Vaisala GMW80 User Manual

M211748EN-G

User Guide

Vaisala CARBOCAP® Carbon Dioxide, Humidity,

and Temperature Transmitters

GMW80 Series

PUBLISHED BY

Vaisala Oyj

Vanha Nurmijärventie 21, FI-01670 Vantaa, Finland P.O. Box 26, FI-00421 Helsinki, Finland

[phone]

Visit our Internet pages at www.vaisala.com.

© Vaisala 2020

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
Table of contents
1.	About this document.....................................................................................	5
1.1	Version information..........................................................................................	5
1.2	Related manuals................................................................................................	5
1.3	Documentation conventions...........................................................................	5
1.4	Trademarks........................................................................................................	6
1.5	Patent notice.....................................................................................................	6
2.	Product overview............................................................................................	7
2.1	Introduction to GMW80 series........................................................................	7
2.1.1	Transmitter parts.......................................................................................	9
2.1.2	GMW87 and GMW88 transmitter parts................................................	10
2.2	Display...............................................................................................................	12
2.2.1	Startup screens.........................................................................................	13
2.2.2	Measurement screen................................................................................	13
2.2.3	Error messages.........................................................................................	14
2.3	Relay..................................................................................................................	15
2.4	CO2 level indicator LEDs.................................................................................	16
2.5	Analog output overrange behavior...............................................................	17
2.6	Safety...............................................................................................................	20
2.7	Regulatory compliance...................................................................................	21
3.	Installation.......................................................................................................	22
3.1	Selecting location...........................................................................................	22
3.2	Opening and closing the transmitter...........................................................	23
3.3	Installing the mounting base........................................................................	24
3.4	Installing GMW87 and GMW88.....................................................................	26
3.5	Wiring...............................................................................................................	27
3.5.1	Wiring GMW83, GMW83D, and GMW83A...........................................	29
3.5.2	Wiring GMW83RP and GMW83DRP.....................................................	30
3.5.3	Wiring GMW84........................................................................................	30
3.5.4	Wiring GMW84S.......................................................................................	31
3.5.5	Wiring GMW86P......................................................................................	32
3.5.6	Wiring GMW87........................................................................................	33
3.5.7	Wiring GMW88........................................................................................	33
4.	Modbus communication............................................................................	34
5.	Maintenance....................................................................................................	36
5.1	Cleaning...........................................................................................................	36
5.2	Replacing the CO2 measurement module (GM10).....................................	36
5.3	Replacing the INTERCAP humidity sensor..................................................	37
6.	Troubleshooting............................................................................................	39
6.1	Solving typical problems...............................................................................	39
6.2	Error state........................................................................................................	42

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7.	Technical data................................................................................................		43
7.1		Specifications..................................................................................................	43
7.2		Spare parts and accessories.........................................................................	46
7.3		Dimensions......................................................................................................	47
Appendix A: Modbus reference..................................................................			49
A.1		Function codes...............................................................................................	49
A.2		Data encoding................................................................................................	49
A.2.1		32-bit floating point format...................................................................	49
A.2.2		16-bit integer format..............................................................................	50
A.3		Modbus registers............................................................................................	50
A.3.1		Measurement data registers..................................................................	50
A.3.2		Status registers.........................................................................................	51
A.3.3		Test value registers...................................................................................	51
A.4		Device identification objects.........................................................................	52
A.5		Modbus communication example................................................................	53
Maintenance and calibration services........................................................			55
Warranty............................................................................................................			55
Technical support............................................................................................			55
Recycling...........................................................................................................			55

