Vaisala DPT145 User Manual

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USER'S GUIDE
Vaisala Multiparameter Transmitter
DPT145 for SF6
Gas
M211371EN-D
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PUBLISHED BY
Vaisala Oyj Street address: Vanha Nurmijärventie 21, FI-01670 Vantaa, Finland Mailing address: P.O. Box 26, FI-00421 Helsinki, Finland Phone: +358 9 8949 1 Fax: +358 9 8949 2227
Visit our Internet pages at www.vaisala.com.
© Vaisala 2014
No part of this manual may be reproduced, published or publicly displayed in any form or by any means, electronic or mechanical (including photocopying), nor may its contents be modified, translated, adapted, sold or disclosed to a third party without prior written permission of the copyright holder. Translated manuals and translated portions of multilingual documents are based on the original English versions. In ambiguous cases, the English versions are applicable, not the translations.
The contents of this manual are subject to change without prior notice.
This manual does not create any legally binding obligations for Vaisala towards customers or end users. All legally binding obligations and agreements are included exclusively in the applicable supply contract or the General Conditions of Sale and General Conditions of Service of Vaisala.
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Table of Contents

CHAPTER 1
GENERAL INFORMATION ............................................................................ 7
About This Manual ................................................................... 7
Contents of This Manual ....................................................... 7
Version Information ............................................................... 8
Related Manuals ................................................................... 8
Documentation Conventions ................................................. 8
Safety ......................................................................................... 9
ESD Protection .................................................................... 10
Recycling ................................................................................ 10
Regulatory Compliances ....................................................... 11
Patent Notice .......................................................................... 11
Trademarks ............................................................................. 11
Software License .................................................................... 12
Warranty .................................................................................. 12
CHAPTER 2
PRODUCT OVERVIEW ................................................................................ 13
Introduction to DPT145 .......................................................... 13
Basic Features and Options .................................................. 14
Transmitter Parts .................................................................... 15
Weather Shield ....................................................................... 16
CHAPTER 3
FUNCTIONAL DESCRIPTION ..................................................................... 17
Measurement Needs of SF6 Insulation ................................. 17
Sensor Technology ................................................................ 18
MPS1 Multiparameter Sensor ............................................. 18
DRYCAP® Technology ....................................................... 18
Auto-Calibration ............................................................. 19
Sensor Purge ................................................................. 19
BAROCAP® Technology .................................................... 19
DPT145 Start-up Sequence ................................................... 20
CHAPTER 4
INSTALLATION ............................................................................................ 21
Transmitter Configuration Before Installation .................... 21
Selecting the Location ........................................................... 22
Warning – Read Before Installation ...................................... 23
Installation Without Weather Shield ..................................... 24
Installation With Weather Shield .......................................... 25
Wiring ...................................................................................... 28
Standard Wiring .................................................................. 28
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User's Guide _______________________________________________________________________
Alternate Wiring for Power Supply ...................................... 29
Stabilization of Dewpoint Reading After Installation .......... 29
CHAPTER 5
OPERATION ................................................................................................. 30
Transmitter Start-Up ............................................................... 30
Serial Communication ............................................................ 31
Connecting to the Serial Interface ....................................... 31
Installing the Driver for the USB Service Cable ............. 31
Terminal Application Settings .............................................. 32
List of Serial Commands ....................................................... 33
Device Information ................................................................. 34
Show Device Information..................................................... 34
Show Currently Active Errors .............................................. 35
Show Command List ........................................................... 35
Show Firmware Version ...................................................... 36
Show Serial Number ............................................................ 36
Serial Line Output Commands .............................................. 36
Start Measurement Output .................................................. 36
Stop Measurement Output .................................................. 36
Set Output Interval ............................................................... 37
Output a Reading Once ....................................................... 37
Configuring Measurement Parameters ................................ 38
Set Mixing Ratio .................................................................. 38
Set Molar Weight of Other Gas ........................................... 38
Set Pressure Normalization Temperature ........................... 38
Set Measurement Output Format ........................................ 39
Select Unit ........................................................................... 41
Configuring Serial Line Operation ........................................ 41
Set Serial Line Operating Mode .......................................... 41
Set Serial Line Settings ....................................................... 42
Set Transmitter Address ...................................................... 42
Set Serial Line Response Time ........................................... 43
Other Commands.................................................................... 43
Opening the Transmitter in POLL Mode.............................. 43
Closing the Connection to a Transmitter in POLL Mode ..... 44
Show Transmitter Uptime .................................................... 44
Reset Transmitter ................................................................ 44
Restore Factory Settings ..................................................... 44
Modbus Communication ........................................................ 45
Addressing with Modbus Protocol ....................................... 45
Accessing Serial Port Command Interface from
Modbus Mode ................................................................. 45
Configuration Commands Related to Modbus ............... 46
CHAPTER 6
MAINTENANCE ............................................................................................ 47
Periodic Maintenance ............................................................. 47
Cleaning .............................................................................. 47
Calibration and Adjustment ................................................. 47
Field Check Using an MI70 Indicator .................................. 47
Repair Maintenance ................................................................ 49
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CHAPTER 7
TROUBLESHOOTING ................................................................................. 50
Solving Typical Problems...................................................... 50
Error Messages ...................................................................... 51
Unknown Serial Settings ....................................................... 52
Technical Support .................................................................. 52
Product Returns ..................................................................... 53
CHAPTER 8
TECHNICAL DATA ...................................................................................... 54
Specifications ......................................................................... 54
Spare Parts and Accessories ................................................ 57
Dimensions in mm ................................................................. 57
APPENDIX A
MODBUS REFERENCE ............................................................................... 60
Default Communication Settings .......................................... 60
Supported Modbus Functions .............................................. 60
Modbus Register Map ............................................................ 61
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List of Figures
Figure 1 DPT145 with DILO DN20 Adapter ............................................ 14
Figure 2 DPT145 Transmitter Parts and Adapters ................................. 15
Figure 3 Weather Shield ......................................................................... 16
Figure 4 MPS1 Sensor ............................................................................ 18
Figure 4 DPT145 Startup Sequence ....................................................... 20
Figure 5 DPT145 Configuration with the MI70 Indicator ......................... 21
Figure 6 Indoor Installation in a Circuit Breaker ..................................... 22
Figure 7 Wiring Non-Isolated RS-485 ..................................................... 28
Figure 8 Wiring Power Supply Using Port I ............................................ 29
Figure 9 PuTTY Terminal Application ..................................................... 33
Figure 10 Comparing Dewpoint Readings on MI70 .................................. 48
Figure 11 DPT145 Dewpoint Measurement Accuracy ............................. 55
Figure 12 DPT145 with DILO DN20 Adapter ............................................ 57
Figure 13 DPT145 with DILO DN8 Adapter .............................................. 58
Figure 14 DPT145 with ABB Malmkvist Adapter ...................................... 58
Figure 15 DPT145 with Alstom G1/2" Adapter ......................................... 59
Figure 16 DPT145 with DILO DN20 Adapter and Weather Shield ........... 59
List of Tables
Table 1 Manual Revisions ....................................................................... 8
Table 2 Related Manuals ......................................................................... 8
Table 3 Output Parameters of DPT145 ................................................. 13
Table 4 Default Serial Interface Settings ............................................... 32
Table 5 List of Serial Commands .......................................................... 33
Table 6 FORM Command Parameters .................................................. 40
Table 7 FORM Command Modifiers ...................................................... 40
Table 8 Selection of Output Modes ....................................................... 41
Table 9 Configuration commands for Modbus RTU .............................. 46
Table 10 Troubleshooting Table .............................................................. 50
Table 11 Error Messages ........................................................................ 51
Table 12 Measured Parameters .............................................................. 54
Table 13 Calculated Parameters ............................................................. 54
Table 14 Performance ............................................................................. 54
Table 15 Operating Environment ............................................................. 55
Table 16 Outputs ..................................................................................... 55
Table 17 General ..................................................................................... 56
Table 18 DPT145 Spare Parts and Accessories ..................................... 57
Table 19 Default Communication Settings .............................................. 60
Table 20 Supported Function Codes ....................................................... 60
Table 21 Modbus Register Map ............................................................. 61
Table 22 Device Identification Objects .................................................... 62
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Chapter 1 _________________________________________________________ General Information
CHAPTER 1

GENERAL INFORMATION

This chapter provides general notes for the manual and the DPT145.

