Vaisala DRYCAP DMT143 User Manual
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Vaisala DRYCAP DMT143 User Manual

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  • Page 1 M211435EN-J User Guide â Vaisala DRYCAP Dew Point Transmitter DMT143...
  • Page 2 Vaisala Oyj Vanha Nurmijärventie 21, FI-01670 Vantaa, Finland P.O. Box 26, FI-00421 Helsinki, Finland +358 9 8949 1 Visit our Internet pages at www.vaisala.com. © Vaisala Oyj 2019 with the local rules and No part of this document may be...

  • Page 3: Table Of Contents

    Documentation Conventions................7 Trademarks......................8 Product Overview................... 9 Introduction to DMT143 ...................9 Basic Features and Options................10 2.2.1 Connectivity to Vaisala Insight Software..........11 DMT143 and DMT143L Transmitter Parts............12 2.3.1 DMT143 with G1/2” ISO228/1 Thread............. 12 2.3.2 DMT143 with NPT Thread................ 13 2.3.3...
  • Page 4 DSC74 Sampling Cell with Quick Connector and Leak Screw... 29 4.6.4 DSC74B Two-Pressure Sampling Cell........... 30 Operation......................36 Transmitter Start-up..................36 Vaisala Insight Software................36 5.2.1 Connecting to Insight Software.............37 Operation with DM70 Handheld Dew Point Meter........38 Modbus Communication................40 Serial Communication................. 41 Connecting to the Serial Interface..............41...
  • Page 5 Table of Contents Serial Line Output Commands..............50 7.7.1 Start Measurement Output..............50 7.7.2 Stop Measurement Output..............50 7.7.3 Set Output Interval................. 50 7.7.4 Output a Reading Once................51 Configuring Measurement Parameters............51 7.8.1 Set Measurement Output Format............51 7.8.2 Set Measurement Filtering..............53 7.8.3 Set Pressure Compensation Value............
  • Page 6 DMT143 User Guide M211435EN-J Appendix A: Modbus Reference..............75 Default Communication Settings..............75 Function Codes....................75 Data Encoding....................75 A.3.1 32-Bit Floating Point Format..............75 A.3.2 16-Bit Integer Format................76 Modbus Registers................... 76 A.4.1 Measurement Data Registers..............77 A.4.2 Status Registers..................77 A.4.3 Configuration Registers................78 A.4.4 Test Value Registers................80 A.4.5...
  • Page 7 List of Figures List of Figures Figure DMT143 Parts – Model with ISO Thread.............12 Figure 2 DMT143 Parts – Model with NPT Thread............13 Figure 3 DMT143L Parts ....................14 Figure 4 Nokeval 301 Loop-powered Display............15 Figure 5 DMT143 Startup Sequence................20 Figure 6 DMT143 Digital and Analog Connectors...........
  • Page 8 DMT143 User Guide M211435EN-J List of Tables Table Document Versions (English)................7 Table 2 Related Manuals....................7 Table 3 Output Parameters of the DMT143..............9 Table 4 Alarm LED States....................20 Table 5 Connector Pinouts.................... 24 Table 6 Default Modbus Serial Communication Settings........40 Table 7 Default Serial Interface Settings..............

  • Page 9: About This Document

    Chapter 1 – About This Document 1. About This Document 1.1 Version Information This manual provides information for installing, operating, and maintaining Vaisala DRYCAPâ Dewpoint Transmitter DMT143. Table 1 Document Versions (English) Document Code Date Description February 2019 This manual. Modbus protocol added. Added information about M211435EN-J Vaisala Insight PC software.

  • Page 10: Trademarks

    Lists tools needed to perform the task. Indicates that you need to take some notes during the task. 1.4 Trademarks Vaisalaâ and DRYCAPâ are registered trademarks of Vaisala Oyj. Windowsâ is either a registered trademark or trademark of Microsoft Corporation in the United States and other countries.

  • Page 11: Product Overview

    2. Product Overview 2.1 Introduction to DMT143 Vaisala DRYCAPâ Dew Point Transmitter DMT143 is a small and lightweight dew point transmitter suitable for a wide range of OEM applications. DMT143 is easy to install and the mechanics have been designed for harsh environments requiring protection against dust, dirt and splashed water.

