Knowledge Base

Airmar Ultrasonic Weather Station X2 Integration Guide


The Airmar WX-series weather stations measure a host of atmospheric and environmental parameters while maintaining a common GPS fix. The sensors are compatible with the X2 data logger via the RS-232 communication protocol. Below is information on the settings required for integration with an X2 data logger.

Figure 1: Airmar Ultrasonic Weather stations

 

Wiring

In nearly all applications involving NexSens integration, a connectorized UW8 plug will be added to the included NMEA0183 weather station cable that comes with purchasing an Airmar weather station. Refer to the appropriate wiring diagram within the Airmar Owner’s Guide & Installation Instructions if purchased separately Airmar Owner’s Guide & Installation Instructions. For configuring within the Airmar WeatherCaster software (described below), NexSens utilizes the NMEA0183 weather station cable outlined on page 18 of the Owner’s Guide, along with an RS-232 serial connection.

NMEA0183 Cable Wire ColorNMEA0183 Cable SignalRS-232 source signal
Black, Shield & OrangeGround (V-)Ground (V-)
WhiteRS-232 TxRS-232 Tx
YellowRS-232 RxRS-232 Rx
RedWX models: 9-40VDC
Heater models: 24VDC only*		No Connection

*Note: The X2 data logger is not able to provide 24VDC power to heater models of the Airmar weather station. It is recommended to use a separate power source.

 

Configure Communication

Enable NMEA0183 messages

NMEA0183 messages on the Airmar sensor can be configured using the Airmar WeatherCaster software. The pre-loaded X2 script for the Airmar weather stations includes the following NMEA0183 messages, which must be activated before the sensor detection:

  • GGA
  • VTG
  • HDG
  • HDT
  • MDA
  • MWV
  • XDR (A & B)

Follow the process below to enable only the appropriate NMEA0183 messages.

  1. Open the Airmar WeatherCaster software and apply power to the weather station.
    • Allow the software to automatically detect the sensor and open the main interface.

Figure 2: Main interface in Airmar WeatherCaster software.

 

  1. Once data populates the various dials, click Advanced Setup at the top.
    • A new interface will appear.

Figure 3: Advanced setup interface.

 

  1. Click the Enable/Disable Functionality to view the currently enabled NMEA0183 messages. Check the box next to the following NMEA0183 messages:
    • GGA
    • HDG
    • HDT
    • MDA
    • MWV (R)
    • VTG
    • XDR (A)
    • XDR (B)
      • Ensure to disable all other NMEA0183 messages not included within the list above and leave the intervals at default.

Figure 4: Enable/Disable functionality.

 

  1. Click Save when finished.
    • Ensure the Self-Test Status on the following page states PASS.
  2. Close out of the WeatherCaster software.

 

View live readings and adjust internal settings

Utilize a terminal emulator program such as Tera Term or Procomm to communicate with the device. The following communication settings must be matched in the program for new airmars:

  • Baud rate: 4800
  • Data: 8-bit
  • Parity: None
  • Stop bits: 1
  • Flow control: None

During integration, NexSens makes the following adjustments to the internal settings on the Airmar weather station.

NMEA CommandNMEA ResponseDescription
$PAMTX,0*4C^M^J—Airmar weather stations output data continuously once powered. This command is sent to temporarily stop data transmission.
$PAMTC,WIND,FILTER,Q*22^M^J$PAMTR,WIND,FILTER,1,10*7EThis command queries for the current IIR filter constant. The response shown should come from a new Airmar.
$PAMTC,WIND,FILTER,SET,1,1200*03^M^J—This command sets the IIR filter to 120 seconds. NexSens sets this filter to set wind averaging to 120 seconds. The unit is set in tenths of seconds, which is why a 1200 value corresponds to 120 seconds.
$PAMTC,WIND,FILTER,Q*22^M^J
(After the IIR filter constant has been changed)		$PAMTR,WIND,FILTER,1,1200*7CThis example command and response displays the query for the adjusted IIR filter.
$PAMTC,ALT,SET,<2>,1,1*hh
(<2> is the fixed altitude to the nearest 0.1m
& hh is the checksum)*		—The barometric pressure readings from the MDA message are compensated for altitude above sea level. By default, the instrument will use the GPS altitude reading when it has a 3D fix and will fall back to the fixed altitude setting when it does not. To prevent inconsistent barometric pressure readings when there is not a GPS fix, a fixed altitude of the final deployment location should be programmed into the instrument.
$PAMTC,ALT,Q*43$PAMTR,ALT,<2>,<3>,<4>*hh
(<2> is the new altitude)		After setting the altitude for the final deployment location, use this command to ensure the altitude was set successfully.
$PAMTX,1*4D^M^J—This command is sent to restart data transmission. This command must be sent before exiting the emulator program and powering down the weather station.

*Calculate the checksum for the command using the NMEA Checksum Calculator.

 

 

X2 Script Information

The X2 data logger includes a pre-loaded Airmar script. Use the CONNECT software to enable the script for sensor detection.

Configure Sensor Scripts

X2 Script NumberCommunication ProtocolBaud RatePower TypeWarmup Period (sec)Frame
3000RS-2324800Continuous180N81

 

 

Script Parameters

NMEA 0183 MessageDescriptionX2 Parameters
$GPGGANMEA 0183 standard GPS Fix DataUTC Time (hhmmss)
Latitude (Degree)
Longitude (Degree)
Altitude (m)
$GPVTGNMEA 0183 standard Course Over Ground and Ground SpeedCourse Over Ground- COG (True Degree)
Speed Over Ground- SOG (Magnetic Degree)
$WIMDANMEA 0183 Standard Meteorological Composite

(Wind parameters with respect to north)

Relative Barometric Pressure (inHg)
Air Temperature (C)
Relative Humidity (%)
Dewpoint (C)
Wind Direction (Degree)
Magnetic Wind Direction (Degree)
Wind Speed (m/s)
$HCHDTNMEA 0183 standard Heading relative to True NorthHeading (True Degree)
$HCHDGNMEA 0183 standard Heading, Deviation and VariationHeading (Magnetic Degree)
 

$WIMWV

 

NMEA 0183 standard Wind Speed and Angle, in relation to the vessel’s bow/centerline

Wind Direction (Degree)
Wind Speed (Knots)
$YXXDR-ANMEA 0183 Transducer Measurements. Used in the WX Series WeatherStation Sensor to provide wind chill, heat index, and barometric station pressure.Aids in calculations measured

by the $WIMDA message

$YXXDR-BNMEA 0183 Transducer Measurements. Used in the WX Series WeatherStation Sensor to provide vessel attitude (pitch and roll) data.Pitch (Degree)
Roll (Degree)

 

Note: If any of the NMEA0183 messages are disabled upon sensor detection, the corresponding parameters will not upload to WQData Live.