About This Manual

This manual provides information for installing, operating, and maintaining Vaisala Multiparameter Transmitter DPT145 for SF6 Gas.

Contents of This Manual

This manual consists of the following chapters:
- Chapter 1, General Information, provides general notes for the manual and the DPT145
- Chapter 2, Product Overview, introduces the features, advantages, and the product nomenclature.
- Chapter 3, Functional Description, describes the primary application and the sensor technology of DPT145.
- Chapter 4, Installation, provides you with information that is intended to help you install the DPT145.
- Chapter 5, Operation, contains information that is needed to operate the DPT145.
- Chapter 6, Maintenance, provides information that is needed in basic maintenance of the DPT145.
- Chapter 7, Troubleshooting, describes common problems, their probable causes and remedies, and provides contact information for technical support.
- Chapter 8, Technical Data, provides the technical data of the DPT145.
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Manual Code
Description
M211371EN-C
This manual. Added a minimum baud rate
shipment.
M211371EN-C
Previous version.
Manual Code
Manual Name
M211369EN
DPT145 Quick Guide

Version Information

Table 1 Manual Revisions
requirement when using the Modbus protocol. Added a packing recommendation for return

Related Manuals

Table 2 Related Manuals

Documentation Conventions

WARNING
CAUTION
NOTE
Throughout the manual, important safety considerations are highlighted as follows:
Warning alerts you to a serious hazard. If you do not read and follow instructions very carefully at this point, there is a risk of injury or even death.
Caution warns you of a potential hazard. If you do not read and follow instructions carefully at this point, the product could be damaged or important data could be lost.
Note highlights important information on using the product.
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Chapter 1 _________________________________________________________ General Information
Ground the product and verify outdoor installation grounding periodically to minimize shock hazard.
Do not or lead to malfunction.
Do not drop or hit the transmitter. The sensor is fragile and may break from a sudden shock.
When transporting the transmitter, use the original shipping box Vaisala.
Do not open the connection between the adapter and the transmitter. They are connected at the factory, and the connection should remain unopened to guarantee tightness.
Use tools only on the nut of the adapter, where the transport p cap is connected.
Keep the transmitter dry and clean.
Do not remove the yellow transport protection cap before you are ready to install the transmitter. Uncapped transmitters will absorb moisture which will affect the dewpoint measurement.
Connect the transmitter directly to the main SF a sampling line.
After installation, the transmitter will have a small amount of moisture inside it. In still, dry gas it takes a long time until vapor pressure inside the measurement cell reaches equilibrium with the main gas tank. It is not unusual for the stabilization after installation.

Safety

The DPT145 transmitter delivered to you has been tested for safety and approved as shipped from the factory. Note the following precautions:
WARNING
CAUTION
CAUTION
CAUTION
NOTE
modify the unit. Improper modification can damage the product
from
rotection
NOTE
of the dewpoint reading to take several days
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gas volume, not behind
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ESD Protection

Electrostatic Discharge (ESD) can cause immediate or latent damage to electronic circuits. Vaisala products are adequately protected against ESD for their intended use. It is possible to damage the product, however, by delivering electrostatic discharges when touching, removing, or inserting any objects inside the equipment housing.
To make sure you are not delivering high static voltages yourself:
- Handle ESD sensitive components on a properly grounded and protected ESD workbench.
- When an ESD workbench is not available, ground yourself to the equipment chassis with a wrist strap and a resistive connection cord.
- If you are unable to take either of the above precautions, touch a conductive part of the equipment chassis with your other hand before touching ESD sensitive components.
- Always hold component boards by the edges and avoid touching the component contacts.

Recycling

Recycle all applicable material.
Dispose of the unit according to statutory regulations. Do not dispose of with regular household refuse.
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Chapter 1 _________________________________________________________ General Information

Regulatory Compliances

The Vaisala Multiparameter Transmitter DPT145 for SF6 Gas is in conformity with the provisions of the following EU directive(s):
- EMC-Directive
Conformity is shown by compliance with the following standards:
- EN 61326-1: Electrical equipment for measurement, control, and laboratory use – EMC requirements – for use in industrial locations.
- EN 550022: Information technology equipment – Radio disturbance characteristics – Limits and methods of measurement.

Patent Notice

The Vaisala Multiparameter Transmitter DPT145 for SF6 Gas is protected by, for example, the following patents and their corresponding national rights:
Finnish patent 98861, French patent 6650303, German patent 69418174, Japanese patent 3585973, UK patent 0665303, and U.S. patent 5607564.

Trademarks

BAROCAP® and DRYCAP® are registered trademarks of Vaisala Oyj.
Windows® is a registered trademark of Microsoft Corporation in the United States and/or other countries.
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Software License

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

Warranty

Visit our Internet pages for more information and our standard warranty terms and conditions: www.vaisala.com/warranty.
Please observe that any such warranty may not be valid in case of damage due to normal wear and tear, exceptional operating conditions, negligent handling or installation, or unauthorized modifications. Please see the applicable supply contract or Conditions of Sale for details of the warranty for each product.
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Chapter 2 ___________________________________________________________ Product Overview
Parameter
Abbreviation
Metric Unit
Non-Metric Unit
Dewpoint/frost point temperature*
Tdf
ºC
ºF
Dewpoint/frost point temperature*, converted to atmospheric pressure
Tdfatm
ºC
ºF ppm moisture, by volume
H20
ppm
ppm
Pressure, absolute
P
bara
psia
Pressure, normalized to 20 °C (68 °F)
Pnorm
bara
psia Density
Rhoo
kg/m3
kg/m3
Temperature
T
ºC
ºF
CHAPTER 2

PRODUCT OVERVIEW

This chapter introduces the features, advantages, and the product nomenclature.

Introduction to DPT145

Vaisala Multiparameter Transmitter DPT145 for SF6 Gas is a digital transmitter with a non-isolated RS-485 output. Its compact size makes it well suited for integration into OEM systems.
DPT145 is always delivered with an integrated mechanical adapter: DILO DN20, DILO DN8, ABB Malmkvist, or Alstom G1/2". The connection between the adapter and the transmitter is helium leak tested at the factory.
DPT145 combines online measurement of dewpoint, pressure, and temperature. DPT145 also calculates four other quantities, including SF6 density.
Table 3 Output Parameters of DPT145
* When the dewpoint is below 0 °C, the transmitter outputs frostpoint for Td
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Basic Features and Options

- Utilizes the Vaisala MPS1 multiparameter sensor with Vaisala’s BAROCAP® and DRYCAP® technologies.
- Measurement ranges of measured parameters:
- Dewpoint -50 ... +30 °C (-58 ... +86 °F) Td
- Pressure, absolute 1 ... 12 bar (14.5 ... 174 psi)
- Temperature -40 ... +80 °C (-40 ... +176 °F)
- Measurement is configurable for pure SF6 or mixed gas.
- Non-isolated RS-485 digital output.
- Easy verification of dewpoint measurement with the Vaisala DRYCAP® Hand-Held Dewpoint Meter DM70.
- Delivered with an integrated mechanical adapter that must be specified during ordering. The adapter options are:
- DILO DN20
- DILO DN8
- ABB Malmkvist
- Alstom G1/2"
- Optional accessories:
- Weather shield: necessary for outdoor installations.
- USB service cable for configuration and calibration.
1107-031
Figure 1 DPT145 with DILO DN20 Adapter
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Chapter 2 ___________________________________________________________ Product Overview
1 = Port I: Supply voltage only (optional)
2 = Port II: RS-485 line and supply voltage
3 = Type label
4 = Connection between transmitter body and adapter – do not open
5 = DILO DN20 adapter: 50 mm nut with M45X2 inner thread / DILO DN8 adapter: 32 mm nut with M26X1.5 inner thread
6 = ABB Malmkvist adapter
7 = Alstom G1/2" adapter
8 = Transport protection cap – remove only when ready to install
5
6
7
8
3
4
1
2

Transmitter Parts

1107-033
Figure 2 DPT145 Transmitter Parts and Adapters
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Weather Shield

The transmitter and its connectors are rated IP65. However, installing the transmitter outside without protection is not recommended. The installation should be such that the transmitter is not exposed to direct rain, icing, or solar radiation.
A suitable weather shield is available from Vaisala. The weather shield is designed to clamp over the adapter, and to accommodate the available cable options.
1108-022
Figure 3 Weather Shield
DPT145 is assembled to the weather shield at the factory if the weather shield is ordered with the transmitter. Weather shields are also available separately.
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Chapter 3 _______________________________________________________ Functional Description
CHAPTER 3

FUNCTIONAL DESCRIPTION

This chapter describes the primary application and the sensor technology of DPT145.

