure 2 GMP231 parts.......................................................................................................11

Figure 3 CARBOCAPâ sensor of the GMP231........................................................... 12

Figure 4 CO2 measurement inside the incubator......................................................13

Figure 5 Probe installation depth..................................................................................18

Figure 6 Probe dimensions without silicone plug.................................................... 18

Figure 7 Probe dimensions with silicone plug...........................................................19

Figure 8 Electronics housing dimensions................................................................... 19

Figure 9 Attachment bracket dimensions.................................................................20

Figure 10 Recommended installation............................................................................ 21

Figure 11 PuTTY terminal application...........................................................................27

Figure 12 Hardware schematic.......................................................................................50

Figure 13 Changing the ﬁlter...........................................................................................70

Figure 14 Changing the silicone plug.............................................................................71

Figure 15 Inserting the calibration adapter over the ﬁlter.......................................72

Figure 16 CO2 reading on MI70 screen......................................................................... 75

Figure 17 CO2 reading with Tcomp and Pcomp on MI70 screen...........................76

Figure 18 GMP231 compensation settings on MI70 screen.....................................76

List of tables

Table 1 Document versions (English)...........................................................................7

Table 2 Related manuals.................................................................................................. 7

Table 3 Applicable patents..............................................................................................8

Table 4 GMP231 connector pinout...............................................................................22

Table 5 Cable ....................................................................................................................23

Table 6 Default serial interface settings....................................................................24

Table 7 Basic serial commands.................................................................................... 27

Table 8 Advanced serial commands...........................................................................28

Table 9 ? Command........................................................................................................ 29

Table 10 SNUM command............................................................................................... 29

Table 11 VERS command................................................................................................ 30

Table 12 SYSTEM command...........................................................................................30

Table 13 TIME command................................................................................................. 30

Table 14 HELP command.................................................................................................30

Table 15 R command......................................................................................................... 31

Table 16 S command.........................................................................................................32

Table 17 INTV command..................................................................................................32

Table 18 SEND command................................................................................................ 32

Table 19 FORM command................................................................................................33

Table 20 Output commands for FORM command....................................................34

Table 21 Modiﬁers for FORM command...................................................................... 35

Table 22 Compensation mode commands................................................................. 35

Table 23 ENV command...................................................................................................36

Table 24 STANDBY command........................................................................................ 38

Table 25 SMODE command.............................................................................................38

Table 26 SERI command.................................................................................................. 39

Table 27 ADDR command............................................................................................... 39

Table 28 SDELAY command...........................................................................................40

Table 29 ECHO command............................................................................................... 40

Table 30 CCO2 command................................................................................................40

Table 31 CDATE command...............................................................................................41

Table 32 CTEXT command.............................................................................................. 42

Table 33 CT command......................................................................................................42

Table 34 CP command......................................................................................................43

Table 35 ASEL command.................................................................................................44

Table 36 AMODE command............................................................................................44

Table 37 AOVER command.............................................................................................45

Table 38 ATEST command..............................................................................................46

Table 39 PASS command................................................................................................. 47

Table 40 OPEN command................................................................................................47

Table 41 CLOSE command..............................................................................................47

Table 42 ERRS command................................................................................................ 48

Table 43 RESET command.............................................................................................. 48

Table 44 FRESTORE command......................................................................................49

Table 45

GMP231 I2C Address..........................................................................................51

List of tables

GMP231 User Guide M211501EN-E

Table 46 GMP231 Device Address...................................................................................51

Table 47 Timing................................................................................................................... 51

Table 48 Status Byte..........................................................................................................52

Table 49 Status word content.........................................................................................53

Table 50 Get_Interface_Version invoke message.....................................................54

Table 51 Get_Interface_Version response message................................................55

Table 52 Get_Parameter invoke message...................................................................55

Table 53 Get_Parameter response message..............................................................56

Table 54 Read CO2 measurement sequence example.............................................56

Table 55 Set_Parameter invoke message....................................................................57

Table 56 Set_Parameter response message.............................................................. 58