  • Page 12: Basic Features And Options

    • None (DMT143 and DMT143L, digital output only) • Digital output: RS-485 (non-isolated). The following protocols are supported: • Modbus RTU • Vaisala Industrial Protocol • LED for dew point level alarm and transmitter diagnostics • DRYCAPâ polymer sensor: • Autocalibration ensures accuracy in changing measurement conditions •...

  • Page 13: Connectivity To Vaisala Insight Software

    ‣ Connecting to the Serial Interface (page 41) ‣ DMT143 Specifications (page 69) 2.2.1 Connectivity to Vaisala Insight Software The transmitter can be connected to Vaisala Insight software using a Vaisala USB cable (order code 219690). With the Insight software, you can: • See device information and status.

  • Page 14: Dmt143 And Dmt143L Transmitter Parts

    DMT143 User Guide M211435EN-J 2.3 DMT143 and DMT143L Transmitter Parts 2.3.1 DMT143 with G1/2” ISO228/1 Thread Figure 1 DMT143 Parts – Model with ISO Thread Transmitter body. Type label is applied here. Digital output: non-isolated RS-485 Alarm LED Analog output Sealing ring. Must be used with the G1/2” ISO228/1 connection thread. 24 mm nut Connection thread: G1/2"...

  • Page 15: Dmt143 With Npt Thread

    Chapter 2 – Product Overview 2.3.2 DMT143 with NPT Thread Figure 2 DMT143 Parts – Model with NPT Thread Transmitter body. Type label is applied here. Digital output: non-isolated RS-485 Alarm LED Analog output 30 mm nut Connection thread: NPT 1/2" DRYCAPâ 180D sensor protected with sintered filter...

  • Page 16: Dmt143L With G1/2" Iso228/1 Thread

    DMT143 User Guide M211435EN-J 2.3.3 DMT143L with G1/2” ISO228/1 Thread Figure 3 DMT143L Parts Transmitter body. Type label is applied here. Digital output: non-isolated RS-485 Alarm LED Analog output Sealing ring. Must be used with the G1/2” ISO228/1 connection thread. 24 mm nut Connection thread: G1/2"...

  • Page 17: Connection Cables

    More Information ‣ Spare Parts and Accessories (page 73) 2.5 Connection Cables Vaisala supplies shielded cables with M8 female straight threaded connector. Standard cables are available in four lengths: • 0.3 m (1.0 ft) • 3 m (9.8 ft) •...

  • Page 18: Sampling Accessories

    2.7.1 ESD Protection Electrostatic Discharge (ESD) can damage electronic circuits. Vaisala products are adequately protected against ESD for their intended use. However, it is possible to damage the product by delivering electrostatic discharges when touching, removing, or inserting any objects in the equipment housing.

  • Page 19: Regulatory Compliances

    Chapter 2 – Product Overview • If you are unable to take either precaution, touch a conductive part of the equipment chassis with your other hand before touching ESD-sensitive components. • Hold component boards by the edges and avoid touching component contacts. 2.8 Regulatory Compliances This product is in conformity with the provisions of the following EU directives: •...

  • Page 20: Functional Description

    The self-diagnostic procedures that are conducted are called autocalibration, sensor purge, and sensor warming. DMT143 and DMT143L use different versions of the Vaisala DRYCAPâ sensor: • DMT143 uses the DRYCAPâ 180D sensor designed for applications such as plastic dryers and small industrial compressed air dryer (sensor filter length 22.5 mm, probe length 91.6...

  • Page 21: Sensor Warming In High Humidities And Freezing Conditions

    Chapter 3 – Functional Description 3.1.3 Sensor Warming in High Humidities and Freezing Conditions DMT143 has a sensor warming feature that improves the sensor’s performance in high humidities and freezing conditions. Sensor warming does not interrupt the transmitter’s T value output. In high humidity, sensor warming prevents the sensor and filter from becoming wet.

  • Page 22: Alarm Led

    The alarm LED functionality is preset at the factory according to order form. You can configure it as follows: • You can use Vaisala Insight software or the ALARM command on the serial line to change the alarm limit, enable/disable the dew point alarm, or turn on/off the LED completely.
  • Page 23 Chapter 3 – Functional Description More Information ‣ Vaisala Insight Software (page 36) ‣ Operation with DM70 Handheld Dew Point Meter (page 38) ‣ Configure the Alarm LED (page 60)

  • Page 24: Installation

    You may wish to configure your transmitter before physically installing it. For easy access to configuration options, use either Vaisala Insight PC software with the USB service cable (Vaisala order code 219690), or connect to the serial line using the USB service cable and a terminal program on a PC.