Measurement Needs of SF6 Insulation

Sulphur hexafluoride (SF6) is used as an insulating gas in transmission and distribution equipment such as switchgears and circuit breakers. It effectively prevents arcing during switch-offs and protects equipment from failures.
In order to maintain SF6 insulation properties and to reduce the formation of unwanted secondary decomposition products, the amount of water vapor in the gas insulated system (GIS) should be kept to a minimum. Also, the SF6 system needs to be pressure tight for best insulation performance and safe operation of the equipment.
There is always some diffusion of water molecules from high ambient water vapor pressure to low vapor pressure inside the system. The more connection points the higher the diffusion rate. DPT145 is ideally suited to the online monitoring of dewpoint, pressure, and temperature in such a system. Sudden and minor leakages are immediately detected by the direct normalized pressure measurement, while online dewpoint measurement alerts the user to moisture issues.
With online monitoring, on-site visits can be kept to a minimum. The long calibration interval of DPT145 means practically service-free operation.
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Sensor Technology

MPS1 Multiparameter Sensor

DPT145 combines Vaisala’s proven DRYCAP® sensor technology for industrial dewpoint measurement with BAROCAP® pressure sensor technology. Both technologies are integrated on the same MPS1 multiparameter sensor element, allowing for a highly compact and versatile transmitter.
1108-021
Figure 4 MPS1 Sensor
There are several important advantages in using a transmitter with an integrated sensor:
- Reduces installation work and cost.
- Improves the leak tightness of the system as connection points are minimized.
- Enables online monitoring of all supported parameters.

DRYCAP® Technology

Vaisala DRYCAP® dewpoint measurement technology ensures accurate measurement with excellent long term stability. This results in very low maintenance requirements for the transmitter. The lasting performance is achieved with microprocessor technology and software that automatically performs self-diagnostic functions in addition to the normal dewpoint measurement. The self-diagnostic procedures that are conducted are called auto-calibration and sensor purge.
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Chapter 3 _______________________________________________________ Functional Description
Auto-Calibration
The auto-calibration feature of the MPS1 multiparameter sensor is an automatic procedure which greatly reduces the possible drift in the dry end of the dewpoint measurement. It is performed at one hour intervals, and when the power is switched on. During auto-calibration the sensor is warmed for a short period (< 1 min) and the sensor capacitance values are evaluated at the elevated temperature. The possible dry end drift is then corrected to correspond to the calibrated values. During the auto­calibration the transmitter outputs the dewpoint value prior to the procedure.
Auto-calibration is carried out only if several criteria for the measurement environment are fulfilled. This ensures the reliability of the adjustments, and maintains the excellent long term stability. These criteria include, for example, a stable enough moisture level in the measured atmosphere. If the conditions are not fulfilled, the auto­calibration function is postponed until satisfactory conditions are reached.
Sensor Purge
Sensor purge is also an automatic procedure that minimizes the drift at the wet end readings of the dewpoint measurement. Sensor purge is performed twice a day, and five minutes after the power is switched on. The sensor is heated for several minutes which will then evaporate all excess molecules out of the sensor polymer. This, together with the auto­calibration, results in a very small drift of the sensor due to the very linear behavior of the polymer technology.

BAROCAP® Technology

The BAROCAP® silicon capacitive absolute pressure sensor was developed by Vaisala for barometric pressure measurement applications. The BAROCAP® sensor has excellent hysteresis and repeatability characteristics, low temperature dependence, and a very good long-term stability. The ruggedness of the BAROCAP® sensor is outstanding and the sensor is resistant to mechanical and thermal shocks. The pressure measurement of the MPS1 multiparameter sensor is based on an advanced RC oscillator and reference capacitors against which the capacitive pressure sensor is continuously measured. The microprocessor of the transmitter performs compensation for pressure linearity and temperature dependence.
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The transmitter always performs this sequence when starting up. Keep the transmitter co performance and availability.
Normal output Normal output
5 s
Output frozen
5 min 3 ... 6 min
Time
Purge*
3 ... 4 min
Autocal**
<2 min
* Purge will repeat every 12 hours ** Autocal will repeat every 60 minutes (is postponed if environment is not suitable)
Startup

DPT145 Start-up Sequence

When the transmitter is powered up, it will perform the sequence shown in Figure 5 below. After a five-second startup, the transmitter will measure normally for five minutes, after which it will perform the sensor purge and auto-calibration functions. This can take up to six minutes, during which time the output is frozen: it will display the last measured values before the sensor purge began.
Normal operation and output is typically achieved no later than 11 minutes after startup. The sensor purge will repeat every 12 hours, and auto-calibration every hour. The output will again be frozen for their duration.
NOTE
1108-033
Figure 5 DPT145 Startup Sequence
ntinuously powered to optimize its measurement
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Chapter 4 ________________________________________________________________ Installation
CHAPTER 4

INSTALLATION

This chapter provides you with information that is intended to help you install the DPT145.

Transmitter Configuration Before Installation

Depending on your application, you may need to configure some transmitter features before physically installing it.
1. By default, DPT145 transmitters are configured for single transmitter operation. Serial operation mode is STOP and address is 0.
To configure transmitters for operation on a common line, you must give each transmitter a unique address (range 0 ... 255) and set their serial operation mode to POLL.
2. The default serial line settings may not be right for your RS-485 line.
3. You may need to change the transmitter’s settings for the measured gas. You can configure the mixing ratio of SF6, and the molar weight of the other gas.
An easy way to configure the measured gas is to connect the DPT145 to the MI70 indicator using the MI70 connection cable (Vaisala order code
219980). You can change the settings in the Measurement Settings
menu. See Figure 6 below.
1108-039
Figure 6 DPT145 Configuration with the MI70 Indicator
For full configuration options, use the USB service cable and a terminal program on a PC. Instructions for using the serial line and the serial commands are provided in Chapter 5, Operation, on page 30.
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Selecting the Location

Online dewpoint measurement in still gas is much more demanding than pressure or temperature measurement. A very tight installation is crucial: not only pressure tight, but also vapor tight.
It is always best to connect the transmitter directly to the main SF6 gas volume, not behind a sampling line. Avoid extension pipes, T-pieces, and multi-connection points.
1108-034
Figure 7 Indoor Installation in a Circuit Breaker
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Chapter 4 ________________________________________________________________ Installation

Warning – Read Before Installation

CAUTION
Do not drop or hit the transmitter. The sensor is fragile and may break from a sudden shock.
When transporting the transmitter, use the original shipping box from Vaisala.
CAUTION
Do not open the connection between the adapter and the transmitter. They are connected at the factory, and the connection should remain unopened to guarantee tightness.
Use tools only on the nut of the adapter, where the transport protection cap is connected.
NOTE
Keep the transmitter dry and clean.
Do not remove the yellow transport protection cap before you are ready to install the transmitter. Uncapped transmitters will absorb moisture which will affect the dewpoint measurement.
NOTE
Connect the transmitter directly to the main SF gas volume, not behind a sampling line.
After installation, the transmitter will have a small amount of moisture inside it. In still, dry gas it takes a long time until vapor pressure inside the measurement cell reaches equilibrium with the main gas tank. It is not unusual for the stabilization of the dewpoint reading to take several days after installation.
6
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1. Remove the yellow transport protection plug when
2. Install the transmitter to the mechanical coupling
3. Use a wrench to tighten the connection. Turn from
4. Connect the cable to port II on the transmitter.