Table 57 Set_Parameter return codes..........................................................................58

Table 58 Set compensation temperature sequence example............................... 59

Table 59 Get_Parameter_Info invoke message........................................................ 60

Table 60 Get_Parameter_Info response message................................................... 60

Table 61 Parameter data types......................................................................................60

Table 62 Parameter persistence......................................................................................61

Table 63 Adjust invoke message.....................................................................................61

Table 64 Adjust response message................................................................................61

Table 65 Adjustment subcommands............................................................................62

Table 66 Adjustment parameters..................................................................................62

Table 67 Adjustment return codes................................................................................62

Table 68 Data formats...................................................................................................... 64

Table 69 GMP231 register table......................................................................................64

Table 70 Possible problem situations and their remedies.......................................81

Table 71 Measurement performance............................................................................83

Table 72 Operating environment...................................................................................84

Table 73 Inputs and outputs...........................................................................................84

Table 74 Mechanical speciﬁcations...............................................................................85

Table 75 Spare parts and accessories for GMP231....................................................85

Chapter 1 – Commands

1. Commands

1.1 Version information

This document provides information for installing, operating, and maintaining the Vaisala CARBOCAPâ Carbon Dioxide Probe GMP231.

Table 1 Document versions (English)

Document code Date Description

M211501EN-E April 2020 • Corrected initial CRC calculation value in section

M211501EN-D December 2014 Applicable from software version 1.1.0 onward.

M211501EN-C May 2014 Updated description for ENV command in section

1.2 Related manuals

Checksum (page 52)

• Updated examples in sections Get_Parameter

(page 55) and Set_Parameter (page 57)

• Updated section GMP231 speciﬁcations (page 83)

• Updated document to new visual appearance

Updated section Status word (page 52).

Changing measurement settings (page 35).

Table 2 Related manuals

Document code Name

M211603EN GMP231 Quick Guide

1.3 Documentation conventions

WARNING!

follow instructions carefully at this point, there is a risk of injury or even death.

CAUTION!

follow instructions carefully at this point, the product could be damaged or important data could be lost.

Warning alerts you to a serious hazard. If you do not read and

Caution warns you of a potential hazard. If you do not read and

GMP231 User Guide M211501EN-E

Note highlights important information on using the product.

Tip gives information for using the product more eciently.

Lists tools needed to perform the task.

Indicates that you need to take some notes during the task.

1.4 Trademarks

CARBOCAPâ is a registered trademark of Vaisala Oyj.

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 Oce US 5,827,438

US 6,177,673

European Patent Oce EP0776023

EP0922972

German Patent and Trade Mark Oce 69615635

Japan Patent Oce 4263285

Finnish Patent Oce 112005

105598

Chapter 2 – Product overview

2. Product overview

2.1 Introduction to GMP231

Vaisala CARBOCAPâ Carbon Dioxide Probe GMP231 is designed for incubator manufacturers requiring accurate and reliable carbon dioxide measurements and sterilization durability at high temperatures.

GMP231 probe is based on patented Vaisala CARBOCAPâ technology and a new type of infrared light source. The probe can remain in place during high-temperature sterilization cycles that heat the chamber interior to +180 °C. Special design of the probe enables easy installation through the incubator wall and ensures that the sensor optics and electronics are separated and thermally insulated.

Sensor performance is optimized at 5 %CO2 measurement. GMP231 also has an internal pressure sensor, which allows compensation of the measurement according to ambient

pressure. Since dust and most chemicals do not aect the measurement, and the eect of water vapor can be compensated for, GMP231 is accurate and stable at CO2 incubator

conditions.

Figure 1 GMP231 installed through a chamber wall

GMP231 User Guide M211501EN-E

2.2 Basic features and options

• CO2 measurement range 0 … 20 %CO2.

• Temperature durability in standby mode up to +195 °C (+383 °F).

• Vaisala CARBOCAPâ CO2 sensor with excellent long-term stability.

• Measurement compensated for eects of pressure, temperature, and background gas. Pressure compensation based on integrated pressure sensor.