2

List of figures

List of figures

Figure	1	GMW80 series transmitter parts...................................................................	9
Figure	2	GMW80 series component board parts....................................................	10
Figure	3	GMW87 transmitter parts...............................................................................	11
Figure	4	GMW88 transmitter parts..............................................................................	12
Figure	5	Example startup screens................................................................................	13
Figure	6	Example measurement screens...................................................................	14
Figure	7	Example error message on display.............................................................	14
Figure	8	Relay indicator LED on GMW84S................................................................	15
Figure	9	Rotary switch....................................................................................................	15
Figure 10		CO2 level indicator LEDs on model GMW83A..........................................	16
Figure	11	Overrange behavior of CO2 measurement with
		4 ... 20 mA output............................................................................................	17
Figure 12		Overrange behavior of CO2 measurement with 0 ... 10 V output.......	18
Figure	13	Overrange behavior of active temperature measurement...................	19
Figure 14		Overrange behavior of relative humidity measurement......................	20
Figure	15	Examples of good installation locations...................................................	22
Figure	16	Examples of unsuitable installation locations.........................................	23
Figure 17		Mounting GMW87 and GMW88..................................................................	26
Figure 18		Routing the cable from behind (GMW83, GMW84, and
		GMW86 models)..............................................................................................	27
Figure 19		Locations of the breakaway tabs................................................................	28
Figure 20		Wiring from below with cable tie strain relief ........................................	29
Figure 21		Wiring for GMW83, GMW83D, and GMW83A.........................................	29
Figure 22		Wiring for GMW83RP and GMW83DRP...................................................	30
Figure 23		Wiring for GMW84.........................................................................................	30
Figure 24		Wiring for GMW84S........................................................................................	31
Figure 25		Wiring for GMW86P.......................................................................................	32
Figure 26		Wiring for GMW87..........................................................................................	33
Figure 27		Wiring for GMW88..........................................................................................	33
Figure 28		GMW87 component board with DIP switches and screw
		terminals............................................................................................................	34
Figure 29		Modbus device address DIP switch example...........................................	35
Figure 30		Disconnecting the GM10 module................................................................	36
Figure 31		Dimensions for GMW83, GMW83A, GMW83RP, GMW84,
		GMW84S, and GMW86P...............................................................................	47
Figure 32		Dimensions for GMW83D and GMW83DRP............................................	47
Figure 33		Dimensions for GMW87 and GMW88.......................................................	48

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GMW80 Series User Guide M211748EN-G

List of tables

Table	1	Document versions (English)............................................................................	5
Table	2	Applicable patents or applications.................................................................	6
Table	3	GMW80 series transmitters...............................................................................	7
Table	4	Relay setpoints....................................................................................................	15
Table	5	Troubleshooting table, transmitters with analog output........................	39
Table	6	Troubleshooting table, transmitter model GMW87...................................	41
Table	7	GMW80 models..................................................................................................	43
Table	8	GMW80 measurement performance............................................................	43
Table	9	GMW80 compliance.........................................................................................	44
Table 10		GMW80 operating environment...................................................................	44
Table 11		GMW80 inputs and outputs...........................................................................	45
Table 12		GMW80 mechanical specifications..............................................................	46
Table 13		Modbus function codes....................................................................................	49
Table 14		Interpretation of 16-bit signed integer values...........................................	50
Table 15		Modbus measurement data registers (read-only)...................................	50
Table 16		Modbus status registers (read-only).............................................................	51
Table 17		Modbus test registers (read-only)..................................................................	51
Table 18		Device identification objects...........................................................................	52

4

Chapter 1 – About this document

1. About this document

1.1 Version information

This document provides detailed instructions for using and maintaining Vaisala CARBOCAPâ Carbon Dioxide, Temperature, and Humidity Transmitter Series GMW80 devices.

Table 1 Document versions (English)

	Document code	Date	Description
	M211748EN-G	November 2020	This manual. Information on new product model GMW87
			added throughout the document. Note about use of shielded
			cables added in Wiring (page 27). Added sections Modbus
			communication (page 34) and Modbus reference
			(page 49). Updated section Technical data (page 43).
	M211748EN-F	January 2018	Previous version. Added new product model GMW88. Wiring
			and mounting instructions updated. Document template
			updated. Removed product models GMW83T and GMW86PT.
	M211748EN-D	November 2015	Added new product models: GMW84 and GMW84S.

1.2 Related manuals

	Document code	Name
	M211660EN	Vaisala Carbon Dioxide Module GM10 Quick Reference Guide

1.3 Documentation conventions

WARNING! 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! Caution warns you of a potential hazard. If you do not read and follow instructions carefully at this point, the product could be damaged or important data could be lost.

Note highlights important information on using the product.

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1.4 Trademarks

Vaisalaâ, CARBOCAPâ, and INTERCAPâ are registered trademarks of Vaisala Oyj. Modbusâ is a registered trademark of Schneider Automation Inc.

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 patent applications and their corresponding national rights:

Table 2 Applicable patents or applications

Issuing office	Publication number
United States Patent and Trademark Office	US 5,827,438
	US 6,177,673
European Patent Office	EP0776023
	EP0922972
German Patent and Trade Mark Office	69615635
Japan Patent Office	4263285
Finnish Patent Office	112005
	105598

6

Chapter 2 – Product overview

2. Product overview

2.1 Introduction to GMW80 series

Vaisala GMW80 series CARBOCAPâ carbon dioxide, humidity, and temperature transmitters are wall-mount transmitters designed to fulfill the needs for CO2 measurements in standard

demand controlled ventilation applications.