Installation Without Weather Shield

you are ready to install the transmitter.
and tighten by hand.
the adapter, not from the transmitter body!
Use sufficient force to achieve a tight installation. The system must be leak-free for accurate measurement.
Use a cable with a suitable connector for your installation (straight or angled).
Let some of the cable hang from the back of the transmitter, so that condensation cannot run along the cable to the transmitter.
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Chapter 4 ________________________________________________________________ Installation
1. When DPT145 is ordered with the weather
2. Use an 8 mm box-end wrench to loosen
3. Remove the yellow transport protection

Installation With Weather Shield

shield, the transmitter is delivered already attached to the shield.
If you have ordered the weather shield separately, attach the transmitter to the weather shield before continuing this procedure. Fit the clamp of the weather shield over the adapter, not the transmitter body. For ABB Malmkvist and Alstom G1/2" type adapters, place the clamp over the notches in the adapter.
the four bolts that hold the weather shield cover. Remove the cover.
It is not necessary to remove the bolts, they can remain in place during installation.
plug. Make sure the surfaces are clean and dry.
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4. Install the transmitter to the mechanical
5. Use a wrench to tighten the connection.
If the weather shield is tilted after the
the two nuts that keep the clamp
coupling and tighten by hand. Try to keep the weather shield level.
Turn from the adapter, not from the transmitter body!
Use sufficient force to achieve a tight installation. The system must be leak-free for accurate measurement.
installation, you can straighten it by loosening tight. Tighten the nuts after weather shield is straight.
Note: The cable with the angled connector has a fixed direction, and is designed to be routed straight down from port II. If you rotate the transmitter inside the weather shield, or if you have the Alstom G1/2" type adapter, you may have to use a cable with a straight connector.
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Chapter 4 ________________________________________________________________ Installation
6. Connect the cable to port II on the
transmitter, and route the cable to the cable
condensation cannot run along the cable to
For cables with a straight connector:
7. Replace the weather shield cover using an
clamp on the underside of the weather shield. Attach the cable using a crosshead screwdriver.
Note: Let some of the cable hang from the back of the transmitter, so that
the transmitter.
move the rubber plug to the bottom hole and route the cable from the back of the weather shield.
8 mm box-end wrench.
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Pin
Connection on Port I
Connection on Port II
Wire Color
1
VDC supply+
VDC supply+
Brown
2 RS-485 D0-
White
3
GND
GND
Blue
4 RS-485 D1+
Black
15 ... 28 VDC
RS-485 +
RS-485 -
GND
+
SHIELD
-
1
2
3
4
2
4
1 3

Wiring

Standard Wiring

Connect supply voltage and RS-485 to port II. Port I does not need to be used at all, and can remain covered.
1108-015
Figure 8 Wiring Non-Isolated RS-485
Wire Colors for Vaisala Cables
Note the following:
- The ground pin (pin 3) on both ports is internally connected to each other and to transmitter chassis. The chassis connection is through a 1 MΩ resistor and a 40 nF capacitor that are connected in parallel.
- The frames of the M8 connectors are not connected to the chassis.
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Chapter 4 ________________________________________________________________ Installation
1 = VDC+
3 = GND
2
4
1 3
15 ... 28 VDC
+
-

Alternate Wiring for Power Supply

If necessary, you can provide supply voltage using Port I, and only wire RS-485 for Port II. Do not supply power from both ports.
1108-016
Figure 9 Wiring Power Supply Using Port I

Stabilization of Dewpoint Reading After Installation

After installation, the transmitter will have a small amount of moisture inside it. In still, dry gas it takes a long time until vapor pressure inside the measurement cell reaches equilibrium with the main gas tank. It is not unusual for the stabilization of the dewpoint reading to take several days after installation.
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CHAPTER 5

OPERATION

This chapter contains information that is needed to operate the DPT145.

Transmitter Start-Up

When the transmitter is connected to power supply, there is a delay of five seconds as the transmitter starts up. After the start-up is complete, the transmitter will behave according to the configured serial mode:
- In STOP mode, the transmitter outputs the transmitter model and software version.
- In RUN mode a measurement output starts immediately.
- In POLL mode the transmitter does not output anything after power­up.
- In MODBUS mode, the transmitter does not output anything after power-up.
For a description of the modes, see section Set Serial Line Operating Mode on page 41.
For a description of how the diagnostic functions of the sensor affect the availability of live measurement at start-up, see section DPT145 Start-up Sequence on page 20.
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Serial Communication

Connecting to the Serial Interface

DPT145 can be connected to a PC using the RS-485 line on Port II. It is recommended that you use the USB service cable (Vaisala order code 219690) for the connection, since the cable also provides the operating power from the USB port.
If you have not used the USB service cable before, install the driver that came with the cable. Refer to section Installing the Driver for the USB Service Cable below for detailed instructions.
Installing the Driver for the USB Service Cable
Before taking the USB service cable into use, you must install the provided USB driver on your PC. When installing the driver, you must acknowledge any security prompts that may appear. The driver is compatible with Windows 2000, Windows XP, Windows Server 2003, and Windows Vista.
1. Check that the USB service cable is not connected. Disconnect the cable if you have already connected it.
2. Insert the media that came with the cable, or download the driver from www.vaisala.com.
3. Execute the USB driver installation program (setup.exe), and accept the installation defaults. The installation of the driver may take several minutes.
4. After the driver has been installed, connect the USB service cable to a USB port on your PC. Windows will detect the new device, and use the driver automatically.
5. The installation has reserved a COM port for the cable. Verify the port number, and the status of the cable, using the Vaisala USB Instrument Finder program that has been installed in the Windows Start menu.
Windows will recognize each individual cable as a different device, and reserve a new COM port. Remember to use the correct port in the settings of your terminal program.
There is no reason to uninstall the driver for normal use. However, if you wish to remove the driver files and all Vaisala USB cable devices, you can do so by uninstalling the entry for Vaisala USB Instrument Driver from the Add or Remove Programs (Programs and Features in Windows Vista, or later) in the Windows Control Panel.
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Property
Description / Value
Baud rate
19200
Parity
None
Data bits
8
Stop bits
1
Flow control
None

Terminal Application Settings

The serial interface settings of the DPT145 RS-485 line are presented in Table 4 below.
Table 4 Default Serial Interface Settings
The steps below describe how to connect to the DPT145 using the PuTTY terminal application for Windows (available for download at
www.vaisala.com) and a USB serial interface cable:
1. Connect the USB serial interface cable between your PC and the RS-485 port of DPT145 (port II).
2. Start the PuTTY application.
3. Select the Serial settings category, and check that the correct COM port is selected in the Serial line to connect to field.
Note: You can check which port the USB cable is using with the Vaisala USB Instrument Finder program that has been installed in the Windows Start menu.
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. Click the Open button to open the connection window and start using the serial line.
Note: If PuTTY is unable to open the serial port you selected, it will show you an error message instead. If this happens, restart PuTTY and check the settings.
6. You may need to adjust the Local echo setting in the Terminal category to see what you are typing on the serial line. To access the configuration screen while a session is running, click the right mouse button over the session window, and select Change Settings... from the pop-up menu.
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If the DPT145 is in Modbus mode, to access the serial port command interface, follow the procedure in Accessing Serial Port Command Interface from Modbus Mode on page 45.
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Command
Description
?
Show device information
??
Show device information (overrides poll mode)
ADDR [0 … 255]
Show or set transmitter address
CLOSE
Close the temporary connection and return the device to POLL mode
ERRS
Display the currently active errors
FORM [modifier string]
Set output format
FRESTORE
Restore factory settings
HELP
Show list of currently available serial commands
INTV [0 ... 255 S/MIN/H]
Set the continuous output interval (for RUN mode and R command)
OPEN [0 … 255]
Open a line to transmitter at defined address
R
Start the continuous outputting
RESET
Reset the transmitter
S
Stop the continuous outputting
SDELAY [0 … 255]
Set response sending delay
SEND [0 … 255]
Output readings once (specify address for transmitters in POLL mode)
0807-004
Figure 10 PuTTY Terminal Application

List of Serial Commands

All commands can be issued either in uppercase or lowercase. In the command examples, the keyboard input by the user is in bold type.
The notation <cr> refers to pressing the carriage return (Enter) key on your computer keyboard. Enter a <cr> to clear the command buffer before starting to enter commands.
Table 5 List of Serial Commands
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Command
Description
SERI [baud p d s]
Show or set the serial interface settings
SMODE [mode]
Show or set startup serial mode: RUN, STOP, POLL, or MODBUS
SNUM
Display transmitter serial number
TIME
Show transmitter uptime
UNIT [m/n]
Select metric or non-metric units
VERS
Show transmitter firmware version
PNORMT [-100 ... 100]
Show or set the temperature for pressure normalization
MIXRATIO [0 ... 100]
Show or set ratio (%) of SF6 in the measured environment
N2MOLW [weight]
Show or set molecular weight of other gas