• Heating to avoid condensation on optical elements.

• Analog output: one current output channel (0 … 20 mA or 4 … 20 mA).

• Digital output:

• I2C.

• RS-485 (non-isolated) with Vaisala Industrial Protocol.

More information

‣

Operating principle of CO2 measurement (page 12)

‣

Environmental compensation (page 13)

‣

Thermal management (page 17)

Chapter 2 – Product overview

2.3 GMP231 parts

Figure 2 GMP231 parts

1 Electronics housing. Contains the main component board, including the digital pressure

sensor.

2 Holes for M4 screws on both sides of the housing. Maximum screw depth 8 mm. Two

screws included, type BN 10649 M4.

3 Type label on housing cover (not shown). 4 8-pin M12 connector. 5 Probe body. 6 Measurement cuvette with optics and CARBOCAPâ CO2 sensor.

7 PTFE ﬁlter. 8 Silicone plug for sealing the lead-through. Recommended accessory, suitable for

∅ 44 mm lead-throughs.

CAUTION!

parts inside. All wiring is done through the M12 connector (4).

More information

‣

Wiring (page 22)

Do not open the electronics housing; there are no user serviceable

GMP231 User Guide M211501EN-E

2.4 Operating principle of CO2 measurement

Vaisala CARBOCAPâ sensor used in the GMP231 is a silicon-based, non-dispersive infrared (NDIR) sensor for the measurement of gaseous carbon dioxide. It is especially designed to tolerate high temperatures in standby mode, up to +195 °C (+383 °F). This allows it to be used in applications that utilize high temperature for heat sterilization. The operating temperature range of the sensor is 0 … +70 °C (+32 ... +158 °F).

Figure 3 CARBOCAPâ sensor of the GMP231

1 Cuvette 2 Mirror 3 Window 4 Sensor chips

The sensitivity to carbon dioxide is based on absorption of infrared light at a characteristic wavelength. The light is emitted by a novel, silicon-based microchip emitter into the cuvette which contains the gas to be measured. After reﬂection from the mirror, the light intensity is measured with a thermopile chip at a wavelength chosen by a micromechanical Fabry–Pérot interferometer (FPI) and a band pass ﬁlter. A hermetically sealed sapphire window is used to protect the sensor chips from moisture and contamination. A heater chip is utilized to prevent condensation in normal operation.

The carbon dioxide measurement consists of two steps: First, the FPI is electrically tuned so that its pass band coincides with the characteristic absorption wavelength of carbon dioxide and the signal is recorded. Second, the pass band is shifted to a wavelength where no absorption occurs in order to get a reference signal. The ratio of these two signals, one at the absorption wavelength and the other at the reference wavelength, gives the fraction of light absorption from which the carbon dioxide concentration is calculated. The reference signal compensates the possible eects of sensor aging and signal attenuation due to dirt on optical surfaces, making the sensor very stable over time.

3 4

9 10

Chapter 2 – Product overview

Figure 4 CO2 measurement inside the incubator

1 Chamber wall 2 Chamber interior 3 Light source 4 Band pass ﬁlter 5 Ambient air (400 … 1000 ppm CO2)

6 Light absorbed by CO2 in the incubator gas 7 Thermopile detector

8 Fabry-Perot interferometer 9 Sapphire window. Separates the sensor’s active components from the

measured environment.

10 Gold-plated mirror

2.5 Environmental compensation

GMP231 improves the CO2 measurement accuracy by applying various environmental compensations. GMP231 compensates for the eects of:

• Pressure

• Temperature

• Background gas oxygen (O2) content

• Background gas relative humidity (%RH)

Compensation parameters are conﬁgured on the order form when ordering the probe, and can later be updated using serial commands, MI70 Indicator, or I2C protocol. If the probe is

integrated in a system that measures one or more of the compensation parameters, they can be updated to the probe continuously.

GMP231 User Guide M211501EN-E

You can also turn o any of the compensations. In that case, GMP231 uses the default compensation value that is mathematically neutral for the probe’s internal compensation model.

