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KTA-282 Modbus TCP Weather Station Gateway

Connects a Davis VantagePro2 or Vantage Vue 

to a Modbus network

Modbus RTU over RS-485 and Modbus TCP/IP 

over Ethernet compatible

Easy Modbus TCP/IP configuration via webpage, 

Modbus registers, or onboard switches

Supports three simultaneous Modbus TCP 

masters.

Various selectable metric and imperial unit 

conversions

Compatible with new Davis firmware; provides 

additional weather data

Allows weather station configuration directly

Overview

The KTA-282 Modbus TCP Weather Station Gateway allows the easy connection of a PLC (Programmable Logic 
Controller), RTU (Remote Telemetry Unit) or SCADA System to a Davis Instruments Weather Station. Using the 
Modbus RTU (Binary), or Modbus TCP/IP (Ethernet) protocols, it enables a programmable controller to monitor and
carry out actions based on wind speed, wind direction, temperature and many other weather based variables.
The KTA-282 Modbus TCP Weather Station Gateway is a major upgrade to our popular GWY-141 Modbus-
VantagePro2 Gateway. It provides all the functionality of the GWY-141, with the following improvements:

Addition of Ethernet:

o

Allows the KTA-282 to be polled by up to three Modbus TCP/IP masters simultaneously

o

Provides a webpage whereby TCP/IP settings can be easily monitored and altered. Also shows 
current settings, weather data, and communications statuses.

o

Can be interrogated over HTTP to return Modbus register values in XML format

Allows all 125 registers to be polled at once – previously limited to 30.

Supports the new LOOP 2 command in compatible devices

1

 (VantagePro 2 firmware V1.90 or later, and 

Vantage Vue). This provides an additional 16 packets of previously unavailable weather data.

Provides a method to setup the weather station for first use, without the need to connect it to your PC.

Notes: 1. The Weatherlink cable can be used to update the firmware of your weather station; allowing it to respond 
to the loop 2 command.

Device Compatibility

The KTA-282 is compatible with the following Davis Instruments weather stations (Davis Instruments product 
numbers in bold):

6152C

  Cabled VantagePro2

6162C

  Cabled VantagePro2 Plus

6152

  Wireless VantagePro2

6162

  Wireless VantagePro2 Plus

6153

  Wireless Vantage Pro 2 Fan Aspirated

6163

  Wireless Vantage Pro 2 Plus Fan Aspirated

6250

  Vantage Vue

6316

  Wireless Weather Envoy

6316C

  Cabled Weather Envoy 

7/05/2013

www.oceancontrols.com.au

Page 1 of 25

Summary of Contents for KTA-282

Page 1: ...ddition of Ethernet o Allows the KTA 282 to be polled by up to three Modbus TCP IP masters simultaneously o Provides a webpage whereby TCP IP settings can be easily monitored and altered Also shows cu...

Page 2: ...command 13 Modbus TCP Manual Socket Severing 13 Webpage 13 XML Request 14 Open Collector Outputs PCB Rev 5 and later 16 KTA 282 PC Application 17 Configuring Communications 17 Serial Switch Settings...

Page 3: ...use latitude longitude elevation etc Table 1 Davis Instruments Jargon Weather Station Set Up Begin by assembling your weather station and sensors using the documentation provided by Davis You will nee...

Page 4: ...Description Vs Power Positive 8 to 28V DC 100mW COM Power Negative Ground D RS 485 Data D RS 485 Data GND Ground Male DE 9 Serial communications RS 232 between KTA 282 and Weather station via WeatherL...

Page 5: ...see the red LED next to the DE 9 connector flash once every 5 seconds This confirms the card is on and functional Continue by connecting the DE 9 cable from your weather station via the WeatherLink t...

Page 6: ...re the TCP IP settings are loaded from when power is applied to the KTA 282 With this switch off settings are loaded from the current values of the switches regardless of previous settings With the sw...