Device Information

Show Device Information

The ? command outputs a listing of device information.
?<cr>
Command ?? is a similar command that is designed to be used if the transmitter is in POLL mode but its address is unknown. The transmitter will respond to the ?? command even while in POLL mode. Do not use the ?? command if you have more than one transmitter on an RS-485 line.
Example:
?
DPT145 1.0.23 Serial number : F4040007 Batch number : F3420050 Module number : F3410001 Sensor number : F1610000 Cal. date : 20110907 Cal. info : Vaisala/HEL Time : 02:41:01 Serial mode : STOP Baud P D S : 19200 N 8 1 Output interval: 5 S Serial delay : 10 Address : 0 Mixing ratio : 100.00% SF6 and 0.00% ideal gas Ideal gas MolW : 2.8013401e-02 kg/mol
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Show Currently Active Errors

Use the ERRS command to display the currently active transmitter error messages. Possible errors and their causes are listed in Table 11 on page
51.
ERRS<cr>
Example:
errs
No errors
Example (one active error, caused by physical damage to the sensor):
errs
T MEAS error

Show Command List

Use the HELP command to list the serial commands:
HELP<cr>
Example:
help
ADDR CLOSE ERRS FORM FRESTORE INTV OPEN R RESET SDELAY SEND SERI SMODE SNUM TIME UNIT VERS PNORMT MIXRATIO N2MOLW
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Show Firmware Version

VERS<cr>
Example:
vers
DPT145 1.0.23

Show Serial Number

SNUM<cr>
Example:
snum
Serial number : F4040007

Serial Line Output Commands

Start Measurement Output

Use the R command to start the continuous outputting of measurement values as an ASCII text string to the serial line. The format of the measurement message is set with the FORM command.
R<cr>
Example (measurement message in default format):
r
Tdf= 12.5 'C Tdfatm= 13.6 'C H2O= 15561 ppm P= 0.947 bara Pnorm= 0.943 bara Rhoo= 1.1 kg/m3 T= 24.5 'C Tdf= 12.5 'C Tdfatm= 13.6 'C H2O= 15563 ppm P= 0.947 bara Pnorm= 0.942 bara Rhoo= 1.1 kg/m3 T= 24.5 'C Tdf= 12.5 'C Tdfatm= 13.5 'C H2O= 15555 ppm P= 0.948 bara Pnorm= 0.943 bara Rhoo= 1.1 kg/m3 T= 24.5 'C ...
Outputting the results continues in intervals issued with the command INTV. You can stop the output by pressing the Esc key, or with the command S. Since the interface is half-duplex, you must enter the commands when the transmitter is not outputting.

Stop Measurement Output

You can stop the measurement output by pressing ESC, or with the S command:
S<cr>
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where n = time interval, range 0 ... 255
xxx
=
time unit = "S", "MIN", or "H"
where
address
=
Address of the transmitter, range 0 ... 255.
with the OPEN command.

Set Output Interval

Use the INTV command to change the output interval of the automatically repeating measurement messages. The measurement messages are repeated in the RUN mode, or after the R command has been given.
INTV [n xxx]<cr>
The shortest output interval (with n = 0) outputs the measurement messages as quickly as the transmitter’s internal measurement cycle produces them, without additional delay.
Example:
intv 1 min
Output interval: 1 MIN

Output a Reading Once

Use the SEND command to output a single measurement message. The output message is sent in the format that has been set using the FORM command.
SEND [address]<cr>
Specifying the address is only necessary if the target transmitter is in POLL mode, and has not been accessed
Example:
send
Tdf= 15.4 'C Tdfatm= 16.2 'C H2O= 18539 ppm P= 0.959 bara Pnorm= 0.951 bara Rhoo= 1.1 kg/m3 T= 25.4 'C
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where
ratio
=
Amount of SF6 in the measurement environment, range 0 ... 100%.
where
weight
=
Molar weight of the other gas in kg/mol. The default is
2.8013401e-02, which is the molar mass of N2.
where t = Temperature in Celsius, range -100 ... 100. The default is 20.

Configuring Measurement Parameters

Set Mixing Ratio

Use the MIXRATIO command to set the mixing ratio of SF6 and the other gas.
MIXRATIO [ratio]<cr>
Example:
mixratio 50
MIX RATIO : 50.00 %

Set Molar Weight of Other Gas

Use the N2MOLW command to set the molar weight of the other gas (not SF6) in the measurement environment.
N2MOLW [weight]<cr>
Example:
n2molw
OTHER GAS MOLAR: 2.8013401e-02 kg/mol ?

Set Pressure Normalization Temperature

Use the PNORMT command to set the temperature that is used to calculate the normalized pressure parameter.
PNORMT [t]<cr>
Example:
pnormt 20
P_NORM_T : 20.00 'C
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where
modifier string
=
String of parameters and modifiers that defines the output format, length 1 ... 153 characters. Maximum length may be shorter when text strings are used. See
, and
examples below.

Set Measurement Output Format

Use the serial line command FORM to change the measurement message sent by the transmitter. You can freely define the output message to include the desired parameters, formatting options, text strings, and additional fields.
FORM [modifier string]<cr>
Table 6 and Table 7 on page 40
You can return to the default format using the "FORM /" command.
Example of default output (continuous output from RUN mode):
Tdf= 8.1 'C Tdfatm= 8.2 'C H2O= 10870 ppm P= 1.002 bara Pnorm= 0.992 bara Rhoo= 6.0 kg/m3 T= 22.8 'C Tdf= 8.1 'C Tdfatm= 8.2 'C H2O= 10878 ppm P= 1.002 bara Pnorm= 0.992 bara Rhoo= 6.0 kg/m3 T= 22.8 'C ...
Command to set output format as Tdf and P with Modulus-256 checksum:
form 3.1 "Tdf=" Tdf U3 3.3 "P=" P " " U4 " " CS2 \r \n
Output example:
Tdf= 12.5'C P= 0.949 bara 72 Tdf= 12.5'C P= 0.950 bara 6A ...
Command to set output format as Tdf and P, with start of text (ASCII character 002) and end of text (003) ASCII codes, and without line feed and carriage return at the end:
form #002 3.1 "Tdf=" Tdf U3 3.3 "P=" P " " U4 #003
Output example (ASCII codes not visible here):
Tdf= 11.6'C P= 0.952 baraTdf= 11.6'C P= 0.951 baraTdf=
11.6'C P= 0.951 baraTdf= 11.6'C P= 0.950 baraTdf= 12.5'C P= 0.951 baraTdf= 12.3'C P= 0.952 bara
...
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Measured Parameter
Abbreviation in FORM Command
Dewpoint/frost point temperature
Tdf
Dewpoint/frost point temperature, converted to atmospheric pressure
Tdfa ppm moisture, by volume
H20
Pressure, absolute
P
Pressure, normalized
Pnorm
Density
Rhoo
Temperature
Ta
Modifier
Description
x.y
Length modifier (number of digits and decimal places)
#t
Tabulator
#r
Carriage-return
#n
Line feed
""
String constant, length 1 ... 15 characters
#xxx
ASCII code value (decimal) of a special character; for example, #027 for ESC
ADDR
Transmitter address (0 ... 255)
ERR
Currently active transmitter errors in a four bit field:
bit3 Flash csum error
SN
Transmitter serial number
TIME
Time since transmitter was started or reset
Ux
Shows the name of the measurement unit using “x” number
measurement unit with three characters
CS2
Modulus-256 checksum of message sent so far, ASCII encoded hexadecimal notation
CS4
Modulus-65536 checksum of message sent so far, ASCII encoded hexadecimal notation
CSX
NMEA xor-checksum of message sent so far, ASCII encoded hexadecimal notation
Table 6 FORM Command Parameters
Table 7 FORM Command Modifiers
bit0bit1bit2bit3bit4
bit0 T MEAS error bit1 P out of range error bit2 Fmeas error
of characters. For example, U3 shows the name of the
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where
x = Selects the unit type to output: m = metric units, for example, Celsius n = nonmetric units, for example, Fahrenheit
where mode
=
STOP, RUN, or POLL.
Mode
Measurement Output
Available Commands
STOP
Only with the SEND command.
All (default mode).
RUN
Automatic output.
Only command S.
POLL
Only with the SEND [addr]
SEND [addr] and OPEN [addr].
the same line.
MODBUS
Must be read from the
protocol.
Modbus protocol only; see
on page 60.