  • Page 25: Installing The Transmitter

    The DMT143 is light in weight, which means that it can be installed in a sample pipeline in the sampling cells without the need of any additional mechanical support. You can use a standard G1/2" T-shaped pipe fitting (not available from Vaisala) when installing DMT143 into a pipeline. More Information ‣...

  • Page 26: Wiring

    DMT143 User Guide M211435EN-J 3. Tighten the connection by turning with a wrench (max. 50 Nm). Wrench size is 24 mm for ISO threaded transmitters, 30 mm for NPT threaded model. 4. Connect the signal and power cable to the DMT143. More Information ‣...

  • Page 27: Power Supply Requirements

    Chapter 4 – Installation Digital Analog Figure 6 DMT143 Digital and Analog Connectors ＋ 12 ... 28 VDC － RS-485 + RS-485 - Figure 7 Wiring the Digital Connector ＋ ＋ 12 ... 28 VDC － － ＋ ＋ 18 ... 28 VDC －...

  • Page 28: Figure 9 Example Of Current Consumption During Purge

    DMT143 User Guide M211435EN-J Current consumption during normal operation is <10 mA. The consumption increases during the sensor self-diagnostics (autocalibration and sensor purge). Typical current consumption is 220 mA pulsed current. The DMT143 can be powered by the MI70 indicator or the USB service cable. You can plug in the MI70 indicator or the USB service cable to the digital port while the transmitter is powered from the analog port.

  • Page 29: Sampling From A Process

    Chapter 4 – Installation The following figure shows a typical duty cycle during autocalibration at room temperature with 24 VDC supply voltage. Also the autocalibration current varies with supply voltage and operating temperature. 250 mA 0 mA Duration 16 s 250 mA 0 mA Duration 200 ms...

  • Page 30: Sampling Accessories

    Make sure there is sufficient flow of gas to the sensor (for example, 1 l/min) to give a representative sample. To simulate the effect of pressure change to dew point, you can use the Vaisala Humidity Calculator at: www.vaisala.com/humiditycalculator. 4.6 Sampling Accessories 4.6.1 DMT242SC Sampling Cell...

  • Page 31: Dsc74 Sampling Cell With Quick Connector And Leak Screw

    Chapter 4 – Installation Figure 11 Sampling Cells DMT242SC2 (left) and DMT242SC (right) Male pipe welded connector Swagelok 1/4" G1/2" G1/4" G3/8" 4.6.3 DSC74 Sampling Cell with Quick Connector and Leak Screw The DSC74 has been designed especially for compressed air lines. The sampling cell contains an adjustable leak screw that allows keeping up the pipeline pressure at the sensor.

  • Page 32: Dsc74B Two-Pressure Sampling Cell

    Harmful gases can be recovered by connecting a collection system at the outlet (not available from Vaisala). In the basic operation of the DSC74B, the gas flows to the sensor from the front and the outlet is on the side.

  • Page 33: Figure 13 Dsc74B

    Chapter 4 – Installation DSC74B parts are: • Sampling cell, thread G3/8" • Connection part with a needle valve and an integrated leak screw • Reducing Nipple (thread adapter), G3/8" - G1/2" • Reducing Adapter (thread adapter), G3/8" - G1/4" Figure 13 DSC74B Gas goes in Gas comes out...

  • Page 34: Figure 14 Removing The Leak Screw

    DMT143 User Guide M211435EN-J Figure 14 Removing the Leak Screw 4.6.4.1 DSC74C Two-Pressure Sampling Cell with Coil The DSC74C with an outlet coil is designed for the most critical measurements at atmospheric pressure. In the DSC74C, the coil is connected to the sampling cell outlet to protect the sensor from ambient humidity disturbing the measurement.

  • Page 35: Figure 15 Default Assembly Of Dsc74C

    Chapter 4 – Installation Figure 15 Default Assembly of DSC74C Gas goes in. The coil can also be used here. Gas comes out Coil Valve...

