Honeywell hmr3000 TruePoint User Manual page 13

HMR3500 User's Guide
declination and issue a DWMM message reporting the computed declination. The declination value is saved to the
compass' non-volatile memory and is used by the compass as the current declination value when computing azimuth.
The current magnetic declination is displayed in the Initialization dialog box (see Figure 7). To perform the calculation,
issue a WMM message. Because the calculations are extensive, the compass performs them in background mode, but
the calculated declination will be posted, and reported in a DWMM message, about one-half second later.
Name: WMM/DWMM
ID: 0x55
Request Data: 15 bytes:
Data Type
Day uchar
Month uchar
Year uchar
Lat float
Lon float
Alt float
The Day, Month, Year and Lat, Lon, Alt fields contain the date and position information needed by the World Magnetic
Model algorithm.
Reply Data: 23 bytes:
Data Type
Status uchar
Magnetic Kang
declination
Source char[20]
Version
Version Name: VRSN/DVRSN
ID: 0xC3
Request Data: None
Reply Data: 12 bytes:
Data Type
Major Int
Minor Int
Options uint
Serial Number ulong
www.honeywell.com
Byte Offset Description
0 Day of month [1..31]
1 Month of year [1.12]
2 Year – 2000
3-6 Latitude (degrees)
7-10 Longitude (degrees)
11-14 Altitude (meters)
Byte Offset Description
0 0 = calculation inhibited
1 = calculation completed and posted
2 = calculation in process
3 = awaiting date and/or location
4 = flash write failure
1-2 Current variation (declination).
3-22 Name of USGS file from which model was derived (null
terminated)
Byte Offset Description
0-1 Major firmware version number
2-3 Minor firmware version number
4-5 Firmware builds options as individual bit flags. Contact Honeywell for
details.
6-9 This unit's serial number.
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