Select Unit

Use the UNIT command to select metric or non-metric output units.
UNIT [x]<cr>
Example:
unit m
Units : Metric

Configuring Serial Line Operation

Set Serial Line Operating Mode

Use the SMODE command to set the start-up operating mode of the serial line.
SMODE [mode]<cr>
Table 8 Selection of Output Modes
command.
Other commands available after opening a line to the transmitter using the OPEN command.
Use with RS-485 buses where multiple transmitters can share
If the Modbus mode is activated, serial port commands cannot be used with the device. To access the serial port command interface, follow the procedure in Accessing Serial Port Command Interface from Modbus Mode on page 45.
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transmitter using MODBUS
Appendix A, Modbus Reference
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where
b = baud rate (300, 600, 1200, 2400, 4800, 9600, or 19200)
p = parity (n = none, e = even, o = odd)
d = data bits (7 or 8)
s = stop bits (1 or 2)
where address
=
Transmitter address, range 0 ... 255.
Selected output mode will be activated at next reset or power up.
Example:
smode poll
Serial mode : POLL

Set Serial Line Settings

Use the SERI command to set the serial line settings. The new settings will be taken into use when the transmitter is reset or powered up.
Note that changing the serial line settings will slightly alter how the transmitter works with the MI70 indicator. If you are not using the default settings of 19200 N 8 1, you will have to power off the MI70 before it can find the transmitter (you will not be able to connect it on­the-fly).
When using the Modbus protocol, the baud rate must be 9600 or higher.
SERI [b p d s]<cr>
Example:
seri 9600 e 7 1
Baud P D S : 9600 E 7 1

Set Transmitter Address

To operate in the POLL mode, the transmitter must have an address. If multiple transmitters share the same serial line, each transmitter must have a different address.
For a description of the serial interface modes, see section Set Serial Line Operating Mode on page 41.
ADDR [address]<cr>
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where delay
=
Serial line delay, range 0 … 255.
where address
=
Transmitter address, range 0 ... 255.
Example:
addr
Address : 0 ?

Set Serial Line Response Time

With the SDELAY command you can set delay (response time) of the serial line, or view the currently set delay value. Increasing the value by one increases the delay by 4 milliseconds. For example, the default value is 10 which equals a ~40 ms answer delay.
SDELAY [delay]<cr>
Example:
sdelay 20
Serial delay : 20

Other Commands

Opening the Transmitter in POLL Mode

Use the OPEN command to connect to a transmitter that is in POLL mode.
OPEN [address]<cr>
Example (target transmitter in POLL mode, with address 5):
open 5
DPT145 5 line opened for operator commands
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Closing the Connection to a Transmitter in POLL Mode

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

Show Transmitter Uptime

Use the TIME command to show how long the transmitter has been operating since it was last reset or powered up.
TIME<cr>
Example:
time
Time : 00:51:41

Reset Transmitter

Use the RESET command to reset the transmitter.
RESET<cr>
When the RESET command is given, the transmitter will restart as if it had just been powered on. All transmitter settings are retained. The serial line mode of the transmitter will be set to the mode that was set using the SMODE command.

Restore Factory Settings

Use the FRESTORE command to restore the factory settings to the transmitter. All user settings will be lost.
FRESTORE<cr>
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Request:
0x01
0x03
0x00
0x04
0x00
0x02
0x85
0xCA
addr.
func.
reg. 5
2 registers
CRC check
Response:
0x01
0x03
0x04
0xBC
0xC0
0x41
0xC2
0x6E
0x5E
addr.
func.
len.
reg. 5
reg. 6
CRC check

Modbus Communication

Addressing with Modbus Protocol

The Modbus variant used in DPT145 communication is Modbus RTU. An example of Modbus addressing is shown below.
For a list of available Modbus registers, see Appendix A, Modbus Reference on page 60.
Accessing Serial Port Command Interface from Modbus Mode
You cannot change configuration settings (other than Modbus address) while the device is in the Modbus mode. To use the configuration commands on a Modbus-enabled device:
1. Connect the USB service cable to the PC and install the driver, if
necessary.
2. Open the terminal program and open a connection to the
corresponding COM port using settings 19200, 8, N, 1, no flow control.
3. Plug the service cable to the connector II of the instrument.
4. In less than five seconds, send a hash character (#) and carriage
return (Enter) to the device using the terminal program. The device is now ready for configuration commands. The Modbus mode is restored on next power-up unless Modbus is disabled with command SMODE.
For example, if you want to deactivate the Modbus mode on a DPT145 device, follow the procedure above and deactivate the Modbus mode with the command SMODE STOP. On subsequent power-ups, the serial command interface will be activated.
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Service Command
Description
SMODE MODBUS
Enable Modbus communication protocol.
41.
SERI b p 8 s
Change baud rate and parity.
See section Set Serial Line Settings on page 42.
ADDR a
Set Modbus address.
See section Set Transmitter Address on page 42.
SDELAY d
Add extra Modbus response delay.***
See section Set Serial Line Response Time on page 43.
Configuration Commands Related to Modbus
In addition to enabling the Modbus protocol in the device, Modbus over RS-485 needs the following software settings: serial bit rate, parity, number of stop bits, and Modbus device address.
Use the service commands listed in Table 9 below to configure the Modbus RTU using the USB service cable.
Table 9 Configuration commands for Modbus RTU
See section Set Serial Line Operating Mode on page
b = baud rate (minimum 9600 when using Modbus) p = parity (E, N, or O) 8 = number of data bits must be 8 s = number of stop bits (2 if parity is N, 1 otherwise*)
NOTE
a = new address (0…255)**
d = new delay in units of 1/250 seconds (0…255)
* Modbus specification defines that two stop bits must be used if parity is N. ** Setting address to zero switches the instrument offline from the Modbus bus. Addresses 248 … 255 are not supported by the Modbus standard but DPT145 works with them. *** Extra response delay can be used, for example, to avoid problems caused by direction-switching delays in bus converters.
The instrument must be switched off and on before the configuration changes made with the service cable take effect.
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CHAPTER 6

MAINTENANCE

This chapter provides information that is needed in basic maintenance of the DPT145.

Periodic Maintenance

Cleaning

The body of the transmitter can be cleaned by wiping with a moistened lint-free cloth. Do not immerse the transmitter in liquid, and do not use cleaning agents or solvents.

Calibration and Adjustment

DPT145 is fully calibrated as shipped from factory. If there is a reason to believe that the device is not within the accuracy specifications, you can perform a field check using the DM70 hand-held dewpoint meter, or an MI70 indicator with another DPT145.
If the field check indicates that the DPT145 is not within its accuracy specifications, contact a Vaisala Service Center or your local Vaisala representative to have the DPT145 adjusted.

Field Check Using an MI70 Indicator

Vaisala recommends the following equipment for field checking:
- A fully charged MI70 indicator (the measurement display that is
included in the DM70 package)
- A calibrated reference probe that is suitable for the intended
measurement environment and dewpoint range. The DMP74C probe is recommended for checking the dewpoint and temperature measurement accuracy. For checking all parameters, you can use another DPT145 transmitter as a reference.
- You also need a connection cable (Vaisala order code: 219980) to
connect the DPT145 to the MI70 indicator. If you have two DPT145 transmitters, you need two cables.
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In the procedure below, the readings of the probe are checked simultaneously. You can also check the reference probe and the DPT145 separately if they cannot be connected at the same time.
NOTE
transmitter and the reference
Perform the check as follows:
1. Place the reference probe and the DPT145 in the reference environment.
2. Connect the reference probe and the DPT145 to the MI70 indicator:
- Reference probe to Port I
- DPT145 to Port II
3. Turn on the MI70 indicator.
4. Check and adjust the environment settings if prompted. Refer to the DM70 User’s Guide for the settings of the DMP74C probe.
5. Disable the Auto power off function of the MI70 indicator to prevent the indicator from powering off in the middle of the check. Check the setting in the Settings - User Interface menu, and change if necessary.
6. The MI70 can display three parameters at one time. To compare
the readings of the DPT145 and the reference probe, select the desired parameter from the DisplayQuantities and Units menu of the MI70. Select the same parameter from port I and II, and the delta parameter that shows the difference between the two. For example, ∆T
shows the
d/f
difference in dewpoint between the two probes.
1108-039
Figure 11 Comparing Dewpoint Readings on MI70
7. After the measurement has stabilized, check the difference between the readings. It will give you an indication of the approximate drift of the DPT145 and its need for calibration. The difference between the readings should be no greater than the combined measurement uncertainty of the DPT145 and the reference probe.
8. Write down the results and repeat the comparison for each parameter you want to check.
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Some notes on using the MI70 indicator with the DPT145:
9. If adjustment is required, contact a Vaisala Service Center or your
local Vaisala representative to have the DPT145 adjusted.
NOTE
- If you disconnect the DPT145 while the MI70 indicator is on,
the quantities measured will remain on the screen, but no measurement will be shown.
- Temperature measured by the DPT145 is shown as parameter
Ta (not T) in the MI70.
- The messages from the transmitter will appear in English even if
the MI70 has been set to another language.