  • Page 36: Figure 16 Alternative Assembly Of Dsc74C (For Tight Spaces)

    DMT143 User Guide M211435EN-J Figure 16 Alternative Assembly of DSC74C (for Tight Spaces) Gas comes out Coil Thread, max. size 7 mm Gas goes in Valve The thread size cannot exceed 7 mm. Use the provided adapter to avoid damage to the transmitter.

  • Page 37: Figure 17 Dm240Fa With Dmt143

    Figure 17 DM240FA with DMT143 Measured gas Recommended additional hole (plugged) for T field check reference measurement probe (for example, Vaisala DM70) DM240FA flange (thread G1/2” ISO228/1) DMT143 transmitter...

  • Page 38: Operation

    ‣ Set Serial Line Operating Mode (page 57) 5.2 Vaisala Insight Software You can use Vaisala Insight PC software to check and configure DMT143 transmitters intuitively, without typing any serial commands. The software guides you when changing the settings on the transmitter. The transmitter can be connected to Insight software using a Vaisala USB cable for computer connection (order code 219690).

  • Page 39: Connecting To Insight Software

    3. Connect the USB cable to the digital port of the transmitter. 4. Wait for Insight software to detect the transmitter. If the transmitter is not detected, disconnect and reconnect the Vaisala USB cable to the digital port connector of the transmitter.

  • Page 40: Operation With Dm70 Handheld Dew Point Meter

    DMT143 User Guide M211435EN-J 5.3 Operation with DM70 Handheld Dew Point Meter You can connect the DMT143 to the MI70 indicator (the handheld measurement display included in the DM70 package) using the MI70 connection cable (order code 219980SP). This allows you to view and use the measurement data with the MI70 indicator. You can, for example, perform a field check of the measurement accuracy.
  • Page 41 Chapter 5 – Operation You can also return the DMT143 to its factory configuration by using the Factory settings option in the Settings menu. This option is equivalent to using the FRESTORE command on the serial line. Note that also the MI70 indicator will revert to its factory configuration when using the Factory settings option on the MI70.

  • Page 42: Modbus Communication

    19200 Parity Number of data bits Number of stop bits Modbus device address Serial delay Communication mode Modbus RTU Use Vaisala Insight software to change the Modbus serial communication settings if needed. More Information ‣ Vaisala Insight Software (page 36)

  • Page 43: Serial Communication

    PC using the RS-485 line on the Digital port. 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 first the driver that came with the cable.

  • Page 44: Accessing Serial Interface In Devices With Modbus Output

    Follow the steps below to connect to the serial line with a transmitter with Modbus output. You can also use the procedure to retrieve the communication settings of your device, if you do not know them. You must use the Vaisala USB cable (Vaisala order code 219690) for the connection.

  • Page 45: List Of Serial Commands

    Chapter 7 – Serial Communication 2. Open the terminal program and open a connection to the corresponding COM port using the default settings 19200, 8, N, 1, no flow control. 3. Keep the Enter key pressed down and connect the other end of the USB cable to the transmitter.

  • Page 46: Device Information

    DMT143 User Guide M211435EN-J Command Description INTV [0 ... 255 Set the continuous output interval (for RUN mode and R S/MIN/H] command) Show user adjustment values Set user adjustment values OPEN [0 ... 255] Open a line to transmitter at defined address PRES [0.001 ...

  • Page 47: Show Analog Output Mode

    7.5.3 Show Firmware Version VERS<cr> Example: vers DMT143 1.0.2 7.5.4 Show Firmware Information SYSTEM<cr> Example: system Device Name : DMT143 Copyright : Copyright (c) Vaisala Oyj 2012. All rights reserved. SW Name : DMT143 SW date : 2012-05-10 SW version : 1.0.2...

  • Page 48: Show Currently Active Errors

    DMT143 User Guide M211435EN-J 7.5.5 Show Currently Active Errors Use the ERRS command to display the currently active transmitter error messages. ERRS<cr> Example: errs No errors Example (one active error, caused by physical damage to the sensor): errs T MEAS error Table 9 Error Messages on ERRS Command ERRS Command Response Corresponding Error...