The following table lists the GMW80 series transmitters and their features.

Table 3 GMW80 series transmitters

	Model name	CO2 output	T output	RH	Display	CO2	Relay	T setpoint
				output		LEDs
	GMW83	0 ... 10 V	0 ... 10 V	No	No	No	No	No
	GMW83A	0 ... 10 V	0 ... 10 V	No	No	Yes	No	No
	GMW83D	0 ... 10 V	0 ... 10 V	No	Yes 1)	No	No	No
	GMW83RP	0 ... 10 V	0 ... 10 V	0 ... 10 V	No	No	No	No
			Pt1000
			(passive)
	GMW83DRP	0 ... 10 V	0 ... 10 V	0 ... 10 V	Yes 1)	No	No	No
			Pt1000
			(passive)
	GMW84	4 ... 20 mA	4 ... 20 mA	No	No	No	No	No
	GMW84S	4 ... 20 mA	4 ... 20 mA	No	No	No	Yes	No
	GMW86P	4 ... 20 mA	Pt1000	No	No	No	No	No
		0 ... 10 V	(passive)
	GMW87	RS-485	No	No	No	No	No	No
		Modbus RTU
		output
	GMW88	4 ... 20 mA	No	No	No	No	No	No
		0 ... 10 V

1)Temperature measurement data displayed in Celsius scale only.

Letters at the end of the model name stand for the following features:

P	Passive temperature measurement
D	Display
A	CO2 indicator LEDs

RHumidity measurement

SRelay

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GMW80 Series User Guide

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The CO2 measurement is based on the Vaisala proprietary CARBOCAPâ sensor, which uses a

novel, silicon-based microchip emitter instead of an incandescent light bulb. The internal reference in the CO2 sensor guarantees the best stability and operation also in constantly

occupied buildings without frequent readjustments.

CARBOCAPâ sensors give correct CO2 measurements immediately when powered on. As they

have a built-in reference measurement, they do not need a lengthy learning phase before the measured values are correct. Proper operation can be verified immediately after snapping on the device cover.

All GMW80 series transmitters measure carbon dioxide (CO2) and temperature (T) with the exception of GMW87 and GMW88, which measure only CO2. Certain models also include

relative humidity (RH) measurement. Humidity measurement utilizes the Vaisala INTERCAPâ sensor.

For measurements in more demanding conditions (for example, dusty or humid installation locations), the GMW87 and GMW88 models provide an IP64-rated enclosure with a cable gland. The GMW87 model can be accessed with the Modbus RTU protocol over an RS-485 interface. The communication settings for the protocol are entered with DIP switches on the GMW87 component board.

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Chapter 2 – Product overview

2.1.1 Transmitter parts

1	8
2	9

3

10

4

11 5

6

7

Figure 1 GMW80 series transmitter parts

1Opening tab

2Screw terminals. The wiring information is marked on the mounting base next to the terminals.

3Barrier to prevent the cable from being routed below the GM10 measurement module. The area to avoid is marked NO CABLES on the mounting base.

4Orientation arrow. Should point up after mounting base has been installed.

5Opening for cable when wiring from behind (recommended)

6Place for cable tie (optional, for cable strain relief)

7Breakaway tab for routing the cable from below

8Locking screw. Supplied with the transmitter.

9Breakaway tab for routing the cable from above

10CO2 level indicator LEDs (on models with the letter A) or relay indicator LED (on models with the letter S)

11Display (on models with the letter D)

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GMW80 Series User Guide

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1

5

2	9	0	1
	8		2
3	7		3
	6	5	4
4

Figure 2 GMW80 series component board parts

6

1Pins connecting the transmitter cover to the screw terminals when the transmitter cover is in place

2Vaisala INTERCAPâ humidity sensor (on models with the letter R)

3Pt1000 temperature sensor for passive temperature measurement (on models with the letter P)

4Active temperature sensor

5GM10 carbon dioxide measurement module

6Rotary switch for relay setpoint (on models with the letter S)

2.1.2 GMW87 and GMW88 transmitter parts

The enclosure of the IP64-rated GMW87 and GMW88 transmitter models differs from the other GMW80 transmitter models. In GMW87 and GMW88, the screw terminal block is located on the cover of the enclosure instead of the mounting base. Wires are led into the enclosure either through a cable gland on the bottom of the mounting base or a sealed lead-through at the back. The enclosure is opened and closed with 4 screws instead of the opening tab used in other models.