Repair Maintenance

There are no user serviceable parts inside the transmitter. If there is a problem with your transmitter that you are unable to solve yourself or with the help of the Vaisala Helpdesk, contact a Vaisala Service Center to have the transmitter repaired.
For troubleshooting instructions and Vaisala contact information, see Chapter 7, Troubleshooting, on page 50.
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Problem
Possible Causes and Solutions
Dewpoint reading is not stable
indicates slow drying.
This is normal behavior after installation. See
After Installation on page 29.
Pressure reading is not stable:
temperature may be rising.
Leak in the measurement environment.
Transmitter outputs stars "****"
Possible causes: damaged sensor, incorrect
power supply.
Unable to access transmitter on
Possible causes: Incorrect wiring, unknown
transmitter respond in POLL mode.
CHAPTER 7

TROUBLESHOOTING

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

Solving Typical Problems

Some problems can be solved by simply resetting the transmitter. You can reset the transmitter by disconnecting the power or issuing the RESET command using the service port.
If resetting does not help, and if the problem is related to transmitter software or settings, you can restore the factory configuration of the transmitter by issuing the FRESTORE command. If you are unable to solve your problem with the transmitter, contact Vaisala technical support. See section Technical Support on page 52.
Table 10 Troubleshooting Table
after installation: reading
reading indicates falling pressure. Dewpoint
instead of measurement data
section Stabilization of Dewpoint Reading
Locate and repair the leak.
supply voltage, and unsuitable measurement environment.
Power cycle or reset the transmitter, and see if the problem continues. Check the active errors using the ERRS command. Check the
the RS-485 line.
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serial settings, transmitter in POLL mode with unknown address.
Check wiring. Try connecting as instructed in section Unknown Serial Settings on page 52. Issue the ?? command to make the
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Error Message
Possible Cause and Solution
T MEAS error
MPS1 sensor damaged or missing. Contact a Vaisala Service Center.
F meas error
Voltage error
Supply voltage out of range. Check and correct.
Voltage too low error
Program flash check sum error
Internal transmitter error. If the error
Parameter flash check sum error
INFOA check sum error
SCOEFS check sum error
CURRENT check sum error

Error Messages

The transmitter has error codes that can be displayed on the serial line using the ERRS command. See section Show Currently Active Errors on page 35.
Table 11 Error Messages
remains after a reset and restoring the factory settings, contact a Vaisala Service Center.
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Unknown Serial Settings

If you are not sure what the current serial settings of your transmitter are, follow the steps below to connect to the transmitter. This procedure assumes you have the USB service cable available.
For more information on the USB service cable and the PuTTY terminal application, see section Serial Communication on page 31.
1. Connect the USB service cable to your PC, but do not connect it to the transmitter yet.
2. Start a terminal application and open a terminal session using the default serial settings of 19200 8 N 1.
3. Plug the USB service cable into the transmitter, and immediately send the hash character # to the serial line:
#
4. The normal startup of the transmitter is now interrupted, and the transmitter is available for commands with the default serial settings.
5. You can now check the transmitter’s information by issuing the ? command:
?
The transmitter’s currently stored serial settings are visible on the line marked Baud P D S.

Technical Support

For technical questions, contact the Vaisala technical support by e-mail at
helpdesk@vaisala.com. Provide at least the following supporting
information:
- Name and model of the product in question
- Serial number of the product
- Name and location of the installation site
- Name and contact information of a technically competent person who
can provide further information on the problem.
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Chapter 7 ____________________________________________________________ Troubleshooting

Product Returns

If the product must be returned for service, see www.vaisala.com/returns.
It is important to protect the product from damage during the return shipment:
- Put the yellow transport protection cap on the sensor head, if
available.
- Pack the product in the original product package.
- If the original package is not available, wrap at least 2 cm of
protective material around each individual product, for instance, bubble wrap or plastic foam.
For contact information of Vaisala Service Centers, see
www.vaisala.com/services/servicecenters.
VAISALA ________________________________________________________________________ 53
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User's Guide _______________________________________________________________________
Parameter
Measured Range
Dewpoint
-50 ... +30 °C (-58 ... +86 °F)
Pressure, absolute
1 ... 12 bar (14.5 ... 174 psi)
Temperature
-40 ... +80 °C (-40 ... +176 °F)
Parameter
Measured Range
Pressure, normalized to 20 °C (68 °F)
1 ... 12 bara (14.5…174 psia)
SF6 or SF6/N2 mixture density
0 ... 100 kg/m3
ppm moisture, by volume
40 ... 40 000 ppm
Dewpoint, converted to atmospheric pressure
-65 … +30 °C (-85 ... +86 °F)
Property
Description / Value
Dewpoint accuracy
±3 °C (±5.4 °F), see Figure 12 on page 55
Dewpoint stability
typical drift < 2 °C (3.6 °F)/5a
Pressure accuracy at 23 °C (73.4 °F)
±0.04 %FS
Pressure temperature dependence
±0.01 bar/10 °C (18 °F)
Temperature accuracy
0 ... +40 °C (+32 ... +104 °F)
±0.5 °C (± 0.9 °F)
-40 ... +80 °C (-40 ... +176 °F)
±1 °C (± 1.8 °F)
Density accuracy (pure SF6, 1 ... 10 bara)
0 ... 40 °C (+32 ... +104 °F)
±1 %FS
-40 ... +60 °C (-40 ... +140 °F)
±2.2 %
ppm accuracy, typical (5 ... 1000 ppm, 7 bar)
±(7 ppm + 15 % of reading)
Sensor response time
Pressure response time
< 1 s
Dewpoint response time* 63% [90%] at 20°C and 1 bar
-50 -> -10 °C Tdf
5 s [10 s]
-10 -> -50 °C Tdf
10 s [2.5 min]
CHAPTER 8

TECHNICAL DATA

This chapter provides the technical data of the DPT145.