  • Page 49: Configuring Analog Output

    Chapter 7 – Serial Communication HELP<cr> Example: help ADDR AERR ALARM AMODE AOVER AOUT ASEL ATEST CLOSE ERRS FILT FORM FRESTORE HELP INTV OPEN PRES RESET SDELAY SEND SERI SMODE SNUM SYSTEM TIME UNIT VERS XPRES 7.6 Configuring Analog Output 7.6.1 Set Analog Output Parameters and Scaling Use the ASEL command to show or set the output parameter and the scaling of the analog output.

  • Page 50: Set Analog Output Error Notification

    Parameter that is output on analog channel. Available parameters are TDF, TDFA, H2O. If the transmitter has been ordered from Vaisala with a relative humidity output on the analog channel, also parameter RH is available. lowlimit Lower limit of parameter scaling.

  • Page 51: Extend Analog Output Range

    V or mA. The command output shows the test value of the analog output as well as diagnostic information that may be useful to Vaisala Service Center if there is a problem with the analog output.

  • Page 52: Enable Or Disable Analog Output

    DMT143 User Guide M211435EN-J 7.6.5 Enable or Disable Analog Output Use the AOUT command to enable or disable the analog output channel. AOUT [ON/OFF]<cr> Example (turn analog output off): aout off AOUT : OFF 7.7 Serial Line Output Commands 7.7.1 Start Measurement Output Use the R command to start the continuous outputting of measurement values as an ASCII text string to the serial line.

  • Page 53: Output A Reading Once

    Chapter 7 – Serial Communication 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 7.7.4 Output a Reading Once Use the SEND command to output a single measurement message.

  • Page 54: Table 10 Form Command Parameters

    Dew point/frost point temperature, converted to atmospheric pressure ppm moisture, by volume Relative humidity RH is available only if transmitter has been ordered from Vaisala with a relative humidity output on the analog channel. Table 11 FORM Command Modifiers Modifier Description...

  • Page 55: Set Measurement Filtering

    Chapter 7 – Serial Communication Modifier Description Modulus-256 checksum of message sent so far, ASCII encoded hexadecimal notation Modulus-65536 checksum of message sent so far, ASCII encoded hexadecimal notation NMEA xor-checksum of message sent so far, ASCII encoded hexadecimal notation FORM Command Examples You can return to the default format using the "FORM /"...

  • Page 56: Set Pressure Compensation Value

    DMT143 User Guide M211435EN-J Syntax Description a.aaaaa Range 0.00001 ... 1.0 1.0 = No filtering, latest measurement is output without averaging 0.5 = Average of last two measurements 0.1 = Average of approx. 16 measurements (default) Example (show current setting): filt Filter 0.10000...

  • Page 57: Select Unit

    Chapter 7 – Serial Communication The pressure conversion coefficients from other pressure units to bars is given in the table below. Table 12 Pressure Conversion Coefficients From To bar 0.00001 ² PaN/m mmHg torr 0.001333224 inHg 0.03386388 0.00009806650 0.002490889 1.01325 0.980665 0.06894757 For example: 29.9213 inHg = 29.9213 ×...

  • Page 58: Set User Adjustment Parameters

    This command is provided primarily for applying an offset to the Tdf measurement. Do not adjust the other parameters unless instructed to do so by a Vaisala Service Center. LI<cr> After entering the command, you will be prompted to enter new values one at a time. Press ENTER without giving a value to move to the next parameter.

  • Page 59: Configuring Serial Line Operation

    Chapter 7 – Serial Communication 7.9 Configuring Serial Line Operation 7.9.1 Set Serial Line Operating Mode Use the SMODE command to set the start-up operating mode of the serial line. SMODE [mode]<cr> Syntax Description mode STOP, RUN, POLL, or MODBUS. Table 13 Selection of Output Modes Mode Measurement Output Available Commands...

  • Page 60: Set Transmitter Address

    DMT143 User Guide M211435EN-J If you have altered the DMT143 serial line settings and start using the MI70 hand- held indicator, always switch off the other power supply (disconnect “Analog” cable if in use) before powering up the MI70. SERI [b p d s]<cr> Syntax Description baud rate (4800, 9600, or 19200)

  • Page 61: Set Serial Line Response Time

    Chapter 7 – Serial Communication 7.9.4 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. SDELAY [delay]<cr> Syntax Description delay Serial line delay, range 0 … 255. One unit of delay corresponds to 4 milliseconds.