For more information on the eect of the compensations on measurement accuracy, see

GMP231 speciﬁcations (page 83).

2.5.1 Pressure compensation

There is a pressure sensor on the component board of the GMP231 that provides a live measurement of ambient pressure. GMP231 can compensate the CO2 measurement based on

this pressure reading, or it can use a ﬁxed setpoint. Using the GMP231’s own sensor is recommended for most applications.

If pressure compensation is turned o, GMP231 uses the default compensation value of 1013.2 hPa.

2.5.2 Temperature compensation

GMP231 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 GMP231.

If temperature compensation is turned o, GMP231 uses the default value of +37 °C (+98.6 °F).

2.5.3 Background gas compensations

Compensation for background gas parameters are based on setpoint values only, as GMP231 has no internal measurement for oxygen concentration or humidity. The default setpoint values are as follows:

• Oxygen concentration: 19.7 %O

• Relative humidity: 93 %RH

If background gas compensations are turned o, GMP231 uses the value 0% for both.

2.6

Probe startup

When powered on, GMP231 starts up within 10 seconds. Measurements from the outputs (digital and analog) become available during this time but note that they only reach speciﬁed accuracy after a one minute warm-up period. For this reason, you should design the incubator’s control system so that it does not rely on measurements from GMP231 during this time.

Speciﬁcally note that the CO2 reading rises to the correct reading as the sensor's infrared emitter achieves operation temperature.

Chapter 2 – Product overview

2.7 Analog output overrange behavior

Analog output of the GMP231 has a deﬁned behavior when the values measured by the probe are outside the scaled analog output range:

• Output is allowed to go 10% over the scaled range.

• Output is set to error state when measured value is more than 10% outside the scaled range.

• Output resumes normal function when measured value returns to within 10% of the selected range.

For example, consider a GMP231 with 0 ... 20 mA analog output, scaled to 0 ... 10 %CO2.

• When measured CO2 rises above 10 %CO2, the output rises above 20 mA.

• The output keeps rising until the measurement is 11 %CO2, at which point the probe outputs 22 mA.

• If the CO2 level rises above 11 %CO2, the output enters the error state, which is 23 mA for the 0 ... 20 mA output.

This overrange and error state behavior is speciﬁc to the analog output, and does not aect the readings provided by the digital outputs.

You can change the analog output overrange behavior using the

More information

‣

Analog output error state (page 81)

2.8

Safety

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

WARNING!

has not been exposed to dangerous contamination, and is safe to handle without special precautions.

CAUTION!

documentation. Improper modiﬁcation or use may lead to safety hazards, equipment damage, failure to perform according to speciﬁcation, or decreased equipment lifetime.

When returning a product for calibration or repair, make sure it

Do not modify the unit or use it in ways not described in the

AOVER command.

GMP231 User Guide M211501EN-E

CAUTION!

serviceable parts inside the probe body.

Do not attempt to open the probe body. There are no user

2.8.1 ESD protection

Electrostatic Discharge (ESD) can damage 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, removing, or inserting any objects in the equipment housing.

To avoid delivering high static voltages to the product:

• Handle ESD‑sensitive components on a properly grounded and protected ESD workbench or by grounding yourself to the equipment chassis with a wrist strap and a resistive connection cord.

• If you are unable to take either precaution, touch a conductive part of the equipment chassis with your other hand before touching ESD‑sensitive components.

• Hold component boards by the edges and avoid touching component contacts.

2.9

Regulatory compliances

The probe is in conformity with the provisions of the following EU directives:

• EMC-Directive

• RoHS-Directive

The conformity is declared with using 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 – Immunity requirements for equipment to be used in a basic EMC environment.

• EN 55032: Class B. Electromagnetic compatibility of multimedia and information technology equipment – Emission requirements.