Specifications

Table 12 Measured Parameters
Table 13 Calculated Parameters
Table 14 Performance
* system equilibrium related response time is typically longer
54 ___________________________________________________________________ M211371EN-D
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Chapter 8 _____________________________________________________________ Technical Data
Property
Description / Value
Operating temperature of electronics
-40 … +60 °C (-40 ... +140 °F)
Pressure
0 … 50 bar (0…725 psi) Relative humidity
0 ... 100 %
Measured gases
SF6 SF6/N2 mixture
Property
Description / Value
Digital output
RS-485, non-isolated, Vaisala protocol
Connector
4-pin M8
0 20
20
0
10
30
-
10
-
20
-
3
0
10 30
4
0 5
0 6
0
4
0
Dew
po
int
te
mpera
ture (°
C)
Temperature of meas
u
re
d
ga
s (°C)
-40 -30 -20 -10 7
0 8
0
-4
0
-50
-60
Not recommended for
c
ontinuous measurement
Dewpoint measurement low limit
-70
Accurac
y
no
t s
p
ec
if
i
ed
Accurac
y
±
3 °
C
Td
1107-032
Figure 12 DPT145 Dewpoint Measurement Accuracy
Table 15 Operating Environment
Table 16 Outputs
VAISALA ________________________________________________________________________ 55
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User's Guide _______________________________________________________________________
Property
Description / Value
Sensor
Vaisala MPS1 multiparameter sensor
Operating voltage
15 ... 28 VDC
20 ... 28 VDC in cold temperatures (-40 ... -20 °C (-40 ... -4 °F))
Supply current
during normal measurement
20 mA
during self-diagnostics
max 300 mA pulsed
Housing material
AISI316L
Housing classification
IP65 (NEMA4)
Weather shield to be used for continuous outdoor installations
Storage temperature range
transmitter only
-40 … +80 °C (-40 ... +176 °F)
shipment package
-20 … +80 °C (-4 ... +176 °F)
Mechanical connection
DILO DN20, DILO DN8, ABB
connector
Weight (with DILO adapter)
765 g (27.0 oz)
Electromagnetic compatibility
Complies with EMC standard
environment
Tested levels
EN/IEC 61000-4-2, Electrostatic Discharge
8kV con / 15kV air
EN/IEC 61000-4-3, RF field immunity
10V/m (80MHz-4.2GHz)
EN/IEC 61000-4-4, Electric Fast Transient
±2kV power and signal
EN/IEC 61000-4-5, Surge
±2kV power line to ground
and power line to line
EN/IEC 61000-4-6, Conducted RF Immunity
10Vemf power line and digital output
Mechanical vibration
EN/IEC 60068-2-6,
5-500 Hz sweep 60 min/axis, 3-axis
Table 17 General
Malmkvist, or Alstom G1/2" compatible
EN61326-1, Electrical equipment for measurement, control and laboratory use - EMC requirements; Industrial
Fc Sinusoidial vibration
/ ±1kV signal line to ground
±6 g,
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Chapter 8 _____________________________________________________________ Technical Data
Description
Order Code
Connection cable for MI70 Indicator / DM70 Dewpoint Meter
219980 USB connection cable
219690
Protection plug for connector
218675SP
1.5 m shielded PUR cable with 90° connector
231519SP
3m shielded PUR cable with 90° connector
231520SP
5 m shielded PUR cable with 90° connector
231521SP
10 m shielded PUR cable with 90° connector
231522SP
3.0m shielded FEP cable with straight connector
226902SP
15 m shielded PUR cable with straight connector
236407SP
20 m shielded PUR cable with straight connector
235859SP
Weather shield
ASM210326SP
7
160
83
20
3
0.
6
AW
32
29
.5
M45x2
AW
50
57.7
7
160
83
20
30.6
AW
32
29.
5
M45x2
AW
50
57.7

Spare Parts and Accessories

Table 18 DPT145 Spare Parts and Accessories

Dimensions in mm

VAISALA ________________________________________________________________________ 57
1108-017
Figure 13 DPT145 with DILO DN20 Adapter
Page 58
User's Guide _______________________________________________________________________
63.5
20
145.5
7
53.5
29.5
M30x2
AW2
7
AW
36
41.6
63.5
20
145.5
7
53.5
29.5
M30x2
A
W27
AW
36
41.6
1311-249
Figure 14 DPT145 with DILO DN8 Adapter
1108-018
Figure 15 DPT145 with ABB Malmkvist Adapter
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Chapter 8 _____________________________________________________________ Technical Data
20
6
5
70
152
60
7
29.5
A
W2
7
33
20
6
5
70
152
60
7
G1/2 ISO 228-1
29.5
AW27
33
8
37
4444 80
200
2 5
59
51
4.8
30
AW8
8
37
4444 80
200
2 5
59
51
4.8
30
AW8
1108-019
Figure 16 DPT145 with Alstom G1/2" Adapter
1108-020
Shield
Figure 17 DPT145 with DILO DN20 Adapter and Weather
VAISALA ________________________________________________________________________ 59
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User's Guide _______________________________________________________________________
Setting
Default Value
Configuration Command for Changing the Value)*
Bit rate
19200
SERI
Number of data bits
8
Parity
E
Number of stop bits
1
Device address
240
ADDR
Response delay
0
SDELAY
Communication mode
MODBUS
SMODE
Function
(decimal)
Function Code
Function Name
specification)
Notes
3
03
Read Holding Registers
See Table 21 on page 61 for available registers.
16
10
Write Multiple Registers
See Table 21 on page 61 for writable registers.
43 14
2B 0E
Read Device Identification
See Table 22 on page 62 for available device identification objects.
APPENDIX A

MODBUS REFERENCE

This appendix describes the Modbus protocol implementation of the DPT145 transmitters.

Default Communication Settings

Table 19 below shows the default communication settings when Modbus is enabled at the factory.
Table 19 Default Communication Settings
* See Table 5 on page 33.
NOTE
You can also change device address with Modbus itself (register 1537).

Supported Modbus Functions

Table 20 Supported Function Codes
Code
NOTE
(hexadecimal)
After power-up, wait for five seconds before sending Modbus requests.
(as defined by the
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Appendix A _________________________________________________________ Modbus Reference
Logical
(decimal)
PDU Address
Register Description
Data
Register
Notes
5
00 04
T (measured)
LSW MSW
32-bit float
read-only
°C 6
00 05
7
00 06
T
(measured)
LSW MSW
32-bit float
read-only
°C 8
00 07
11
00 0A
T
(atm) (measured)
LSW MSW
32-bit float
read-only
°C 12
00 0B
21
00 14
H2O (measured)
LSW MSW
32-bit float
read-only
ppmv 22
00 15
45
00 2C
P (measured)
LSW MSW
32-bit float
read-only
bara 46
00 2D
47
00 2E
ρ (measured)
LSW MSW
32-bit float
read-only
kg/m3 48
00 2F
49
00 30
P
(measured)
LSW MSW
32-bit float
read-only
bara 50
00 31
513
02 00
Fault status
16-bit boolean
read-only
1 = no errors
514
02 01
Online status
16-bit boolean
read-only
1 = online data available
516
02 03
Error code
LSW MSW
32-bit bit field
read-only
0 = no errors 517
02 04
775
03 06
Molar mass of other gas (set value)
LSW MSW
32-bit float
read/write
kg/mol 776
03 07
781
03 0C
Gas mixing ratio (set value)
LSW MSW
32-bit float
read/write
0 …100 % of SF6
782
03 0D
783
03 0E
Pressure
value)
LSW
32-bit
read/write
-100 … 100°C 784
03 0F 1283
05 02
Automatic purge on/off*
16-bit boolean
read/write
1= automatic purge on
1284
05 03
Start-up purge on/off*
16-bit boolean
read/write
1 = start-up purge on
1285
05 04
Purge in progress*
16-bit
read/write
1 = purge in progress, write 1 for manual start
1537
06 00
Address
16-bit
read/write
1…255 (1 …
Modbus)
PDU address
Actual address bytes used in a Modbus Protocol data unit
LSW
Least significant word (bits 15 … 0)
MSW
Most significant word (bits 31 … 16)
16-bit integer
Numeric value in range 0 … 65535
16-bit boolean
Numeric value, 0 or 1
32-bit bit field
32 individual values, each 0 or 1
32-bit float
Floating point, IEEE 754 format
read-only
Register value cannot be changed with Modbus functions
read/write
Register value can be changed with Modbus functions

Modbus Register Map

Table 21 Modbus Register Map
Address
(hexadecimal)
d/f
d/f
norm
Format
Type
normalization temperature (set
MSW
float
boolean
integer
247 allowed in
*Device specifications are valid only if purge functions are kept enabled. Do not modify registers 1283, 1284, and 1285. Regular purge is needed to guarantee accurate measurements. Modify only if instructed to by Vaisala.
VAISALA ________________________________________________________________________ 61
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User's Guide _______________________________________________________________________
Object Id
Object Id
Object Name (as
specification)
Example
0
00
VendorName
Vaisala
1
01
ProductCode
DPT145
2
02
MajorMinorVersion
1.3.27
3
03
VendorUrl
http://www.vaisala.com
4
04
ProductName
Vaisala Multiparameter Transmitter DPT145 for SF6 Gas
128
80
SerialNumber*
D0710040
129
81
CalibrationDate*
2009-08-07
130
82
CalibrationText*
Vaisala/HEL
Table 22 Device Identification Objects
(decimal)
*
Vaisala-specific device information object
NOTE
(hexadecimal)
Both stream access and individual access to the device identification objects are supported.
defined by the
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*M211371EN*
www.vaisala.com
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