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Chapter 2 – Product overview

3	4	5
2		6
1
		7

8

Figure 3 GMW87 transmitter parts

1DIP switches for Modbus settings

2Screw terminals. The screw terminal block is detachable for easy installation.

3Transmitter cover with captive screws (4 pcs)

4GM10 carbon dioxide measurement module

5Mounting base

6Screw holes for mounting on top and bottom of mounting base (2 screws, Ø 3.5 mm)

7Alternative lead-through for wiring through the back (break seal, transfer cable gland here and seal cable gland hole on bottom of transmitter)

8Cable gland for leading the input/output cable (Ø 4 ... 8 mm) inside the enclosure

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GMW80 Series User Guide M211748EN-G

3

4

2

5

1

6

7

Figure 4 GMW88 transmitter parts

1GM10 carbon dioxide measurement module

2Screw terminals. The wiring information is printed on a label on the mounting base.

3Transmitter cover with captive screws (4 pcs)

4Mounting base

5Screw holes for mounting on top and bottom of mounting base (2 screws, Ø 3.5 mm)

6Alternative lead-through for wiring through the back (break seal, transfer cable gland here and seal cable gland hole on bottom of transmitter)

7Cable gland for leading the input/output cable (Ø 4 ... 8 mm) inside the enclosure

More information

Installing GMW87 and GMW88 (page 26)

Dimensions (page 47)

2.2 Display

GMW80 series transmitters with the letter D in the model name (for example, GMW83D) are equipped with a display.

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Chapter 2 – Product overview

2.2.1 Startup screens

When a GMW80 series transmitter with a display is powered on, it shows a sequence of information screens. The screens are shown for a few seconds each.

Figure 5 Example startup screens

The first screen shows the following information:

•Transmitter model, software version, and serial number.

•Serial number of the connected GM10 CO2 measurement module. If the module is disconnected, no serial number is shown.

•Transmitter status: OK or ERROR. If the status is ERROR, the cause of the error will be shown on the measurement screen after the startup is completed.

The following screen(s) show the configuration of the active analog outputs:

•Output type (for example, 0 ... 10 V).

•Output parameter and unit (for example, CO2 (ppm)).

•Output scaling (for example, 0 ... 2000 ppm).

2.2.2 Measurement screen

After the startup screens the transmitter shows the measurement screen. It shows the measured parameters and an air quality indicator based on the current CO2 level.

•Good air quality: 0 ... 800 ppm CO2

•Fair air quality: 800 ... 1200 ppm CO2

•Poor air quality: >1200 ppm CO2

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GMW80 Series User Guide

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Figure 6 Example measurement screens

Note that temperature measurement data is displayed in Celsius scale only.

2.2.3 Error messages

If there is a problem with measurement, affected readings are replaced with stars. The alarm indicator and an error message will also appear on the screen. If more than one error is active, the display will cycle through the errors, showing each error for a few seconds.

For a list of possible errors and their causes, see Solving typical problems (page 39).

Figure 7 Example error message on display

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Chapter 2 – Product overview

2.3 Relay

Transmitter model GMW84S has one SPST-NO relay (max. 50 VDC / 50 VAC, 500 mA) that is activated when the measured CO2 level rises above the setpoint. When the relay is active

(contact is closed), a green LED is lit on the transmitter cover.

Figure 8 Relay indicator LED on GMW84S

Relay setpoint is set using a rotary switch on the component board. Use a small flat head screwdriver to turn the switch. The switch has ten positions with predefined setpoints.

9 8

7 6

0	1
	2
	3
5	4

Figure 9 Rotary switch

Table 4 Relay setpoints

	Switch position	Setpoint in ppm CO2
	0	600 ppm (default)
	1	700 ppm
	2	800 ppm

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GMW80 Series User Guide	M211748EN-G
Switch position	Setpoint in ppm CO2
3	900 ppm
4	1000 ppm
5	1200 ppm
6	1400 ppm
7	1600 ppm
8	1800 ppm
9	2000 ppm

A hysteresis of 50 ppm is applied to prevent the relay from switching back and forth when the measured value is near the setpoint value. The relay is activated/deactivated when the measured CO2 value passes the setpoint, plus/minus 50 ppm.

For example, consider a transmitter that has the relay setpoint set to 1000 ppm CO2. As the measured CO2 value rises, the relay is activated at

1051 ppm. The relay remains activated until the measured value falls to 949 ppm.

2.4 CO2 level indicator LEDs

Figure 10 CO2 level indicator LEDs on model GMW83A

16