Chapter 3 – Installation

3. Installation

3.1 Thermal management

GMP231 is designed to remain installed during typical heat sterilization cycles that raise the chamber temperature to 180 °C (356 °F). Since 180 °C is the target temperature for sterilization, it is likely that there are hotspots inside the chamber that are above this temperature. Avoid installing the GMP231 near such hotspots, for example near heating elements. Do not expose the GMP231 to temperatures higher than 195 °C / 383 °F.

The following considerations are most important for achieving the speciﬁed heat durability and measurement stability:

• Only the sensor and its ﬁlter should be exposed to heat. The ﬁlter must be completely in the heated chamber. The probe body must remain inside the unheated chamber wall so that only the end of the probe body extends exactly 2.5 mm into the chamber.

• During the sterilization cycle, you must set the GMP231 to standby mode (turns o the CO2 measurement), or power o the probe completely. The GMP231 automatically stops

its measurement cycle if it detects a high temperature, but it is best if the incubator’s control system sets the GMP231 to standby mode when the sterilization cycle is started.

• The installation tube must be sealed from the chamber side to limit heat conduction, and to prevent CO2 in the chamber from entering the probe. Vaisala recommends a 44 mm

diameter installation tube together with Vaisala’s silicone plug.

• If the chamber wall contains heating elements, or has a construction where hot air is circulated inside the wall, design the installation tube so that excessive heat is not conducted to the GMP231.

3.2

Avoiding condensation

The sensor head of the GMP231 is heated during normal operation, which prevents condensation from forming inside the ﬁlter and on the optical surfaces. The heating is not on when GMP231 is in standby mode or unpowered. For this reason, keep the probe powered and operating when the incubator is in use and humidity inside the chamber is high.

Correct installation depth of the probe is also important for preventing condensation from running to the sensor along the chamber wall.

3.3

Probe installation depth

GMP231 must be installed so that only the sensor element and the ﬁlter are inside the chamber. If the probe is longer than the installation tube, the extra length should extend to the outside of the chamber.

The installation depth must be 2.5 mm. This installation depth provides the speciﬁed heat durability of the probe, and allows the silicone plug to seal the Ø 44 mm installation tube properly.

2.5 mm

163

118.5

Screw BN 10649 M4 x 8 mm (for 1 mm thick sheet metal attachment)

1121

Ø 30.2

1.3°

Ø 19

Ø 24.8

Position only the filter inside the heated chamber

GMP231 User Guide M211501EN-E

Figure 5 Probe installation depth

3.4

Dimensions

Figure 6 Probe dimensions without silicone plug

163

118.5

Screw BN 10649 M4 x 8 mm (for 1 mm thick sheet metal attachment)

1121

Ø 30.2

Ø 19

2.5

Incubator’s inner wall

1.3°

Position only the filter inside the heated chamber

Recommended diameter for installation tube 44 mm

Figure 7 Probe dimensions with silicone plug

M12

54.4

Reserve space for M12 cable

Chapter 3 – Installation

Figure 8 Electronics housing dimensions

4 × Ø3.5

GMP231 User Guide M211501EN-E

Figure 9 Attachment bracket dimensions

3.5

Recommended installation

GMP231 is designed to be installed through a chamber wall, and attached to the chamber chassis using an attachment bracket and the two screw holes on the side of the probe. As the installation depth of the probe inside the chamber is critical, the mounting method must allow the probe to be positioned exactly.

The probe and electronics housing must remain outside the heated chamber. The electronics housing should be in a ventilated space that is open to ambient air.

1 2 3

Figure 10 Recommended installation

Chapter 3 – Installation

1 Ambient air 2 Chamber wall 3 Chamber interior 4 GMP231 electronics housing 5 M4 screw holes on both sides of the probe housing 6 8-pin M12 connector 7 Cable 8 CARBOCAPâ sensor under PTFE ﬁlter. The ﬁlter must be inside the chamber completely. 9 Silicone plug. Insert the plug over the probe from inside the chamber. 10 Ø 44 mm installation tube through the chamber wall. The diameter is important for

proper sealing by the silicone plug.