  • Page 62: Configure The Alarm Led

    DMT143 User Guide M211435EN-J 7.10.3 Configure the Alarm LED Use the ALARM command to configure the alarm LED functionality. ALARM [LED] [Alarm] [Level]<cr> Syntax Description Enable or disable the entire LED functionality. Allowed values: ON - Enable the LED functionality. OFF - Turn off the LED completely. Alarm Enable or disable the dew point alarm.

  • Page 63: Reset Transmitter

    Chapter 7 – Serial Communication alarm on off LED display : ON Alarm display : OFF Setpoint Td(°C): -40.00 Example (turn off the LED completely): alarm off LED display More Information ‣ Alarm LED (page 20) 7.10.4 Reset Transmitter Use the RESET command to reset the transmitter. RESET<cr>...

  • Page 64: Maintenance

    DM70 handheld dew point meter. If the field check indicates that the DMT143 is not within its accuracy specifications, contact a Vaisala Service Center or your local Vaisala representative to have the DMT143 adjusted. 8.1.3 Changing the Filter Replace the filter if it is contaminated.

  • Page 65: Field Check Using Dm70 Handheld Dew Point Meter

    • A calibrated reference probe that is suitable for the intended measurement environment and dew point range. The DMP74B probe is recommended for checking the dew point temperature measurement accuracy. • You also need a connection cable (Vaisala order code 219980SP) to connect the DMT143 to the MI70 indicator.
  • Page 66 DMT143 User Guide M211435EN-J In the following procedure, the readings of the transmitter and the reference probe are checked simultaneously. You can also check the reference probe and the DMT143 separately if they cannot be connected at the same time. The messages from the transmitter will appear in English even if the MI70 has been set to another language.

  • Page 67: Repair Maintenance

    If there is a problem with your transmitter that you are unable to solve yourself or with the help of Vaisala Helpdesk, contact a Vaisala Service Center. In case of mechanical or electrical failure, the Service Center may replace the transmitter with a new one.

  • Page 68: Troubleshooting

    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. Table 14 Troubleshooting Table...

  • Page 69: Error Messages In Insight Software

    [53] Non-volatile memory read/write failure. [57] In case of constant error, contact a Vaisala Service Center. More Information ‣ Technical Support (page 85) 9.3 Error Codes in MI70 Handheld Meter If several errors are active at the same time, the MI70 shows the sum of currently active error codes.

  • Page 70: Unknown Serial Settings

    You can check the current serial settings of your transmitter by connecting to the serial line, or with Vaisala Insight software. More Information ‣ Accessing Serial Interface in Devices with Modbus Output (page 42) ‣ Vaisala Insight Software (page 36)

  • Page 71: Technical Data

    Chapter 10 – Technical Data 10. Technical Data 10.1 DMT143 Specifications Table 17 Measurement Performance Property Description/Value Sensor Vaisala DRYCAPâ 180D Sensor protection Stainless steel sintered filter Recommended calibration interval to confirm 2 years the specified accuracy Dew Point Temperature Measurement range (typical) -70 …...

  • Page 72: Table 18 Operating Environment

    DMT143 User Guide M211435EN-J Property Description/Value Option 3 Free scaling Response time 63 % [90 %] at +20 °C gas temperature and 1 bar pressure and 1 liter/min flow rate: -70 → -20 °C T (-94 → -4 °F T 5 s [15 s] (typical) 45 s [10 min] (typical) -20 →...

  • Page 73: Table 20 Mechanical Specifications

    Property Description/Value Typical temperature dependence 0.005 % of span/°C Digital output RS-485, non-isolated Vaisala Industrial Protocol Modbus RTU protocol Connector 4-pin M8 (IEC 60947-5-2) Supply Current at +20 °C (Uin 24 VDC) Normal measurement Typical 10 mA + load current...

  • Page 74: Dimensions

    DMT143 User Guide M211435EN-J 10.2 Dimensions AW24 G1/2” ISO228/1 57 [2.24] 22.5 [0.89] 91.6 [3.61] Figure 20 DMT143 Dimensions – Model with ISO Thread Ø32 [1.26] AW30 NPT1/2” 22.5 [0.89] 49.1 [1.93] 91.6 [3.61] Figure 21 DMT143 Dimensions – Model with NPT Thread...