Page 7: ...b browser to the IP Address of the KTA 282 to retrieve this page Below the current weather readings is a web form with provision to set the TCP IP settings of the KTA 282 The form fields will be popul...

Page 8: ...Location in the archive memory where the next data packet will be written This can be monitored to detect when a new record is created 4 1 Barometer 0 001 inHg 5 1 Inside Temperature 0 1 F 6 1 Inside...

Page 9: ...ther an estimation based on temperature and dewpoint Use as an indication only Loop 2 Data Only recent Davis Instruments hardware Vantage Pro 2 firmware V1 9 or later Vantage Vue will return the loop...

Page 10: ...e to the latest firmware at oceancontrols com au The units of the readings can be changed by writing to the Modbus holding registers shown in table 16 The following table shows the multiplier and unit...

Page 11: ...ocol Docs on the Ocean Controls website Each argument of these commands is coupled to a Modbus register Any weather station EEPROM can therefore be written using Modbus communications The BAR command...

Page 12: ...hange to a 1 upon EEPROM write success This completes setting the latitude of the Davis weather station Note consult the EEPROM configuration settings section of Vantage Serial Protocol Docs on the Oc...

Page 13: ...ngs will load from dynamic value This text will read either switches or memory based on the status of TCP switch 1 It is important to realise that the TCP IP settings may still be read from the switch...

Page 14: ...ml Using a web browser with the gateway at its default address 192 168 1 100 registers xml Figure 4 Complete register listing HTTP request using browser Error Request If the GET request is of the wron...

Page 15: ...urn On or Off 119 1 Direction Sets the direction of the switching behaviour 0 output active below setpoint 1 output active above set point 120 2 Register Sets the Holding Register containing the weath...

Page 16: ...communications statuses o Modbus RTU over RS485 o Modbus TCP IP o Communications with the weather station Two buttons named bind all comms and release all comms These controls are designed mainly for...

Page 17: ...d units using the dropdown boxes and commit the selections to the gateway using the Write to KTA 282 button Writes holding registers 105 to 108 Change TCP IP Settings Displays a screen that allows the...

Page 18: ...port It should flash red roughly once every 5 seconds If so move to step 3 If not 1 Check the wires of the power supply are the correct way around 2 Probe the power terminals with a multimeter to ens...

Page 19: ...twork to ensure the KTA 282 has a unique IP address within the subnet The best way to do this is via your router if applicable Otherwise you could power off the gateway and then send a ping request to...

Page 20: ...nd go to properties 3 4 Click on Internet Protocol TCP IP and go to properties 3 5 Click on use the following IP address and set the values to IP Address 192 168 1 1 Subnet Mask 255 255 255 0 Default...

Page 21: ...Extra Humidities 1 24 1 Rain Rate 0 01 Inches hour 25 1 UV Index 1 26 1 Solar Radiation 1 W m2 27 1 Storm Rain 0 01 Inches 28 1 Current Date Of Storm Rain 1 29 1 Day Rain 0 01 inches 30 1 Month Rain 0...

Page 22: ...ctet Note 84 1 Subnet Mask 1st octet Note 85 1 Subnet Mask 2nd octet Note 86 1 Subnet Mask 3rd octet Note 87 1 Subnet Mask 4th octet Note 88 1 Default Gateway 1st octet Note 89 1 Default Gateway 2nd o...

Page 23: ...memory write command is successful 117 1 Open Collector 1 register to monitor 118 1 Open Collector 1 threshold 119 1 Open Collector 1 Direction 0 down 1 up 120 1 Open Collector 1 register to monitor 1...

Page 24: ...KTA 282 Modbus TCP Weather Station Gateway 7 05 2013 www oceancontrols com au Page 24 of 25...

Page 25: ...KTA 282 Modbus TCP Weather Station Gateway 7 05 2013 www oceancontrols com au Page 25 of 25...

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