More information

‣

Wiring (page 22)

5 6 7

4 8

GMP231 User Guide M211501EN-E

3.6 Wiring

GMP231 provides several outputs you can use. Connect the output pins you need, and the power supply and ground pins. Use a shielded cable, and connect the shield to the chassis of the GMP231’s M12 connector, and to ground on the other side.

Ground pin 5 to put the probe in standby mode (stops CO2 measurement). The probe resumes normal measurement operation when pin 5 is no longer grounded, unless its internal

measurement shows the temperature is too high.

Table 4 GMP231 connector pinout

Male 8-pin M12 Pin # Function

2 RS-485 D-

4 Analog output +

5 Standby

6 RS-485 D+

7 Power supply +

8 Ground

- Shield

I2C SDA

I2C SCL

Vaisala’s standard connection cable for the GMP231 (item code DRW240977) is a 90 cm long cable with female 8-pin M12 connector on one end, and open ended wires on the other. It supports all outputs from the GMP231, and connects the cable shield to the connector chassis.

6 8

Chapter 3 – Installation

Table 5 Cable

Female 8-pin M12 Pin # Function Wire color

2 RS-485 D- Brown

4 Analog output + Yellow

5 Standby Gray

6 RS-485 D+ Pink

7 Power supply + Blue

8 Ground Red

- Shield Black

I2C SDA

I2C SCL

White

Green

3.7 Power supply

The supply voltage range of GMP231 is 11 … 30 VDC. If the analog output is used, the supply voltage range is 20 … 30 VDC.

The maximum power consumption is 1 W.

GMP231 User Guide M211501EN-E

4. Vaisala Industrial Protocol

4.1 Overview of Vaisala Industrial Protocol

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

4.2 Serial interface settings

Table 6 Default serial interface settings

Property 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 3-wire interface. The data lines are RS-485 D- and RS-485 D+. Ground is shared with power supply.

The connector is an 8-pin male M12.

More information

‣

Wiring (page 22)

4.4

Connecting with a computer

Connecting with a computer allows you to conﬁgure and troubleshoot your probe using serial line commands.

When connecting using a computer, use a compatible Vaisala USB service cable (item code

221040) and a suitable terminal application.

Chapter 4 – Vaisala Industrial Protocol

More information

‣

Installing driver for the USB service cable (page 25)

‣

Connecting to probe (page 26)

‣

Serial commands (page 27)

4.4.1 Installing driver for the USB service cable

Only Windowsâ operating systems are supported by the driver of the USB service cable.

1. Connect the USB service cable to a USB port on your computer. Windowsâ detects the new device and installs the appropriate driver.

2. Open Devices and Printers from the Windowsâ Start menu. Use search to ﬁnd it if necessary (search for "devices").

3. Locate the cable in the list of devices:

• If the device is listed as Vaisala USB Device with a COM port number in brackets, the cable is ready for use. Note the COM port number, you will need it later.

• If the device is listed as Vaisala USB Instrument Cable without a COM port number listed, you must install the driver manually.

4. To install the driver manually:

a. Disconnect the USB service cable from the computer.

b. Download the Vaisala USB driver at http://www.vaisala.com/software (select the

appropriate USB Instrument Driver Setup for your cable).

c. Run the USB driver installation program Vaisala USB Device Driver

Setup.exe. Accept the installation defaults.

d. Go back to step 1 and verify that the driver installation works as expected.

GMP231 User Guide M211501EN-E

4.4.2 Connecting to probe

The following steps describe how to connect to the probe using the PuTTY terminal application for Windows (available for download at www.vaisala.com) and a USB service cable:

1. Connect the USB service cable between your computer and the M12 connector of the probe.

2. Start the PuTTY application.

3. Select Connection > Serial & USB and check that the correct COM port is selected in the Serial or USB line to connect to ﬁeld. If you are using the PuTTY terminal application supplied by Vaisala, you can press the USB Finder button to open the Vaisala USB Instrument Finder program.

4. Check that the other serial settings are correct for your connection, and change if necessary. Flow control should be set to None unless you have a reason to change it.

5. Select Open to open the connection window and start using the serial line.

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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