  • Page 75: Spare Parts And Accessories

    Chapter 10 – Technical Data AW24 G1/2" ISO228/1 Figure 22 DMT143L Dimensions 10.3 Spare Parts and Accessories Table 22 Spare Parts and Accessories Item Order Code Connection cable for DM70 219980SP 219690 USB cable for PC connection Loop powered external display 226476 Loop powered external display with relays 234759 Installation flange ISO ½...
  • Page 76 DSC74SP Two-pressure sampling cell DSC74BSP Two-pressure sampling cell with coil DSC74CSP Cooling/venting coil DMCOILSP See the DSS70A product page at www.vaisala.com for further information about the sampling cells available for DM70. Vaisala Insight software for Windows is available at www.vaisala.com/insight.

  • Page 77: Appendix A: Modbus Reference

    Appendix A – Modbus Reference Appendix A. Modbus Reference A.1 Default Communication Settings The following table lists the default Modbus serial settings of devices ordered with the Modbus configuration option. Table 23 Default Modbus Serial Communication Settings Description Default Value Serial bit rate 19200 Parity Number of data bits...

  • Page 78: 16-Bit Integer Format

    DMT143 User Guide M211435EN-J Despite the specification, some Modbus masters may expect "big-endian" word order (most significant word first). In such a case, you must select "word-swapped" floating point format in your Modbus master for the Modbus registers of the device. Reading the measurement data registers with incorrect floating point format setting may occasionally result in correct-looking values.

  • Page 79: Measurement Data Registers

    Appendix A – Modbus Reference A.4.1 Measurement Data Registers Table 26 Modbus Measurement Data Registers (Read-Only) Register Address Register Description Data Unit Number (Hexadecimal) Format (Decimal) 0000 Relative humidity (RH) 32-bit float 0006 Dew/frost point temperature 32-bit float °C 000A Dew/frost point temperature at 32-bit float °C 1 atm (T...

  • Page 80: Configuration Registers

    DMT143 User Guide M211435EN-J Register Address Register Description Data Notes Number (Hexadecimal) Format (Decimal) 0203 Error code 32-bit 0 = No errors integer Table 28 Error Codes on Modbus Interface Error Code Register Corresponding Error Value No errors. Temperature measurement error. [44] Humidity measurement error.
  • Page 81 Appendix A – Modbus Reference Register Address Register Description Data Unit / Valid Number (Hexadecimal) Format Range (Decimal) Settings 031A Filtering factor 32-bit float 0.00001 … 1 Communication 1537 0600 Address 16-bit 1 ... 247 integer 1538 0601 Bit rate (b/s) 16-bit 5 = 9600 integer...

  • Page 82: Test Value Registers

    Configuration code (for example "G1A1A1A0A0ASX") Serial number of the device (for SerialNumber example “J1140501") Main calibration date in YYYY-MM-DD CalibrationDate format. Empty string if not set/valid. Main calibration information text. CalibrationText Empty string if not set/valid. Vaisala-specific device identification object.

  • Page 83: Modbus Communication Examples

    Appendix A – Modbus Reference A.5 Modbus Communication Examples Reading Dew Point/Frost Point Temperature Value Device address used in the following examples is 240 (F0 The values returned by the device differ depending on the ambient conditions and/or device settings. Your device might not return exactly the same values. Request Response Bytes on the Line...
  • Page 84 DMT143 User Guide M211435EN-J Writing Filtering Factor Value Request Response Bytes on the Line Description Bytes on the Line Description (Hexadecimal) (Hexadecimal) (silence for 3.5 bytes) Start of Modbus RTU (silence for 3.5 bytes) Start of Modbus RTU frame frame Transmitter address Transmitter address Function (Write...
  • Page 85 Appendix A – Modbus Reference...
  • Page 86 DMT143 User Guide M211435EN-J...

  • Page 87: Warranty

    Please see the applicable supply contract or Conditions of Sale for details of the warranty for each product. Technical Support Contact Vaisala technical support at helpdesk@vaisala.com. Provide at least the following supporting information: • Product name, model, and serial number •...
  • Page 88 DMT143 User Guide M211435EN-J...
  • Page 90 www. v aisala.com...

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