Vaisala CARBOCAP GMW80 Series 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
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 CO2level 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 CO2measurement 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
Table of contents
1

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
GMW80 Series User Guide M211748EN-G
2

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 CO2level indicator LEDs on model GMW83A..........................................16
Figure 11 Overrange behavior of CO2measurement with
4 ... 20 mA output............................................................................................ 17
Figure 12 Overrange behavior of CO2measurement 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
List of figures
3

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
GMW80 Series User Guide M211748EN-G
4

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 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.
WARNING!
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.
CAUTION!
Note highlights important information on using the product.
Chapter 1 – About this document
5

1.4 Trademarks
Vaisalaâ, CARBOCAPâ, and INTERCAPâare registered trademarks of Vaisala Oyj.
Modbusâis 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 oce Publication 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
GMW80 Series User Guide M211748EN-G
6

2. Product overview
2.1 Introduction to GMW80 series
Vaisala GMW80 series CARBOCAPâcarbon dioxide, humidity, and temperature transmitters
are wall-mount transmitters designed to fulfill the needs for CO2measurements in standard
demand controlled ventilation applications.
The following table lists the GMW80 series transmitters and their features.
Table 3 GMW80 series transmitters
Model name CO2output T output RH
output
Display CO2
LEDs
Relay T setpoint
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
Pt1000
(passive)
0 ... 10 V No No No No
GMW83DRP 0 ... 10 V 0 ... 10 V
Pt1000
(passive)
0 ... 10 V Yes 1) No No No
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
0 ... 10 V
Pt1000
(passive)
No No No No No
GMW87 RS-485
Modbus RTU
output
No No No No No No
GMW88 4 ... 20 mA
0 ... 10 V
No No No No No No
1) Temperature measurement data displayed in Celsius scale only.
Letters at the end of the model name stand for the following features:
PPassive temperature measurement
DDisplay
ACO2indicator LEDs
RHumidity measurement
SRelay
Chapter 2 – Product overview
7

The CO2measurement is based on the Vaisala proprietary CARBOCAPâsensor, which uses a
novel, silicon-based microchip emitter instead of an incandescent light bulb. The internal
reference in the CO2sensor guarantees the best stability and operation also in constantly
occupied buildings without frequent readjustments.
CARBOCAPâsensors give correct CO2measurements 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.
GMW80 Series User Guide M211748EN-G
8

2.1.1 Transmitter parts
9
11
8
1
2
3
4
5
6
7
10
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
10 CO2level indicator LEDs (on models with the letter A) or relay indicator LED (on models
with the letter S)
11 Display (on models with the letter D)
Chapter 2 – Product overview
9

0
1
2
3
4
5
6
7
8
9
5
1
2
3
4
6
Figure 2 GMW80 series component board parts
1Pins connecting the transmitter cover to the screw terminals when the transmitter cover is
in place
2Vaisala INTERCAPâhumidity 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 diers 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.
GMW80 Series User Guide M211748EN-G
10

6
7
8
5
3
2
1
4
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
Chapter 2 – Product overview
11

4
3
2
1
5
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 Din the model name (for example, GMW83D) are
equipped with a display.
GMW80 Series User Guide M211748EN-G
12

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 CO2measurement 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 CO2level.
•Good air quality: 0 ... 800 ppm CO2
•Fair air quality: 800 ... 1200 ppm CO2
•Poor air quality: >1200 ppm CO2
Chapter 2 – Product overview
13

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, aected 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
GMW80 Series User Guide M211748EN-G
14

2.3 Relay
Transmitter model GMW84S has one SPST-NO relay (max. 50 VDC / 50 VAC, 500 mA) that is
activated when the measured CO2level 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.
0
1
2
3
4
5
6
7
8
9
Figure 9 Rotary switch
Table 4 Relay setpoints
Switch position Setpoint in ppm CO2
0 600 ppm (default)
1 700 ppm
2 800 ppm
Chapter 2 – Product overview
15

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 CO2value 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 CO2value rises, the relay is activated at
1051 ppm. The relay remains activated until the measured value falls to 949 ppm.
2.4 CO2level indicator LEDs
Figure 10 CO2level indicator LEDs on model GMW83A
GMW80 Series User Guide M211748EN-G
16

Transmitter model GMW83A has indicator LEDs for the measured CO2level on the front cover.
The LEDs provide a visual indication of the measured CO2level to the occupant of the
monitored space.
The LEDs are lit as follows:
• Red LED (top): lit between 1200 ... 2000 ppm CO2, blinking > 2000 ppm CO2.
• Yellow LED (center): lit between 800 ... 1200 ppm CO2.
• Green LED (bottom): lit between 0 ... 800 ppm CO2.
2.5 Analog output overrange behavior
Analog outputs of the GMW80 series transmitters have a defined behavior when the values
measured by the transmitter are outside the scaled analog output range.
• At the top end of the output range, the output is clipped to the maximum value of the
output. This means that even if the measured parameter rises, the value does not change
anymore.
• At the low end of the output range, the output stays at the minimum value when the
measured parameter falls below the scaled range.
• The output is eventually set to the error state if the measured parameter is far enough
from the scaled output range. The exact limits for this behavior are parameter dependent;
see the figures below.
For more information on the error state, see Error state (page 42).
20.0
0
02000 6000
Output clipping limit
Error level
CO2 (ppm)
-100
Output
(mA)
Scaled output range:
4 ... 20 mA
0 ... 2000 ppm
3.6
4.0
Figure 11 Overrange behavior of CO2measurement with 4 ... 20 mA output
Chapter 2 – Product overview
17

Negative ppm values cannot physically exist but the behavior of the output is defined to
account for cases where a low CO2reading, combined with sensor drift, could cause a negative
result.
11.0
10.0
0
02000 6000
Output clipping limit
Error level
CO2 (ppm)
-100
Output
(V)
Scaled output range:
0 ... 10 V
0 ... 2000 ppm
Figure 12 Overrange behavior of CO2measurement with 0 ... 10 V output
GMW80 Series User Guide M211748EN-G
18